Predicting resectability of primary tumor and mesenteric lymph-node masses in patients with small-intestine neuroendocrine tumors.

BACKGROUND

Vascular infiltration may jeopardize resection of the primary tumor and mesenteric metastatic masses in small-intestine neuroendocrine tumors (SI-NETs). However, other factors may play a role in predicting resectability.

METHODS

After computed tomography (CT) scan, three radiological parameters were considered: (1) degree of superior mesenteric artery involvement (SMA) according to a previous classification (2) degree of superior mesenteric venous involvement (SMV) as either absent, peripheral or proximal (3) presence or not of mesenteric fibrosis retraction (MF). Pre-surgical parameters were matched to surgical outcome.

RESULTS

Forty-nine consecutive patients were submitted to laparotomy. Of them, 37 had complete primary tumor and mesenteric masses resection. SMA (p = 0.001), SMV (p = 0.008), metastasis site (p = 0.001) and MF (p < 0.001) were all significantly associated with the likelihood to receive resection at univariate analysis. All the five patients with infiltration of SMV proximal to middle colic vein were unresectable. At multivariable analysis excluding SMA stage, the absence of MF (HR 13.1, I.C. 1.44-119; p = 0.002) was the only factor associated with the likelihood to receive primary tumor and mesentery radical surgery.

CONCLUSIONS

SMA stage 3-up and/or signs of MF, as well as infiltration of SMV proximal to middle colic vein at CT scan are predictive of operative failure in patients with SI-NETs. The assessment of such factors should be always considered in the decision-making process of such patients especially in those with asymptomatic disease with synchronous unresectable liver metastases.