Novel Postneoadjuvant Prognostic Breast Cancer Staging System.

Area of Science:

• Oncology
• Clinical Research
• Biostatistics

Background:

• Neoadjuvant chemotherapy (NACT) is increasingly used for cancer treatment.
• Current American Joint Committee on Cancer (AJCC) staging lacks prognostic assessment post-NACT.
• Accurate staging is crucial for patient management and outcome prediction.

Purpose of the Study:

• To develop and validate a prognostic staging system that incorporates response to NACT.
• To address the deficiency in AJCC staging for patients receiving NACT.
• To improve prognostic accuracy by including standardized staging variables and response categories.

Main Methods:

• Utilized the National Cancer Database (2010-2018) for 140,605 NACT-treated patients.
• Categorized response to NACT into no response, partial response, and complete response (pCR).
• Performed univariate and multivariate analyses, validating predictive models using bootstrap techniques and calibration plots.

Main Results:

• Validated models showed significant survival differences based on postneoadjuvant prognostic stage.
• Patients achieving pCR were predominantly assigned ypStage I (94.2%) versus those with no response (35.5%).
• Clinical stage impacted OS differently based on response: small impact with pCR, profound decrease with no response in TNBC/HER2+ disease.

Conclusions:

• A novel, validated prognostic staging system predicting overall survival (OS) based on NACT response has been developed.
• This system provides essential AJCC stage assignments for the growing population of patients treated with NACT.
• The findings enhance prognostic accuracy and clinical decision-making for NACT-treated individuals.