Comparing Local Recurrence and Distant Metastasis Between Breast-Conserving Therapy with Radiotherapy and Total Mastectomy in Candidates for PET/CT Assessment

Background: This study aimed to compare the recurrence rate of breast cancer between women treated with breast-conserving therapy (BCT) with/without radiotherapy and those treated with total mastectomy using 18F-fluorodeoxyglucose positron emission tomography/computed tomography18 (F-FDG PET/CT). Methods: The current study retrospectively included 588 patients suffering from breast cancer who had been referred to the PET/CT department of Masih-e-Daneshvari Hospital in Tehran between April 2013 and September 2019. Data of all female patients with breast cancer were extracted from the recorded hospital files. Based on the treatment plan, patients were divided into two groups: BCT with/without radiotherapy (n=168) and total mastectomy (n=420). Local, locoregional, and distant metabolically active lesions were determined in18 F-FDG PET/CT and compared between groups. Results: BCT and total mastectomy were comparable regarding local (28.5% vs. 25.7%, P=0.200) and locoregional (21.4% vs. 22.8%, P=0.712) recurrence, while distant recurrence was significantly higher with total mastectomy (88.5% vs. 64.2%, P<0.001). Also, lymph node invasion (42.9% vs. 60%m P<0.001) and positive PET/CT (78.5% vs. 88.5%, P=0.002) were significantly higher with total mastectomy. According to multivariate analysis, age, clinical stage, positive margin are independently correlated with the rate of distant metastasis. Conclusion: According to our analysis, breast-conserving therapy could be a suitable choice of surgery in selected patients since local and locoregional recurrence rate did not significantly differ between patients who underwent breast-conserving surgery compared to those who were treated with total mastectomy. Higher rate of distant metastasis in patients with total mastectomy seems to be influenced by many confounding variables such as age, higher stage of diagnosis and positive margin rather than type of surgery