Roles of the pathologist in evaluating surrogate markers for medical therapy in adrenocortical carcinoma.

Adrenocortical carcinoma is a rare malignancy. Medical treatment including op'DDD or mitotane with or without platinum-based cytotoxic chemotherapy is frequently administered to the patients in an adjuvant setting following surgery or in advanced disease, because of aggressive clinical behavior in some cases. Potential roles of pathologists in determining the clinical algorithm of medical therapy are histopathological confirmation of adrenocortical carcinoma, both malignant features using the criteria of Weiss and adrenocortical origin applying immunohistochemistry of steroid factor-1 (SF-1); providing the relevant pathological information to determine the precise pathological stage in individual patients; and providing the accurate Ki67 labeling index of the patients. There are no established pathological surrogate markers for response to mitotane or op' DDD therapy available at this juncture but as in other malignancies, Ki67 LI could provide information as to the potential clinical response to platinum-based cytotoxic chemotherapy. Epidermal growth factor receptor (EGFR) is significantly overexpressed in adrenocortical carcinoma but the absence of gene mutations could limit the therapeutic application of anti-EGFR antibody and/or EGFR tyrosine kinase inhibitor in the patients.