Assessment of Response to Neoadjuvant Chemotherapy in Locally Advanced Breast Carcinoma Using Image-Guided Clip Placement.

Abstract

Background The present study aims to evaluate the response of locally advanced breast carcinoma (LABC) to neoadjuvant chemotherapy (NACT) using image-guided clip placement based on Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria. Methods Thirty-four patients with LABC were included in the study. Consent for three-dimensional titanium clip placement (400/300/200 mm Liga clips) under local anesthesia with USG guidance was obtained. Serial sonographic/X-ray evaluations of tumor bed size were conducted before every cycle of NACT. All data were recorded in millimeters of concentric tumor regression/non-regression. Tumor regression in a concentric or Swiss cheese pattern and non-responders were evaluated. Assessment of the response to NACT was performed using RECIST criteria, dividing it into four categories. Tumor response was confirmed with computerized tomography (CT) conducted before and after the completion of NACT. Patients underwent surgical management, mostly modified radical mastectomy (MRM), as they had locally advanced breast carcinoma. Following MRM, the clips in the specimen guided the original site of the tumor for histopathological evaluation and response to chemotherapy. Results Tumor response was classified into four types: complete response (CR), partial response (PR), progressive disease (PD), and stable disease. RECIST 1.1 criteria were elaborated and defined. Data for all patients were entered into an Excel sheet (Microsoft Corporation, Redmond, Washington)to prepare a master chart, and the following observations were made and analyzed using SPSS software. The duration of chemotherapy for the study population ranged from 32 to 206 days, with a mean (±SD) of 111.82 (± 52.64) days and a median (IQR) of 81 (63, 158) days. The mean period between clip insertion and completion of NACT was 111.82 days. The baseline sum diameters and post-NACT diameters of the tumors were 70.50 (±13.60) mm before NACT and 17.75 (±17.20) mm after NACT. Hence, the mean size of the lump was statistically significantly lower after NACT, with a mean difference of 52.75 (p<0.05). The mean rate of reduction in tumor diameter was found to be 74.32% (±23.44%) based on RECIST 1.1 criteria. Pathological response was observed in all patients except for 8.8% of the patients. Clinical complete response was seen in 35.29% of patients, and partial response was observed in 52.92% of the patients based on RECIST 1.1 criteria. The study thus demonstrates the effectiveness of NACT in LABC, with a mean reduction in tumor diameter of 74.32%, assessed with the help of RECIST 1.1 criteria. Conclusion NACT for patients with LABC has shown a significant reduction in tumor size. NACT should be the initial mode of management for patients with LABC. RECIST 1.1 criteria are effective and can be used to assess tumor response to NACT. This has aided in the stratification of the response of NACT for further management through systemic therapy (adjuvant chemotherapy) after the surgical excision of the tumor.