An Investigation of Eight Reported Cases of Small Intestinal Carcinoid Carcinoma in Multiple Family Members

There have not been any studies published which specifically describe the medical, environmental, and genetic factors in carcinoid tumors cases that have carcinoid in family members. While rare, with an incidence of four per 100, 000, carcinoid represents the most frequent malignancy affecting the small intestine. Because nearly half (49%) of the cases of gastrointestinal carcinoid tumors have hepatic metastasis at diagnosis, identification of the risk factors associated with carcinoid has the potential to increase early diagnosis and cure. Carcinoid tumors are thought to occur spontaneously and not associated with an inherited genetic abnormality that would increase a family member's risk for developing carcinoid cancer. There is a known inherited genetic abnormality that is associated with bronchial carcinoid tumors but only less than 10%. Gastrointestinal carcinoid tumors are not thought to be associated with a inherited genetic abnormality. There have been several small studies that have examined gastrointestinal carcinoid in multiple family members. It remains uncertain if these cases of carcinoid in multiple family members are characteristic of a heritable or environmental etiology. Most carcinoid cancer is not inherited; however, less than 10% of neuroendocrine carcinoid cancer is thought to be due to a change (called a "mutation") in a gene inherited from a parent. There are several genes that are suspected to be associated with carcinoid cancer, two of interest in this study is the Multiple Endocrine Neoplasia Type1 (MEN1), and succinate dehydrogenase complex, subunit D (SDHD) genes.