Endocrine Abstracts

Background

Adrenocortical carcinoma (ACC) is a rare but very aggressive endocrine malignancy with poor survival. Histopathology is important for diagnosis, while in some cases immunohistochemical markers and gene profiling of the resected tumor may be superior to current staging systems to determine prognosis.

Aim

Herein, we aimed to present the 20year experience at a tertiary Hospital in patients with ACCs and correlate the immunohistochemical characteristics of ACCs with the clinical and morphological characteristics of the tumors and the survival of the patients.

Material and methods

45 patients with ACC operated in a single center were included in the study. The tumor size and weight and the disease stage (ENSAT classification) were examined along with Weiss score and Helsinki score. Immunohistochemical expression of Inhibin-a, Melan A, Calretinin, Ki67, Synaptophysin, p53, Vimentin, CKAE1/AE3 was also examined.

Results

45 patients were diagnosed with ACC. The male to female ration was 1:1.37. The median age at diagnosis was 55.5 years (IQR 19–77). ENSAT stage I, II, III and IV was 6.6%, 62.3%, 26.7% and 4.4%, respectively. The median size of ACCs was 9 cm (IQR 3.5–22 cm) and the median weight 127 gr (IQR 18–1400 gr). The median follow up period was 18 months (IQR 1–96). Twelve patients (31.58%) had ≤ 1-year survival and 17 (44.74%) demonstrated ≤ 5-year survival. Survival was significantly higher in patients with stage I–II as compared to patients with stage III–IV ACC (62 ± 8.7 months vs 31 ± 12.1 months, P = 0.02). A significant correlation between tumor volume (P = 0.011, r = 0.418), diameter (P = 0.005, r = 0.449), weight (P = 0.04, r = 0.339) and Weiss score was observed. An association between Weiss score and the expression of vimentin (P = 0.02) was also observed. A larger tumor diameter > 10 cm (P = 0.007), tumor volume > 500 cm³ (P = 0.0003), tumor weight > 300 gr (P = 0.03), Ki-67 index > 4% (P = 0.04), Weiss score > 5 (P = 0.001), Helsinki score > 8 (P = 0.06) were significantly associated with shorter overall survival (OS) in the univariable analysis. The expression of Melan A and lower expression of Ki-67 (≤ 4) were independently associated with longer OS time (P = 0.01). No statistical significance was observed regarding the correlation between IHC markers and ENSAT staging (I/II vs III/IV).

Conclusion

Adrenocortical carcinoma is a rare and very aggressive endocrine malignancy. The most important factors that determine long-term prognosis of ACC are the disease stage at diagnosis, the Weiss score, and the Ki67 index. Immunohistochemical markers such as Melan A could also serve as prognostic factors.