Case Control Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Aug 15, 2020; 12(8): 893-902
Published online Aug 15, 2020. doi: 10.4251/wjgo.v12.i8.893
Clinical and pathological characteristics and prognosis of 132 cases of rectal neuroendocrine tumors
Yong-Jun Yu, Yu-Wei Li, Yang Shi, Zhao Zhang, Min-Ying Zheng, Shi-Wu Zhang
Yong-Jun Yu, Yu-Wei Li, Yang Shi, Zhao Zhang, Department of Colorectal Surgery, Tianjin Union Medical Center, Tianjin 300121, China
Min-Ying Zheng, Shi-Wu Zhang, Department of Pathology, Tianjin Union Medical Center, Tianjin 300121, China
Author contributions: Zhang SW designed the study, interpreted the data, and contributed to manuscript writing; Yu YJ and Li YW collected and analyzed the data; Shi Y and Zhang Z collected, analyzed, and interpreted the data; Zheng MY collected the data and gave constructive comments on the manuscript; all authors approved the manuscript before submission.
Institutional review board statement: The Ethics Committee of Tianjin Union Medical Center approved related screening, treatment, data collection, and follow-up of these patients.
Conflict-of-interest statement: The authors declare that they have no conflict of interest related to this manuscript.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Shi-Wu Zhang, PhD, Director, Department of Pathology, Tianjin Union Medical Center, Hongqiao District, Jieyuan Road, Tianjin 300121, China. zhangshiwu666@aliyun.com
Received: March 4, 2020
Peer-review started: March 4, 2020
First decision: April 26, 2020
Revised: May 26, 2020
Accepted: July 19, 2020
Article in press: July 19, 2020
Published online: August 15, 2020
Processing time: 161 Days and 7.8 Hours
Abstract
BACKGROUND

Neuroendocrine tumors (NETs) frequently occur in the gastrointestinal tract, lung, and pancreas, and the rectum and appendix are the sites with the highest incidence. Epidemiology statistics show that an estimated 8000 people every year in the United States are diagnosed with NETs occurring in the gastrointestinal tract, including the stomach, intestine, appendix, colon, and rectum. The pathological changes and clinical symptoms of NETs are not specific, and therefore they are frequently misdiagnosed.

AIM

To investigate the clinical symptoms, pathological characteristics, treatment, and prognosis of rectal neuroendocrine tumors (RNETs) by analyzing the clinical and pathological data of 132 RNET cases at our hospital.

METHODS

All RNETs were graded according to Ki-67 positivity and mitotic events. The tumors were staged as clinical stages I, II, III, and IV according to infiltrative depth and tumor size. COX proportional hazard model was used to assess the main risk factors for survival.

RESULTS

These 132 RNETs included 83 cases of G1, 21 cases of G2, and 28 cases of G3 (neuroendocrine carcinoma) disease. Immunohistochemical staining showed that 89.4% of RNETs were positive for synaptophysin and 39.4% positive for chromogranin A. There were 19, 85, 23, and 5 cases of clinical stages I, II, III, and IV, respectively. The median patient age was 52.96 years. The diameter of tumor, depth of invasion, and pathological grade were the main reference factors for the treatment of RNETs. The survival rates at 6, 12, 36, and 60 mo after operation were 98.5%, 94.6%, 90.2%, and 85.6%, respectively. Gender, tumor size, tumor grade, lymph node or distant organ metastasis, and radical resection were the main factors associated with prognosis of RNETs. Multivariate analysis showed that tumor size and grade were independent prognostic factors.

CONCLUSION

The clinical symptoms of RNETs are not specific, and they are easy to misdiagnose. Surgery is the main treatment method. The grade and stage of RNETs are the main indices to evaluate prognosis.

Keywords: Neuroendocrine tumors; Prognosis; Univariate analysis; Tumor size; Tumor grade; Neuroendocrine carcinoma

Core tip: Tumor size and grade were the most significantly associated factors, and tumor size was the sole factor that was independently related to survival in a multivariate analysis. Patients with tumors larger than 2 cm had a ten-fold higher risk of death. Patients with advanced neuroendocrine carcinomas had a significantly decreased 5-year overall survival compared to patients with grades 1 and 2 disease.