November 14 (HealthDay News) -- Eating foods high in saturated fats -- such as red and processed meats -- may be a risk factor for cancer of the small intestine.

That's the conclusion of a U.S. National Cancer Institute study that included half a million men and women who provided information about their eating habits over eight years.

Previous research had identified a link between red and processed meats and cancer of the large intestine, but this is the first prospective study to examine the association between meat and fat intake and cancer of the small intestine.

During the study, 60 adenocarcinomas and 80 carcinoid tumors of the small intestine were diagnosed among the participants, and an elevated risk for these cancers was associated with saturated fat intake, the NCI researchers reported in the current issue of the journal Cancer Research.

"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 some unknown reason, the large intestine is much more susceptible to malignant transformation," the study's lead author, Amanda Cross, said in a news release.

"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," she added.

Cancer of the small intestine is relatively rare, but rates of the disease have been increasing since the 1970s. People who develop this type of cancer are at increased risk for developing a second primary cancer, particularly colorectal cancer, the researchers said.

"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," Cross said.

SOURCE: American Association for Cancer Research, news release, Nov. 13, 2008