Occasionally radiation is added after mastectomy to help decrease the likelihood of local recurrence of cancer. However, at a major cancer institute within the metropolitan area, the vast majority of women in the same time frame were treated with mastectomy. There was no obvious medical reason for this. The result was best explained by different medical philosophies. Studies from around the world have shown that the two treatments are equivalent as far as survival but that lumpectomy with radiation offered improved cosmetic results and the likelihood that a woman would live her life most likely with her breast intact.
SEER data is a collection of medical information from selected locales across the country.
They assessed characteristics of different areas of the United States to evaluate whether breast-conserving surgery was performed. It should be noted the study took place prior to widespread American data showing equivalence of the two treatment methods. Included were 19,661 women with breast cancer. The women were classified as either having breast-conserving surgery or not. It may well be useful that all women see photographs of different cosmetic results of the two dramatically different treatment modalities before choosing.