I pulled this off of Sear's (the zone) site.
I think a low carb Paleo diet would be more effective than his 
recommendation, however, this is interesting.

New research sheds light on tumor spread

By Emma Patten-Hitt
NEW YORK, Feb 01 (Reuters Health) - Three teams of researchers have 
discovered how tumors create vessels that carry lymph--the colorless fluid 
that drains into the lymph nodes and clears the body of infections. Because 
the lymph system is one way in which tumors spread, blocking this "highway 
building" process may help halt the spread of cancer--a process known as 
metastasis that is the number one killer of cancer patients.
Three reports in February's issue of Nature Medicine describe researchers' 
attempts to understand more about that process.
It appears that new vessel growth is triggered by a specific protein, called 
vascular endothelial growth factor (VEGF), which interacts with a receptor on 
the surface of cells called the VEGF receptor. The three teams discovered 
that two VEGF subtypes--VEGF-C and VEGF-D--are the key players in the 
formation of new lymph vessels.
In one study performed in mice, Dr. Steven Stacker of the Ludwig Institute 
for Cancer Research, Melbourne, Australia and colleagues, found that a 
certain molecule stimulated VEGF-D, leading to the growth of vessels inside 
tumors and the spread of cells to lymph nodes. Blocking VEGF-D with an 
antibody, however, halted the spread of the cells.
In another study, Dr. Michael Detmar of Massachusetts General Hospital, 
Boston and colleagues, transplanted human breast tumors into mice. They found 
that cells engineered to produce extra-high levels of VEGF-C were much more 
likely to spread to the lymph nodes and lungs.
"This could provide a new target for therapy," said Detmar in a prepared 
statement. "By blocking the interaction of VEGF-C with its receptor on the 
lymphatic system, we may be able to block metastasis from occurring."
In the third study, Dr. Kari Alitalo and colleagues, of the University of 
Helsinki, Finland, showed that a form of the VEGF receptor can block VEGF-C 
and VEGF-D in genetically engineered mice. The receptor blocked the formation 
of new lymph vessels and caused vessels that had already formed to regress.
Alitalo speculates that this might form the basis of a treatment for human 
lymphedema, a swelling of the limbs due to faulty lymph drainage.
"On the basis of our results, I would be very optimistic about the 
possibility of future treatment of lymphedema," Alitalo told Reuters Health.
In a related editorial, Dr. Karl H. Plate from the Erlangen-Nürnberg 
University, Germany, notes that these studies provide the first direct 
experimental evidence that tumors can trigger the growth of new lymph 
vessels. Until now, it wasn't entirely clear how important this process is to 
the spread of cancer.
However, Plate noted that all the studies were conducted in animals and these 
results need to be tested for human cancers as well.
"If the results are true, then inhibition of this pathway could be a tool to 
treat and prevent cancer from spreading through the lymph system," he told 
Reuters Health.

Source: Nature Medicine 2001;7:151-152, 186-191, 192-198, 199-205.


Dr. Sears' Comments:

Growth factors such as VEGF operate using the IP3/DAG pathway as does 
insulin. This helps explain the relationship of elevated insulin to cancer 
progression. Rather than blocking the VEGF production, it makes better sense 
to lower the stimulation of the IP3/DAG which can be done by following the 
Sears Diet.