Postoperative Radiotherapy for Salivary Adenoid Cystic Carcinoma With Positive Surgical Margins

PURPOSE: Salivary adenoid cystic carcinoma (SACC) is characterized by a jump growth pattern, making complete resection difficult in some cases. The objective of this study is to evaluate the effect of postoperative radiotherapy (PORT) on the prognosis of SACC with positive surgical margins (PSM). METHODS: Patients with SACC were identified from the medical database of Shanghai Ninth people's Hospital. Kaplan-Meier analysis, univariate and multivariate Cox regression were conducted to assess the effect of PORT on the prognosis of SACC among different groups. RESULTS: A total of 104 patients with SACC were retrospectively reviewed. The 5-year OS and DFS rates were 85.6% and 69.8%, respectively. Multivariate analysis indicated that clinical lymph node stage and distant metastasis were independent prognostic factors for both OS and DFS. Furthermore, pairwise comparisons revealed that the OS in the R1/1 group was comparable to that in the R0/0 group (p = 0.362) and significantly higher than that in the R1/0 group (p = 0.028). The DFS of the R1/1 group also showed a superior outcome compared to the R1/0 group, although without statistical significance (p = 0.104). CONCLUSION: PORT is an effective adjuvant treatment for SACC patients with PSM, which is strongly recommended for SACC patients with PSM to improve the prognosis.