Pedunculated Morphology of T1 Colorectal Tumors Associates With Reduced Risk of Adverse Outcome

Abstract

In a retrospective study of patients with T1CRC, we found pedunculated morphology to be associated independently with a decreased risk of adverse outcome in a T1CRC population at high risk of adverse outcome. Incorporating morphologic features of tumors in risk assessment could help predict outcomes of patients with T1CRC and help identify the best candidates for surgery.

Are Morphologic and Histologic Risk Factors for T1 Colorectal Cancer Friends or Enemies?

“…In a retrospective series of 1656 T1 CRCs, the risk of both metastasis and residual cancer were substantially and independently lower in pedunculated vs nonpedunculated T1 CRCs after adjustment for all the possible histologic and endoscopic risk factors. 8 The dramatic 40% decrease in the risk of an adverse outcome simply driven by a pedunculated morphology gives plausibility to the unproven postulate that the stalk may act as a submucosal buffer, preventing the distant spread of metastatic cells. The large magnitude of the enrolled population and the consistency of the main results at different levels of multivariate analysis add strength to the study results.…”

“…The large magnitude of the enrolled population and the consistency of the main results at different levels of multivariate analysis add strength to the study results. 8 Before incorporating morphology into T1 CRC management, further clarification on its interaction with histologic risk factors and surgery-related risks must be addressed. First, morphology does not exclude or marginalize histology at any level.…”

“…The 5-fold difference in risk of an adverse outcome between (histologically) low-and high-risk T1 CRC remains dominant over the less than 2-fold difference between pedunculated and nonpedunculated T1 CRC. 8 Second, morphology seems to add little if any to the management of nonpedunculated T1 CRC when R0 resection is achieved. When excluding cases with incomplete information, more than 90% of the sessile/flat T1 CRCs already are high-risk because of unfavorable histology or R1/RX resection.…”

“…When excluding cases with incomplete information, more than 90% of the sessile/flat T1 CRCs already are high-risk because of unfavorable histology or R1/RX resection. 8 However, the very favorable outcome of the few low-risk nonpedunculated low-risk T1 CRCs with R0 resection underlines the potential contribution of new advanced endoscopic techniques, such as endoscopic submucosal dissection, able to achieve an R0 resection of even large sessile/flat lesions, especially when located in the rectum. 9 Third, there is no role for surgery for low-risk pedunculated polyps.…”

“…The crude risk of an adverse outcome is only 14% for pedunculated when matched with the 21% risk for nonpedunculated T1 CRCs. 8 This is clinically relevant when compared with the risk of surgery-related morbidity and mortality that may be predicted accurately by clinical scores. In addition, these estimates represent a slight overestimation, and not the opposite, for a postendoscopic setting, because patients with a primary curative surgery were included.…”