Assessment of residual cancer burden and survival in neoadjuvant chemotherapy of inoperable stage III breast cancer: A ten-year follow-up analysis in Vietnam

Background: Prognostic scores such as Residual Cancer Burden (RCB), Clinical Pathological Score (CPS), and NeoBioscore have been introduced to categorize breast cancer patients into different prognostic risk groups after neoadjuvant chemotherapy (NAC). Purpose: To evaluate the prognostic value of the residual cancer burden index in a large group of Vietnamese breast cancer patients treated with neoadjuvant chemotherapy in real-world settings. Methods: 126 patients diagnosed with stage III breast cancer received neoadjuvant chemotherapy according to the AP regimes. After operation of BC, pathologic complete response (pCR) and Residual cancer burden (RCB) were evaluated. All breast cancer patients' survival were analyzed by using Kaplan-Meier and Log-Rank models. Results: The average overall survival (OS) time was 75 months, with 90 (71.4%) recurrence and 82 (65%) mortality. The Kaplan Meier curve between OS and DFS with subgroups RCB indicate that the groups with higher RCB had a lower probability of survival, with statistical significance. Adjusted Cox regression model for age, menstruation, side of breast, clinical respose and overall stage illustrate that patients in RCB group 3 had a 2.7 times higher risk of mortality (95% CI: 1.28-5.67) compared to RCB group 0, p = 0.01. Patients with higher RCB levels had a higher risk of mortality. Conclusion: Stage IIIC, RCB score and RCB group are the independent prognostic factors for predicting survival time of breast cancer patients receiving neoadjuvant treatment.