Early-stage breast cancer treatment among medically underserved women diagnosed in a national screening program, 1992-1995

Background. Little research has been conducted on the breast cancer treatment of low income, underserved women. This study was designed to describe initial treatment of breast cancer among low-income women diagnosed through federally funded screening programs in Detroit, Michigan, and the states of New Mexico and California; and to compare the treatment received by program women with early-stage breast cancer with that of all women diagnosed in those regions. Methods. Data from the three screening programs were linked with cancer registry data from the corresponding geographic areas. All women diagnosed between 1992 and 1995 through the state-based screening programs and all women contemporaneously diagnosed with breast cancer in the three regions were studied. Descriptive analyses were done of the proportion of women with breast cancer receiving treatment; the proportion of early-stage breast cancer (stage I or II) cases treated with breast-conserving surgery, and the proportion treated with mastectomy; and among women with breast-conserving surgery, the proportion receiving radiation therapy. Logistic regression models controlled for age and stage at diagnosis, race or ethnicity and geographic region. Results. Less than 2% of program women diagnosed with breast cancer received no treatment. More than two of five women with early-stage breast cancer underwent breast-conserving surgery, with 72% of these women receiving radiation therapy. Multivariate regression analysis revealed that women with stage IIA or IIB breast cancer had lower odds of undergoing breast-conserving surgery than women with stage I (0.51 [95% CI = 0.30-0.87] and 0.36 [95% CI = 0.19-0.70], respectively). Women over age 65 and those with incompletely staged cancer had the lowest odds for receiving radiation therapy after breast-conserving surgery (0.29 [95% CI = 0.09-0.99] and 0.14 [95% CI = 0.03-0.72], respectively). Women diagnosed through the screening programs had odds of undergoing breast-conserving surgery similar to those of all women in the regions (1.11 [95% CI = 0.89-1.39]). Conclusions. Treatment patterns for women diagnosed with early-stage breast cancer through three state-based screening programs appear to have been similar to those reported in the literature. In addition, their treatment appears to have been similar to that of other women during the same time period.