Cervical biopsy sampling variability in ALTS

Objective. To determine histologic sampling variability among clinical center colposcopists and quality control reviewers in the Atypical Squamous Cells of Undetermined Significance/Low-grade Squamous Intraepithelial Lesion Triage Study. Materials And Methods. Clinical center colposcopists and quality control reviewers independently indicated need for biopsy, number of biopsies needed, and optimal biopsy location on customized computer software and digitized colposcopic images while examining subjects or monitoring colposcopists in the Atypical Squamous Cells of Undetermined Significance/Low-grade Squamous Intraepithelial Lesion Triage Study. Results were compared using percentages of agreement, κ statistics, McNemar, and paired t tests. Results. Colposcopists and reviewers agreed whether a cervical biopsy was indicated for 2,631 (72.9%) of 3,610 evaluable subjects and 415 (91.6%) of 453 subjects with cervical intraepithelial neoplasia 2 or worse by histologic diagnosis. Only 3 of 41 colposcopists indicated 20% or greater of their biopsy sites to be more than 10 mm from reviewers' recommended sites. The mean of the greatest colposcopist-to-reviewer biopsy site distance was significantly greater than the mean maximum distance between reviewers' biopsy sites (14.9 vs 12.2 mm, p < .0001, respectively). Colposcopists indicated a significantly greater number of biopsy sites compared with consensus of reviewers (p < .0001). Conclusions. When cervical cancer precursors are present in women with minor cytologic abnormalities, most colposcopists obtain a biopsy. However, biopsy site placement can vary considerably. Only a minority of colposcopists sample significantly beyond recommended areas and less biopsy site variability occurs among experts.