The average lifespan of the American woman continues to rise well past 80 years. Assuming a healthy heart and no other major medical illnesses, the chance for breast cancer is still present. Women over 70 have been under-represented in clinical trials, and there is still a little controversy about mammography for elderly women (which I believe is now resolved).
A pooling of clinical trials by the NSABP (National Surgical Adjuvant Breast and Bowel Project) showed that elderly women tolerated and benefited from adjuvant chemotherapy. But in real life, the dilemmas are much harder.
Most of the time elderly women develop a subtype of breast cancer that is relatively less aggressive - node negative, ER+ and or PR+, with a high cure rate and benefit from hormonal therapy. It is when there are multiple nodes involved that adjuvant chemotherapy may increase the chance of cure - and this is a harder problem to overcome.
Dr. Hyman Muss from the University of Vermont has written extensively on the treatment of elderly women with breast cancer. There is a chronological age (e.g. 72, 75, 81) and a “biologic” age for patients. So a woman who is 72 may actually be healthier than many 52 year olds. These patients in general can tolerate more aggressive therapy better. We also refer to this at times as “performance status” meaning how vigorous a patient appears.
Where this breaks down, and where I find the papers and guidelines not too helpful, is the fact that no matter how healthy a person appears, their bone marrows chronological age is still their bone marrows chronological age. This means that when a patient gets chemotherapy, their chance of having their blood count drops depends to a large extent, on their chronological age. The older a patient is, the less their bone marrow bounces back from cytotoxic chemotherapy.
There has been progress with the development of G-CSF (and a newer form - the long acting “depot” form of G-CSF) that can decrease the risk of neutropenic fever. But as patients get to be older than 70, they still are at risk for significant toxicity from chemotherapy. And even if their bone marrow does tolerate the chemotherapy reasonably well in terms of preserving blood counts - the chemotherapy itself often causes so much fatigue that it may not be tolerated.
For some women who have made it to their 70s and have no other illnesses their life expectancy is good enough to warrant adjuvant chemotherapy. And several patients currently under my care are in this situation - it makes me a little nervous but as usual one goal of being a treating oncologist is to always “do the right thing”.