According to results presented at the 29th Annual San Antonio Breast Cancer Symposium (SABCS), a low-fat diet appears to significantly reduce the risk of recurrences among women with estrogen-negative breast cancer.

Environmental factors, such as diet, and associations to the development or outcomes of various cancers are becoming an increasing focus of clinical studies. Results have indicated that smoking, exercise, and diet appear to have a significant effect on the incidence and possibly survival gpt different types of cancers Research into these issues continues to be evaluated.

Follow-up results from a large clinical trial referred to as the women’s intervention nutrition study (WINS) evaluating the effects of a low-fat diet on recurrence rates among patients with breast cancer were presented at the 2006 SABCS and are published in the December 2006 issue of the Journal of the National Cancer Institute.

This trial included over 2,400 women with early, resected breast cancer who were followed for nearly 6 years. Following diagnosis, patients were prospectively randomized to either continue with a normal diet (control group), or a diet in which 20% or fewer calories were from fat.  Patients on the low-fat diet lost an average of 5-6 pounds.

• Overall, relapse-free survival increased by approximately 22% in the patients who were on a low-fat diet, which did not reach statistical significance.
• However, relapse-free survival for patients with estrogen-receptor negative disease was significantly improved—by approximately 50% (HR=0.46) for women on a low-fat diet compared to those in the control group, but not significantly improved among those with estrogen-receptor positive disease (HR=0.92).
• Overall survival among patients on a low-fat diet was significantly improved among those with estrogen-receptor negative cancer, but not those with estrogen-receptor positive cancer. 

The researchers concluded that a low-fat diet appears to improve relapse-free and overall survival among patients with estrogen-receptor negative breast cancer. The presenter stated that it is not clear whether weight loss or lower fat in the diet contributed to this phenomenon; additionally, the types of fat in a patient’s diet was not analyzed. During the question period following the presentation, it was noted that results of this magnitude are comparable to the use of standard treatment. 

Reference: Chlebowski R, Blackburn G, Elashoff R, et al. Proceedings from the 2006 annual San Antonio Breast Cancer Symposium (SABCS). Oral presentation December 16, 2006. Abstract #32.