Objective: To study the clinicopathologic features and expression of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) in adrenocortical tumors.
Methods: Forty-two cases of adrenocortical tumors operated at the Beijing Union Medical College Hospital during the period from July, 2001 to July, 2010 were retrospectively reviewed. Immunohistochemical study for EGFR and VEGF was carried out. The clinical information and follow-up data were analyzed.
Results: The cases included 21 adrenocortical carcinomas (ACC) and 21 adrenocortical adenomas (ACA). Nine patients suffered from primary aldosterone syndrome, including 8 cases with ACA and 1 case with ACC. The average tumor size, tumor weight, and duration between disease onset and diagnosis in the 21 cases of ACC were 11.7 cm, 542 g and 8.5 months, respectively. This was in contrast to 3 cm, 9.8 g and 45.6 months, respectively in cases of ACA. Histologically, the WEISS score in all the 21 cases of ACA was ≤ 2 (average = 0.9). None of the ACC cases had score less than 4 (average = 6.6). The presence of sinus invasion correlated with tumor metastasis (P < 0.01). Immunohistochemical study showed that EGFR was expressed in 61.9% of ACC patients (13/21), whereas EGFR staining was mostly negative in ACA (except for weak staining in 5 cases and moderate staining in 1 case). The difference of EGFR expression between ACC and ACA was statistically significant (P = 0.030). On the other hand, the positive rate of VEGF in ACC was 71.4% (15/21), including 28.6% (6/21) with strong expression and 28.6% (6/21) with moderate expression. In contrast, the expression rate of VEGF in ACA was 30.0% (7/21), including 14.3% (3/21) with moderate expression. The difference of VEGF expression between ACC and ACA was statistically significant (P = 0.013). There was correlation between VEGF expression and venous invasion (P = 0.028). The average duration of survival in patients with ACC was shorter than that in ACA. The tumor weight in ACC also correlated with prognosis.
Conclusions: Tumor size, weight and presence of endocrine symptoms may help in the differential diagnosis between ACC and ACA. A WEISS score of ≥ 3 highly suggests ACC. The presence of sinus invasion is associated with metastasis. EGFR or VEGF expression may also be important in differentiating ACC from ACA.