Small bowel carcinoma revealing HNPCC syndrome

Epidemiology, Risk Factors and Diagnosis of Small Bowel Adenocarcinoma

Simple Summary

Small bowel adenocarcinoma is a rare tumor. Diagnosis is often obtained at an advanced stage and prognosis remains poor. The aim of this review is to report the recent epidemiological and risk factor data related to small bowel adenocarcinoma. New diagnostic tools are also described in this review.

Abstract

Adenocarcinomas of the small intestine are rare tumors but their incidence is increasing. There is a slight male predominance. The median age at diagnosis is the 6th decade. The most frequent primary location is the duodenum. There is no clearly identified environmental risk factor, but adenocarcinomas of the small intestine are associated in almost 20% of cases with predisposing diseases (Crohn’s disease, Lynch syndrome, familial adenomatous polyposis, Peutz–Jeghers syndrome and celiac disease).

Epidemiology of Cancers of the Small Intestine: Trends, Risk Factors, and Prevention

The latest data from the United States and Europe reveal that rare small intestine cancer is on the rise, with the number of cases having more than doubled over the past 40 years in the developed world. Mortality has grown at a slower pace, thanks to improvements in early diagnosis and treatment, as well as a shift in the etiology of neoplasms affecting the small intestine. Nevertheless, 5-year survival for small intestine adenocarcinomas has lingered at only 35%. Lifestyle in developed nations, including the rise in obesity and physical inactivity, consumption of alcohol, tobacco, and red and processed meats, and occupational exposures may be to blame for the proliferation of this rare cancer. Identification of hereditary and predisposing conditions, likely to blame for some 20% of cases, may help prevent and treat cancers of the small intestine. Studies of the neoplasm have been limited by small sample sizes due to the rarity of the disease, leaving many questions about prevention and treatment yet to be answered.

Pancreatic non-functioning neuroendocrine tumor: a new entity genetically related to Lynch syndrome

Some pancreatic neuroendocrine tumors (P-NETs) are associated with hereditary syndromes. An association between Lynch syndrome (LS) and P-NETs has been suggested, however it has not been confirmed to date. We describe the first case associating LS and P-NETs. Here we report a 65-year-old woman who in the past 20 years presented two colorectal carcinomas (CRC) endometrial carcinoma (EC), infiltrating ductal breast carcinoma, small intestine adenocarcinoma, two non-functioning P-NETs and sebomatricoma. With the exception of one P-NET, all these conditions were associated with LS, as confirmed by immunohistochemistry (IHC) and polymerase chain reaction (PCR). LS is caused by a mutation of a mismatch repair (MMR) gene which leads to a loss of expression of its protein. CRC is the most common tumor, followed by EC. Pancreatic tumors have also been associated with LS. Diagnosis of LS is based on clinical criteria (Amsterdam II and Bethesda) and genetic study (MMR gene mutation). The association between LS and our patient's tumors was confirmed by IHC (loss of expression of proteins MLH1 and its dimer PMS2) and the detection of microsatellite instability (MSI) using PCR.

Small Bowel Adenocarcinoma

Small bowel adenocarcinomas (SBAs) are rare tumors, but their incidence is increasing. The most common primary location is the duodenum. Even though SBAs are more often sporadic, some diseases are risk factors. Early diagnosis of small bowel adenocarcinoma remains difficult, despite significant radiologic and endoscopic progress. After R0 surgical resection, the main prognostic factor is lymph node invasion. An international randomized trial (BALLAD [Benefit of Adjuvant Chemotherapy For Small Bowel Adenocarcinoma] study) will evaluate the benefit of adjuvant chemotherapy. For metastatic disease, retrospectives studies suggest that platinum-based chemotherapy is the most effective treatment. Phase II studies are ongoing to evaluate targeted therapy in metastatic SBA.

Small bowel adenocarcinoma in Lynch syndrome: A case report

Small bowel adenocarcinoma is part of the tumor spectrum of Lynch syndrome, which is caused by germline mutations in the mismatch repair genes. The present study describes the case of a 51-year-old man fulfilling the Amsterdam II criteria for Lynch syndrome, who had a 15-mm early-stage colorectal cancer resected endoscopically from the ascending colon. Due to upper abdominal discomfort after eating and consequent anorexia, a computed tomography scan performed 1 month later showed a tumoral mass of the upper jejunum with local lymphadenopathy. The laparotomy revealed a completely obstructing mass. Intraoperative frozen section showed a small bowel adenocarcinoma. Subsequent genetic testing confirmed the germline mutation of mutL homolog 1. The patient received 6 cycles of an adjuvant folinic acid, fluorouracil and ocaliplatin chemotherapy regimen. The latest CT scan, 16 months after the chemotherapy, did not show any recurrence. This case highlights the importance of considering the possibility of small bowel adenocarcinoma in patients with upper bowel obstruction, particularly for patients with Lynch syndrome.

Small bowel adenocarcinoma: epidemiology, risk factors, diagnosis and treatment

Small bowel adenocarcinomas are rare tumours, but their incidence is increasing. Their most common primary location is the duodenum. The few studies that have collected data regarding small bowel adenocarcinoma are not homogeneous and are widely spread over time. Even though these tumours are most often sporadic, some predisposing diseases have been identified, among which Crohn's disease and genetic syndromes. Early diagnosis of small bowel adenocarcinoma remains difficult despite significant radiological and endoscopic progress. After surgical resection the main prognostic factor is node invasion; in this case, adjuvant chemotherapy can be expected to be beneficial, although this has not been established by randomised trials. For metastatic disease, platinum-based chemotherapy seems to be the most effective treatment. Targeted therapies have not yet been evaluated in this type of cancer.