Endocrine Abstracts

Objective: Adrenocortical carcinoma (ACC) is a rare malignancy, whose prognosis is mainly dependent on the stage at diagnosis. The identification of disease-associated markers representing solid biomarkers for early diagnosis and drug monitoring is mandatory to improve survival rate and life quality of patients. CTC are tumor cells originating from primary tumor or metastases. The tumor-induced angiogenesis and invasion allow aggressive tumors to release CTC into blood stream before any detectable metastases are established. Therefore, CTC detection may have enormous potential of assisting malignancy diagnosis, estimating prognosis and monitoring the disease. The presence of CTC in ACC patients have never been investigated so far.

Design and methods: CTC analysis was performed in 14 ACC and 10 adrenocortical adenoma (ACA) patients. Blood samples obtained before (n=3 patients) and after (n=10 patients) surgery were filtered on Screencell devices (Screencell®), polycarbonate membranes with 8 μm pores which isolate CTC on size-base.

Results: CTC were isolated in all ACC but not in ACA samples. Immunocytochemistry on CTC, compared to the primary tumors, revealed positivity for adrenocortical markers, confirming the adrenocortical origin. When ACC patients were stratified in two classes according to the cut-off of the median value of the clinical parameters (tumor diameter, Ki67, and Weiss) or to the presence/absence of metastasis, a statistical significant difference was found in the number of CTC post-surgery only when diameter (CTC/ml mean±S.D.: 2.70±3.70 vs 0.59±0.67, P=0.028 for diameter ≥8 and <8 cm respectively) and metastatic stage (CTC/ml mean±S.D.: 3.91±4.83 vs 0.70±0.70, P=0.031, for stage=4 vs the others respectively) were considered.

Conclusions: Our findings provide the first evidence that circulating tumor cells (CTC) may represent a valid and useful marker to support diagnosis in adrenocortical tumor pathologies. Moreover, CTC seem to correlate with some clinical parameters. Although very preliminary, these results, which need confirmation in a larger series, suggest a potential use of this so called ‘liquid biopsy’ for prognosis and for non-invasive monitoring progression and response to treatments.