Postmastectomy radiation therapy for T3N0: a SEER analysis

Area of Science:

• Oncology
• Radiation Oncology
• Surgical Oncology

Background:

• Conflicting evidence exists on the benefits of postmastectomy radiation therapy (PMRT) for T3N0M0 breast cancer.
• This study investigates PMRT's impact on survival in this specific patient group.

Purpose of the Study:

• To evaluate the efficacy of postmastectomy radiation therapy (PMRT) in improving overall survival (OS) and cancer-specific survival (CSS).
• To analyze the benefit of PMRT in patients with pathologic stage T3N0M0 breast cancer treated with modified radical mastectomy.

Main Methods:

• Utilized the Surveillance, Epidemiology, and End Results (SEER) database for patients diagnosed between 2000-2010.
• Included 2525 patients with T3N0M0 breast cancer who underwent modified radical mastectomy, excluding specific criteria.
• Employed univariate and multivariate statistical analyses, including Cox proportional hazards regression, to assess survival outcomes.

Main Results:

• Postmastectomy radiation therapy (PMRT) was associated with improved 8-year OS (76.5% vs 61.8%) and CSS (85.0% vs 82.4%) on univariate analysis.
• Multivariate analysis confirmed PMRT significantly improved OS (HR 0.63, P<.001) and CSS (HR 0.77, P=.045).
• Low tumor grade and being married were also predictors of improved CSS.

Conclusions:

• Postmastectomy radiation therapy (PMRT) demonstrates significant improvements in both CSS and OS for T3N0M0 breast cancer patients.
• PMRT should be strongly considered for patients diagnosed with T3N0M0 breast cancer undergoing modified radical mastectomy.
• The findings support the routine consideration of PMRT in this patient population based on SEER data.