Endoscopic resection of high risk colorectal carcinoma does not negatively affect patient outcomes

WASHINGTON — Patient outcomes are not negatively affected by the endoscopic resection of high-risk colorectal carcinomas followed by surgery, according to study findings presented at DDW 2015.

There are no histologic risk factors for lymph node metastases at baseline for about 25% of T1 colorectal carcinomas. These can be treated by endoscopic resection only, however, during colonoscopy, it is difficult to tell the difference between low-risk and high-risk invasive cancers, according to Anouk Overwater, MD, a gastroenterologist in the department of gastroenterology and hepatology at the University Medical Center Utrecht, Netherlands.

Overwater and colleagues conducted this study to determine the effect, if any, of endoscopic resection of high-risk T1 colorectal carcinomas followed by surgery on lymph node metastases or rate of recurrence compared to primary surgery.

“A T1 colorectal carcinoma without risk factors for lymph node metastases can be treated with endoscopic resection only,” Overwater said in her presentation. “If the polyp does contain risk factors for lymph node metastases, additional surgical resection is required.

“Since this risk estimation can only be made after the endoscopic resection based on the histologic features of the resected specimen, it is important to note that the endoscopic resection does not harm the patient. The risk of perforation and performing an incomplete resection are points of contention.”

Researchers identified 388 patients with high-risk T1 colorectal carcinomas who were treated with primary or secondary surgical resection at one of seven Dutch hospitals between 2000 and 2012. The patients were divided into two groups: those who had a primary surgical resection (n = 206) and those who had endoscopic resection with an additional surgical resection (n = 182). Those in the primary group were predominantly female and older.

Median follow-up was 50 months (range, 22.3-80.2) in the primary group and 56 months (range, 22.2-79.8) in the secondary group. Recurrence occurred in 5.9% of the overall population, which included 3 local recurrences and 20 distant metastases.

Polyps treated in the primary group tended to be larger, right-sided and had a flatter morphology. No difference was found between the two groups for lymph node metastases at baseline (9.7 in the primary group, 8.8 in the secondary group). The adjusted OR was 1.1 (95% CI, 0.5-2.5). There was also no difference in recurrence rate with 7.3% in the primary group and 4.4% in the secondary group (adjusted HR, 1.04; 95% CI, 0.3-3.2). The recurrence rates were 15.9/1,000 person-years in the primary group and 9.5/1,000 person-years in the secondary group (P = .233).

Additionally, between the primary group and secondary group, there was no difference in treatment-related mortality (1.5% vs.2.2%) and morbidity (21.8% vs. 29.1%).

“These findings justify an attempt to remove polyps suggestive of T1 colorectal carcinoma to prevent surgery of low-risk T1 colorectal carcinoma and polyps containing intra-mucosal carcinomas,” Overwater said. – by Anthony SanFilippo

For more information: Overwater A, et al. Abstract 101. Presented at: Digestive Disease Week; May 15-19, 2015; Washington.

Disclosure: Overwater reported no relevant financial disclosures. See the faculty disclosure index on the DDW website for a full list of disclosures.