Saturated fats a possible risk factor for cancer of the small intestine

Findings published in the journal Cancer Research, a journal of the American Association for Cancer Research, identify dietary intake of saturated fats as a possible risk factor for cancer of the small intestine, advancing the understanding of cancer development in this and other areas of the digestive tract.

While relatively rare, rates of cancer of the small intestine have been increasing since the 1970s. Individuals with this cancer are at increased risk of developing a second primary malignancy, particularly colorectal cancer.

"Identifying modifiable risk factors for cancer of the small intestine is important not only because the incidence of this cancer is on the rise, but it may enable us to further understand other gastrointestinal malignancies" said Amanda Cross, Ph.D., a National Cancer Institute researcher and the study's lead author.

Diets high in red and processed meats are associated with cancer of the large intestine. However, this is the first prospective study to examine meat and fat intake in relation to cancer of the small intestine.

Cross and other researchers from the National Cancer Institute used food frequency questionnaires to track food intake in a half million men and women enrolled in the NIH -AARP Diet and Health study over an eight-year period. Through state cancer registries and national death indexes researchers noted the development of 60 adenocarcinomas and 80 carcinoid tumors of the small intestine.

While findings showed no clear connection between red and processed meat and these tumors, they suggested a noticeably elevated risk for carcinoid tumors in the small intestine in association with saturated fat intake.

"Furthermore, there is some evidence to suggest that cancers of the small and large bowel both arise from adenomatous polyp precursor lesions, suggesting the adenoma-carcinoma sequence is relevant to both sites. For unknown reasons, the large intestine is much more susceptible to malignant transformation," said Cross. "Identifying risk factors that are unique as well as those that are similar for the two sites may aid our understanding of the comparative resistance of the small intestine to carcinogenesis."

These associations need to be further investigated in other populations and different types of saturated fat need to be studied specifically in order to understand the potential mechanisms involved, said Cross.