Diet may influence survival after treatment for stage III colon cancer

Patients with stage III colon cancer who have undergone surgery and chemotherapy with the goal of cure may have a higher risk of relapsing and dying early if they follow a predominantly Western diet of red meat, fatty foods, refined grains, and desserts, according to research led by investigators at Dana-Farber Cancer Institute in Boston.

The findings were presented at the American Society of Clinical Oncology's annual meeting in Chicago.

"This is the first large prospective trial to look at how diet impacts on colon cancer survivors, and while the results are preliminary, they are highly suggestive that diet may impact on the outcome of these patients," said Dana-Farber's Jeffrey Meyerhardt, MD, the study's lead author.

The research involved 1,009 patients with stage III colon cancer (cancer localized to the large bowel area with positive lymph nodes near the tumor) who were participating in a randomized, phase III clinical trial of adjuvant chemotherapy. They recorded their dietary intake on questionnaires for six months after chemotherapy, and researchers then tracked them for cancer recurrence or death.

The questionnaires indicated that participants, dietary patterns fell into two categories, dubbed ,prudent, and Western by researchers. The prudent pattern was characterized by high fruit, vegetable, poultry, and fish intakes; the Western pattern was marked by high intake of red meat, fat and desserts.

Researchers found that cancer tended to recur significantly faster in participants whose diets most closely followed the Western pattern. A Western diet was also associated with a lower overall survival rate. These findings remained consistent after researchers controlled for factors such as gender, age, body mass index, degree of cancer spread to lymph nodes, or physical activity level.

By contrast, researchers found that a prudent pattern diet did not significantly influence cancer recurrence or mortality.