Geographic variation in the treatment of localized breast cancer

Breast-conserving surgery followed by radiation therapy is as effective as modified radical mastectomy in treating women with localized breast cancer, as demonstrated by clinical trials reported during the 1980s. The extent to which breast-conserving surgery has been adopted in various regions of the United States is not known.

We assessed variations in the use of breast-conserving surgery from 1983 to 1986 in 18,399 non-Hispanic white, 324 Hispanic, and 1174 black women with breast cancer in nine areas of the United States, using data from the Surveillance, Epidemiology, and End-Results Program of the National Cancer Institute.

The proportion of white women with localized breast cancer who underwent breast-conserving surgery ranged from 9.2 percent (Iowa) to 32.1 percent (Seattle) in 1983-1984 and from 19.6 percent (Iowa) to 41.5 percent (Seattle) in 1985-1986. Between 1983 and 1986, the use of breast-conserving surgery increased in each area, but the relative rankings of the areas changed little. The frequency of the use of breast-conserving surgery in black and Hispanic women was comparable to that in white women. The proportion of women who received radiation therapy after breast-conserving surgery also varied geographically and increased from 1983 to 1986 in all areas. Older women in all areas and black women in Atlanta and Detroit were less likely than other women to receive radiotherapy after breast-conserving surgery.

There is marked variation in the United States in the use of breast-conserving surgery for localized breast cancer. The variation is not explained by demographic factors, although race and age affect the use of radiotherapy after breast-conserving surgery.