Background: Breast cancer remains the most common malignancy among women worldwide. Neoadjuvant chemotherapy (NACT) is increasingly used to downstage tumors and improve surgical outcomes. The Residual Cancer Burden (RCB) system has emerged as a reliable tool to quantify treatment response across various breast cancer subtypes. Objective: This study aimed to assess clinicopathological features of breast cancer patients before and after NACT, evaluate treatment response using RCB class categories, and examine the associations between RCB classes and clinicopathological parameters. It also explored the impact of NACT on axillary lymph node retrieval and surgical trends in Iraq. Methods: A retrospective cross-sectional study included 113 patients with primary invasive breast cancer who received NACT followed by surgical resection. Data were collected from Al-Yarmouk Teaching Hospital and private laboratories between January and October 2024. Results: The mean patient age was 48.7 years. Invasive ductal carcinoma accounted for 92.9% of cases, and 77% of tumors were grade II. Hormonal receptor-positive/HER2-negative tumors were the most frequent subtype (57.5%). Post-NACT, 65.5% had residual invasive disease, and 23.9% had residual in situ carcinoma. RCB class II was the most common (34.5%). Significant associations were found between RCB classes and tumor grade, receptor subtype, in situ carcinoma, lymphovascular invasion, and pathological tumor/node stage (p < 0.001–0.032). No significant association was observed between tumor stage and age. Mastectomy (72.6%) and axillary dissection (90.3%) were predominant. RCB class correlated significantly with the number of retrieved lymph nodes (p = 0.003). Conclusion: RCB classification is a valuable indicator of treatment response and correlates with key pathological features. Surgical trends in Iraq still favor mastectomy and full axillary dissection.
Matti et al. (Wed,) studied this question.