Immunohistochemical nuclear staining for p53, PCNA, Ki-67 and bcl-2 in different histologic variants of basal cell carcinoma.

BACKGROUND Basal cell carcinoma is the most common form of human cancer. Increased expression of p53 has been found in the majority of basal cell carcinomas (BCCs); however, UV-light-induced signature mutations are present in only about 50% of cases. Increased nuclear staining with an immunohistochemical marker of proliferation and apoptosis has been correlated with aggressive behavior in BCC. OBJECTIVE Our purpose was to correlate markers expression of apoptosis (p53 and bcl-2) and cell proliferation (Ki-67 and PCNA) with histological indicators of tumor severity. METHODS We used immunohistochemical stains for p53, PCNA, and Ki-67, in superficial, nodular and sclerosing BCC, to determine whether the staining patterns differ in these different histologic variants of BCC. RESULTS Bcl-2 expression was significant in basal cell carcinomas said to be aggressive (morpheaform and nodular types). Of the studied tumors, 66.7% (n=14) strongly expressed p53. Our results show a greater expression of Ki-67 in nodular and superficial basal cell carcinoma. PCNA showed a strong expression in all types of tumors. CONCLUSION Studies employing molecular and genetic biology techniques, associated with histomorphology, lead to the identification of risk factors in the development of more recurring and aggressive lesions.