epidemiological study of non-melanoma skin cancers qazvin province, iran

background non-melanoma skin cancers (nmsc) are the most common cancers worldwide. these cancers are not accompanied by high mortality however they lead to various complications. evaluation of nmsc predisposing factors could result in preventive measures, improvement of quality of life and reduction of medical costs. objectives this study aimed to determine predisposing factors of non-melanoma skin cancers in the province of qazvin (iran). materials and methods a total of 484 proven cases of nmsc were evaluated for demographic characteristics, clinical findings, pathological type, location of lesion, and the existence of known or possible predisposing factors such as skin type, exposure to sunlight, and family and drug history within a ten-year period from 2001 to 2011. data were recorded in a questionnaire through interview and clinical examination of patients by a physician and a dermatologist, respectively. data were analyzed using the spss version 16 software and statistical tests including t-test and chi-square tests. results of the 484 patients, 294 (60.7%) were male and 190 (39.3%) were female. most cases of carcinoma were found in basal cells (77.7%) and the rest of squamous cells. the most common sites of involvement were the head and scalp. the most frequent predisposing factors were working in the open air (70.7%), history of previous radiation for treatment of tenia capitis (26.1%), and chronic skin diseases such as burn eschar, chronic lesion, fistula and actinic keratosis (35.7%). the most prevalent fitzpatrick skin phenotypes were ii or iii (75.4%). there were significant correlations between the incidence of nmsc and hookah smoking and oral contraceptive pill (ocp) consumption. conclusions skin phenotypes ii and iii were the most common types found in the present study and this could be due to the higher frequency of these phenotypes among the study population. the lower incidence of nmsc in areas other than the neck and scalp could be associated with the importance of covering style used by the population under study. known risk factors for the incidence of nmsc were also observed in the present study. a history of radiotherapy for treatment of tenia capitis was observed in a considerable percentage of patients, which could lead to the incidence of cancer several decades later. further studies are needed to determine the role of hookah smoking and the use of ocp in the occurrence of nmsc.