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Appendiceal neuroendocrine tumours, when to operate?
Imogen Watt1, Luke Henry1, Jamish Gandhi1
1Auckland City Hospital, Auckland, New Zealand.
Introduction:
Appendix neuroendocrine tumours (ANETs) carry variable risk depending on histopathological risk factors. Completion right hemicolectomy (RH) is recommended for tumours over 2 cm, with those under 1 cm considered cured by appendectomy. Evidence for RH in ANETs between 1 and 2 cm is unclear.
Aim:
To determine if a non-surgical approach is appropriate for patients with well-differentiated 1-2 cm ANETs, alongside reviewing outcomes for under 1 cm and over 2 cm tumours.
Methods:
A retrospective cohort study of all ANETs resected by index appendicectomy in Auckland between 1995 and 2012, using the New Zealand NETwork! registry.
Results:
Two hundred and four patients with ANETs met inclusion criteria; 157 under 1 cm (77%), 40 between 1 and 2 cm (20%), 7 over 2 cm (3.4%). RH was performed in 20 patients, seven in the under 1 cm cohort, 9 in the 1-2 cm cohort and 4 in the over 2 cm cohort. One patient with an over 2 cm ANET had subsequent RH histology demonstrating lymph node metastasis. Follow-up was radiological, median follow-up 62 months (range 2-204). Eight 1-2 cm ANETs had histological risk factors but did not undergo RH and had no evidence of recurrence or metastasis on follow-up. No patients died from their ANET.
Conclusion:
Patients' with ANETs under 2 cm did not exhibit metastases. Our data support RH in patients' with ANETs over 2 cm and a more conservative approach in those under 2 cm.
