according to a recent study.
Since STSC was faster to apply than APC and results in lower cost and plastic waste (because of APC requiring an additional catheter), STSC was the preferred option.
“The reduction in recurrence rate with thermal margin treatment is arguably the most important development in endoscopic mucosal resection in the past 2 decades,” said lead author Douglas Rex, MD, AGAF, a distinguished professor emeritus at the Indiana University School of Medicine and director of endoscopy at Indiana University Hospitals, both in Indianapolis.
Dr. Douglas K. Rex
“Margin thermal therapy with STSC should now be standard treatment after piecemeal EMR in the colorectum,” he said. “Before applying STSC, the endoscopist must ensure that the entire lesion is resected down to the submucosa. Then STSC should be aggressively applied to 100% of the margin.”
The study was published in Clinical Gastroenterology and Hepatology .
Comparing Treatments
Dr. Rex and colleagues performed a randomized three-arm trial in nine U.S. centers, comparing STSC with APC and no margin treatment in patients undergoing colorectal EMR of nonpedunculated lesions of 15 mm or greater.
All lesions underwent conventional injection and snare resection EMR using electrocautery, but the endoscopist chose the injection fluid and snare type and size. Areas with residual polyp that weren’t removable by snare resection because of flat shape or fibrosis were removed by hot or cold avulsion. After that, patients were randomized to one of the three arms.
Patients were scheduled for a follow-up appointment six months after the initial EMR. Any visible recurrence was resected using methods at the discretion of the endoscopist, and if no visible recurrence was present, EMR site biopsies were recommended.
Among 384 patients with 414 lesions, 308 patients with 328 lesions completed at least one follow-up appointment. The median interval to the first follow-up was 6.4 months, ranging from 2 to 37 months. The primary endpoint was the presence of recurrent or residual polyp at first follow-up.
The median polyp size was 25 mm, and 65 of the 414 polyps (15.7%) were 15-19 mm in size. Overall, 14.8% of lesions were resected en bloc, with no difference between the study arms.
The proportion of lesions with residual polyp at first follow-up was 4.6% with STSC, 9.3% with APC, and 21.4% among control subjects with no margin treatment.
The odds of having a residual polyp at first follow-up were lower for STSC and APC when compared with control subjects (odds ratio [OR] of 0.182 and 0.341, or P = .001 and P = .01, respectively). There wasn’t a significant difference in the odds of recurrence between STSC and APC (OR, 1.874).
In 259 lesions in 248 patients that were 20 mm or greater, the recurrence rates at first follow-up were 5.9% for STSC, 10.1% for APC, and 25.9% for the control group. In these lesions, STSC and APC remained associated with a lower risk of recurrence versus the control (OR, 0.18 and 0.323, respectively). The difference in recurrence rates between STSC and APC wasn’t significant.
Even still, STSC took less time to apply than APC, with a median time of 3.35 minutes vs 4.08 minutes.
The rates of adverse events were low, with no difference between the three arms. There were no immediate or delayed perforations in any arm, and the overall occurrence of delayed bleeding was low at 3.6%.
“I think STSC won the trial because it was numerically (though not statistically) superior to APC, was faster to apply, and using STSC results in lower cost and less plastic compared to APC,” Dr. Rex said.
