Should a colorectal mass be biopsied before resection?

From the Guidelines

A colorectal mass should not be biopsied before resection in all cases, but rather the decision to biopsy should be based on individual patient factors and polyp features.

Key Considerations

• The management of malignant polyps aims to reduce over- and underuse of surgery while minimizing the chances of recurrent or metastatic cancer 1.
• In nonpedunculated lesions with features of deep submucosal invasion, endoscopic biopsy is followed by surgical resection 1.
• The decision to recommend adjuvant surgery is based on polyp shape, whether there was en bloc resection and adequate histologic assessment, the presence or absence of unfavorable histologic features, the patient’s risk for surgical mortality and morbidity, and patient preferences 1.
• Pathology reports of malignant colon polyps should contain specific mention of prognostically significant histologic features, including the distance between the invasive tumor and the cauterized biopsy margin, tumor differentiation, and the status of lymphatic or vascular invasion 1.
• In the absence of unfavorable features, the polypectomy is considered curative, and additional biopsy examinations may not be necessary 1.
• For patients with a high risk of surgical mortality or morbidity, a decision to forgo surgery may be appropriate even when an unfavorable histologic feature is present 1.

Biopsy and Resection

• Endoscopic biopsy is recommended in cases where the polyp has features of deep submucosal invasion or when the patient's comorbidities and life expectancy suggest a high risk of surgical complications 1.
• Surgical resection is generally advisable in healthy patients with unfavorable histologic criteria, while in poor surgical candidates, surgery should be avoided even if unfavorable features are present 1.

From the Research

Biopsy Reliability

• The reliability of biopsies in reflecting the true histopathology of large colorectal polyps is questionable, with a study finding that biopsies did not provide a correct dysplastic grade in 39% of cases compared to final pathology after complete resection 2.
• Another study found that pre-resection biopsy (PRB) histology was upstaged in 26.1%, downstaged in 13.8%, and unchanged in 60.1% after endoscopic mucosal resection (EMR) 3.
• The sensitivity of PRB was 77.2% for low-grade dysplasia and 21.2% for high-grade dysplasia, suggesting that PRB may not reliably detect advanced histology 3.

Clinical Value of Biopsies

• The clinical value of forceps biopsies in lesions suitable for endoscopic resection is questionable, considering that endoscopic resection of lesions containing superficial cancer is plausible 2.
• A study found that routine PRB of large nonpedunculated colorectal polyps did not reliably detect advanced histology and may have affected EMR complexity 3.
• Another study suggested that local resection should be performed to confirm diagnosis, and for highly suspected malignant tumors, a radical transabdominal surgery is recommended even without biopsy-proven malignancy 4.

Management of Colorectal Lesions

• A study found that a large proportion of biopsy-proven colorectal high-grade intraepithelial neoplasia lesions are invasive cancers, and therefore, local resection should be performed to confirm diagnosis 4.
• Preoperative colonoscopy has been recommended to identify synchronous polyps and/or cancers, which may alter surgical therapy or follow-up 5.
• Surgical treatment and/or follow-up were altered in 33% of patients as a consequence of the colonoscopic evaluation, suggesting that colonoscopy prior to surgery for colorectal carcinoma is highly desirable and may potentially improve long-term survival 5.