Bloger: Maria Ryssdal Kraby, PhD-Candidate, Department of Clinical and Molecular Medicine

Breast cancer survival is high. However, many cancer survivors experience long-term side effects from treatment which impact their quality of life. For this reason, the Breast Cancer Subtypes Project studies a group of women we call Super survivors. They are so named because they survived breast cancer before today’s treatment options were available. If we can identify what characterises a Super survivor, we may have found a patient group which does not need all of the therapy they receive today.

This year, the Pink Ribbon campaign focuses on long-term effects: “Cancer-free, but not in good health. One in three women who survive breast cancer have long-term side effects from treatment.” It is important that the Pink Ribbon campaign highlights long-term effects, which impact the quality of life of so many people. One in 12 Norwegian women will develop breast cancer before turning 75 years of age. That corresponds 1784 of the seats at Lerkendal Stadium.

Luckily, breast cancer patients as a group have high survival rates. As many as 89.7% are alive 5 years after diagnosis. However, many of them must go through extensive treatment, often a combination of several treatment modalities. Breast cancer is treated with surgery, radiation, chemotherapy, antibodies and hormone therapy. Ninety percent are recommended hormone treatment and/or chemotherapy in addition to surgery. Side effects from breast cancer treatment include brittle bone disease, blood clots, hot flushes, hair loss, cardiovascular disease and neuropathy (tingling and reduced feeling in the hands and feet).

Breast cancer is not just one disease. Breast cancer is several, very different diseases which have differing biology and dissimilar survival.

There is an increasing focus on individualised treatment. That entails tailored therapy strategies for each patient, so that she receives the best treatment and follow-up for her breast cancer. Because breast cancer is not just one disease. Breast cancer is several, very different diseases which have differing biology and dissimilar survival.

Patients who have a disease with poor prognosis should have extensive therapy. But what about those that have a less aggressive form of breast cancer with a very good prognosis? How much therapy do they really need? In men with prostate cancer, there are some subgroups with such a good survival and such a low probability of disease spreading, that one chooses to refrain from treatment and follow the patient closely instead. Perhaps similar subgroups are to found in breast cancer, where removal of the tumour is sufficient?

Super survivors – What is it that separates them from others?

In the Breast Cancer Subtypes Group at NTNU, we study tissue samples from close to 2000 women from Trøndelag born between 1886 and 1977. About 900 of these were diagnosed with breast cancer before today’s treatment options were available. Even though most of them were only treated with surgery, several women lived long after they were diagnosed, and died from causes other than breast cancer. This could imply that they did not need any more than the limited treatment they received. We can call these women Super survivors. One of our goals is to identify them. What is it that separates them from others?

We search for the answer within the tumour. By examining proteins and genes in a tumour, it is possible to learn more about the woman’s prognosis and what kind of treatment would be most effective. Our research group has reclassified breast cancer tumours into 6 subgroups (subtypes) with differing biology and survival. Now, we want to study which proteins or genes in the tumour that can be used to determine the patient’s prognosis within each subtype. We call it a search for prognostic markers in the subtypes.

From Engstrøm et al. A: Classification algorithm to reclassify breast cancer tumours into subtypes. Oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), cytokeratin (CK5), epidermal growth factor receptor (EGFR). B: Survival curves for breast cancer specific survival, divided by subtype. Best prognosis in Luminal A, and poorest prognosis in HER2 type.

Without a blood supply, tumour size cannot exceed 1-3mm³. For this reason, cancer cells stimulate nearby blood vessels to grow into the tumour, so that it can become larger and spread within the body. To find out more about the biology of each subtype, and to find out whether the amount of blood vessels could have prognostic value, I have counted blood vessels in breast cancer tumours.

We compared blood vessels in the subtype with the best prognosis, Luminal A, to a subtype with a much poorer prognosis called the Basal Phenotype (BP). In order to see the blood vessels, we used immunohistochemistry, a method that visualises specific proteins in the tumour. Then, using a microscope, I counted the number of blood vessels in total, and the number of growing blood vessels. For Luminal A, patients with few blood vessels in their tumour had a better survival than those with many blood vessels. For the BP, the number of blood vessels had no influence on survival.

This supports the hypothesis that there are different prognostic markers for each subtype. Whether the amount of blood vessels provides prognostic information in the Luminal A subtype, must be confirmed in a study with a larger sample size. If our findings persist, the number of vessels in Luminal A tumours might add new information that could aid in the identification of Super survivors.

Photo: AM Bofin and MR Kraby. A: Tissue sample from tumour stained with haematoxylin, eosin and saffron. B: Tissue sample stained with immunohistochemistry so that blood vessels become brown and cells in proliferation become blue.

The Breast Cancer Subtypes Project is made possible through financial support from the Norwegian Cancer Society, the Research Council of Norway, the Central Norway Regional Health Authority, Kreftfondet at St. Olavs University Hospital and the legacy of Rakel og Otto Kr. Bruun.

Blogger: Tonje Husby Haukaas, Senior engineer
MR Cancer Group at the Department of circulation and medical imaging

Could there be a better day to write my first blog? Especially when it’s a “pink” one! The 1^st of October marks the beginning of Breast cancer awareness month. This is a month that has the aim to improve knowledge among the population, show compassion for breast cancer patients, and raise funds for breast cancer research.

In the coming days and weeks, the streets will be filled with pink ribbons, balloons, and accessories, and a variety of pink activities will be organized throughout the country. With this blog I hope to teach you something you didn’t know about breast cancer. I also want to show you what research funding can contribute to.

Breast cancer affects many lives, not only the people who are diagnosed. It is the most common cancer among women in Norway, and just today eight women will be diagnosed with breast cancer. Luckily, due to early detection and improved treatment, 90 % of women with breast cancer are still alive 5 year after the diagnosis. But no two tumors are exactly alike, which makes it hard to predict who will be in the 10 % that respond poorly to the current treatments and have short survival times. Also, even with a good response to treatment the patient can experience post treatment adverse effects and a poorer quality of life.

We wish to improve this.

To provide targeted and optimal treatment that has been tailored to each patient, we first have to learn as much as possible about the cancers’ properties and potential weaknesses. Some important targets are already well established in the clinic, like drugs that attack cancer cells that depend on the hormones estrogen or progesterone to grow. But there are still some cancers that don’t have established targets and researchers are working hard to uncover new ways to treat them.

Important differences can be hidden in cancer metabolism

One of the aims of the MR Cancer group has been to reveal potential treatment targets by exploring cancer metabolism.

Cancer cells grow and divide uncontrollably, which increases the need for energy and building blocks compared to normal cells. This can be observed when MR spectroscopy is used to study which small molecules, called metabolites, are present in tissue samples. The result of such an experiment is called a ‘spectrum’, where the peaks originate from different metabolites (see figure). Some of the metabolites are more common than others, such as glucose and lactate. Others are perhaps less known, such as glycerophosphocholine and glutathione, but are still important to study. The metabolites can tell us something about which processes are ongoing at the time the sample is taken.

Previous studies have shown that the cancer tissue’s metabolic fingerprint, meaning the metabolites present, is related to the tumor grade (how aggressive the cancer is), potential for metastasis, and 5 year survival.

By studying the metabolic fingerprint, it is possible to increase the knowledge about which types of breast cancer exist, how aggressive they are, and at the same time look for more biological markers that can identify new targets for treatment.

The figure shows some of the metabolites we can observe by performing MR spectroscopy on breast cancer tissue.

The Oslo2-study: A large-scale breast cancer study from multiple biological levels

In the Oslo2-study, a large-scale breast cancer study at the Oslo University Hospital, sample material from 228 patients has been sent to Trondheim and analyzed by MR spectroscopy. Based on the samples’ metabolic fingerprints we have identified three new subgroups of breast cancer. These three groups displayed differences in metabolism; understanding what makes them different helps us to identify more precise drug targets specific for each of the three groups.

Three new subgroups of breast cancer, called Mc1, Mc2 and Mc3, was found by comparing their metabolic fingerprint.

The unique feature of this study is that the sample materials from the same group of patients have been analyzed with multiple methods. Both the expression of genes and level of breast cancer related proteins have been analyzed. This gives us the possibility to look for new relationships between genes, proteins, and metabolites in breast cancer. By combining the levels of data, we saw that one group in particular expressed big differences in genes and proteins compared to the two other groups.

Tissue samples are stored in liquid nitrogen prior to MR spectroscopy. The samples are kept frozen while they are cut to fit the sample tubes. Photo: Geir Mogen/NTNU.

Based on this, we suspect that this group has a more aggressive cancer type, and would therefore benefit from a different type of treatment than the two other groups.

We will soon acquire follow-up data from the patients in this study, which will provide us with new information on survival and relapse. Based on our metabolic findings, the hypothesis is that the patient survival is different depending on which metabolic subgroup they belong to. If this hypothesis is correct, it means that the metabolic classification can indicate which patients need extra follow-up, and possibly more intensive treatment to get well.

Finally: Why not wear something pink today to show your appreciation for Breast cancer awareness month?

The research is financed by the K.G. Jebsen Center for Breast Cancer Research.

Reference:

• Haukaas TH et al. Metabolic clusters of breast cancer in relation to gene- and protein expression subtypes. Cancer and Metabolism (2016)

Blogger: Jose Teruel
PhD candidate at MR Cancer group

In a previous post in this blog I described how a new magnetic resonance imaging (MRI) technique called ‘Diffusion weighted MRI” can be applied for the detection of breast cancer due to the random movement of water molecules, or diffusion, which is different in cancer compared to healthy tissue. Therefore, using diffusion MRI we can measure the extent of diffusion and detect cancer. But, can we take advantage of this technique for benign breast lesion assessment as well?

… nowadays there is an excess of what we call ‘unnecessary biopsies’

Differentiation of breast lesions is another important step in the clinic. Let’s imagine the situation; a woman comes into the clinic feeling a lump in her breast, and a routine mammography or ultrasound confirms the presence of a suspicious lesion. The next step in the clinic would be to obtain a biopsy of the lesion to properly establish if the lesion is a malignant tumor, a threat for the patient’s life, or if it is a benign tumor that needs no further treatment.

A needle biopsy is categorized as an invasive procedure. The procedure consists in introducing a needle through the patient breast into the lesion, to obtain a sample (or several) of the tumor tissue that will be analyzed by a pathologist to examine if there is a presence of cancerous cells.

Having explained what a biopsy is, it is important to note that nowadays there is an excess of what we call ‘unnecessary biopsies’, i.e., biopsies that could have been avoided if it would have been possible to characterize the lesion as benign by a different ‘non-invasive’ procedure. Biopsies are in the best case not pleasant for the patients, and the procedure consumes time and resources.

… differentiating malignant and benign lesions without the need of an invasive procedure

So, what could the role of diffusion MRI be in this matter? Diffusion MRI can characterize different tissues based on their microstructure, and this microstructure it is known to be different in malignant and benign lesions. Our preliminary results in the use of this technique suggest a very high accuracy in differentiating malignant and benign lesions without the need of an invasive procedure. This is possible due to the fact that water movement (diffusion) is much more restricted in malignant lesions compared with benign ones and this difference can be measured by different parameters obtained from a diffusion MRI examination.

Left: Benign tumor exhibiting clearly higher values of apparent diffusion coefficient (ADC), a measure of the extent of water diffusion within tissue, compared to much lower values found for cancer on the right panel.

Furthermore, the particular technique used in our work, known as Diffusion Tensor Imaging (DTI), provides information not only in the extent of the water diffusion but also about the directionality of the diffusion. The detailed results of this work performed at NTNU and St. Olavs Hospital, is now in press and will soon be published in the Journal of Magnetic Resonance Imaging under the title “Diffusion weighted imaging for the differentiation of breast tumors: From apparent diffusion coefficient to high order diffusion tensor imaging”.

Further research and validation of our results may strengthen the current opinion that a non-invasive MRI examination can be used before biopsy to confirm if the biopsy is really necessary or if malignancy can be directly ruled out.

… diffusion MRI could save in the future a great extent of unnecessary biopsies

In summary, the use of diffusion MRI could save in the future a great extent of unnecessary biopsies avoiding invasive diagnostic procedures to patients with suspicious breast lesions.

I would finally like to thanks the dedicated volunteers that take part in our study and the funding we receive from the local health authorities and The Norwegian Research Council.

Blog by: Anna M. Bofin
Professor of Medicine (Pathology)

Breast cancer is a disease of the milk-producing glandular cells, the ductal and lobular cells of the breast. In order to survive, cancer cells need nutrients, support and an environment that they thrive in so that they can grow, multiply and spread. At an early stage, cancer cells establish a close dialog with the tissues and cells that surround them. They encourage blood vessels to develop in order to supply them with glucose and oxygen and they stimulate cells in surrounding tissue, stromal cells, to build a scaffold that can support the growing population of cancer cells.

This close communication between cancer cells and their microenvironment and the ability of cancer cells to remodel their surroundings according to their needs, is acknowledged as a vital part of the development of a tumour.

The normal glandular structures of the breast are embedded in a connective tissue stroma that supports and protects the glands in both the resting state and during lactation. This supportive tissue is part of the dynamic microenvironment of the breast. In breast cancer tumour cells develop the ability to modify the connective tissue cells nearby in order to obtain nutrients and to enable the cancer cells to invade adjacent tissue. Indeed, some tumour cells are so adaptable that they themselves can transform from glandular or epithelial cells into stromal or mesenchymal cells. This phenomenon is called epithelial-mesenchymal transition (EMT) and is essential for the development of a tumour.

Much research is being done on the molecular aspects of tumour development, connective tissue changes and EMT. The Breast Cancer Subtypes research group wanted to investigate whether it was possible to identify any changes in connective tissue fibre patterns within the tumour and at its edge compared to normal tissue.

In collaboration with Associate Professor Magnus B Lilledahl at the Department of Physics, NTNU, the Breast Cancer Subtypes research group decided to study collagen fibre patterns in tissue sample from breast cancer. The work was done by medical students Anders Brabrand and Ian Kariuki as their student thesis, using second harmonic generation laser microscopy.

The study was carried out on a small number of cases of breast cancer, but the complexity of the microscopic examinations and the numbers of images necessary for analysis were considerable.  Brabrand and Kariuki became a regular sight at the Department of Physics as they exploited all available time slots in the lab and they frequently worked hard into the night analysing their results.

The outcome of their work was well worth the effort. They discovered that collagen fibres in the tumour microenvironment undergo different changes dependent on whether they are inside the tumour or at its edge. They found that cancer cells induce structural changes in the stroma that are beneficial to themselves.  In normal tissue the fibres are wavy and look a bit like angels’ hair. In the middle of the tumour, the fibres are very straight but lie in a criss-cross pattern. At the growing edge of the tumour, however, they found that the fibres are parallel to each other making a kind of railway track along which the cancer cells can migrate into the surrounding tissue.

Anders Brabrand og Ian Kariuki, medical students at NTNU

Kariuki and Brabrand were awarded a travel stipend for their work by the Oslo Breast Cancer Consortium (OSBREAC) in 2013 and they used it to participate in the 26^th European Congress of Pathology in London, 2014. Their findings were published this year.

At present Magnus Lilledahl is developing a method that will allow more rapid processing of tissue samples in the laser microscope and the research group plans to study collagen fibre patterns in a larger number of samples of breast cancer. This collaboration between the world of physics and the world of pathology has contributed to our knowledge of the effect of cancer cells on their environment. However, none of it would have been possible without the efforts of two medical students who were willing to give up a good night’s sleep for the sake of science.

 This meeting between the world of physics and the world of pathology could contribute to our knowledge of the effect of cancer cells on their environment.

Blogger:

Our bodies constantly renew their cells. In healthy individuals this is tightly regulated so that old cells are removed at the same time as new ones are produced. Cancer arises when this regulation gets out of control due to, for example, mutations in the DNA. A tumour consisting of large numbers of cancer cells is formed.

Lung tissue from mice: Healthy lung cells in blue with metastasis (cancer cells) shown in brown. (Photo: TS Steigedal)

In the environment around the cancer cells there are also many other types of cells that affect how the tumour develops. These cells are called stromal cells and include fibroblasts (connective tissue cells), macrophages (inflammation cells) and endothelium cells (blood vessel cells). Cancer cells can programme the stromal cells to their advantage so that the cancer cells get even better growing conditions.

In addition to cancer cells and stromal cells, there are also many other molecular components in the tumour’s microenvironment. Examples of such proteins include growth factors that stimulate cell division and cytokines that regulate inflammation reactions. In addition there are also large scaffold proteins outside the cells ensuring structure and support to all cells. Without such framework proteins the body would just be a random heap of different types of cells. This type of scaffold is called an extracellular matrix.

Exploiting the environment

Cancer cells exploit the other cells and proteins in the tumour microenvironment to their advantage so that the tumour can grow, divide and eventually spread (metastasise) to other organs. More and more attention is now given to the mapping and understanding of the tumour microenvironment’s composition in connection with cancer development.

Much speaks for the makeup of the tumour microenvironment playing a decisive role in how tumours develop and whether they spread. And perhaps this information could say something about how the tumour will respond to treatment. We now work on characterising tumours’ microenvironment and the goal is to understand how the composition of the microenvironment affects cancer development.

We have used a mouse model of breast cancer which has been modified so that the mice develop breast cancer in a predictable manner. By analysing the tumour microenvironment’s composition in tumours from different stages of cancer, we can say something about how they change throughout the tumour development. We have used advanced methods to map the complete composition of proteins in the tumour microenvironment.

Tumour samples from modified mice models: 1) Low-grade tumour with few cancer cells (red) and very little visible ECM/collagen (blue). White areas are normal fat tissue. 2) Late-stage: invasive, aggressive tumour packed with cancer cells and lots of ECM/collagen. The tumour becomes fibrous and hard. (Photo: TS Steigedal).

New biomarkers for breast cancer?

We now see that some of these proteins also seem to appear in human breast cancer, and we wish to understand what function these proteins have. If we could understand what they mean to the cancer cells, we could perhaps use these proteins as new biomarkers for diagnosis and prognosis, and the goal is also to identify new targets for treatment and therapy of breast cancer.

I have just spent 6 months away from home and worked at one of the well-known and respected breast cancer research groups in the field of magnetic resonance (MR) at Johns Hopkins University School of Medicine, Baltimore, USA.

Baltimore is an interesting city famous for its National history, good university, and high crime rate. To ensure the safety of the people, the city offers free shuttles and buses between campuses and also downtown.

Pictures from Baltimore and my colleagues Asif Rizwan, me, Samata Kakkad and Lu Jiang.

Baltimore is a big contrast to the small town of Trondheim where I have my regular job as a postdoctoral fellow at the research group The MR Cancer Group at NTNU headed by Tone Frost Bathen. Our group has established a solid competence in the field of MR and cancer, being internationally recognized as one of the most experienced groups in large-scale cancer tissue analyses. So even though Trondheim and Baltimore are quite different, we are joined by our interest for breast cancer research.

So, what did I do in Baltimore?  The research project includes biopsies from Norwegian breast cancer patients. The samples were collected for more than 10 years ago. They have been stored in liquid nitrogen (-190 Celsius) to minimized tissue degradation. The quality of the samples is well preserved even with long-time storage. This enables us to perform modern medical analyses that were not available at the time of sample inclusion.

We aimed to identify metabolites (small chemical compounds utilized and produced by the cells) and genes that can be used as new targets for breast cancer treatment. The studies of metabolites and genes are complementary and are important to improve the understanding of cancer biology and how cancer cells react to different treatment. We have performed the metabolite analysis here at NTNU and the gene analysis at Johns Hopkins.

We found that the metabolite profile (a spectrum of detectable metabolites in a sample) of breast cancer can be used to give information about breast cancer survival. Based on the metabolite profiles we were able to discriminate between patients that experienced cancer recurrence and died before 5 years and patients that survived more than 5 years. We identified a gene called GDPD5 that can be associated with tumor aggressiveness by regulating the choline phospholipid metabolism that is known to change in breast cancer.

At present, we are investigating the biological effects of targeting the GDPD5 gene in breast cancer cells. Also, we are developing system to deliver this treatment in animal models to investigate the effect of treatment in a living organism.

Findings from this project can be useful for developing new targeted therapies, especially for patients that have a more aggressive tumor and does not response well to currently available treatments.

A research stay abroad is not just about work, but also a chance to experience a new country, new friends, and colleagues. I have had a great time during my stay and have enjoyed working with people with diverse expertise in breast cancer research. I do think that a research stay abroad is a good opportunity to experience and learn something new.

It is also a good way to establish international collaboration between NTNU and other Universities around the world. However, from my experience, you do need to work hard and have a good and achievable project plan. The preparation beforehand can be time-consuming and tedious, which could make you lose interest, but we do have a good support system at NTNU and the people at the administration have been very helpful. So I would like to thank them, and a special thanks to the patients participating in this research project and Helse Midt-Norge for funding.

Blogger: Riyas M. Vettukattil

When working as a doctor out in the clinic, I was always puzzled by a set of questions which are beyond the routine diagnostic challenges: I always wondered what makes people with similar build, age, ethnic background with a common diet and lifestyle habits end up with such different destinies? Some would die of a heart attack or perhaps a brain tumour within a few months, while others would live for years with no heart disease or cancer. How does a clinician know which person in his or her waiting room is at an immediate risk?

Unpredictable killers?

Cancer and heart disease are the leading causes of mortality in the developed world, and in many developing countries. It is a widely accepted fact that these diseases have “multifactorial” origin in most patients, meaning that these diseases cannot be explained by genetics alone and that the causative elements vary in an unpredictable fashion from patient to patient.

But what would happen if we had a lab test which could say something about risks and best treatments?

We have several laboratory tests, but so far no test can reliably identify who will get these illnesses and who won’t. The existing clinical and pathological tools for both these diseases are insufficient for accurate response prediction and for an individualised treatment.

But what would happen if we had a lab test which could say something about risks and best treatments?

What the metabolites say

Metabolomics, or the study of small molecular metabolites which are chemical substances produced as a result of the cells’ metabolism, could provide some answers. The identification of metabolic biomarkers for cardiac disease and cancer risk prediction, diagnosis and treatment response, could have the power to increase overall survival and the patients’ quality of life, as well as saving huge expenses for society.

As a part of my recently completed PhD research at the MR Cancer Group in Trondheim, we found aerobic fitness dependent differences in serum levels of free choline and phosphatidylcholine in a group of healthy volunteers from the Nord-Trøndelag health study (HUNT). Maximal oxygen uptake (VO_2max) is the maximum capacity of an individual’s body to transport and use oxygen during incremental exercise, which reflects the physical fitness of the individual. In healthy people, VO_2max is the best predictor of future cardiovascular disease (CVD) mortality. Hence, it is interesting to identify new biomarkers for low aerobic fitness that may also have a potential as early biomarkers of cardiovascular disease risk.

As we saw an association between aerobic fitness and serum levels of choline-containing metabolites (choline is an essential nutrient and its metabolites are needed for maintaining structural integrity and signalling roles for cell membranes). These metabolites could be early markers of heart disease risk, although this needs further validation studies. Detecting early warning signs of cardiovascular risks in a healthy population may further help in intervention programmes, such as lifestyle modifications, and thereby improve community health.

MR metabolomics the study of small molecular metabolites. (Photo: Geir Mogen)

In another study, the possibility of differentiating diffuse World Health Organization (WHO) Grade II and IV astrocytoma (a type of brain tumour) based on their metabolic profiles were shown. This is one of the common primary brain tumours in humans, which have very poor prognoses at higher grades. High and low grade astrocytomas are managed differently, and therefore it is essential to identify molecular and metabolic factors that may classify these patients with regards to optimal treatment and prognostication. Identifying new biological indicators using metabolomics offers a new objective diagnostic approach, which depends solely on biomarkers that can improve the accuracy of tumour grading and patient stratification.

These metabolic markers are still a long way from reaching routine clinical use. Still, I strongly believe that these are the first steps in that direction.

In a third study, metabolic markers of chemotherapy-related changes in ovarian serous carcinoma effusions were identified. The collection of fluid in the abdominal cavity and around the lungs (known as malignant effusions in serosal cavities) is seen in advanced stages of ovarian, breast and gastrointestinal cancers. Studying metabolites in theses fluids can provide important information about the exposure to chemotherapy, and metabolic characterisation could be a promising technique to further understand the mechanisms of abnormal fluid collections (effusion) development in malignant tumours, and to target clinical intervention.

These studies show that metabolomics techniques are useful in capturing molecular signatures of cancers and aerobic fitness, and may contribute further to the scientific understanding of the underlying biology.

However, these metabolic markers are still a long way from reaching routine clinical use. Still, I strongly believe that these are the first steps in that direction.

James Paget (photo: wikipedia.org)

“Many of the cells of cancers, for example, may be somewhat like gland cells, yet a practised eye can distinguish them; they are heaped together disorderly and seldom have any lobular or laminar arrangements such as exists in the natural glands or epithelia”

These words were written in 1853 by James Paget who was a surgeon and pathologist, and they describe cancer cells as we see them under the microscope. The cells are different from normal cells. They are mutineers only interested in their own survival at the expense of their host.

To this day, the initial diagnosis of breast cancer is still made by a pathologist examining a tissue sample under a microscope. We know that breast cancers differ greatly in their appearance and that these differences can be explained by differences in their molecular characteristics. These differences are exploited today to give the individual woman a tailor-made treatment based on a set of special tests that have been tried and proven useful for this purpose.

We know that tissue samples from breast cancer harbour even more information that could help us to understand the causes of the disease, determine more effective treatment and avoid overtreatment.

Normal breast tissue (left), breast cancer, ductal type (right)

The Breast Cancer Subtypes research group at NTNU has studied over 900 cases of breast cancer from women in Nord-Trøndelag who took part in a breast cancer screening program organised by the Cancer Registry of Norway over 60 years ago. These women lived in an era before hormone replacement therapy became common and before the implementation of mammography screening. They received limited treatment, often only surgery, making it possible to study the near natural course of this disease.

These samples have now been reclassified into subtypes based on their molecular composition rather that their appearance under the microscope. Follow-up shows that there are differences in survival according to molecular subtype and that most of these differences occur during the first five years after diagnosis. These results were recently published in Breast Cancer Research and Treatment.

Mothers and daughters

Could there be differences in the types of cancer that occur in these two generations?

Like their mothers and grandmothers before them, women in Nord-Trøndelag have continued to contribute to research through their participation in the Nord-Trøndelag Health Study (HUNT). The next step for the Breast Cancer Subtypes research group is to study breast cancer tissue samples from women who took part in HUNT2 between 1995-97. In contrast to their mothers, these women have had access to the contraceptive pill, hormone replacement therapy and mammography screening. Could there be differences in the types of cancer that occur in these two generations?

Breat cancer, lobular type (top left), HER2 protein on the cell membrane (top right), HER2 gene amplification in cell nuclei (bottom left), breast cancer, ductal type (bottom right)

A further question that the Breast Cancer Subtypes group is addressing is survival.

Ultimately, the aim of this work is a better understanding of this complex disease in order to provide the individual woman with a more accurate diagnosis and a more effective treatment of her cancer.

Follow-up over several decades makes it possible to study the molecular characteristics of cancers that have a very good prognosis as well as those with a poor prognosis. Using advanced technology, it is possible to stain and analyse hundreds of tissue samples in a standardised way and study the molecular characteristics of the different cancers. When these data are linked to survival data it will be possible to identify cancers with very good prognosis requiring little or no additional treatment, and others that require individual, tailor-made treatment strategies based on the characteristics of the individual cancer.

Ultimately, the aim of this work is a better understanding of this complex disease in order to provide the individual woman with a more accurate diagnosis and a more effective treatment of her cancer.

One of the best things about being a researcher is that you can work on completely new ideas and concepts without giving much thought to what is actually possible or not. Often it turns out that what you thought was impossible is possible after all if you a) develop a new technology, b) let enough researchers work on it for long enough, or c) have a bit of luck. Preferably all three.

One of the areas where we are still at the starting line is nanomedicine. Even though we are capable of making particles at nanoscale today, we know little about what role they will play in tomorrow’s medicine. In the meantime we can enjoy ourselves with hatching clever, and less clever, ideas and evaluate how far they could contribute to improved treatments in the future.

Electron microscope image of nanoparticles. (Photo: Yrr Mørch/SINTEF)

This is the status at NTNU today: In cooperation with SINTEF, we can under controlled conditions produce particles with a diameter of a few hundred nanometres (which is about as much as your fingernails grow while you read this…). These particles are made from the same plastic materials that are used in superglue. But at SINTEF they let the glue “dry” in such a way that we maintain a whole different level of control over shape, size and characteristics, than if you glue a broken cup together. In this way they produce tiny little plastic particles. They can also put things inside them or decorate them with all sorts on the outside. If you place them in water together with some proteins and give them a shake, they can even join up and produce air-filled bubbles.

You can read more about nanotechnology at SINTEF here.

Gas bubbles made from nanoparticles seen through a confocal microscope. (Photo: Yrr Mørch/SINTEF)

Nanoparticles can be used for many things. At NTNU there are now about 20 researchers looking into how these tiny superglue particles can be used to improve cancer treatment. And so some of us privileged researchers are allowed to be creative.

Could we use these particles to detect cancer? Perhaps by placing a contrast agent inside and decorating the outside with something that recognises cancer cells? Or could it perhaps be smarter to use them to treat cancer? One of the problems with breast cancer treatment is that patients have to stop chemotherapy due to side effects. But if we could make sure that more chemo ends up in the tumour and less ends up in places where it causes side effects, this problem could largely be solved.

Researchers at NTNU, for example, work on filling the superglue droplets with chemo, making them into ‘large’ bubbles (about as much as a fingernail grows in an hour…), so that the superglue-droplet chemo can safely be transported around in the blood stream. And here comes the great trick: By targeting the superglue-droplet chemo-bubbles with ultrasound waves, we could make them burst where we want them to (for example in a tumour) so that the chemotherapy is released just there and nowhere else. This sounds difficult, but NTNU has for many years been a world leader in ultrasound technology. If we gain control over the behaviour of the nanoparticles, this should absolutely be possible.

Superglue, nanoparticles and breast cancer. (Illustration: iStock)

Finally, my own personal dream for the future: Nanoparticles containing chemo which are decorated with 1) structures that recognise cancer cells, and 2) structures making them ‘invisible’ to the body. Such particles could circulate in the blood over longer periods of time, acting as secret agents. When they find a unsuspecting cancer cell in the blood stream, they can attach themselves and deliver a suitable dose of chemo. The application? Well, you could imagine that such particles could help prevent a relapse in breast cancer patients after surgery, because often there will remain a few cancerous cells in the body that could cause a relapse several years after an operation.

Is any of this possible? 10 years ago many would have said a resounding “NO”, but now we can stretch to a “perhaps” or “why not”. The research area is growing, both at NTNU and in other places, thanks to research funding from, for example, the Norwegian Cancer Society and the Research Council of Norway. There is a steep learning curve, and we learn something new about these particles literally every day – a dream existence for a researcher.

When people think about breast cancer research, the first thing that comes to their mind is the picture of these people in white coats, for whom I have of course a great respect, experimenting with new drugs, new treatments and any possible way to treat and cure this disease.

This is of great value and many lives have been saved thanks to these developments, yet there is another kind of research going on in the field. This research is based not in treating the tumor but in detecting it, and that is one of the focuses in our group, the MR cancer group at the Department of Circulation and Medical Imaging.

MRI is the short name for Magnetic Resonance Imaging. The first picture that might come to your mind is this big bore machine, and if you have never seen it in person, you would at least have heard about it in TV shows like House or Emergency Room.

MRI (Photo: Geir Mogen)

MRI for breast cancer is an emerging technology. So far, in the clinic it is used for screening of patients at really high risk, such as patients with genetic mutations (does Angelina Jolie ring any bell?), or for evaluation of inconclusive findings in mammograms or ultrasound exams, as well as for monitoring specific cases of locally advanced breast cancer.

So far, these MRI examinations require the injection of a contrast agent to the patient’s blood. But this scenario could be about to change, as the researchers at the MR cancer group, and several other groups in the world are developing new advanced MRI techniques.

The technique I am talking about it is called Diffusion Weighted Imaging, and it has its origin in detecting areas in the brain affected by strokes. This is a powerful technique, but how does this Diffusion ‘thing’ really work? Actually it has been in front of our eyes for a long time and it was already described by Einstein (I mean the concept of Diffusion, of course not its application to MR). Just get a glass of water and drop some dye in it (orange juice or wine will make it as well). The dye will start coloring all the water starting from the dropping place, and this is happening because the water molecules of the dye (yes, everything is water in a high percent, even us and here it is the point) are moving. So, the concept is that the water molecules in any fluid will be moving freely as long as there is nothing to prevent them to do so.

Now, repeat the experiment introducing plastic balls full of water in the glass and you will see how the dye cannot move into the water inside the balls, now there is a barrier an there will be less diffusion in the glass, diffusion (freedom of water molecules to move) has been restricted.

Now, let’s go back to the breasts… In a healthy situation the water in your cells, extracellular fluid, fluid (or milk) in your ducts will be moving according with the natural structures of your breasts. The water will have a natural freedom to move and will be restricted by natural barriers, so its diffusion will be in a certain ‘healthy’ range. But then, if the bad guys (cancer cells) start invading those structures and reduce the freedom of the water, the scenario is changed. The water molecules can no longer move in the same way because the environment is invaded (that is why we call tumors ‘invasive’) by hordes of malignant cells.

Water diffusion recreation from MRI data. Each ellipsoid represents the distance traveled in average by an imaginary water molecule situated in the center of the voxel. Red arrows point out an area of low diffusion (invasive ductal carcinoma). Blue arrow points out healthy tissue with healthy range of diffusion. Blue arrow points out a too high diffusion area (tumor necrosis).

Green arrow points out healthy tissue with healthy range of diffusion. Blue arrow points out a too high diffusion area (tumor necrosis).”

Going back to the technique, what Diffusion Weighted Imaging does it is to use the power of MRI technology to measure the diffusion of water molecules within tissue and look for values out of the normal limits. Physical models are used to help with this task, and two important ones are diffusion tensor imaging (DTI), that looks at diffusion in specific directions; and intravoxel incoherent motion (IVIM) that takes in account that water in blood will be naturally moving faster and in an established direction.

Tumor detection is a key point as early stage breast cancer patients have a really high survival rate (over 80%). We are doing our best to develop these new techniques with the aim of making early accurate detection of breast cancer a better reality each day. This would be impossible without the dedicated volunteers that take part in our studies and the funding we receive from the local health authorities, The Norwegian Research Council, and the Norwegian Cancer Society.