Diet high in meat, fat and refined grains linked to risk for colon cancer recurrence, death

Patients treated for colon cancer who had a diet high in meat, refined grains, fat and desserts had an increased risk of cancer recurrence and death compared with patients who had a diet high in fruits and vegetables, poultry and fish, according to a study in the August 15 issue of JAMA.

Previous research has indicated that diet and other lifestyle factors have a significant influence on the risk of developing colon cancer. However, few studies have assessed the influence of diet on colon cancer recurrence and survival, according to background information in the article.

Jeffrey A. Meyerhardt, M.D., M.P.H., of the Dana-Farber Cancer Institute, Boston, and colleagues examined the influence of two distinct dietary patterns on cancer recurrence and survival in a group of 1,009 stage III colon cancer patients (cancer present in the colon and lymph nodes) enrolled in a clinical trial of postoperative chemotherapy in addition to other treatment. Patients reported dietary intake using a food frequency questionnaire during and six months after supplemental chemotherapy. Two major dietary patterns were identified, prudent and Western. The prudent pattern was characterized by high intakes of fruits and vegetables, poultry, and fish; the Western pattern was characterized by high intakes of meat, fat, refined grains, and dessert.

Patients were followed up for cancer recurrence or death. During a median (midpoint) follow-up of 5.3 years, 324 patients had cancer recurrence, 223 patients died with cancer recurrence, and 28 died without documented cancer recurrence.

The researchers found that a higher intake of a Western dietary pattern after cancer diagnosis was associated with a significant increase in the risk of cancer recurrence or death. Compared with patients in the lowest Western dietary pattern quintile (bottom 20 percent), those in the highest quintile (top 20 percent) experienced a 3.3 times higher risk for cancer recurrence or death. Patients in the highest quintile of Western dietary pattern were 2.9 times more likely to have cancer recur than those in the lowest quintile. Similarly, a significantly higher overall risk of death with increasing Western dietary pattern was observed. In contrast, the prudent dietary pattern was not significantly associated with cancer recurrence or death.

“Studies have shown an improved disease-free survival among patients who receive adjuvant chemotherapy following the surgical resection of stage III colon cancer. This is the first study, to our knowledge, in a potentially cured population of colon cancer survivors to address the effect of diet. Because this was an observational study, causality cannot and should not be drawn from these data. Nonetheless, the data suggest that a diet characterized by higher intakes of red and processed meats, sweets and desserts, french fries, and refined grains increases the risk of cancer recurrence and decreases survival. Further analyses are under way to better delineate specific nutrients or food groupings that may have the strongest association,” the authors write.###