Case Report
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Oncol. Jun 24, 2021; 12(6): 500-506
Published online Jun 24, 2021. doi: 10.5306/wjco.v12.i6.500
Long-term complete response in metastatic poorly-differentiated neuroendocrine rectal carcinoma with a multimodal approach: A case report
Silvia Della Torre, Germana de Nucci, Pietro Maria Lombardi, Samuele Grandi, Gianpiero Manes, Roberto Bollina
Silvia Della Torre, Roberto Bollina, Oncology Unit, ASST Rhodense, Rho 20017, Italy
Germana de Nucci, Department of Gastroenterology, Garbagnate Milanese Hospital, ASST Rhodense, Garbagnate Milanese 20024, Italy
Pietro Maria Lombardi, Minimally Invasive Surgery Division, Niguarda Hospital, Milan 20110, Italy
Samuele Grandi, Robotic and Emergency Surgery, General Surgery Division, Manzoni Hospital, Lecco 23900, Italy
Gianpiero Manes, Gastroenterology Unit, ASST Rhodense-Garbagnate Milanese, Garbagnate Milanese 20054, Italy
Author contributions: Della Torre S is the guarantor of the article; Lombardi PM contributed to data analysis and interpretation; de Nucci G drafted and revised the article, and issued final approval of the article; Grandi S provided critical revision of the article, and issued final approval of the article; Manes G provided critical revision of the article for important intellectual content, and issued final approval of the article; Bollina R contributed to the drafting of the article, data analysis and interpretation, and final approval of the article; all authors approved the final version of the article, including the authorship list.
Informed consent statement: The patient provided consent to the writing and publication of this case report.
Conflict-of-interest statement: The authors declare that they have no conflicts of interest.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
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:
Corresponding author: Silvia Della Torre, MD, Doctor, Oncology Unit, ASST Rhodense, Corso Europa 2, Rho 20017, Italy.
Received: October 23, 2020
Peer-review started: October 23, 2020
First decision: December 4, 2020
Revised: December 24, 2020
Accepted: March 3, 2021
Article in press: March 3, 2021
Published online: June 24, 2021

Neuroendocrine gastrointestinal tumors (NETs) are rare and have different natural behaviors. Surgery is the gold standard treatment for local disease while radiotherapy has been demonstrated to be ineffective. Poorly differentiated neuroendocrine carcinomas (NECs) represent only 5%-10% of digestive NETS. Due to aggressive growth and rapid metastatic diffusion, early diagnosis and a multidisciplinary approach are mandatory. The role of surgery and radiotherapy in this setting is still debated, and chemotherapy remains the treatment of choice.


A 42-year-old male with an ulcerated bleeding rectal lesion was diagnosed with a NEC G3 (Ki67 index > 90%) on May 2015 and initially treated with 3 cycles of first-line chemotherapy, but showed early local progressive disease at 3 mo and underwent sphincter-sparing open anterior low rectal resection. In September 2015, the first post-surgery total-body computed tomography (CT) scan showed an early pelvic disease relapse. Therefore, systemic chemotherapy with FOLFIRI was started and the patient obtained only a partial response. This was followed by pelvic radiotherapy (50 Gy). On April 2016, a CT scan and 18F-fluorodeoxyglucose positron emission tomography imaging showed a complete response (CR) of the pelvic lesion, but pathological abdominal inter-aortocaval lymph nodes were observed. Due to disease progression of abdominal malignant nodes, the patient received radiotherapy at 45 Gy, and finally obtained a CR. As of January 2021, the patient has no symptoms of relapse and no late toxicity after chemotherapy or radiotherapy.


This case demonstrates how a multimodal approach can be successful in obtaining long-term CR in metastatic sites in patients with high grade digestive NECs.

Keywords: Neuroendocrine tumor, Multimodal therapy, Rectal carcinoma, Surgery, Radiotherapy, Case report

Core Tip: Neuroendocrine gastrointestinal tumors are rare with different clinical behaviors. Prognostic factors are tumor differentiation, Ki-67 index and the presence of distant metastases. Most of these tumors are well differentiated neuroendocrine tumors with a good prognosis and a 5-year overall survival of 60%-90%. Surgery is the gold standard treatment in local and metastatic disease, while radiotherapy is ineffective. Poorly differentiated neuroendocrine carcinomas represent only 5%-10% of digestive neuroendocrine gastrointestinal tumors. Here we describe the rare case of a patient diagnosed with poorly differentiated rectal metastatic neuroendocrine carcinoma treated with a different treatment approach and with complete remission after 5 years.