Factors contributing to underuse of radiation among younger women with breast cancer

Abstract

Background: Evidence-based literature has confirmed the effectiveness of radiation therapy (RT) after breast-conserving surgery (BCS), especially for young women. However, women with young children may be less likely to be compliant. This study explores factors associated with noncompliance of RT among insured young patients.

Method: Using the MarketScan Database, we identified the study cohort as women aged 20 to 64 years who had a BCS between January 1, 2004, and December 31, 2009, and had continuous enrollment 12 months before and after the date of BCS. Patients who had any radiation claims within a year of BCS were considered compliant. Adjusted odds of compliance were estimated from logistic regressions for the full sample and age-stratified subgroups. Sensitivity analyses were performed to evaluate the robustness of study findings. All statistical tests were two-sided.

Results: Eighteen thousand one hundred twenty of 21 008 (86.25%) nonmetastatic BCS patients received RT. Among patients aged 20 to 64 years, those with children aged 7 to 12 years, those with children aged 13 to 17 years, and those with no children or children aged 18 years or older were more likely to receive RT than patients with at least one child aged less than 7 years (7-12 years: odds ratio (OR) = 1.32, 95% confidence interval (CI) = 1.05 to 1.66, P = .02; 13-17 years: OR = 1.41, 95% CI = 1.13 to 1.75, P = .002; no children or ≥18 years: OR = 1.38, 95% CI = 1.13 to 1.68, P = .001). Stratified analyses showed that the above association was primarily driven by women in the youngest age group (aged 20-50). Other important factors included breast cancer quality of care measures, enrollment in health maintenance organizations or capitated preferred provider organizations, travelled to a Census division outside their residence for BCS, and whether patients were primary holders of the insurance policy.

Conclusions: Competing demands from child care can constitute a barrier to complete guideline-concordant breast cancer therapy. Younger patients may be confronted by unique challenges that warrant more attention in future research.

Figure 1.

Flow chart for data selection step. BCS = breast conserving surgery; ICD-9 = International Classification of Diseases, 9th Edition.

Figure 2.

Adjusted odds ratios in sensitivity analyses for family structure variables, by subgroups. Error bars represent 95% confidence intervals. All statistical tests were two-sided. DCIS = ductal carcinoma in situ.