Transformation zone sampling rate is a useful performance indicator for practitioners collecting cervical samples using SurePath^TM liquid‐based cytology system

Abstract

An analysis of the reports of 53 982 liquid-based cytology (LBC) samples processed at the Royal Victoria Infirmary, Newcastle, reveals a significant relationship between the transformation zone (TZ) sampling rate observed in specimens submitted from different practices and their overall detection rate for dyskaryosis. The observed correlation (R = 0.184; P = 0.033, CI = 0.017 to 0.397) is very similar to that described previously using conventional cervical smears and confirms the potential relevance of TZ sampling rates as an indicator of consistently effective specimen collection. The correlation between unsatisfactory sample rates and detection rates for high-grade dyskaryosis (R = -0.188, P = 0.030, CI = -0.865 to -0.045) also shows a significant relationship for LBC samples which was not previously seen in conventional smears. The essential role of smear taker feedback, the use of transformation zone sampling and unsatisfactory smear rates as key indicators and the practical issues relating to routine reporting of transformation zone components are discussed.

Glandular neoplasia and borderline endocervical reporting rates before and after conversion to the SurePathTM liquid‐based cytology (LBC) system

“…The findings indicated that simply changing the sampler did improve sample quality as indicated by a significant decrease in the percentage of unsatisfactory samples (from5.96% to 4.77%, P < 0.001) with a concurrent 4.23% ( P < 0.001) increase in the percentage of samples containing identifiable transformation zone elements. Narine and Young had previously identified a significant link between the percentage of samples containing transformation zone elements and the increased detection of cervical disease 24. This improvement may be in part related to the new sampling device, but also to the efficient cell transfer one observes by keeping the broom head in the vial.…”

Gynecologic cytology on conventional and liquid‐based preparations: A comprehensive review of similarities and differences

“…For both CPS and LBPs, an adequate transformation zone component requires at least 10 well‐preserved endocervical (EC) or squamous metaplastic cells, singly or in clusters 23, 24. EC glandular lesions, such as adenocarcinoma in situ (AIS) may not be detected by Pap if TZ is spared, 54 vs. 25% ( P = 0.036) 25…”

Transformation zone sampling rate used as a performance indicator for cervical liquid‐based cytology sample‐takers

“…Young and Narine and Young have demonstrated a correlation between TZSR and the overall detection rate for dyskaryosis in both conventional and SurePath TM LBC cervical samples. An association between the presence of TZ cells in LBC samples and a higher detection rate of high‐grade squamous intraepithelial lesions was also noted by Leung et al .…”

“…Young and Narine and Young recommended the use of TZSR as a personal performance indicator for practitioners; however, both studies concerned the TZSR and detection of dyskaryosis by practice. In our study, we were able to produce data by the practitioner because of the laboratory's strict rejection policy on samples submitted without a registered ST number.…”

“…Although there is an extensive programme of training and update for the sample takers, and they are deemed competent in a final assessment by an external assessor, there is no NHSCSP recommended method of measuring and monitoring the quality of their sampling technique. Previous studies have measured the transformation zone sampling rate (TZSR) per surgery for both conventional and SurePath TM cervical samples and have correlated this with the detection of cytological abnormality . These authors suggested that TZSRs should be audited for individual practitioners.…”