Expression of Ki-67 and estrogen receptor beta in primary malignant melanoma as a potential indicator of regional lymph node positivity

Abstract

Background Malignant melanoma (MM) is one of the tumors with fastest-growing incidence, also deadliest form of skin cancer. In the early stages of the disease it is extremely difficult to adequately predict risk from hematogenic and lymphatic metastasis. We assumed that the determination of Ki-67 and estrogen receptor beta (ER beta) in cells of MM could predict their biological behavior. Objectives To examine whether the level of expression of Ki-67 and ER beta in cells of MM are in correlation with status of regional lymph nodes (LN), and compare the relationship between melanoma thickness (pT) and status of LN. Methods Expression of Ki-67 and ER beta was examined by immunohistochemistry, and then staining positivity assessed and correlated with relevant clinical and pathological parameters. Results Logistic regression analysis showed that when ER beta levels increase by 1% the risk of positive LN decreases by 7% (OR = 0.930, 95%CI 0.87-0.99, p = 0.036), and when the Ki67 expression increases by 1% that the risk of LN positivity increases by 10% (OR = 1.108, 95%CI 1.02 to 1.19, p = 0.009). Conclusions Correlation between melanoma thickness and the status of LN has less prognostic significance than the relationship between expression of Ki-67 and ER beta and the status of LN. Our study showed a significant prognostic value of Ki67 expression in predicting the behavior of MM, and potential prognostic significance of ER beta.