Elevated frequency of p53 genetic mutations and AgNOR values in squamous cell carcinoma

Background: Epidermal squamous cell carcinoma (SCC) is a common malignancy in Pakistan. We hypothesize that it is characterized by higher frequency of p53 genetic mutations and increased AgNOR values compared with squamous cell papilloma (SCP) and basal cell carcinoma (BCC). Experimental design: To test our hypothesis, 140 skin biopsies (including 20 normal skin, 20 SCP, 20 BCC and 80 SCC samples of various grades) were examined for p53 mutations using immunohistochemistry (IHC) and polymerase chain reaction (PCR). AgNOR staining was used for histological determination of AgNOR index. Results: Both markers were undetectable in normal skin and were low in SCP. They were upregulated in BCC and SCC. PCR experiments revealed p53 mutations in 70% and 96.25% of BCC and SCC, respectively. Higher AgNOR values were seen in SCC than in BCC (mean AgNOR count = 5.81 ± 31 and 8.36 ± 19; percentage of AgNOR was 43.5% and 53% in BCC and SCC, respectively). Finally, p53 IHC score was found to be related to the AgNOR index in the histological grading of BCC and SCC (r = +0.983, p < 0.0001). Conclusion: Our results suggest that a higher frequency of p53 genetic mutations and increased AgNOR values exist in SCC compared with BCC and SCP. ‘Consequently, SCC patients may have poorer prognosis’.