A total of 6626 patients with CRC who were initially referred for endoscopic polypectomy were enrolled from the Surveillance Epidemiology and End Results Database.
Most enrolled patients (6557/6626, 99.0%) were at T0-T1 stage (American Joint Committee on Cancer staging system). Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were used to reduce selection bias, which resulted in balanced groups of patients with and without lymphadenectomy, with no difference in CSS ( = .99 and .074, respectively). In the subgroup analysis, insufficient lymphadenectomy (lymph node yield [LNY] < 12) was associated with poor CSS compared with no lymphadenectomy. The multivariate analysis identified adequate lymphadenectomy with an LNY ≥ 12 as an independent favorable prognostic factor. However, nearly half of the patients (59/127, 46.5%) referred for lymph node resection did not undergo adequate lymphadenectomy.
The prognosis of CSS cannot be improved by lymphadenectomy for most patients (T0-T1) who are referred for endoscopic therapy because of the low rate of lymph node metastasis. Nonetheless, adequate lymphadenectomy should be performed instead of diagnostic lymph node resection if lymph node involvement is suspected.