Circulating Tumor Cells as Diagnostic Marker of Adrenocortical Carcinoma: Preliminary Results of a Single Center Study
Cristian Scatena, Pamela Pinzani, Francesca Salvianti, Milena Paglierani, Michaela Luconi, Massimo Mannelli, Gabriella Nesi. University of Florence, Florence, Italy
Background: Adrenocortical carcinoma (ACC) is a rare and heterogeneous malignancy which gains access to the circulation very early during disease progression. Circulating tumor cells (CTC) detection may have enormous potential in establishing a diagnosis of malignancy, estimating prognosis and monitoring disease progression. To our knowledge, CTC detection rate in ACC patients is presently unknown.
Design: CTC analysis was carried out in 11 ACC and 10 adrenocortical adenoma (ACA) patients. Blood samples obtained before and after surgery were filtered on Screencell devices (Screencell®), polycarbonate membranes with 8 µm pores which isolate CTC by size. Filters and sections of the corresponding primary tumors were assessed immunohistochemically for adrenocortical markers (i.e. MART-1, alpha-inhibin and synaptophysin) and proliferation status (Ki67).
Results: CTC were seen in all ACC but not in ACA samples. Immunocytochemical analysis with MART-1, alpha-inhibin and synaptophysin identified circulating adrenocortical cells as weak to moderately stained cells. CTC numbers were significantly lower in the samples obtained after surgery (mean CTC number/blood ml±SD: before, 3.80±4.4 and after, 0.64±0.62, P=0.007). A statistically significant linear relationship was found between the number of CTC recovered after surgery and the tumor diameter (R=0.867, R2=0.752, P=0.001) and Ki67 expression (R=0.795, R2=0.632, P=0.007).
Conclusions: We identified CTC in the peripheral blood of ACC but not of ACA patients. This suggests that CTC may represent a promising diagnostic marker of malignancy. Considering that there is a reduction in the number of CTC isolated after surgery, CTC detection could also assist in estimating prognosis and monitoring treatment success in ACC patients.
Monday, March 4, 2013 2:15 PM
Proffered Papers: Section H, Monday Afternoon