Gastric Pouch Mixed Adenoneuroendocrine Carcinoma With a Mixed Adenocarcinoma Component After Roux-en-Y Gastric Bypass

Gastric cancer after Bariatric Bypass Surgery. Do they relate? (A Systematic Review)

Bariatric bypass surgery has been an effective treatment for morbid obesity. However, there is an increasing number of reported cases of gastric cancer after bypass surgery. Our systematic review showed an increasing trend of gastric cancer cases after bariatric bypass surgery in the last decade, mostly located in the excluded stomach (77%) and diagnosed in an advanced stage. In addition to known risk factors such as tobacco smoking (17%), H. pylori infection (6%), and family history of gastric cancer (3%), bile reflux, a recently proposed cancer-promoting factor, was also estimated in 18% of the cases. Our data suggest that gastric cancer risk assessment should be considered before gastric bypass surgery, and further investigations are needed to determine the value of post-operative gastric cancer surveillance.

Gastroesophageal Cancer After Gastric Bypass Surgeries: a Systematic Review and Meta-analysis

Data comparing the occurrence of gastroesophageal cancer after gastric bypass procedures are lacking and are only available in the form of case reports. We perform in this study a systematic review and a meta-analysis of all the reported cases of gastroesophageal cancer following Roux-en-Y gastric bypass (RYGB) and loop gastric bypass-one anastomosis gastric bypass/mini gastric bypass (LGB-OAGB/MGB). We conducted a systematic review of all the reported cases in articles referenced in PubMed/Medline, Cochrane, and Scholar Google. Only cases of gastro-esophageal adenocarcinoma following RYGB or LGB-OAGB/MGB are included. Statistical analysis was done accordingly. Fifty cases were identified, along with 2 reported in this paper. Sixty-one percent (27/44) of the cancers after RYGB were in the gastric tube compared to 37.5% (3/8) after LGB-OAGB/MGB. This resulted in an odds ratio of 0.38 (p-value = 0.26), which failed to prove an increase in cancer occurrence in the gastric tube after LGB-MGB/OAGB compared to RYGB. The most common symptoms were dysphagia for cancers occurring in the gastric tube (15/30) and abdominal pain for those occurring in the excluded stomach (10/22). Twenty-nine/thirty of the cancers in the gastric tube were diagnosed by gastroscopy and 13/22 of the cancers in the excluded stomach were diagnosed by CT scan. Gastroesophageal cancers after gastric bypass procedures occur commonly in the excluded stomach where many are not identified by conventional means. Physician awareness and patient education as well as lifelong follow-up are essential for maintaining bypass surgeries on the beneficial side.

Mixed Neuroendocrine Non-Neuroendocrine Neoplasms: A Systematic Review of a Controversial and Underestimated Diagnosis

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) represent a rare diagnosis of the gastro-entero-pancreatic tract. Evidence from the current literature regarding their epidemiology, biology, and management is of variable quality and conflicting. Based on available data, the MiNEN has an aggressive biological behaviour, mostly driven by its (often high-grade) neuroendocrine component, and a dismal prognosis. In most cases, the non-neuroendocrine component is of adenocarcinoma histology. Due to limitations in diagnostic methods and poor awareness within the scientific community, the incidence of MiNENs may be underestimated. In the absence of data from clinical trials, MiNENs are commonly treated according to the standard of care for pure neuroendocrine carcinomas or adenocarcinomas from the same sites of origin, based on the assumption of a biological similarity to their pure counterparts. However, little is known about the molecular aberrations of MiNENs, and their pathogenesis remains controversial; molecular/genetic studies conducted so far point towards a common monoclonal origin of the two components. In addition, mutations in tumour-associated genes, including TP53, BRAF, and KRAS, and microsatellite instability have emerged as potential drivers of MiNENs. This systematic review (91 full manuscripts or abstracts in English language) summarises the current reported literature on clinical, pathological, survival, and molecular/genetic data on MiNENs.

Prognostic factors for survival after curative resection of gastric mixed adenoneuroendocrine carcinoma: a series of 80 patients

BACKGROUND

To assess the prognostic factors and investigate the optimal treatment of gastric mixed adenoneuroendocrine tumors.

METHODS

We retrospectively analyzed clinical data from 80 patients with gastric mixed adenoneuroendocrine carcinoma that received radical resection in our department from January 2007 to December 2016. Risk factors for relapse and survival were analyzed using a multivariate Cox proportional hazards regression model. Gastric mixed adenoneuroendocrine carcinoma was divided into neuroendocrine carcinoma and adenocarcinoma based on the predominant type in the tumor.

RESULTS

The 3-year overall survival was 40% in the neuroendocrine carcinoma group and 75% in the adenocarcinoma group (P = 0.006). The neuroendocrine carcinoma (NEC)-dominant tumors and a Ki-67-positive index ≥60% were independent risk factors for worse overall survival. The 3-year recurrence-free survival was 33% in the neuroendocrine carcinoma group and 68% in the adenocarcinoma group. NEC-dominant tumors and a Ki-67-positive index ≥60% were independent risk factors for gastric mixed adenoneuroendocrine carcinoma recurrence. Patients in the adenocarcinoma group that received adjuvant chemotherapy exhibited significantly better overall survival than patients that did not receive chemotherapy (median survival time 43 months vs. 13 months, P = 0.026).

CONCLUSION

The NEC-dominant tumors and a Ki-67-positive index ≥60% were significantly associated with worse survival and a higher recurrence rate for gastric mixed adenoneuroendocrine carcinoma patients. Patients in the adenocarcinoma group may benefit from gastric adenocarcinoma treatments.