Long Term Complete Response in Metastatic Poorly-Differentiated Neuroendocrine Rectal Carcinoma With Multimodal Approach: A Case Report

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

Methods Here we present the case of a 42 years old male with an ulcerated rectal lesion, diagnosed as a NEC G3 (ki67 index >90 %) treated initially with 3 cycles of first-line chemotherapy (cisplatinum and etoposide) but with an early local progression disease at 3 months control. After a multidisciplinary evaluation, the patient underwent to open anterior low rectal resection, sphincter-sparing. In September 2015 however the first post-surgery total-body CT scan showed an early pelvic relapse of disease without any other localization of disease in 18F-FDG PET/CT.

Results So systemic chemotherapy with FOLFIRI was made a Partial Response (RP). A pelvic radiotherapy (50 Gy) followed. On March 2016, CT scan and 18F-FDG PET/CT imaging showed CR of pelvic lesion, pathological abdominal inter-aortocaval lymph-nodes emerged instead. Because of early progression from systemic treatment in abdominal malignant nodes, we directed the patient to 45Gy radiotherapy on metastatic sites, obtaining a CR. He has now days after 5 years no symptoms of relapse e had no late toxicity after chemotherapy or radiotherapy.

Conclusions Our case demonstrates how a multimodal approach can be successful to obtain a long CR in local e metastatic sites in patients with high grade digestive NEC.

Citation: de Nucci G, della Torre S, Mandelli ED et al. eP243 LONG TERM COMPLETE RESPONSE IN METASTATIC POORLY-DIFFERENTIATED NEUROENDOCRINE RECTAL CARCINOMA WITH MULTIMODAL APPROACH: A CASE REPORT. Endoscopy 2021; 53: S177.

Publication History

Article published online:
19 March 2021