Does experience in colposcopy improve identification of high grade abnormalities?

Abstract

Objective

This study investigates whether experience in colposcopy improves identification of high grade abnormalities. The sensitivity and positive predictive value (PPV) of colposcopy in identifying high grade intra-epithelial lesions (HSIL) performed by relatively inexperienced as compared to experienced colposcopists are evaluated.

Study design

Of 18,421 colposcopies performed at the Royal Women's Hospital, Melbourne, Australia, between 1999 and 2004 by 5 senior and 11 junior colposcopists, the colposcopic impression was correlated with the histopathology result of the biopsy taken at 6020 colposcopies, with respect to the experience of the colposcopist.

Results

Colposcopy had a 60% sensitivity and 60% PPV in identifying HSIL in this study. In case of a high-grade referral smear the sensitivity and PPV in identifying HSIL were, respectively 76% and 73%, compared with 26% and 48% in case of a low-grade referral smear, no difference in overall colposcopic performance between experienced and inexperienced colposcopists was observed. However, the sensitivity of identifying HSIL was significantly higher with inexperienced colposcopists, and the PPV was significantly higher with experienced colposcopists.

Conclusion

In this study experience did not improve colposcopic performance, but differences in colposcopic strategy between the two groups were noted. The rather low overall sensitivity and PPV of colposcopy in identifying HSIL, especially in case of a low-grade referral smear, indicate that the role of colposcopy in the detection and treatment of cervical abnormalities is to assess size, site, and extent of an abnormality, rather than to assess the severity of this abnormality. Histology must remain the gold standard for treatment.

Introduction

Cancer of the uterine cervix is the second most frequent invasive cancer and the major cause of cancer deaths in women worldwide. With the introduction of population-based screening programs, both the incidence and the mortality of cervical cancer have been reduced. This reduction is mainly the result of diagnosis and treatment of pre-malignant lesions of the uterine cervix [1].

Women with an abnormal smear result in screening programs are generally referred for colposcopy [1], [2]. The role of colposcopy is to assess size, site and extent of a lesion, and select the most severe part of the abnormality to take a biopsy [3], [4]. Alternatively, colposcopy is often used to assess the severity of the abnormality as part of a ‘see and treat’ policy [5], [6].

Interpreting colposcopic epithelial patterns and subsequently selecting the site for biopsy is likely to be a subjective procedure that is strongly correlated to the colposcopist's skill and experience [7], [8], [9]. A meta-analysis has shown that colposcopy has a 57% positive predictive value (PPV) in detecting high grade intra-epithelial lesions (HSIL), however the PPV in these studies varied between 20% and 84% [10]. For low-grade squamous intra-epithelial lesions (LSIL) the PPV is lower [3], [10].

Many professionals and professional bodies claim that experience in colposcopy is the main deciding factor in correctly identifying the severity of a lesion [7], [10]. Guidelines indicate that a minimum number of colposcopies is needed to acquire and maintain colposcopy skills. In some countries, specific training and examination programs are compulsory before practitioners can be certified as a colposcopist [2], [11], [12]. In other countries no specific certification with local professional bodies is required [13], [14].

With this study we wanted to investigate whether experience in colposcopy improves identification of high grade abnormalities. For this reason, the sensitivity and PPV of colposcopy in identifying HSIL performed by relatively inexperienced colposcopists is compared to that of experienced colposcopists.