The most prevalent small bowel cancers are well-differentiated, low-grade neuroendocrine tumors (NETs). These tumors tend to metastasize despite having slow-growing growth patterns and grades typically; in fact, at presentation, about 50% of patients have nodal metastases, and 30% have distant metastases, even though they may have a longer survival time. The ideal nodal yield in small-bowel resections was poorly described in the literature, and there was the ongoing discussion over the clinical importance of nodal metastases and the lymph node ratio (LNR) at this location.
For a study, researchers sought to investigate and evaluate information on the impact of nodal status, the effectiveness of lymphadenectomy, and LNR on the prognosis of small bowel NETs using specified endpoints (progression-free survival, recurrence-free survival, and overall survival). LNR was proven to be a prognostically relevant characteristic. Some surgical studies have shown that prolonged regional mesenteric lymphadenectomy, along with primary tumor resection, is related to better patient survival.
The study explored and evaluated the novel characteristic of mesenteric tumor deposits (MTDs; neoplastic deposits discovered in the mesenteric perivisceral adipose tissue that was not LN related), which appeared to be a stronger prognostic predictor in small-bowel NETs than nodal metastases. More tumor deposits were associated with a higher risk of disease-specific mortality, and MTDs appear to be associated with peritoneal carcinomatosis.