Surgical Delay Risk Varies by Breast Cancer Subtype

TOPLINE:

Surgical delay beyond 42 days after breast cancer diagnosis led to exponential growth in mortality risk for patients with hormone receptor–positive/human epidermal growth factor receptor 2–negative (HR+/HER2−) breast cancer. Time to surgery from diagnostic biopsy showed varying impacts across breast cancer subtypes, with patients with HR+/HER2− breast cancer facing the highest risk.

METHODOLOGY:

• Previous research showed inconsistent findings regarding the impact of surgical delays across breast cancer subtypes, highlighting the need for comprehensive investigation.
• Researchers conducted a retrospective cohort study using Surveillance, Epidemiology, and End Results-Medicare database of 34,248 women aged 66 years or older diagnosed with locoregional breast cancer between 2010 and 2017.
• Analysis included patients who received surgery as their first treatment, with time to surgery from diagnostic biopsy evaluated as a continuous variable referenced to 30 days.
• Breast cancer–specific mortality was assessed using Fine and Gray competing risk regression models adjusted with inverse propensity score weighting for demographic, clinical, and treatment variables.

TAKEAWAY:

• Mortality risk increased exponentially 42 days post-diagnosis in patients with HR+/HER2− breast cancer, with the subdistribution hazard ratio (SHR) being 1.21 (95% CI, 1.06-1.37) at 60 days, 1.79 (95% CI, 1.40-2.29) at 90 days, and 2.83 (95% CI, 1.76-4.55) at 120 days.
• Patients with HER2+ breast cancer demonstrated a linear increase in mortality risk at 60 days (SHR, 1.34; 95% CI, 1.02-1.76), although becoming nonsignificant at later timepoints.
• Patients with HR−/HER2− breast cancer showed the smallest linear increase in mortality risk, with changes not reaching statistical significance.
• Median time to surgery was 29 days across all subtypes, with Black patients experiencing longer delays than White patients in HR+/HER2− (34 vs 29 days; P < .001) and HR−/HER2− (36 vs 28 days; P < .001) subtypes.

IN PRACTICE:

“Prevention of surgical delays holds the potential to improve survival outcomes for patients with locoregional breast cancer,” authors of the study wrote.

SOURCE:

The study was led by Macall Leslie Salewon, Stephenson Cancer Center, University of Oklahoma Health Sciences Center in Oklahoma City. It was published online in Breast Cancer Research.

LIMITATIONS:

According to the authors, the study was limited by potential confounders outside the scope of the database, including incomplete reporting of clinical staging and Ki67 status. The cohort’s composition of older Medicare beneficiaries and relatively small sample sizes for HER2+ and HR−/HER2− subtypes, which typically occur more frequently in younger patients, resulted in large confidence bounds that may affect result generalizability.

DISCLOSURES:

The study received support from the National Cancer Institute Cancer Center Support Grant P30CA225520 and the Oklahoma Tobacco Settlement Endowment Trust contract awarded to the University of Oklahoma Stephenson Cancer Center. Additional funding came from the Department of Defense.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.