Breast Conservation Versus Mastectomy

GAO's analysis indicates that--for the kinds of patients GAO examined--the effectiveness of breast-conservation therapy has, on average, been similar to that of mastectomy in community medical practice as well as in randomized studies. Specifically, for medical practice cases, the adjusted 5-year survival rate (averaged across all selected patients) was 86.3 percent for breast-conservation patients and 86.9 percent for mastectomy patients. These results clearly correspond to the results of multicenter randomized studies (88-percent 5-year survival for breast conservation and 88 percent for mastectomy). Single-center studies reported somewhat higher survival for both treatment groups. Thus, on average, for breast cancer patients of doctors in regular medical practice who are similar to patients in randomized studies, there appears to be no appreciable risk linked to choosing breast-conservation therapy rather than mastectomy.

GAO found that: (1) the 5-year survival rates for breast cancer patients treated with breast-conservation therapy were similar to that of mastectomy in community medical practices; (2) patients that were treated at single-center facilities usually had slightly higher survivability rates than patients who received treatment at multi-center facilities; (3) on average, breast cancer patients appear to be at no appreciable risk by selecting breast-conservation therapy rather than mastectomy; (4) although patient survivability data were vulnerable to hidden selection bias, such bias was unlikely since the group of patients reviewed were homogeneous and adjustments were made for patients' health and demographic characteristics; and (5) although a minority of patients who voluntarily chose breast-conservation therapy over recommended mastectomy therapy could have achieved slightly better results with mastectomy, the differences were not statistically significant.