Clinical significance of cytologic atypical squamous cells of undetermined significance.

OBJECTIVE

To analyze the screening status, clinical characteristics, and risk of invasive cervical cancer in women with cytologic atypical squamous cells of undetermined significance (ASC-US) in general populations and to make recommendations for these women.

METHODS

The 95,309 women with initial cytologic ASC-US from the national cervical cancer screening database in Taiwan were divided into unscreened and screened groups based on their previous screening history. Newly diagnosed invasive cervical cancer cases in the follow-up period were retrieved for analysis.

RESULTS

There were 860 cases of invasive cervical cancer during the follow-up period of 556,758 person-years, with an overall incidence rate of 154.5 cases per 100,000 person-years. The incidence was 92.3 and 257.2 cases per 100,000 person-years in the screened and unscreened groups, respectively. Previous screening history was a strong risk predictor of invasive cervical cancer (hazard ratio 2.8, 95% confidence interval 2.4-3.1, P<.001) after adjustments for age, educational status, and hospital setting. Age was also a significant risk factor for developing invasive cervical cancer in the unscreened group but not in the screened group.

CONCLUSION

Women with cytologic ASC-US, especially those without a previous Pap test or older women, were more likely to develop invasive cervical cancer and should be followed up aggressively.

LEVEL OF EVIDENCE: II.