Breast cancer survivor's questions about genetic testing are ahead of the research.
When I was originally diagnosed with a "garden variety" breast cancer (ER+, PR+, HER2Neu, no lymph node involvement, no BRCA1 or BRCA2, less than 1cm) caught early on a routine mammogram almost eight years ago, I was relatively happy — for a cancer survivor that is. My understanding was that I had great odds of beating the breast cancer.
I had what I thought was an 85 percent chance that my breast cancer would not come back. I thought, “Hmm, so if you put 10 of me in a room, maybe 9 of them would never have to cope with breast cancer again.” That sounded great. Testing positive for the recently discovered PALB2 genetic mutation changed that comfort level for me. Based on preliminary information, it may mean that if there are 10 of me in that room, somewhere between 3 to 6 of me might be facing breast cancer again. That did not sound good.
When meeting with the genetic counselor, I heard that my options at this point in time were breast MRIs alternating with mammograms every six months or a prophylactic double mastectomy. Now my question is what about the possibility metastatic breast cancer? I always understood that my breast cancer could come back in the same breast, the opposite breast or bone, brain, liver or lung. Common sense says that with estrogen receptor-positive breast cancer, maybe it makes sense to be on an estrogen-suppressing hormonal therapy medication. Research and treatment protocol has not caught up to prove or disprove this notion.
I talked to my oncologist and to my genetic counselor. It sounds like BRCA1 most often leads to triple-negative breast cancer, so suppressing estrogen to prevent initial breast cancer or a recurrence would not help. BRCA2 is more inclined to be associated with estrogen positive breast cancers as is the PALB2 mutation. Some people who have the BRCA2 choose hormonal therapy to prevent breast cancer, but the research results and treatment protocols do not say that yet. Hormonal therapy has its own risks and side effects to consider as well. The research treatment side has not caught up to the research discovery side of breast cancer.
Knowledge is power and as patients, it wise to remember that we can only make the decisions in the current moment of time. My oncologist wisely suggests that people who have these genetic mutations would benefit by periodically connecting with a major university research hospital or a big cancer center, like the Mayo Clinic in my area. My oncologist also suggests staying in touch with the genetic counselor.
To me, the critical question that does not yet have a scientific answer is: What are the chances of a breast cancer survivor with a genetic mutation getting metastatic breast cancer years later? Are genetic mutations predictive of which early breast cancers will turn up as metastatic breast cancer years later? A broader way to say it is: "Are people with genetic cancer mutations at higher risk for metastatic cancer? It is a nice question to be alive to ask, but it is frustrating that these questions are still ahead of the research. For now, it appears that a prophylactic double mastectomy may reduce my odds of a future breast cancer to less than 5 percent, so I am going to take those odds and run with them.