Risk Factors Of Lymph Node Metastasis And Prognosis In Colorectal Neuroendocrine Neoplasms

Objective:The aim of our study is to analyze the factors affecting the lymph node metastasis and prognosis of the colorectal neuroendocrine tumors(NENs).Methods:A retrospective analysis was conducted to collect the clinical data of 135 patients with colorectal NENs from January 2000 to December 2018 which including clinical manifestations,pathological results,treatment methods and etc.The follow-up was regularly taken to observe the recurrence and metastasis of tumors and survival of patients.Statistical analysis of the results was performed to find the clinical and pathological features of colorectal NENs,risk factors of lymph node metastasis and survival outcomes.Results:Among 135 cases,there were 113 rectal NENs,18 colonic NENs and 4 appendiceal NENs.Endoscopic mucosal resection(EMR)was performed in 18 patients,endoscopic submucosal dissection(ESD)was performed in 35 patients,trans-anal excision was performed in 12 patients,radical resection was performed in 41 patients,palliative resections were performed in 11 patients and the rest 18 patients were treated by chemo-therapy.There were 57(42.2%)patients with lymph node metastasis and the independent risk factor for lymph node metastasis in the multivariable analysis was tumor diameter≥2cm(p=0.040)and tumor grade G3(p=0.001).A total of 119 patients were successfully followed up for 1 to 190 months,the 5-year OS was 71.70%,and 5-year PFS was 69.0%.The multivariate analysis for survival outcomes showed that age≥65 years(PFS:p=0.002;OS<0.001)and lymph node metastasis(PFS:p=0.018;OS:0.025)were independent risk factors affecting both 5-year PFS and 5-year OS in colorectal NENs.The tumor in the colon(p=0.022),CgA moderately positive(++)(p=0.010)and strongly positive(+++)(p=0.007)were independent risk factors for 5-year PFS in colorectal NENs.Conclusions:The clinical and pathological characteristics of rectal and colonic NENs are different.The incidence of rectal NENs was higher than colonic NENs and have a better prognosis.Tumor diameter and tumor grade are independent risk factors for lymph node metastasis in colorectal NENs.Age,tumor location,lymph node status and positive level of neuroendocrine markers CgA are independent risk factors that affect the prognosis of colorectal NENs.