[Clinicopathological characteristics and prognosis analysis of colorectal neuroendocrine neoplasms based on the data from domestic six medical centers].

Objective: To investigate the clinicopathological characteristics and their relationship with prognosis of colorectal neuroendocrine neoplasms (NEN).
Methods: Medical records of 329 patients with colorectal NEN between June 2001 and July 2016 from 6 large scale centers in China were reviewed to investigate the clinicopathological characteristics and their relationship with prognosis of colorectal NEN.
Results: (1) Colonic NEN: A total of 41 patients with colonic NEN were enrolled from The First Affiliated Hospital of Sun Yat-sen University(n=11), Sun Yat-sen University Cancer Center (n=15), Guangdong General Hospital (n=10), Sun Yet-san Memorial Hospital of Sun Yat-sen University (n=3) and Fudan University Shanghai Cancer Center (n=2). 41 cases, including 20 males and 21 females with a mean age of (58.7±4.7) years. Twenty-three colonic NEN originated in hindgut (23/41, 56.1%), and 20 patients were stage IIII( (20/41, 48.8%). Nine cases (22.0%) were neuroendocrine tumor(NET), 25(61.0%) were neuroendocrine carcinoma (NEC) and 7(17.1%) were mixed adenoendocrine carcinoma (MANEC). Six cases (14.6%) were G1 grade, 3(7.3%) were G2 grade and 32(78.1%) were G3 grade. Ulcerative or cauliflower-like tumors were the most common appearance under endoscopy (both 9/41, 22.0%). Thirty-three patients (80.5%) underwent surgery. During follow-up, 19 cases died and the 3-year survival rate was 46.1%. Multivariate analysis revealed that stage IIII( was an independent risk factor of poor prognosis (HR=3.871, 95%CI:1.342 to 11.167, P=0.012) in colonic NEN patients. (2) Rectal NEN: A total of 288 patients with rectal NEN were enrolled from The First Affiliated Hospital of Sun Yat-sen University(n=130), Nanfang Hospital of Southern Medical University (n=115) and Fudan University Shanghai Cancer Center (n=43). Two hundred and eighty-eight cases, including 181 males and 107 females with a mean age of (47.7±1.5) years. One hundred and ninety-seven patients were stage I((197/288, 68.4%). Of 288 rectal NEN cases, 267(92.7%) were NET, 20(7.0%) were NEC and 1(0.3%) was MANEC; 214(74.3%) were G1 grade, 53(18.4%) were G2 grade and 21(7.3%) were G3 grade. Submucosal tumor was the most common appearance under endoscopy(164/288, 56.9%). Most of the rectal NET G1/G2 tumors were submucosal(146/214, 68.2%;18/53,34.0% respectively) while most of G3 tumors were cauliflower-like (14/21,66.7%). A total of 175 patients (60.8%) underwent endoscopic therapy, while 96 patients(33.3%) underwent surgery. During follow-up, 12 cases died and 3-year survival rate was 94.0%. Multivariate analysis revealed that poor differentiation as NEC or MANEC(HR=8.919, 95% CI:1.911 to 41.637, P=0.005) and stage III( to IIII((HR=10.304, 95%CI:1.772 to 59.916, P=0.009) were independent risk factors of poor prognosis in rectal NEN patients.
Conclusions: The clinicopathological manifestations of rectal NEN and colonic NEN are quite different. Rectal NEN are more common with better differentiation and has better prognosis than colonic NEN.