Guideline-concordance along the cancer care continuum and breast cancer mortality by race and ethnicity: a SEER-Medicare study

TL;DR

This study finds that following cancer care guidelines reduces breast cancer deaths, but the benefits vary by race and ethnicity.

Contribution

The study examines how adherence to cancer care guidelines affects mortality across different racial and ethnic groups.

Findings

Non-concordant care increases breast cancer mortality risk for most racial/ethnic groups.

Locoregional treatment adherence is strongly linked to lower mortality across all groups.

Disparities persist despite guideline adherence, highlighting structural inequities.

Abstract

To examine the relationship between guideline-concordant breast cancer care and hazard of cancer death by patient race and ethnicity.

We used SEER-Medicare data to identify 212,555 older women diagnosed with invasive breast cancer between 2000 and 2017. Guideline-concordant diagnostic workup, locoregional treatment, and initiation of systemic therapy were defined using NCCN guidelines. Hazards of breast cancer death 2 and 5 years from diagnosis by each guideline-concordance outcome overall and stratified by race and ethnicity were estimated using Cox proportional hazards models.

Non-concordant diagnostic workup, locoregional treatment, and systemic therapy initiation were each associated with increased hazards of 2- and 5-year breast cancer mortality (diagnostics HR2-year (95% CI) 1.33 (1.25–1.41), HR5-year 1.29 (1.23–1.35); locoregional HR2-year 2.10 (1.98–2.23), HR5-year 1.83 (1.76–1.90); systemics HR2-year 1.67 (1.51–1.84), HR5-year 1.56 (1.45–1.68)). Non-concordant diagnostic workup and systemic therapy initiation were associated with greater hazard of 2- and 5-year breast cancer death among Black, Asian/Pacific Islander, Hispanic White, and non-Hispanic White patients; there was no consistent association among American Indian/Alaska Native patients for either outcome. Locoregional treatment was strongly associated with hazards of cancer death for all groups.

Equitable delivery of guideline-recommended breast cancer care from diagnosis through treatment across racial and ethnic groups may mitigate survival disparities. Efforts to improve access to high-quality care must be informed by and responsive to the social and structural root causes of health inequities.

The online version contains supplementary material available at 10.1007/s10552-025-02099-9.

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