Adrenocortical cancer: pathophysiology and clinical management

Abstract

Adrenocortical cancer (ACC) is a rare tumor with a poor prognosis. By contrast, benign adrenocortical tumors are frequent, underlying the importance of a correct diagnosis of malignancy of such tumors. ACC can be diagnosed by the investigation of endocrine signs of steroid excess, symptoms due to tumor growth or an adrenal incidentaloma. Hormonal investigations demonstrate in most ACC steroid oversecretion, the dominant characteristics being a co-secretion of cortisol and androgens. Imaging by CT-scan or MRI shows a large heterogeneous tumor with a low fat content. Careful pathological investigation with the assessment of the Weiss score is important for the diagnosis of malignancy. Molecular markers can also be helpful and in the future might be important for prognosis. Tumors localized to the adrenal gland (McFarlane stages 1 and 2) have a better outcome than invasive and metastatic tumors (stages 3 and 4). Tumor removal by a specialized team is crucial for treatment and should always aim at complete removal. In patients with metastatic or progressive disease, medical treatment is started with mitotane that requires a close monitoring of its blood level. Surgery is indicated when possible for local recurrence but also in some cases of metastasis. Local treatment (radiofrequency, chemoembolization, and radiation therapy) can have some indications for metastatic disease. In patients with disease progression cytotoxic chemotherapy can be used. Despite the best care, the overall prognosis of ACC is poor with a 5-year survival rate below 30% in most series. Therefore, progress in the understanding of the pathophysiology of ACC is important. Despite the rarity of ACC, significant advances have been made in the understanding of its pathogenesis the last decade. These progresses came mainly from the study of the genetics of ACC, both at the germline level in rare familial diseases, and at the somatic level by the study of molecular alterations in sporadic tumors. These advances underline the importance of genetic alterations in ACC development and point-out to various chromosomal regions (2, 11p15, 11q, 17p13) and genes (IGF-II, p53, beta-catenin, ACTH receptor). This review will summarize these advances as well as the current clinical management of ACC.