Response to radiation therapy in adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare disease which is considered resistant to many treatments. The role of radiotherapy in ACC remains unclear. In general radiotherapy is thought to be ineffective for the treatment of ACC, and therefore not often used. However, recent reports suggest the opposite. The aim of this study was to perform a retrospective analysis to evaluate the application of radiotherapy in Dutch ACC patients, and to determine the occurrence of response.

The Dutch ACC Registry (no.=159) was screened for patients who had received radiotherapy between 1990 and 2008. Tumor response evaluation was performed according to the Response Evaluation Criteria In Solid Tumors (RECIST).

Only 13 patients (8% of registered patients) had received radiation therapy of whom 6 were irradiated for the palliation of painful bone metastases. In all patients this radiation resulted in pain relief. Three patients received adjuvant tumor bed radiation after resection. Four patients were radiated on irresectable tumor recurrence or tumor metastases. Two patients died soon after radiation therapy and therefore follow-up information regarding tumor response after radiation therapy of 2 patients was available. Interestingly, partial tumor response according to RECIST criteria, was observed in both patients.

ACC can be sensitive to radiotherapy and should be considered in the treatment of advanced ACC, particularly in worrisome lesions. The role of radiotherapy in advanced ACC is to complement a systemic treatment such as mitotane or classic cytotoxic agents.