Recurrence Risk after 5 Years
A recent study: (http://jnci.oxfordjournals.org/cgi/content/abstract/djn233 in the Journal of the National Cancer Institute indicates that women who are treated with systemic therapy (chemotherapy and/or hormonal therapy) have a "relatively low" risk of recurrence after five healthy years post treatment. Dr. Abenaa Brewer and her colleagues at the M.D. Anderson Cancer Center in Houston found (not surprisingly) that the risk varied depending on the stage of disease and various pathological features of the tumor. The study looked at 2,838 breast cancer patients who had been treated with surgery, radiation when appropriate, chemotherapy and/or hormonal therapy and who had not experienced a recurrence after five years. Ten years after diagnosis, 89% of all patients were disease free, and fifteen years after diagnosis, 80% remained that way.
Out of 2,838 women, a total of 216 women eventually experienced a recurrence of breast cancer. At five years after diagnosis, the residual rate of risk was estimated to be 7% for women with Stage I cancer, 11% for women with Stage II cancer, and 13% for women with Stage III cancer.
It is striking to me that many news reports headline these results as the "risk of later recurrence being relatively low." I am pretty sure that none of these journalists had a personal history of breast cancer. Although it is certainly better that the late recurrence rates (after five years) are not higher, most of us are not completely soothed by learning that, fifteen years after diagnosis, 80% of all breast cancer patients who were fine at five years remain disease free. This also means that 20% have experienced a recurrence, and it is very likely that many of them have died.
It is especially jarring that the 89% who were healthy and well after ten years declines another 9 percentage points over the following five years. Now, I can do the math, as can you, and we understand that 9% more recurrences in years 10-15 is fewer than the 11% between years 5-10, but it is far from good enough. One suggested explanation is that the increasingly common practice of keeping women with estrogen-receptor-positive tumors on anti-estrogen/hormonal therapies for longer than five years is contributing to delayed recurrences. Without these therapies, some of these women would have recurred sooner. Later is better, for sure. But later is not never, and "later" is not good enough. This study also suggests that more attention and research need to be directed at younger women (meaning women who are still having their periods) as tamoxifen is currently the only available anti-estrogen treatment for them. The aromatase inhibitors are only useful for women who are post-menopausal.
I am curious what your reactions to this study may be.