Treatment patterns for female breast cancer in Minnesota, 1995-1996.

Breast-conserving surgery (BCS) followed by radiation is an accepted alternative to mastectomy for treatment of early-stage breast cancer. This study evaluated age-group, geographic, and cancer-stage variables associated with the likelihood of receiving BCS or receiving mastectomy and the likelihood of receiving radiation therapy following BCS. Minnesota Cancer Surveillance System data on 6,594 women diagnosed with breast cancer in Minnesota during the years 1995-1996 were analyzed. Of those women who underwent breast cancer surgeries, 39% received BCS. Seventy-two percent of cases in which BCS was used were followed by radiotherapy. Women 65 years and older were less likely than younger women to receive BCS. Age and the stage of the cancer were independently associated with the likelihood of receiving radiation therapy following BCS. Breast cancer patients 75 years and older were 73% less likely to receive radiation following BCS than patients ages 40 to 49. Radiation following BCS was more likely among women in the Twin Cities metropolitan area and south central Minnesota than among women in other regions.