Impact of multimodal therapy on margin status on overall survival for patients undergoing adrenalectomy for localized adrenocortical carcinoma

Introduction: Adrenocortical carcinoma is a rare malignancy that typically presents with advanced features and carries a poor prognosis. Complete surgical resection offers patients the best survival outcomes, but this is not always achievable and many require additional therapy for advanced features. Some literature has explored the role of chemotherapy and radiation, but little has been conducted to explore the effects of multimodal therapy. Methods: We retrospectively reviewed the National Cancer Database for adults with primary nonmetastatic adrenocortical carcinoma (ACC) who underwent either partial or radical adrenalectomy. Excluded patients included those with metastatic disease and those with primary tumor >30 cm. Patients were categorized based on adjuvant treatment; chemotherapy, radiation therapy (RT), RT + chemotherapy, or no adjuvant therapy. Overall survival (OS) was compared using survival curves, log rank tests, and multivariate survival analysis. Results: We identified 1644 patients with localized ACC treated with adrenalectomy. The median tumor size was 10.6 cm. A total of 278 patients had positive margin status (R1), and 416 patients had nodal (pN+) disease. Out of all patients, a minority (39.4%) received adjuvant therapy, which was most commonly given as chemotherapy only. Statistically significant increase in OS was noted with the use of RT + chemotherapy in the node-negative, margins-positive (pN0/pNx; R1) subgroup versus patients who did not receive adjuvant therapy (5-year OS 60.5% and 28.2%, respectively [ P = 0.002]). This held true on multivariate analysis with significant improvement in OS in the pN0/pNx; R1 population with RT + chemotherapy compared to those who received no treatment (hazard ratio: 0.40 [95% confidence interval: 0.2–0.9], P = 0.02). Conclusions: Our findings support the use of adjuvant chemotherapy plus RT in patients with positive surgical margins and no nodal disease. Additional studies are required to confirm these findings, clarify the objective benefit of multimodal therapy, and to determine the optimal chemotherapy/RT combination.