Tobacco smoking is associated with cutaneous squamous cell carcinoma but not with basal cell carcinoma or melanoma in adult subjects at risk of skin cancer: A cross-sectional study.

Introduction: The relationship between tobacco smoking and cutaneous photodamage or malignancies is still unclear. In addition to smoking, both ultraviolet radiation and immunosuppression have an impact on carcinogenesis. The purpose was to study the association of smoking with cutaneous photoaging, actinic keratosis (AK), skin cancers, and pigment cell nevi in adult subjects at risk of any type of skin cancer.

Methods: In this cross-sectional study at Kuopio University Hospital, Finland, between May 2017 and October 2020, 488 subjects (aged 21-79 years, 246 males and 242 females, 94 with immunosuppression) were examined for a variety of skin lesions, photoaging severity, nevi, tobacco pack-years (TPY), as well as for possible confounding factors.

Results: In logistic regression analyses, no marked association was found between TPY and total skin photoaging, facial photoaging, AK, or nevi, especially when other confounding factors, such as age, were considered. In addition, TPY was not associated with melanoma, basal cell carcinoma, or any type of skin cancer. However, ever smokers produced an elevated crude odds ratio (OR=1.99; 95% CI: 1.02-3.88, p=0.043) for squamous cell carcinoma (SCC) compared to non-smokers. In further analysis, TPY of ≤10 produced an elevated multivariable adjusted odds ratio (AOR=4.90; 95% CI: 1.31-18.26, p=0.018) for SCC, but TPY >10 did not (AOR=1.14; 95% CI: 0.22-6.05, p=0.876).

Conclusions: Smoking was associated, though not dose-dependently, with an increased likelihood of SCC, but it was not associated with basal cell carcinoma or melanoma. However, the impact of smoking on cutaneous photoaging severity, AK, and nevi, appears to be weak.