Validation of a low-cost, liquid-based screening method for cervical intraepithelial neoplasia

Objective

The objective of the study was to validate a low-cost, liquid-based method for cervical cancer screening.

Study design

We conducted a retrospective, split-sample comparison of 300 liquid-based cervical cytology samples from a group of 150 human immunodeficiency virus–seropositive women and 150 women from low-risk general gynecology clinics whose specimens were screened via standard liquid-based methodology as part of routine care. Residual samples from each specimen were used to prepare a slide using a novel, inexpensive manual membrane method of liquid-based cytology. These slides were screened by a cytotechnologist and abnormal cases were reviewed by a pathologist. Final diagnoses from the manual membrane method of liquid-based cytology slides were compared with the original diagnoses and available cervical biopsy data.

Results

There was good overall agreement between the manual membrane method of liquid-based cytology and original cytology diagnoses (76.3% agreement; kappa = 0.52, 95% confidence interval 0.44 to 0.59). Using available biopsy data to determine the accuracy of each method to identify high-grade squamous intraepithelial lesions, the manual membrane method of liquid-based cytology method was found to have a higher sensitivity (71.4% versus 57.1%) and lower specificity (82.1% versus 89.7%). The slightly higher referral rate to colposcopy using the manual membrane method of liquid-based cytology method was limited to women from the low-risk general gynecology clinics (16.7% versus 12.0%, P = .05).

Conclusion

The low-cost manual membrane method of liquid-based cytology cervical cytology method is comparable with a standard commercial method. Consequently, it may be of value in alternative screening strategies in resource-limited settings.

Key words: Low cost, Liquid-based cytology, Cervical cancer screening