Breast Cancer Screening in Patients With Newly Diagnosed Lung and Colorectal Cancer: A Population-Based Study of Utilization

Abstract

Purpose: To assess breast cancer screening utilization in Medicare beneficiaries with colorectal and lung cancer versus cancer-free controls.

Methods: Female fee-for-service Medicare beneficiaries who were ≥67 years old and diagnosed with lung or colorectal cancer between 2000 and 2011 and who reported to a Surveillance, Epidemiology, and End Results (SEER) registry (case group) were followed for 2 years after their diagnoses, unless death, a diagnosis of breast cancer, or the end of 2013 came first. A similar number of cancer-free controls were individually matched to cases by age, race, registry region, and follow-up time. Screening utilization was defined as the percentage of women with ≥1 screening mammogram during follow-up.

Results: Overall, 104,164 cases (48% colorectal, 52% lung; 30% advanced cancer) and 104,164 controls were included. Among women with lung or colorectal cancer, 22% underwent ≥1 screening mammogram versus 26% of controls (odds ratio [OR] 0.80; 95% confidence interval [CI] 0.78-0.82). Stratified by cancer type, 28% of colorectal cancer cases versus 29% of controls (OR 0.98; 95% CI 0.95-1.01) and 17% of lung cancer cases versus 23% of controls (OR 0.63; 95% CI 0.60-0.65) received ≥1 mammogram. When stratified by stage, 8% with advanced cancer versus 18% of controls (OR 0.33; 95% CI 0.31-0.35) and 30% with early-stage cancer versus 30% of controls (OR 1; 95% CI 0.97-1.02) underwent ≥1 mammogram.

Conclusion: Screening mammography utilization rates are similar between Medicare beneficiaries with early-stage cancer versus controls. Although the majority of patients with advanced-stage cancer appropriately do not pursue screening mammography, a small number (8%) continue with screening.

Keywords: Screening mammography; cancer survivorship period; population-based; utilization.

Fig 1

Study flowchart for primary outcome analysis. CRC = colorectal cancer; DoD = date of death; Dx = diagnosis; SEER = Surveillance, Epidemiology, and End Results.

Fig 2

Plots showing time to event analysis for screening mammography in cases (continuous line) and control (interrupted line) patients for (a) all patients, (b) advanced cancer patients, (c) early-stage cancer patients, (d) colorectal cancer patients, and (e) lung cancer patients.