Cervical Cancer in Women with Normal Papanicolaou Tests: A Korean Nationwide Cohort Study

PURPOSE: This study aimed to evaluate the risk of cervical cancer diagnosed within 1 year after the last of multiple consecutive normal Papanicolau (Pap) tests. MATERIALS AND METHODS: The database of the National Health Insurance Service was used. We obtained Pap test data for 11,052,116 women aged 30–79 between 2007–2012. The cumulative incidence rates and 5-year overall survival rates of cervical cancer diagnosed within 1 year after the last normal Pap test were compared between women with one (N1), two (N2), and three consecutive normal Pap tests (N3). Women who did not receive a Pap test during the study period were assigned in the N0 group. RESULTS: The 1-year cumulative incidence rates of cervical cancer were 58.9, 24.6, 20.3, and 14.2 per 10(5) in the N0, N1, N2, and N3 groups, respectively. Compared to the N1 group, the risk of cervical cancer diagnosed within 1 year of the last normal Pap test decreased by 17% (relative risk [RR], 0.825; 95% confidence interval [CI], 0.716 to 0.951) in the N2 group and 42% (RR, 0.578; 95% CI, 0.480 to 0.695) in the N3 group. However, the 5-year survival rate in women diagnosed with cervical cancer within 1 year of the last normal Pap test in the N3 group was not higher than that of the N1 group (79.6% vs. 81.3%, p=0.706). CONCLUSION: As normal Pap tests are consecutively repeated, cervical cancer risk significantly decreases. However, previous consecutive normal Pap tests are not associated with improving survival outcomes in women shortly diagnosed with cervical cancer after the last normal Pap test.