Expression of matrix metalloproteinase-13 and Ki-67 in nonmelanoma skin cancer in xeroderma pigmentosum and non-xeroderma pigmentosum.

Xeroderma pigmentosum (XP) is a heterogenous group of genetic diseases in which basal cell carcinoma (BCC) is the most common nonmelanoma skin cancer (NMSC) followed by squamous cell carcinoma (SCC). The aim of this study was to investigate the expression of matrix metalloproteinase (MMP)-13 and Ki-67 in SCC and BCC from patients with and without XP to elucidate their roles in the pathogenesis of these highly aggressive tumors in patients with XP. Immunolabeling using MMP-13 and Ki-67 antibodies was performed on tissue sections derived from skin biopsies of SCC and BCC of 15 patients with XP and 40 non-XP patients. There was no significant difference between XP and non-XP patients as regards MMP-13 expression by epithelial and stromal cells of SCC or BCC. Ki-67 expression in SCC and BCC of patients with XP was significantly higher than in non-XP patients. We concluded that the higher expression of Ki-67 in NMSC of patients with XP than of non-XP patients may reflect the growth and invasive capacity of these tumors in patients with XP. MMP-13 is expressed by tumor epithelial cells, stromal and inflammatory cells of NMSC of both XP and non-XP patients.