In early December, San Antonio, Texas, becomes the place to be, as breast cancer advocates, physicians, pharmaceutical reps, and basic scientists converge from throughout the world for the annual San Antonio Breast Cancer Symposium.
The five-day meeting, which was held this year from December 5 through December 9, includes presentations of the latest basic research and clinical studies as well as posters representing smaller studies or early findings. As the last big meeting of the year in the breast cancer world, it’s a time to not only hear the latest research news but catch up with friends, colleagues, and collaborators and make the connections that could lead to future collaborations. Some years there are big announcements in San Antonio. Other years—as was this one–we hear about the steady effort to better understand breast cancer and how best to treat it.
Right now, there is a big focus on circulating tumor cells (CTCs) and circulating DNA and there were many presentations about these topics. This is the fruit of a new technology that allows researchers to take a blood sample (which typically goes by the fancy name “liquid biopsy”) and test it to see if it contains any tumor DNA or cancer cells.
It’s clear we can find these cells and DNA. The problem is that we’re not really sure what they represent. We initially thought the cells circulating in the blood were cells that had left the primary tumor in the breast and were traveling to another organ with the goal of setting up a metastatic site. But the findings from the latest studies reveal a more complex picture.
At one basic science session I attended, researchers presented study findings that showed the tumor discards cells and DNA before it even becomes a lump that can be felt or a lesion that can be seen on a mammogram. What we don’t yet know is why. It’s possible that these circulating cells we can find in the blood are not en route to other organs but rather damaged cells the tumor has rejected. Or it could be that these are cells that don’t have the ability to get into other organs, so they just keep circulating.
Other basic scientists said they had found that in order to set up shop in another organ, the tumor cells appear to have to travel in clumps with their local neighborhood. Bringing their neighborhood with them makes it more likely the cancer cells will be successful in setting up a home in a new organ, much the same way immigrants who arrive in the U.S. with family members or friends are more likely to have an easier time settling into their new community than those that come alone.
Until we know what these circulating cells and DNA represent, it’s hard to figure out how to best use these blood tests clinically to help patients. The best guess at the moment is that the cells are markers of the tumor’s activity; a high level of activity reflects a more aggressive or active cancer that is more rapidly making cells and tossing them into the bloodstream. Finding high levels on a blood test would then suggest it is time to change treatment, making the test similar to some other tumor markers we currently use. So, while at this point the hype is high, there is still much to be learned. Stay tuned.
I was very happy to see several posters reporting research on collateral damage, the term I use to refer to the long-term side effects of cancer and its treatments. A research group in Spain found that 12 out of 88 patients treated with chemotherapy developed heart problems. And a research group from Ireland reported that their study of 83 patients found that 20 were on a statin before starting adjuvant treatment and 17 were on a hypertensive. Also, 9 had a greater than 20% chance of having a heart attack or stroke in the net 10 years while 28% had moderate risk. Seven patients had a risk of having a heart attack or stroke that was higher than their risk of dying of breast cancer. These types of numbers tell me that more needs to be done to talk about the risk of heart attack and stroke in breast cancer patients. Many people believe most women with breast cancer die of breast cancer. But in fact, most women diagnosed with breast cancer die from cardiovascular disease.
Researchers from the Netherlands presented a poster on a study that looked at why women stop their adjuvant hormonal therapy. They found, not surprisingly, that the women with collateral damage (depression, hair loss, and joint pain) were more likely to stop taking their anti-estrogen therapy. While you might want to say “duh” to this conclusion, it sets the stage for breast cancer patients and their doctors to demand pharmaceutical companies either develop drugs that don’t have these consequences or do more research to develop better alternatives.
I was also intrigued by a poster by researchers from the Ohio State Cancer Center who are conducting a study to see if the drug minocycline, which is used to treat acne, can prevent chemo brain by reducing inflammation. The study is ongoing and so we will have to wait for a future San Antonio Breast Cancer Symposium to learn the answer.
For many of the breast cancer advocates and doctors I spoke with, the most exciting study on collateral damage was one where women on aromatase inhibitors were randomized to receive acupuncture, sham acupuncture, or nothing (waiting list) to treat joint pain. The study was very carefully done and, lo and behold, the real acupuncture helped! It is great to see science applied to investigate collateral damage and I hope this study will not only decrease suffering from joint pain but also be a model of how to address the quality of life issues that affect so many breast cancer survivors, in particular women living with metastatic breast cancer.