OBJECTIVETo investigate risk factors associated with lymph node metastasis and prognosis of rectal neuroendocrine tumor (NET).

METHODSClinicopathological data of 69 patients with rectal NET in our department from April 2003 to October 2011 were retrospectively analyzed. Associations of clinicopathological factors with lymph node metastasis and prognosis were examined using univariate and multivariate analysis.

RESULTSOf the 69 patients, 9 cases had lymph node metastasis. The lymph node metastasis was significantly associated with tumor size, T stage and G grade by univariate analysis. Multivariate analysis showed that T stage was the only risk factor associated with lymph node metastasis. The overall 5-year survival rate was 90.3%. Prognosis of rectal NET was significantly associated with tumor size, T stage, N stage, M stage, TNM stage and G grade by univariate analysis. Multivariate analysis showed that M stage was significantly associated with long-term survival in rectal NET patients (P=0.000, HR=2.285, 95%CI:1.484~3.518). There was no significant difference in patients with stage I between local and radical resection, while there were significant differences in those with stage II or higher between the two operations (P=0.046).

CONCLUSIONT stage is associated with lymph node metastasis and both TNM stage and M stage can affect the prognosis of patients with NET, which may be used as potential predictive factors for rectal NET. Local resection should be recommended for patients with stage I and radical resection should be recommended for patients with stage II or higher.