Assessing the Efficacy of Current Histopathological Tumor Reporting Systems for Evaluating the Response to Neoadjuvant Chemotherapy for Breast Carcinoma: Protocol for an Observational Study.

Background: With a predicted 2 million new cases identified globally in 2018, breast carcinomas are the most common cancer in women and the primary cause of cancer-associated mortality. In the management of breast cancer, neoadjuvant chemotherapy treatment (NACT) has become a mainstay, particularly for patients with inflammatory and locally advanced breast cancer. It increases the possibility of breast-conserving surgery, facilitates tumor downstaging, and gives early indications of the effectiveness of treatment. Evaluating the histopathological response after NACT is crucial for prognosis and guiding subsequent treatment decisions. This study explores the various histopathological assessment systems used in breast carcinoma patients after NACT, focusing on the residual cancer burden (RCB) score, Miller-Payne system, Chevallier classification, Sataloff classification, National Surgical Adjuvant Breast and Bowel Project (NSABP) Protocol B-18 system, and the American Joint Committee on Cancer residual tumor size (R) categories. We compare their methodologies, strengths, limitations, and clinical significance, providing a detailed analysis of their roles in improving patient outcomes.

Objective: The aim of this study is to confirm the diagnosis of breast carcinoma based on histopathology, to evaluate various scoring systems through assessments of histomorphological features affecting post-NACT patients with breast carcinoma, to compare the various systems regarding the response to therapy and forming prognoses, and to develop an ideal histomorphological assessment system for breast carcinoma in post-NACT patients. The study also focused on how breast tumors respond to NACT and how this response can guide treatment decisions and improve the formulation of prognoses.

Methods: This observational study will be retrospective and prospective; it will include 128 patients diagnosed with breast carcinomas who have undergone NACT and were referred to a tertiary care hospital between January 2019 and December 2024. Following chemotherapy, a thorough examination of the histopathological specimens will be conducted to assess any changes in histomorphology.

Results: Data collection started in September 2021 and will be completed by December 2025. Data analysis began in January 2025, and the results are expected to be published in December 2025. Institutional ethics committee clearance was obtained prior to commencement of the study. This is a nonfunded academic study.

Conclusions: This project aims to evaluate and compare histopathological assessment systems in patients with breast carcinoma after NACT. Various histopathological systems, such as the RCB score, the Miller-Payne grading system, and other systems, each provide valuable insights into how well tumors respond to chemotherapy. The aim is to reveal essential histopathological parameters, leading to the refinement and potential modification of grading systems to improve clinical decision-making, treatment outcomes, and personalized care; however, challenges persist in standardization and consensus.

International registered report identifier (irrid): DERR1-10.2196/56825.