44.20 Survival Outcome Profile for Appendiceal Neuroendocrine Tumors

Posted on January 26, 2017

T. Oyasiji1, C. Onyemkpa2, T. Oyasiji1,2  1Wayne State University,Oncology,Detroit, MI, USA 2Michigan State University,Surgery,Lansing, MI, USA

Introduction:
Appendiceal neuroendocrine tumors are reported to have better survival outcome profile compared to appendiceal carcinomas. Different pathologic classification and staging methods have evolved over the past 5 years. Much more still needs to be established with regards to biology and survival outcome of these tumors. We sought to define the survival outcome profile for appendiceal neuroendocrine tumors based on established histologic subtypes and AJCC (7th edition) staging classification. We also defined the predictors of survival for these tumors.

Methods:
A retrospective review of all appendiceal neuroendocrine tumors diagnosed between 2010 and 2013 was done, using the SEER national database. For the analysis of survival outcomes, 3 groups were defined based on the histologic subtypes- I (enterochromaffin cell carcinoid, carcinoid tumor NOS), II (goblet cell carcinoids, adenocarcinoid, atypical carcinoid) and III (neuroendocrine carcinoma, mixed adenoneuroendocrine carcinoma). We also analyzed survival outcome based on AJCC (7th edition) staging classification.

Results:
A total of 1222 cases were identified- I (386), II (439) and III (397). AJCC stages were documented for 973 cases (79.6%). 57 % were females and 97% were treated with surgery. Mean age at diagnosis was 50.3 years. There was statistically significant difference in OS among the three groups defined based on histologic subtypes, with group I posting the best survival profile. Significant difference in OS was also noticed among the AJCC stages, with earlier stages recording better OS. On multivariate analysis, age at diagnosis and AJCC stage were independent predictors of overall survival.

Conclusion:

This data demonstrates correlation between survival outcome and biology of appendiceal neuroendocrine tumors. Both pathologic classification ( histologic subtypes) and AJCC TNM classification reliably correlate biology with overall survival.