Impact of opportunistic screening on squamous cell and adenocarcinoma of the cervix in Germany: A population-based case-control study

BACKGROUND: We investigated the uptake of opportunistic cervical cancer screening (CCS) and other risk factors and their association with cervical cancer in Germany in a case-control study. METHODS AND FINDINGS: We recruited incident cases of cervical cancer (ICD-10 C53) diagnosed between 2012 and 2016 and matched with three population-based controls, based on age and region of residence. Cases and controls reported their CCS participation during the past ten years (frequent: every three years; no or infrequent: less than every three years) and other relevant variables. We fitted conditional logistic regression models, reporting odds ratios (OR) and 95% confidence intervals (95% CI). We report overall and stratified analyses by histologic group (squamous cell–SCC, and adenocarcinoma–AC), T category (T1 and T2+), and age (<50 and ≥50 years). We analysed 217 cases and 652 matched controls. 53.0% of cases and 85.7% of controls attended CCS frequently. In the overall adjusted model, no or infrequent participation in CCS (OR 5.63; 95% CI 3.51 to 9.04), having had more than one sexual partner (OR 2.86; 95%CI 1.50 to 5.45) and obesity (OR 1.69; 95% CI 1.01 to 2.83) were associated with cervical cancer. Twelve years of schooling (OR 0.37; 95% CI 0.23 to 0.60) and a net monthly income of €3000 or more (OR 0.50; 95% CI 0.30 to 0.82) were protective factors. In the stratified analyses, no or infrequent participation was associated with T1 (OR 4.37; 95% CI 2.48 to 7.71), T2+ (OR 10.67; 95% CI 3.83 to 29.74), SCC (OR 6.88; 95% CI 4.08 to 11.59) and AC (OR 3.95; 95% CI 1.47 to 10.63). CONCLUSION: Although women who frequently attended CCS were less likely to develop cervical cancer, especially larger tumours, the high proportion of cases who had been frequently screened prior to diagnosis underscores the need to investigate the quality of cytology and treatment of precancerous lesions in Germany.