In an international study involving 500,000 women, researchers concluded for every 2,000 women who had a mammogram, one will have her life prolonged, but ten will undergo unnecessary chemotherapy, radiotherapy and mastectomies. According to Nordic Cochrane Centre researchers, while mammograms do prevent breast cancer death in detecting early-stage breast cancer, it also leads to breast cancer diagnosis in women who would have survived without treatment. Professor John Toy, medical director of Cancer Research UK, is quoted as saying, "Researchers in the field all agree that breast screening saves lives although they differ in their views about the balance of the pros and cons. Benefits need to be balanced against any disadvantages, as is the case with all medical treatments. Certainly women invited for screening should be made aware of both potential benefits and downsides."
This leaves women in a difficult position. As more women are encouraged to go in for breast cancer screening, more early-stage breast cancer is being discovered. The earlier a cancer is discovered, the better the chances of surviving cancer. That's a given.
However, if they cannot predict how the cancer will behave when found in its earliest stage, or if it will ultimately be life-threatening -- and if, as this study suggests, one woman will be helped while ten women will undergo unnecessary chemotherapy, radiotherapy and mastectomies -- how does a woman decide which treatment or non-treatment path to go down? Chemotherapy, radiotherapy and mastectomies are not simple innocuous treatments.
At this point, I am not certain what we should do with the findings of this study other than be confused, worried and uncertain. What do you think?
1. Thanks for highlighting this problem. I had no idea that the Need To Treat numbers were so skewed: a high number of treatments needed to provide just one clear benefit. Does the study appear sound and reputable? It probably is, but the numbers are surprising.
There is a similar problem in prostate cancer as many men can live just fine with prostate cancer and not have a noticeable impact throughout their lives. However, my impression is that the proportion of unnecessary treatments is no where near as high, probably due to that marvelous marker we have, PSA. Other men definitely need treatment to avoid symptoms of advanced disease and often death.
Our prostate cancer community is learning more about who can safely defer therapy while continuing to monitor carefully and employ tactics to hold down or reverse the cancer. These tactics involve nutrition, supplements, diet, exercise, stress reduction, and sometimes some fairly low key medications like finasteride and Avodart.
Jim Waldenfels
Posted at 6:36PM on Oct 18th 2006 by Jim Waldenfels