Prognostic significance of lymph node metastases in patients with high-grade appendiceal cancer

Abstract

Background: In treating high-grade appendiceal cancer, appropriate patient selection for cytoreductive surgery and heated intraperitoneal chemotherapy (CRS/HIPEC) is essential. The effect of lymph node (LN) status on survival is not clear. We hypothesize that LN metastases negatively affect long-term survival.

Methods: Retrospective analysis of peritoneal mucinous carcinomatosis (PMCA) patients from a prospective database was conducted. Using Kaplan-Meier survival curves and Cox proportional hazards ratio analysis, the effect of LN status, completeness of cytoreduction (CC), and peritoneal cancer index (PCI) was studied.

Results: Of 134 patients with appendiceal cancer who underwent CRS/HIPEC, 77 (57%) had PMCA. Mean follow-up was 22 (range, 3-90) months. Overall survival (OS) was 88, 56, and 40% for 1, 3, and 5-year, respectively. Thirty-four patients (44%) had LN metastases, 23 of whom (68%) had CC, whereas in LN negative patients 35 of 43 (81%) had CC (p = 0.191). PCI ≥ 20 was seen in 23 of 34 patients (68%) with LN metastases and 29 of 43 (67%) without metastases (p = 0.191). Five-year OS for patients with LN metastases was 11% compared with 76% for LN negative (p < 0.001). Among patients with complete cytoreduction, 5-year OS for LN positive vs. negative was 21 and 73%, respectively (p = 0.002). On multivariate regression analysis of LN status, CC score and PCI, the following hazard ratios were obtained: 3.4 (95% confidence interval (CI), 1.3-9.0), 2.6 (95% CI, 1.03-6.7), and 2.8 (95% CI, 0.8-10.4), respectively.

Conclusions: Patient selection for CRS/HIPEC should take into consideration LN status, but it should not be a contraindication if preoperative evaluation revealed a high likelihood of complete cytoreduction.