title: Another point of view on p16 and Ki67 expression in melanocytic and non-melanocytic cutaneous lesions.
abstract: The new analysis of the expression of cell cycle regulators (used in various neoplasms) and the nominal immunohistologic assays still represent valid and feasible diagnostic methods in most pathology practice. We examined 114 paraffin-embedded histologic specimens of melanocytic cutaneous lesions. The primary objective of this study was to explore diagnostic potential of the two important cell cycle regulators, p16 and Ki67, also evaluating the variations of expression by use of a semi quantitative graded scale. Another aim was to study the hypothetical correlation between p16 expression (in melanocytic and non-melanocytic lesions) and two independent variables, i.e. patient age and anatomical sites (sun exposed or non-sun exposed) of the lesions. Cell population was considered positive for antibody-specific p16 and Ki67 when at least 33% of the cells showed well-defined nuclear and/or cytoplasmic staining. A special p16 and Ki67 trend was found only in Spitz nevus, atypical Spitz nevus and invasive malignant melanoma (MM). No discriminative values were found regarding other lesions (junctional melanocytic nevus, MM in situ, superficially spreading MM, non-melanoma skin cancers). p16 was over-expressed on sun exposed sites and hypo-expressed on non-sun exposed areas, yielding a statistically significant correlation (p<0.03). According to patient age, p16 was over-expressed in patients aged ≥61 and hypo-expressed in patients aged ≤60 (p=0.09).
authors.affiliation: Giovanni Paolino, MD, San Gallicano Institute of Rome, Via Elio Chianesi, 53, 00144 Rome Italy; gio8519@libero.it.
authors.forename: Pietro
authors.initials: P
authors.lastname: Donati
authors.forename: Giovanni
authors.initials: G
authors.lastname: Paolino
authors.forename: Chiara
authors.initials: C
authors.lastname: Panetta
authors.forename: Carlo
authors.initials: C
authors.lastname: Cota
authors.forename: Marco
authors.initials: M
authors.lastname: Zaccarini
authors.forename: Luca
authors.initials: L
authors.lastname: Muscardin
mesh_terms: D000328:Adult; D000367:Age Factors; D019941:Cyclin-Dependent Kinase Inhibitor p16; D004781:Environmental Exposure; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism*; D008297:Male; D008545:Melanoma / Q000378:metabolism*; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D018332:Nevus, Epithelioid and Spindle Cell / Q000378:metabolism; D009508:Nevus, Pigmented / Q000378:metabolism; D012878:Skin Neoplasms / Q000378:metabolism*; D013472:Sunlight
chemical_list: C000614131:CDKN2A protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D019394:Ki-67 Antigen; D009363:Neoplasm Proteins