Sexually transmitted diseases in cancer patients diagnosed under the age of 20 years – a national registry-based cohort study from Finland

Abstract Background Adolescents with chronic diseases are shown to be vulnerable for risky sexual behavior. Childhood cancer patients seem to engage in risky health behaviors as frequently as general population, but little is known about sexual issues in this group of patients. Material and methods We characterized the risk for sexually transmitted diseases (STD) in a Finnish population-based cohort of over 6,000 childhood cancer patients diagnosed with cancer under the age of 20 years between 1971 and 2009, compared with over 30,000 age- and sex -matched population comparisons. The data were constructed through linkage between national cancer, population, infectious diseases, and hospital discharge registries. We estimated hazard ratios (HRs) with 95% confidence intervals (CIs) using Cox regression modeling with attained age as the underlying time scale. Results Childhood cancer patients had a decreased risk for having an infection with chlamydia, the most common STD in our cohort, when comparing with population comparisons (HR 0.77, 95% CI 0.69–0.86). The risk was lowest among male patients (HR 0.64, 95% CI 0.53–0.79) and patients with central nervous system (CNS) tumors (HR 0.46, 95% CI 0.33–0.63). The overall risk for cervical dysplasia was slightly increased among female cancer patients when compared with their population comparisons (HR 1.28, 95% CI 1.02–1.60). Greatest risk elevation was found among patients diagnosed with cancer in ages 10–14 years (HR 2.31, 95% CI 1.46–3.65) and patients with lymphoma (HR 1.95, 95% CI 1.20–3.16). The risk for all explored outcomes seemed to be decreased among patients with CNS tumors. Conclusions Our findings highlight the importance of integrating sexual issues as a part of psychosocial support and having a systematic transition program in the follow-up care of childhood cancer patients.