low fat diet and early stage bc survival rates

I don't think the study has been published yet but the interim report in 2006 showed the weight loss accrued to the low-fat diet group.
http://www.ncbi.nlm.nih.gov/pubmed/17179478

From the medpagetoday article (http://www.medpagetoday.com/MeetingCoverage/SABCS/49100):

The results "really are pretty remarkable in the ER-negative subset, showing results reducing risk of death that are as good or greater than what we see with our best treatments," conference co-director C. Kent Osborne, MD, of Baylor College of Medicine in Houston, commented at a press conference he chaired.

"What it tells us is we need to pay much more attention to diet than we have in the past," Osborne told MedPage Today. "We know that the appropriate diet ... to maintain normal weight is good for your heart, it's good for everything, including maybe now breast cancer.

He's talking in part about the 54% relative reduction in overall mortality for the ER/PR negative group. That is jaw-dropping. I also thought it was interesting that the results will be analyzed to see if Tamoxifen interfered with weight loss in the ER/PR positive group.