Treatment outcomes of adjuvant radiotherapy in adrenocortical carcinoma - A 13-years experience from a tertiary care centre.

Purpose: Adrenocortical carcinoma (ACC) is a rare and highly aggressive malignant neoplasm, usually diagnosed in advanced stage. Role and efficacy of adjuvant radiotherapy has not been well defined. The objective of this study is to describe the various clinical characteristics and prognostic factors affecting the survival of ACC along with the role radiotherapy on overall survival and relapse free survival.

Methods: A retrospective analysis of 30 patients registered between 2007 and 2019 was carried out. The medical records containing clinical and treatment details were analysed. Data was analysed using SPSS 25.0. Survival curves were computed using Kaplan-Meier method. Univariate and multivariate analyses were performed to analyze the prognostic factors affecting the outcome. A p value of less than 0.05 was considered to be statistically significant.

Results: The median age of patients was 37.5 years (range, 5-72 years). 20 patients were females. Twenty-six patients had advanced stage (III/IV) disease while only four patients presented in early stage. Twenty-six patients underwent total adrenalectomy. Eighty three percent patients received adjuvant radiation therapy. The median follow up was 35.5 months (range, 7 monthss-132months). The estimated three- and 5-years overall survival (OS) was 67.2% and 23.3%, respectively. Capsular invasion and positive margins were the independent prognostic factors influencing both OS and relapse free survival (RFS). Out of 25 patients who received adjuvant radiation, only three patients had local relapse.

Conclusion: ACC is a rare and aggressive neoplasm with majority of patients presenting in advanced stage. Surgical resection with negative margins remains the mainstay of treatment. Capsular invasion and positive margins are independent prognostic factors for survival. Adjuvant radiation reduces the risk of local relapse and is well tolerated. Radiation can be used effectively in adjuvant and palliative settings in ACC.