In this study, doctors from Japan determined the criteria for a conservative approach to patients with locally excised early invasive carcinoma.
The team analyzed 292 early invasive tumors for potential parameters for nodal involvement.
The team divided the tumors into 3 groups:
- Group A = local resection followed by laparotomy (n=80)
- Group B = local resection only (n=41)
- Group C = primarily laparotomy (n=171).
The team examined the status of the endoscopic resection margin for the risk for intramural residual tumor.
The doctors found that unfavorable tumor grade, definite vascular invasion, and tumor budding discriminated the risk for nodal involvement in groups A to C.
They calculated that the nodal involvement rate was 0.7%, 21%, and 36% in the no-risk, single-risk, and multiple-risks group, respectively.
The team assigned 32 patients from group B into the no-risk group. A further 9 patients were assigned to the single-risk group.
When the team considered quantitative risk parameters for submucosal invasion, nodal involvement was not observed in the redefined no-risk group. This group accounted for approximately 25% of patients from groups A and C.
The team found that an insufficiency of endoscopic resection could be evaluated most precisely based on the coagulation-involving tumor, rather than the 1-mm rule for the resection margin.
Dr Hideki Ueno and colleagues concluded, "Provided that the criterion of sufficient excision is satisfied, the absence of an unfavorable tumor grade, vascular invasion, tumor budding, and extensive submucosal invasion would be the strict criteria for a wait-and-see policy".