The number of biopsy specimens can influence the non-lifting sign incolorectal laterally spreading tumors.

Abstract

Although the problem of whether to perform a biopsy before endoscopic treatment for colorectal laterally spreading tumor (LST) troubles clinicians, about 50 % of lesions still undergo a preceding biopsy. We aimed to explore factors affecting the non-lifting sign in LST and examine the influence of "biopsy-related factors", such as the number of biopsy specimens and the interval after biopsy on non-lifting sign in cases with a history of biopsy. Clinical data of 159 LSTs regarding age, gender, history of biopsy, tumor location, tumor size, the depth of submucosal invasion, tumor configuration, histologic type, location with respect to the fold, and result of non-lifting sign testing were investigated retrospectively. For patients with a history of biopsy, the period after biopsy and the number of biopsy specimens also were analyzed. Among 159 cases of LST, 112 were positive and 47were negative for lifting signs. Biopsy history (p = 0.008), tumor size (p = 0.010), and location with respect to the fold (p = 0.022) were identified as factors affecting the non-lifting sign in multivariate analyses. In 75 LST cases with a history of biopsy, only the number of biopsies (p = 0.003) was identified as a factor affecting the non-lifting sign in multivariate analyses. For LST, lesions with larger size, being across the fold, and biopsy history were predictive factors for non-lifting signs. Reducing the number of biopsies would reduce the occurrence of non-lifting signs when biopsy is necessary. The impact of the interval after the biopsy on the non-lifting sign will require further study.