Appendiceal Goblet Cell Carcinoids: Management Considerations from a Reference Peritoneal Tumour Service Centre and ENETS Centre of Excellence.

Background: Appendix goblet cell carcinoids are known to share histological features of adenocarcinoma and neuroendocrine tumours. Due to their low incidence, quality evidence is lacking for the management of these patients.

Methods: We performed a single-centre retrospective study of patients with a confirmed diagnosis of appendiceal goblet cell carcinoid (GCC; 1996-2014). Patients were divided into curative intent (CI) and palliative intent (PI) cohorts. Our primary end point was overall survival (OS).

Results: Seventy-four patients were eligible; 76% were treated with CI [surgery only (36%), cytoreductive surgery (CRS) and hyperthermic intra-peritoneal chemotherapy (HIPEC; 36%), adjuvant chemotherapy (20%) and a combination of CRS and HIPEC followed by adjuvant chemotherapy (9%)], and 23% had advanced-stage disease amenable to palliative treatment (chemotherapy or supportive care) only. Completion right hemicolectomy, performed in 64% of the CI cohort, did not impact on the relapse rate or disease-free survival. FOLFOX chemotherapy was used in both the adjuvant and palliative settings; safety was as expected, and we observed a high rate (60%) of disease control in the palliative cohort. The estimated median OS (all patients), disease-free survival (CI patients) and progression-free survival (PI patients) were 52.1 (95% CI 29.4-90.3), 75.9 (26.6-not reached) and 5.3 (0.6-5.7) months, respectively. Age and stage were independent factors associated with OS in the multivariable analysis. Tang classification showed a trend for impact on OS. No benefit from specific adjuvant approach was identified; however, selection bias for treatment approach was observed.

Conclusion: Prospective trials are needed to define optimal approaches in GCC. All GCC patients should be managed by specialized centres due to their esoteric behaviour; we provide management considerations based on our experience and conclusions.