Clinicopathological features of adrenal malignancies: Analysis of hospital-based cancer registry data in Japan.

OBJECTIVE: To identify the clinicopathological features of adrenal malignancies and analyze the prognoses of patients with adrenal cortical carcinoma (ACC) and malignant pheochromocytoma (MPCC). PATIENTS AND METHODS: We used a hospital-based cancer registry data in Japan to extract cases of adrenal malignancies that were histologically confirmed, diagnosed, and initially treated from 2012-2015. For survival analysis, we used data from the 2008-2009 cohort to estimate 5-year overall survival (OS) by the Kaplan-Meier method. RESULTS: A total of 989 adrenal malignancies were identified in the 2012-2015 cohort. The most common histologies were ACC (26.4%), diffuse large B-cell lymphoma (DLBCL; 25.4%), neuroblastoma (22.2%), and MPCC (11.9%). While most ACC and MPCC patients were in their 60s, DLBCL patients accounted for 61.5% of adrenal malignancies in the over-70 cohort. Among ACC patients with clinical staging data, 46.3% of patients were stage IV. Although surgery was a chief strategy for all stages, younger patients tended to receive combination therapy, including surgery and chemotherapy or hormone therapy. In the 2008-2009 cohort, the 5-year OS rates of ACC (n = 49) and MPCC (n = 23) patients were 56.2% and 86.4% while ACC patients without surgery had 1- and 2-year OS rates of 25.0% and 12.5%. CONCLUSION: In Japan, DLBCL accounted for the majority of adrenal malignancies in older patients. Despite advanced staging, ACC patients were mainly treated with surgery and their prognosis was not satisfactory. Such epidemiological data may be useful in considering initial management strategies.