Postmastectomy radiotherapy indications using pathological prognostic staging in node-positive breast cancer

Area of Science:

• Oncology
• Radiotherapy
• Cancer Staging

Background:

• The role of pathological prognostic staging (PPS) in guiding postmastectomy radiotherapy (PMRT) decisions for breast cancer (BC) patients is not well-defined.
• Node-positive BC presents unique challenges in treatment selection and prognostic assessment.

Purpose of the Study:

• To investigate the impact of pathological prognostic staging (PPS) on the selection of postmastectomy radiotherapy (PMRT).
• To compare the prognostic accuracy of PPS versus anatomical staging (AS) in node-positive breast cancer (BC).

Main Methods:

• Retrospective analysis of 14,830 node-positive BC patients from the Surveillance, Epidemiology, and End Results (SEER) database (2010-2015).
• Statistical analyses included Chi-square tests, ROC curves, and competing-risks analyses using the Fine and Gray model.
• Evaluation of PMRT's impact on 5-year breast cancer-specific mortality based on PPS.

Main Results:

• Pathological prognostic staging (PPS) demonstrated superior prognostic accuracy compared to anatomical staging (AS) (P<0.001).
• A significant downstaging rate (72.0%) was observed with PPS.
• PMRT significantly reduced 5-year breast cancer-specific mortality in patients with stage IIIA, IIIB, and IIIC disease, but not in earlier stages (IA, IB, IIA, IIB).

Conclusions:

• Significant discrepancies exist between anatomical staging (AS) and pathological prognostic staging (PPS) in node-positive breast cancer.
• PPS enhances risk stratification, potentially optimizing postmastectomy radiotherapy (PMRT) selection and improving patient outcomes.
• The findings support the use of PPS to refine treatment strategies and guide the appropriate application of PMRT in specific patient subgroups.