Running since 1977, the San Antonio Breast Cancer Symposium has been the place to exchange new information in experimental biology, prevention, diagnosis, and treatment of breast cancer. Breast Cancer Now joined over 7,500 delegates at the meeting in December to hear the very latest developments in research.

san antonio welcome sign

Herceptin vs Kadcyla

Herceptin, currently used to treat HER2-positive breast cancer, works really well for some, but others still have a high chance of relapse despite treatment. Scientists looking for better treatment options tested if the drug Kadcyla has advantages over Herceptin, and presented their results from the KATHERINE clinical trial.

The KATHERINE trial was investigating if those who have a higher likelihood of recurrence after standard pre-surgery treatment and tumour excision would benefit more from receiving the drug Kadcyla than Herceptin after their surgery. Currently, Kadcyla is only used to treat secondary breast cancer, but the trial showed that it can decrease the risk of breast cancer coming back by 50 per cent in those at higher risk of recurrence.

Kadcyla also had more severe side effects compared to Herceptin, but researchers leading the trial argue that the side effects can be reduced by modifying the dose of the drug. Professor Geyer, the lead author of the trial, believes that these results are practice-changing, and expect medical regulatory bodies to approve the use of Kadcyla to treat primary HER2-positive breast cancer in those with a high likelihood of cancer recurrence.

Can we stop breast cancer coming back?

At this year’s meeting, researchers were discussing in detail what we already know about tumour dormancy – an inactive state tumour cells can enter and remain undetected for a long time before reawakening and giving rise to secondary breast cancer. Finding ways to target these tumour cells or stopping them from waking up could stop breast cancer taking lives.

Professor Lewis Chodosh from the University of Pennsylvania, highlighted that we already know that dormant cancer cells are different from cancer cells found in the primary breast tumour. Understanding these differences and finding unique vulnerabilities dormant cells have is the key to killing them, or preventing them from forming secondary tumours.

With some therapies already being developed to target dormant breast cancer cells, we need to understand who is most likely to see their breast cancer come back. Evidence is gathering that if early on in the disease, disseminated tumour cells (DTCs) can be detected in the bone marrow, it’s a signal that the breast cancer has a high chance of coming back. It’s currently estimated that between 20 and 40% of breast cancers have DTCs.

Researchers in the USA are combining the insight into vulnerabilities of dormant cancer cells and with understanding who may at most risk of relapse in a new clinical trial. The CLEVER trial was set up to find ways to prevent breast cancer recurrence by providing additional targeted therapy for those at high risk, and we hope it will bring some answers as to how we can stop breast cancer returning.

Doing less to achieve more

With progress in science and medicine, we have come far: we have better cancer treatments and more women are living with and beyond breast cancer than ever before. It may be time to evaluate whether we can safely reduce breast cancer treatment for some, to minimise unnecessary and harsh side effects. Of course, reducing breast cancer therapy may not be right for everyone.

At this year’s conference, Dr Eric Winer, an oncologist from Dana-Faber Cancer Institute in the USA, discussed the challenges of reducing breast cancer treatment without compromising survival. Dr Winer believes we need to improve access to high quality care, improve treatment for those at high risk of relapse, but at the same time minimise treatments for those who can do well with less.

What’s the way forward? We need clinical trials and thorough analyses to understand when it is absolutely safe to treat less. However, such clinical trials pose certain challenges.

Firstly, they need to be very big to show that there isn’t a difference between the standard level of treatment and a reduced level. Secondly, we need to understand who the right people are to receive de-escalated therapies. And finally, we need to take into account that the conversation about having less treatment is difficult for both doctors and patients. Research shows that doctors tend to underestimate the side effects of treatments and overestimate the benefit of treatment. The decisions doctors make are also influenced by perceptions of risk and the drive to help patients by offering more treatment may give more hope. For now, we need to have these issues in mind and wait for more research to understand when it’s safe and beneficial to do less.

Some evidence is already accumulating for reduced use of chemotherapy. Analysis of 52 clinical trials presented at the conference, showed that chemotherapy given after surgery may not add any benefit to those who already had an excellent response to chemotherapy given prior to surgery. When pre-surgery chemotherapy works so well that there were no signs of invasive cancer left in the breast or lymph nodes, these people already have a very low chance of their cancer returning. In this case, additional chemotherapy given after surgery would only bring difficult side effects, but no survival benefits.

This research supports the idea that some women could be better off with less treatment. But of course, more research is absolutely necessary to find out what is the right amount of treatment for different breast cancer cases.

AI to aid breast cancer diagnosis

Artificial intelligence (AI) has the potential to revolutionise our lives in many ways, and it is already slowly making its way into breast cancer diagnosis.

There are certain things that computers are much better at than people. Analysing visual results is one of them. Professor Nico Karssemeijer from Radbound University Medical Centre in the Netherlands, highlighted that AI trained with millions of mammograms can learn to classify benign and malicious lesions and can learn to do so better than radiologists. It’s unlikely AI will replace radiologists altogether, but in future it can give them a second opinion in those cases when results are tricky to interpret.

Another field where AI is likely to prove incredibly useful in breast cancer diagnosis is analysis and interpretation of biopsies, or pathology. Dr Andrew Beck, CEO of PathAI, discussed the use of AI in this field.

Biopsy samples can contain healthy tissue, cancerous cells and cells that already have some changes, but don’t yet look like cancer, which can make analysis and interpretation of the results trickier. Properly trained AI can distinguish individual cells, classify them and count cells very precisely, and so holds great potential for the future. Researchers believe it could be trained to analyse samples of non-invasive breast cancer, for example ductal carcinoma in situ (DCIS) as well as pre-invasive cancer stages. It could maybe even help predict tumour’s response to treatment, but we’ll need to wait more for these technological advancements to become a reality.

Exercise, exercise, and most importantly, exercise

We all know exercise has many benefits, and research is bringing even more indisputable evidence that exercise shouldn’t be forgotten, even for people receiving breast cancer treatment.

The Energy Balance and Breast Cancer Aspects-II (EBBA-II) study presented at this year’s conference, suggested that exercise performed during breast cancer treatment may counteract some side-effects the treatment has. The study showed that women who took part in a supervised programme of cardiovascular exercise during their post-surgery treatment, had better cardiovascular health than those who didn’t. Some breast cancer treatments may affect the heart, so strengthening cardiovascular health during and after breast cancer treatment is extremely important.

All women participating in the EBBA-II trial had undergone surgery for stage 1 or 2 breast cancer and were receiving chemotherapy, radiotherapy, hormone therapy, or a combination of these treatments. Women in the exercise group worked out twice a week for 60 minutes in small groups with a trainer doing aerobic exercise, stretching, and weight training. They were also asked to do an additional 120 minutes of physical activity a week on their own, while women in the control arm of the study weren’t recommended any exercise regiments and didn’t benefit from the improvement in their cardiovascular health. These results indicate that many patients undergoing cancer treatment could benefit from exercise. The researchers believe it may not only be beneficial for the heart, but also could help reduce fatigue and improve quality of life

A second study looking at the benefits of exercise and presented at the conference was SUCCESS C. In this trial researchers wanted to evaluate how lifestyle intervention could help survivals of early stage breast cancer to lose weight and reduce risk of breast cancer coming back. Obesity and low physical activity are two factors not only linked to increased risk of developing breast cancer in the first place, but also the chances of cancer coming back.

The researchers were offering either telephone-based personalised lifestyle intervention to women after their breast cancer treatment who had a body mass index (BMI) of 24 or higher, usually classed as overweight, or general recommendations for healthier lifestyle. Women receiving telephone calls from lifestyle coaches were given advice on how to improve their diets, improve physical activity and additional tips tailored to their specific needs.

Interestingly, even though women receiving telephone support had lost an average over one kilogram over the course of two years, while those who given generic healthy lifestyle advice gained an average of 0.95 kg, the scientists didn’t see any differences in survival between these two groups. The reason why hides in the fact that not everyone completed the lifestyle intervention.

When researchers analysed the results only from those who did complete it, the results were different: telephone lifestyle intervention helped to increase the likelihood of disease-free survival. And although the most significant factors affecting an individual’s risk of seeing their breast cancer come back is tumour stage and type, this research suggests there’s still something we can do to modify that risk.


Attending events like this is just one of the many things we do in order to improve our research and the care we can offer to people with breast cancer. You can find out about other research by clicking the button below.

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