Surgical treatment of early-stage breast cancer in the Department of Defense Healthcare System.
BACKGROUND: The choice between breast-conserving surgery and modified radical mastectomy in the treatment of women with early stage breast cancer in the Department of Defense Healthcare System may be influenced by demographic factors. STUDY DESIGN: The Department of Defense Automated Central Tumor Registry (ACTUR) was queried for women diagnosed with American Joint Committee on Cancer Stage I or II invasive breast carcinoma from January 1, 1986, to December 31, 1996. Univariate analysis and multivariate analysis were applied to the study variables. Year of diagnosis, age at diagnosis, tumor size, type of hospital, geographic region, and local availability of radiation therapy were evaluated with respect to the type of surgical treatment performed. Surgical treatment was either breast conservation therapy (BCT) or modified radical mastectomy. RESULTS: After excluding women for whom the data were incomplete (n = 308), 7,815 women were identified who met study criteria. There was a progressive increase in the use of BCT to treat tumors of all sizes from 16% to 47% over the 11 years of the study (p < 0.0001). BCT was more frequently used for smaller tumors (< 2cm), with an odds ratio of 2.46 (2.20-2.76, 95% CI). In 1996, 54% of women with T1 (< 2 cm) tumors were treated with BCT. Women treated with BCT were nearly the same age as those undergoing modified radical mastectomy (55.5 years versus 56.8 years, p < 0.0001). BCT was used at a slightly greater rate in medical centers than in community hospitals (31% versus 28%, p < 0.0001). Use of BCT varied among geographic regions from a low of 24% in the southwestern USA to a peak of 36% in the Northeast and 40% in hospitals outside of the continental United States (p < 0.0001). Local availability of radiation therapy did not influence choice of treatment. CONCLUSIONS: The use of BCT to treat early stage invasive breast carcinoma in the Department of Defense Healthcare System is increasing. But BCT is used less often to treat larger tumors. Regional differences in the use of BCT persist, even after controlling for other factors. Patient age and type of hospital (community versus academic center) appear to exert little influence on the choice of treatment. Local availability of radiation therapy did not seem to influence the choice of treatment. Our data suggest that efforts to promote the use of BCT should target the central and southwestern USA. Use of BCT should also be emphasized for women with larger tumors (> 2 cm).