Is adjuvant chemotherapy beneficial for stage II-III goblet cell tumors of the appendix?

Abstract

796 Background: Goblet cell tumors (GCT) of the appendix are very rare tumors constituting 2.5%-5% of all primary appendiceal neoplasms. Role of adjuvant chemotherapy (AC) is not established for GCT. This study aims to evaluate the impact of AC in stage II-III appendiceal GCT. Methods: Patients with pathological stage II and III GCT who underwent surgical resection between 2006 and 2015 were identified from the National Cancer Database (NCDB) using ICD-O-3 morphology and topography codes: 8243/3, 8245/3 and C18.1. Patients treated with neoadjuvant systemic and/or radiation therapy and adjuvant radiation were excluded. Univariate and multivariable analyses were conducted, and Kaplan-Meier Curves were used to compare overall survival (OS) based on treatment received with Log-rank test. Results: A total of 1,046 patients were identified. 53.7% males and 89.0% Caucasian; median age 56 (range, 20-90) years. Distribution across pathological stages II-III was 83.6% (N = 874) and 16.4% (N = 172) consecutively. 8.3% (N = 73) of stage II and 50.6% (N = 87) of stage III patients received AC. In the total cohort, AC was not associated with better OS compared to no AC in univariate analysis (HR 1.84; 95% CI 1.26-2.67; p = 0.001) or multivariable analysis (HR 0.94; 95% CI 0.57-1.52; p = 0.790). For stage II patients, AC was not associated with better OS in univariate (HR 1.24; 95% CI 0.60-2.57; p = 0.562) or multivariable analyses (HR 1.67; 95% CI 0.76-3.64; p = 0.199). Similarly, in stage III patients, AC was not associated with better OS in univariate (HR 0.78; 95% CI 0.48-1.29; p = 0.340) or multivariable analyses (HR 0.55; 95% CI 0.28-1.04; p = 0.067). In the entire cohort 5-year OS for patients that received AC was 83.9% (80.3%, 86.9%) versus 70.7% (60.9%, 78.5%) (p = 0.001) with no AC. For stage II patients, 5-year OS was 77.3% with AC vs. 87.7% with no AC (p = 0.562). For stage III patients, 5-year OS was 64.8% with AC vs. 54.4% with no AC (p = 0.340). Conclusions: AC was not associated with improved 5-year OS in patients with pathological stage II and III GCT compared to no AC.