OBJECTIVE: There is evidence in Germany that half of the cervical cancer (CC) cases had undergone screening frequently in the decade preceding their diagnosis, signaling cytology quality issues. This study investigates routine smear assessment accuracy in Germany.

METHODS: Within a population-based case-control study in 9 German states, we recruited cases (women with a histologically confirmed diagnosis of CC) and population controls (women with no history of CC or hysterectomy). Two independent expert cytologists audited Pap smears taken within the 10 years preceding CC diagnosis (cases)/study entry (controls). We report the prevalence of positive results, as well as routine assessment's accuracy, as sensitivity, specificity, false-positive and false-negative rates along with 95% confidence intervals (95% CI). We also examined cases' smear history, to investigate possible false-positive recurrence.

RESULTS: We audited 1632 smears of 392 women (18.9% cases, 81.1% controls). In the routine assessment, the overall prevalence of positive results was 4.5% (29.0% among cases). According to the expert audit, the overall prevalence of positive results was 7.7% (40.8% among cases). When restricting analyses to the 3 years preceding diagnosis/study entry, this prevalence increased to 11.9% overall (61.4% among cases). The overall sensitivity of the routine assessment was 54.9% (66.8% for cases).

CONCLUSION: As cytology remains an important part of CC screening, quality issues must be urgently addressed in Germany. Shifting to objective methods such as primary high-risk HPV screening followed by triaging may help CC elimination in Germany.