Role of Bcl-2, p53, and Ki-67 expression in basal cell carcinoma and their association with aggressive and non-aggressive histological phenotypes

Introduction
There is increasing evidence that immunohistochemical expression of p53, Ki-67, and Bcl-2 is associated with aggressive (aBCC) and less aggressive (nBCC) histological subtypes and may have a prognostic role. Aim: To investigate the clinicopathological features and immunohistochemical expressions of p53, Ki-67, and Bcl-2 in cutaneous basal cell carcinoma focusing on histological subtypes. Their roles and possible interactions in the development and progression of BCC are discussed.

Material and methods
A total of 50 BCC samples from 50 patients from Western Mexico between June 2018 and June 2019 were included. Paraffin-embedded samples were immunostained with p53, Ki-67, and Bcl-2 antibodies. Semi-quantitative analysis was performed to determine the intensity and positivity of immunostained cells. Parametrical and non-parametrical tests were performed according to the sample’s distribution.

Results
Samples included 21 nBCC and 29 aBCC. The statistical analysis showed statistical association when grouped as non-aggressive and aggressive subtypes for p53 (p = 0.04) and Bcl-2 (p < 0.01). An inverse negative correlation was found between age and Bcl-2 expression. No statistical association was found between Ki-67 immunoreactivity and any of the other variables.

Conclusions
We found that a high expression of Bcl-2 and a low expression of p53 was associated with more indolent histopathological features of BCC and therefore better outcomes. These findings suggest that examination of p53 and Bcl-2 expression in BCC patients may provide valuable prognostic information. These biomarkers may play a role in the development and progression of some cases of BCC.