When all biopsies were compared with the final diagnosis of the excisional specimen, the colposcopically directed biopsy was less severe 42% to 66% of the time when the excisional histology was read as CIN 3 or AIS. However, when one degree of discrepancy was allowed, as it is in clinical practice, agreement was 92%. This suggests that women in the FUTURE trials, as well as those in real clinical practice, are typically managed appropriately under current protocols that combine cytology and colposcopy results to properly identify women who have cervical lesions that require surgical intervention.
Most CIN 3 lesions were small
Many of the CIN 3 lesions in this trial were small, as they were in the ASCUS LSIL Triage Study (ALTS), in which the median length of CIN 3 lesions was only 6.5 mm. Also in ALTS, lesions in one third of patients were so small that colposcopically directed biopsy did not leave any residual disease to be detected in the loop electrosurgical excision specimen.5 The size of a CIN 3 lesion that has associated invasion is, on average, seven times larger than without invasion.6 Although colposcopy is much less likely to miss large lesions, it is important to miss as little high-grade disease as possible because the risk of invasion is cumulative over time and unpredictable in a given patient.
Multiple biopsies boost detection
Sampling more than one area improves the accuracy of colposcopically directed biopsy, even when one area looks most abnormal. This colposcopy photo shows potential biopsy sites (within the ovals), although other choices may also be reasonable. Several studies have shown that colposcopically directed biopsy of even normal-appearing areas at the squamocolumnar junction or within large ectopies can improve detection of high-grade cervical intraepithelial neoplasia or adenocarcinoma in situ.Studies have shown that it is possible to increase the accuracy of detection of CIN 2+ by increasing the number of biopsies. In this study by Stoler and colleagues, the sensitivity of initial colposcopy improved from 47% (for one biopsy) to 65% (two biopsies) and 77% (three or more) (FIGURE). Overall agreement increased with increasing age, which is consistent with the likelihood that CIN 3 lesions expand with age and become increasingly detectable by colposcopy.
WHAT THIS EVIDENCE MEANS FOR PRACTICE
Colposcopy does work, but the era of biopsying only the most abnormal-appearing area is over. Take more biopsies.
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