Managing atypical squamous cells of undetermined significance in Papanicolaou smears.

OBJECTIVE

To assess strategies using repeated conventional Pap smear and human papillomavirus (HPV) DNA testing, alone or in combination, for identifying women with concomitant cervical intraepithelial neoplasia 2 and 3 (CIN 2/3) in women with atypical squamous cells of undetermined significance (ASCUS) in their Pap smears.

STUDY DESIGN

A total of 360 women cytologically diagnosed with ASCUS were referred for colposcopy and underwent a repeat Pap smear, a biopsy when necessary and HPV testing using three different modes of detection of high-oncogenic-risk HPV types: 1, first-generation Hybrid Capture test (HC-1) (Digene Diagnostics, Gaithersburg, Maryland); 2, second-generation Hybrid Capture test (HC-2); and 3, polymerase chain reaction (PCR).

RESULTS

Nineteen patients (5.3%) had histologic CIN 2/3. The sensitivity and specificity of the repeat Pap smear alone for the detection of CIN 2/3 were 73.7% and 62.9%, respectively, when referring all women with a repeat Pap smear using an ASCUS-positive threshold. The proportion of women referred for colposcopy was 39.0%. When HPV testing for high risk was used for identification of women with histologic CIN 2/3, sensitivity and specificity were, respectively, 68.4% and 85.9% for HC-1, 89.5% and 73.9% for HC-2 and 89.5% and 59.0% for PCR. The rate of referral for colposcopy of these three modes of HPV testing was 16.9%, 29.4% and 44.0%, respectively. The sensitivity and specificity for identification of women with concomitant CIN 2/3 using a combination of repeat cytology showing a low grade squamous intraepithelial lesion or high grade squamous intraepithelial lesion and/or a test positive for high-oncogenic-risk HPV group were, respectively, 94.7% and 73.2% when used in combination with HC-2. The referral rate of women for colposcopy of this combined strategy was 30.4%.

CONCLUSION

As compared to the strategy using abnormal repeat Pap smear alone, those using high-risk HPV testing with Hybrid Capture showed statistically significantly higher specificities and lower proportions of women with ASCUS referred for colposcopy. In particular, a promising strategy would be to refer for colposcopy only women with repeat Pap smears showing squamous intraepithelial lesion and/or those positive for high-risk HPV detected by Hybrid Capture testing.