Tetracycline use and risk of incident skin cancer: a prospective study

BACKGROUND: Tetracycline is a photosensitising medication that increases skin vulnerability to UV-related damage. METHODS: We prospectively examined tetracycline use and risk of incident melanoma, squamous cell carcinoma (SCC), and basal cell carcinoma (BCC) based on 213 536 participants from the Nurses’ Health Study (NHS), NHS2, and Health Professionals Follow-up Study. Information on ever use of tetracycline was asked via questionnaire. Diagnoses of melanoma and SCC were pathologically confirmed. RESULTS: Tetracycline use was associated with a modestly increased risk of BCC (n(case)=36 377), with a pooled hazard ratio (HR) of 1.11 (95% confidence interval (CI)=1.02–1.21, P-trend=0.05 by duration of use). Tetracycline use was not significantly associated with melanoma (n(case)=1831, HR=1.09, 95% CI=0.94–1.27) or SCC (n(case)=3332, HR=1.04, 95% CI=0.91–1.18) risk overall. However, we observed positive interactions between tetracycline use and adulthood UV exposure on SCC risk (P-interaction=0.05). CONCLUSION: Tetracycline use was associated with a modestly increased risk of BCC, but was not associated with melanoma or SCC.