Surgical resection increases overall survival and recurrence-free survival in patients with high-risk T1 colorectal cancer (CRC); however, endoscopic resection with subsequent intensive surveillance may be a less invasive alternative for a specific subgroup of high-risk T1 CRC patients, according to study findings published in Gastrointestinal Endoscopy.
Of 803 total patients, researchers analyzed clinical outcomes of 547 patients with high-risk T1 CRC, who underwent either surgical (n=466) or localized endoscopic (n=81) resections at the National Cancer Center in Korea between January 2001 and December 2014. Researchers excluded the remaining 256 patients due to treatment with preoperative chemoradiotherapy.
The researchers also compared the rates of distant recurrence-free survival (DRFS) and overall survival (OS) between the surgical and endoscopic groups.
Patients were subdivided into favorable and unfavorable populations depending on independent risk factors suggestive of lymph node metastasis. The favorable subpopulation exhibited a combination of the following 5 risk factors:
- positive resection margin only or unconditional for margin status;
- deep submucosal invasion only;
- budding only;
- no background adenoma only; and
- budding plus no background adenoma.
The surgical group demonstrated higher rates of DRFS and OS compared with the endoscopic group (hazard ratio [HR], 0.20; 95% CI, 0.06-0.61; P =.0045 vs HR, 0.41; 95% CI, 0.25-0.70; P =.0010, respectively).
However, when comparing surgical and endoscopic resection groups in the favorable subpopulation only, no significant difference existed in DRFS and OS between the 2 groups (HR, 0.26; 95% CI, 0.02-4.19; P =.3431 vs HR, 0.58; 95% CI, 0.27-1.23; P =.1534, respectively).
“Although it is still standard that surgery should be recommended for the patients with high-risk T1 CRC, intensive surveillance without additional surgery may be another option in selected patients following endoscopic resection of high-risk T1 CRC,” the study authors said.
Study limitations include the retrospective, single-center design; the presence of a selection bias as evidenced by poorer histology in the surgical resection group compared with the localized resection group; and problems with conducting a fully randomized study due to ethical considerations.
Ha RK, Park B, Han KS, et al. Subpopulation analysis of survival in high-risk T1 colorectal cancer: surgery versus endoscopic resection only. Gastrointest Endosc. Published online July 18, 2022. doi:10.1016/j.gie.2022.07.016