Contribution to characterization of skin field cancerization activity: morphometric, chromatin texture, proliferation, and apoptosis aspects()()

BACKGROUND: A skin field cancerization is a cutaneous area with subclinical changes resultant from chronic sun exposure, with a higher predisposition to development of pre-neoplastic and neoplastic lesions. So far, there are no well-defined objective parameters that can indicate their degree of activity. OBJECTIVES: To describe and compare morphometric aspects and expression of factors related to apoptosis and cell proliferation in actinic keratosis (AK), in both photoexposed and photoprotected epidermis. METHODS: A cross-sectional study of patients with actinic keratosis in the forearms, biopsied at two points: the actinic keratosis and the axillary region. The biopsies of the actinic keratosis, perilesional area, and axilla were evaluated through keratinocyte intraepithelial neoplasia (KIN), and immunohistochemistry of p53, survivin, and Ki67. Nuclear morphometry of basal layer cells was performed through digital image analysis: entropy, area, perimeter, Ra, fractal dimension, circularity, color intensity, and largest diameter. RESULTS: There were 13 patients included and 38 actinic keratosis biopsied. In morphometry, 1039 nuclei were analyzed, of which 228 represented axillary skin, 396 demonstrated actinic keratosis, and 415 represented the perilesional area to the actinic keratosis. There was a significant difference (p < 0.05) in all variables tested for the topographies evaluated. A significant correlation was identified between nucellar morphometric elements, KIN, proliferation markers, and apoptosis. Joint patterns of p53, Ki67, and KIN discriminated the topographies sampled. STUDY LIMITATIONS: This was a cross-sectional study with a small number of patients. CONCLUSIONS: There are patterns of proliferation, resistance to apoptosis, and different cellular morphometrics between photoprotected skin and photoexposed skin. The joint expression of p53, Ki67, and KIN can characterize skin field cancerization activity.