Is surgery the best treatment for sporadic small (≤2 cm) non-functioning pancreatic neuroendocrine tumours? A single centre experience

Backgound There is currently there is substantial controversy regarding the best management of non-functioning pancreatic neuroendocrine tumours ≤2 cm. Methods Retrospective study involving 102 surgically treated patients affected by non-functioning pancreatic neuroendocrine tumours. Patients having small tumours (≤2 cm) (Group A) and those having large tumours (>2 cm) (Group B) were compared regarding demographics, clinical and pathological factors with the aim of evaluating the risk of malignancy and survival times. Results The small tumours were T3-4 in 11% and G2-3 in 36.6% of cases; lymph node and distant metastases were present in 31% and 8% of the cases, respectively. When small and large tumours were compared, significant differences were found in relation to the presence of symptoms (P = 0.012), tumour status (P > 0.001), grading (P > 0.001) and years lost due to disability (P = 0.002). Multivariate analysis of the factors predicting malignancy and survival times showed that tumour size was related only to grading (P < 0.001). The years of life lost and disability adjusted life years were influenced by age at of diagnosis, the presence of symptoms and years lost due to disability only by grading. Conclusions Tumour size alone did not seem to be reliable in predicting malignancy because, first, small tumours (≤2 cm) could present lymph node or distant metastases, and could be G2-3 in a non-negligible percentage of cases and second, their risk of malignancy and survival time are similar to large tumours. Additional parameters have to be considered in order to establish the proper management of small tumours, such as age at diagnosis, presence of symptoms and grading.