OBJECTIVETo investigate the principle of management of colorectal high-grade intraepithelial neoplasia(HGIN) based on colonoscopic biopsy.

METHODSPatients diagnosed as colorectal HGIN based on colonoscopic biopsy in the Changhai Hospital from January 2002 to December 2009 were enrolled in the study. The clinical data of all the patients were collected and analyzed. According to the subsequent operation, cases were divided into local complete resection group and radical operation group. The discrepancy between the biopsy diagnosis and postoperative diagnosis was investigated.

RESULTSOf the 203 biopsy-based colorectal HGIN lesions, 156 underwent radical resection, while 47 received local complete resection. Univariate analyses indicated that tumors located in colon(P=0.02), tumors with sessile growth (P=0.00) and large tumors (P=0.00) were more likely to be treated with radical resection. Postoperative diagnosis revealed that 163 cases(80.3%) were invasive cancers, while the other 40 cases(19.7%) were HGIN lesions. Of the 156 cases resected radically, 140 cases were invasive cancers, 16 cases were diagnosed as HGIN. Of the 47 cases who underwent local complete resection, 24 cases were confirmed as HGIN but the other 23 cases were invasive cancers, in which 15 cases received subsequent radical operation.

CONCLUSIONSA large proportion of biopsy-proven colorectal HGIN lesions are invasive cancers. Therefore, local resection should be performed to confirm diagnosis. For highly suspected malignant tumors which can not be removed completely by local resection, if anus can be reserved, a radical transabdominal surgery is recommended even without biopsy-proven malignancy in order to avoid treatment delay.