Patients with neuroendocrine tumors (NETs) in the appendix typically have their appendix removed (appendectomy). Some patients also undergo a partial removal of the large intestine (hemicolectomy). However, there is a growing awareness that patients with small tumors (1–2 cm in size) and, in absence of certain risk factors, may not need this follow up surgery.

An international collaboration involving 40 hospitals from 15 different European countries set out to determine the malignant potential of appendiceal NETs of 1–2 cm in size. The collaboration included the Amsterdam Centre for Endocrine and Neuroendocrine Tumors (ACcENT) and was published in the leading medical journal The Lancet Oncology.

The results of the study showed that small tumors (1-2 cm in size) found in the appendix did not warrant an additional hemicolectomy, when other risk factors were absent. Overall survival was similar between patients with appendectomy and right-sided hemicolectomy. In addition, regional lymph node metastases of appendiceal NETs were found to be clinically irrelevant.

It is expected that this study will change clinical guidelines for hemicolectomy in cases involving small appendix NETs, improving best care practices and quality of life by saving patients an additional operation.

Read the paper here: https://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(22)00750-1/fulltext.

For more information contact Enes Kaçmaz.

Researchers involved at Amsterdam UMC:

Enes Kaçmaz

Els J M Nieveen van Dijkum