Unsatisfactory cervical cytology screening specimens are associated with missed cervical dysplasia and cancer

Abstract

It is essential not to underestimate the significance of unsatisfactory Pap results, especially in populations with extended screening intervals and/or inefficient call-back systems, as this may result in missed opportunities to diagnose significant disease and prevent cervical carcinoma. Thus, it is recommended that the clinical performance results from the study population in which unsatisfactory specimens were excluded be interpreted with caution. j Unsatisfactory cervical cytology screening specimens are associated with missed cervical dysplasia and cancer References Author's ReplySir, Thank you for the opportunity to respond to the informative letter by Dr Nance, 1 this highlights the importance of unsatisfactory smear reports in the interpretation of the clinical performance of cervical cytology tests.As stated in our manuscript, 9% of conventional smears were reported as unsatisfactory as opposed to 3% for SurePath tests. Clearly, these tests represent a missed opportunity for the detection of high-grade lesions. The clinical significance or risk of the unsatisfactory smear depends on the prevalence of high-grade abnormalities in the population, the likelihood of a repeat smear being taken and whether women are having regular smears.Despite the high unsatisfactory rate in our study and a high incidence of high-grade abnormalities, on an intention-to-treat basis, the improved sensitivity in the liquidbased arm did not reach statistical significance. Similarly, in the large randomised study reported by Ronco et al. 2despite an almost double risk of unsatisfactory reports in the conventional arm, the improvement in detection of high-grade histological abnormalities failed to reach statistical significance.In New Zealand, the incidence of an unsatisfactory smear report is about 4%. During the New Zealand Cervical Cancer Audit, 3 smear histories were reviewed. In addition, 336 smears taken in the 4 years prior to the diagnosis of cervical cancer and not reported as high grade were reread in a blinded fashion as were 3785 control smears. In this time period, all smears were conventional pap tests. There was no evidence of an excess number of smears reported as unsatisfactory in women who subsequently developed cancer. Of reread smears taken prior to the diagnosis of cancer 5% were reclassified as unsatisfactory compared with 3% of control smears. However, 21% of reread smears were upgraded to high grade, and the audit's major finding was that only 21% of women with cancer were taking part in regular cervical screening.Therefore, as Dr Nance states the unsatisfactory rate is of importance in the evaluation of a cervical cytology test, and all single studies should be interpreted with caution.