Introduction Nonmelanoma skin cancer is the most common malignancy in white individuals. The risk factors for squamous cell carcinoma, which belongs to the family of nonmelanoma skin cancers, have not been studied in Colombia. Objective To determine the risk factors for squamous cell carcinoma in patients at a national referral center for skin diseases in Colombia. Material and methods We conducted a case-control study that evaluated sociodemographic, epidemiological, and clinical factors among 332 individuals. Risk was calculated as odds ratio (ORs) using the multivariate conditional logistic regression analysis method. Results The following risk factors were identified: family history of skin cancer (OR, 6.55; 95percent-flag-change CI, 1.4-28.9), living in a rural area after the age of 30 years (OR, 3.13; 95percent-flag-change CI, 1.3-7.2), a lifetime working outdoors (OR, 2.98; 95percent-flag-change CI, 1.5-5.7), smoking more than 10 cigarettes a day (OR, 2.96; 95percent-flag-change CI, 1.3-6.5), actinic conjunctivitis (OR, 2.68; 95percent-flag-change CI, 1.2-5.9), poikiloderma of Civatte (OR, 3.29; 95percent-flag-change CI, 1.7-6.1), numerous facial actinic keratoses (OR, 9.23; 95percent-flag-change CI, 4.9-17.1), and numerous freckles (OR, 3.68; 95percent-flag-change CI, 1.3-10.1). Conclusions We have documented clinical characteristics and personal history factors that should guide the physician in making decisions on the preventive and follow-up measures to be adopted for individuals at risk of squamous cell carcinoma. These findings may help guide policy for controlling the disease using local information.
