Postmastectomy radiotherapy for breast cancer: patterns, correlates, communication, and insights into the decision process

Abstract

Background: Given accumulating evidence supporting postmastectomy radiotherapy (PMRT) in selected patients, it is important to evaluate patterns and correlates of PMRT utilization, including communication and attitudinal factors.

Methods: The authors surveyed 2382 patients diagnosed with breast cancer in 2002 and reported to the Los Angeles and Detroit Surveillance, Epidemiology, and End Results registries (n=1844, 77.4% response rate). Analyses were restricted to patients with nonmetastatic invasive breast cancer treated by mastectomy who had decided whether or not to undergo PMRT (n=396). The authors assessed rates of explanation, recommendation, and receipt of radiation by indication grouping, defined primarily by the 2001 American Society of Clinical Oncology guidelines. They evaluated correlates of PMRT receipt, including tumor and sociodemographic characteristics. They also explored patients' self-reported reasons for nonreceipt of PMRT.

Results: The adjusted proportion in each indication group reporting that a provider had explained radiation was high (77% of those in whom PMRT was indicated, 76% of those in whom medical opinion was divided, and 73% of those in whom PMRT was not indicated; P=.10). The adjusted proportions reporting recommendations for radiation (86%, 35%, and 17%, respectively) and receipt (81%, 34%, and 10%, respectively) varied significantly by indication grouping (P<.001). On multivariate analysis, tumor size (P<.001), lymph node status (P<.001), comorbidity (P=.02), and chemotherapy receipt (P=.003) were found to be independent significant correlates of PMRT receipt. The most common reasons cited for not pursuing PMRT were lack of physician recommendation and perceived lack of need.

Conclusions: PMRT receipt is strongly correlated with clinical indication. The authors found no sociodemographic disparities in utilization. However, approximately one-fifth of patients with strong indications did not receive treatment.

FIGURE 1

This figure demonstrates the rates with which patients reported that radiotherapy (RT) was explained (P = .10), recommended (P < .001), and received (P < .001) by indication grouping. Rates were adjusted for age, race, education, marital status, and comorbidities.

FIGURE 2

This figure demonstrates rates of receipt of postmastectomy radiotherapy (RT) by indication grouping and concern regarding radiation effects. Rates were adjusted for age, race, education, marital status, and comorbidities (P < .001). *Indicates the number of patients in each cell.