169. PROPENSITY SCORE MATCHING ANALYSIS OF THE EFFECT ON PROGNOSIS OF PROPHYLACTIC NECK DISSECTION FOR ESOPHAGEAL CANCER

Abstract

Abstract Background There is still no definite evidence regarding the prognostic effect of #104 prophylactic dissection. Materials and Methods: We conducted a retrospective study of patients who underwent esophagectomy regarding the prognostic effect of #104 prophylactic dissection by propensity score matching analysis. Between 2012/1 and 2020/12, 302 patients with esophageal malignant tumors underwent radical subtotal esophagectomy via the right thoracic approach at our hospital. The histological types were limited to squamous cell carcinoma, adenocarcinoma, and basal cell carcinoma, and clinical (c)T4b (TNM 7th edition), cM1, cervical esophageal cancer, salvage surgery cases, R1/2 cases, and cases with synchronous advanced multiple cancers were excluded. This resulted in the analysis of the 220 cases comparing between the 3-filed and 2-filed dissection groups. R version 4.1.2 was used for statistical analysis. The predicted probability of #104 dissection was calculated by logistic regression model. Propensity score matching was performed to match patients between 2 groups according to age, tumor location, preoperative treatment, postoperative pneumonia, pathological (p)T factor, and pN factor by nearest neighbor method within caliper. P < 0.05 was considered statistically significant. Results Both DSS and DFS were significantly better in the 2-filed dissection group. Baseline characteristics showed that the 3-filed dissection group had significantly more patients of tumor location Mt and Ut, more squamous cell carcinoma as the histologic type, and more cases with preoperative treatment. In the 3-field dissection group, operative time was significantly longer and the postoperative complications was increased such as recurrent nerve palsy and cervical lymphatic leakage. Pathologic results showed higher grades of pT and pN. Four patients in the 3-field dissection group had p104 metastasis, and only 1 of these survived without recurrence. On the other hand, 5 patients of the 2-field dissection group had #104 as the first recurrence site, and 3 of these had simultaneous distant metastasis. There was no significant difference in DSS and DFS between groups after propensity score matching (DSS p = 0.852, DFS p = 0.768). Conclusions This retrospective study did not confirm a prognostic benefit of prophylactic dissection of the #104 region. This will be elucidated by results of the ongoing RCT, JCOG2013 trial.