Cancer Health Disparities Among Patients With Early-Stage Estrogen Receptor–Positive Breast Cancer: Impact of Public Versus Private Health Care on Diagnosis-to-Treatment Interval in Brazil

PURPOSE In 2013, Brazil implemented a federal law (Law 12.732/2012) mandating cancer treatment to begin within 60 days of diagnosis. Among women with newly diagnosed estrogen receptor–positive (ER+) nonmetastatic breast cancer, we describe the diagnosis-to-treatment interval, patient and tumor characteristics, and the type of treatment received, and we assess these metrics by public versus private health care setting. METHODS The study included patients with early-stage ER+ breast cancer from 14 centers in Brazil who had completed locoregional care and received >6 months of adjuvant endocrine therapy (ET). Patient, tumor, and treatment characteristics were abstracted from clinical documentation and collected in REDCap. Qualitative variables were compared between groups using the chi-square or Fisher exact tests. For quantitative variables, the nonparametric Mann-Whitney test was used. P < .05 was considered significant. RESULTS From June 2021 to March 2024, 774 women enrolled in the study. The mean age at diagnosis was 56.5 years, and 55.2% received public health care. Women who received care at public institutions were more likely to be premenopausal at diagnosis (45.3% public v 29.2% private, P < .0001), living with no partner (45.6% public v 34.7% private, P = .002), and have lower educational levels (43.6% public v 6.8% private, P < .0001). Women treated in the public sector had more advanced disease with stage III tumors (29.3% public v 13.5% private, P < .0001) and were more likely to receive mastectomies (36.8% public v 29.8% private, P = .0003), axillary dissections (43.1% public v 18.1% private, P < .0001), chemotherapy (73.8% public v 58.5% private, P < .0001), and radiotherapy (87.0% public v 78.7% private, P = .002). Regarding adjuvant ET, women treated in the public sector had lower ovarian function suppression (6.8% public v 18.8% private, P < .0001) and higher tamoxifen use (52.4% public v 29.4% private, P < .0001). The diagnosis-to-treatment interval was longer in the public versus private system (93 v 41 days, P < .0001). CONCLUSION Our study revealed significant disparities in cancer care between patients with stage I to III ER+ breast cancer treated in public versus private health care systems in Brazil. Law 12.732/2012 has proven ineffective for patients treated in the public sector and is not being adequately observed or enforced by Brazilian authorities.