What’s interesting in cancer research right now? What do we most need to know about? This is the latest post in a series in which we review several of the most notable cancer research stories that have come out over the previous two to three months.
These are a few of the recent stories that seem to have the greatest potential impact, at least from my perspective, and that I know I’ll want to follow as they develop further.
Topics covered this time include medical decision-making, inherited breast cancer risk and a new drug for HER2-positive breast cancer.
Over the last ten years or so, there has been a large increase in the number of women diagnosed with cancer in one breast who choose to have the other breast removed in order to reduce the risk of a new cancer occurring in that other breast. These women are choosing the surgery even though they have no known genetic mutation that would increase breast cancer risk.
In view of this trend, researchers conducted a study to evaluate the actual survival benefits conferred by this type of surgery, known as contralateral prophylactic mastectomy or “CPM”. Their findings were reported in the Journal of the National Cancer Institute. The study found that, for women with stage I or II breast cancer and no BRCA mutation, there is very minimal survival benefit from the surgery, i.e. an absolute 20-year survival benefit of less than 1%.
An subsequent article about the study in the New York Times by Peggy Orenstein ignited heated discussion in media and blogs. The piece discusses the study’s findings and also some of the reasons women choose to have CPM–even though most do understand that, without a BRCA mutation, their risk of being diagnosed with a new cancer in the other breast is already low.
In “Decision-making in the midst of medical un/certainty”, Gayle Sulik, author of the book, Pink Ribbon Blues, discusses the response to the article and why it hit such a nerve.
It seems that in any medical decision, the evidence from scientific studies is an essential starting point, but it is just that–an educated starting point. Each individual represents a unique set of circumstances–which may not exactly match the population-based averages on which a study’s findings are based.
As AnneMarie Ciccarella of Chemobrainfog points out, medicine is both art and science, and this is where the art of medical decision-making needs to come into play. Beth Gainer of Calling the Shots shares the decision-making process she went through in electing a prophylactic bilateral mastectomy after a breast cancer diagnosis and treatment years earlier, showing how complex this process can sometimes be.
In another very balanced commentary, “On Mastectomies, Pink Ribbon Culture, and Women’s Choices,” Karuna Jagger of Breast Cancer Action, summed it up this way:
There is no single right answer for all women, but in order for each of us to make the choice that is best for us in our own circumstances and lives, we must balance fear with facts, and to do so, we need good information like the studies to which Orenstein is pointing. After that, we must trust the fact that every woman is doing her best in difficult circumstances and honor her decisions as her own.
Inherited Breast Cancer Risk
An inherited mutation in a gene known as PALB2 increases a woman’s breast cancer risk, much the way a mutation in the BRCA1 or BRCA2 gene does, according to a study reported in the New England Journal of Medicine. The existence of the gene has been known for a while, but scientists didn’t know by how much the mutation increased risk.
The study found that, for a woman with no family history of breast cancer, the PALB2 mutation increases her risk of being diagnosed with breast cancer to 35% by age 70. If she has two or more first-degree relatives who are diagnosed with breast cancer at age 50 or younger, her risk rises to about 58% by age 70.
An article about the study 0n Medpage Today pointed out that the frequency of the PALB2 mutation in the general population of women remains to be determined.
Depending on a woman’s known risk factors for breast cancer, any genetic testing that she undergoes could potentially include testing for the PALB2 mutation. A short article on “Other Abnormal Gene Testing” at Breastcancer.org provides additional information about genetic testing and changes in genes other than BRCA1 and BRCA2 that are associated with breast cancer.
Breast Cancer Treatment
Preliminary clinical trial results were reported for a potential new drug therapy for patients with HER2-positive breast cancer. Use of the new drug, called neratinib, was studied in a randomized, Phase III clinical trial of over 2,800 women. The drug was given as additional treatment for women with stage II-III HER2-positive breast cancer.
All of the women in the trial had undergone surgery and had also completed treatment with Herceptin. The women were randomized to receive either neratinib or a placebo as additional treatment for one year. The goal of the treatment was to further reduce the risk of recurrence for these higher-risk patients.
Preliminary results from the trial were positive, showing a 33% improvement in disease-free survival for neratinib compared to the placebo. Full results of the trial are expected later this year.
The discovery that a third inherited genetic mutation raises risk for breast cancer has led to increased interest in genetic testing. An article entitled “Cancer and the Secrets of Your Genes” in the New York Times gives an interesting overview of the benefits as well as the limitations of genetic testing in these early days.
The Dr. Susan Love Research Foundation’s latest post, “New Understanding of Cancer and Which Cells Are Important,” is about the diversity of cell types within tumors and how this is beginning to affect thinking about cancer and what is being seen in the clinical setting.
That’s it for this time. If there was another recent cancer research story or article that caught your attention or if you have thoughts on any of what I’ve included, I’d love to hear from you!