Endoscopic Resection of T1 CRC Before Radical Surgery Is Not a Risk Factor for Cancer Recurrence

colon cancer cell
colon cancer cell
Researchers investigated whether endoscopic resection of T1 CRC before secondary surgery adversely affects recurrence risk.

Endoscopic resection before radical surgery in patients with T1 colorectal cancer (CRC) with high-risk histologic features does not unfavorably affect long-term recurrence-free survival (RFS), according to a study in Gastrointestinal Endoscopy.

Researchers sought to determine whether endoscopic resection of T1 CRC before surgery (secondary surgery) adversely affects long-term RFS when compared against surgery without prior endoscopic resection (primary surgery). They reviewed the medical records of patients who underwent surgery for T1 CRC with high-risk histologic features between 2011 and 2016 at a tertiary referral hospital in Korea.

The study included a total of 852 patients (mean age, 60.1 ± 10.5 years; 61% male). Of this cohort, 388 patients had primary surgery and 464 underwent secondary surgery. During a median follow-up of 57.0 months (interquartile range, 41.0-63.0 months), cancer recurred in 18 of 852 (2.1%) patients, and the mean interval from surgery to recurrence was 25.6 ± 17.9 months. Cancer recurred in 11 of 388 (2.8%) patients in the primary surgery group and in 7 of 464 (1.5%) patients in the secondary surgery group (P = .180).

There was no significant difference in the RFS rates between the primary and secondary surgery groups (P =.194). The 1-, 3-, 5-, and 7-year RFS rates were 99.7%, 97.6%, 97.0%, and 97.0% in the primary group and 99.6%, 98.9%, 98.5%, and 96.1% in the secondary.

Multivariable Cox proportional regression analysis showed that baseline serum carcinoembryonic antigen level was an independent risk factor for cancer recurrence (hazard ratio, 1.464; 95% confidence interval, 1.242-1.725; P < .001), but prior endoscopic resection of T1 CRC was not (P = .201).

“We found no difference in cancer recurrence after surgery for T1 CRC between the primary and secondary surgery groups,” the researchers stated. “The RFS rates did not differ between the groups, even in the subanalyses by nodal stage and number of high-risk histologic features.”

The study has a few limitations, according to the investigators. It was performed at a single tertiary center that specialized in therapeutic endoscopy, and thus the generalizability of the findings will need to be evaluated in further multicenter studies. In addition, the study authors did not investigate the total number of patients who underwent endoscopic resection of T1 CRC and how many underwent endoscopic mucosal resection, ESD, or hybrid ESD.

“Prior endoscopic resection of T1 CRC with high-risk histological features did not unfavorably affect the long-term RFS after secondary surgery,” the researchers concluded. “Therefore, endoscopic resection of suspected T1 CRC with superficial submucosal invasion can be attempted without concerns about worsening the cancer-related prognosis to avoid unnecessary surgery-related morbidity and mortality.”


Oh EH, Kim N, Hwang SW, et al. Comparison of long-term recurrence-free survival between primary surgery and endoscopic resection followed by secondary surgery in T1 colorectal cancer. Gastrointest Endosc. Published online February 19, 2021. doi: 10.1016/j.gie.2021.02.021