hexaphosphate (IP-6) and Breast Cancer
Subject: Published data are become more convincing that IP-6 may
be useful in the treatment of breast cancer.
Inositol hexaphosphate (IP-6) has been around for a number of years as
a nutritional supplement. It is sold as a way to promote immune
function especially in the treatment of cancer. I have had a standard
line I've used when asked what I thought about it; "I would definitely
take it if I was a rat."
IP-6 is a combination of Inositol and phytic acid, a chemical commonly
found in wheat bran. The early research on IP-6 involved a
great number of rat studies. Rats were injected with human cancer
cell lines and adequate doses of IP-6 allowed them to survive. I
always had a lingering question whether this information could be extrapolated
to humans. Rats like to eat whole grains. Perhaps their immune
systems were more dependent on phytic acid than human immune systems.
Would IP-6 play as big a role in humans as in rats?
I did not know the answer but hesitated to put IP-6 on the top of my lists
for cancer patients. It is time to change that idea. Whether
or not IP-6 will act as a stimulant to the human immune system isn't as
important as I first thought. IP-6 on its own, irregardless of immune
system involvement, is starting to look like a valuable player, especially
in breast cancer.
First it now appears that IP-6 will slow the growth rate of various cancer
cells including both estrogen positive and negative breast cancer cells
and colon cancer cells by about 20%. 
Second, IP-6 enhances the effects of Adriamycin and tamoxifen in breast
cancer. A recent study looked at the effect of IP-6 on three breast
cancer cell lines, one estrogen receptor positive, one estrogen receptor
negative and one Adriamycin resistant. All three cell lines were
sensitive to the growth inhibitory effects of IP-6. The "data
not only confirm the IP-6 alone inhibits growth of breast cancer cells;
but it also acts synergistically with Adriamycin or tamoxifen, being particularly
effective against ER alpha-negative cells and Adriamycin-resistant cell
Third, IP-6 may inhibit cancer cell metastasis. Two studies came
out in Fall, 2003 examining the effect IP-6 has on metastasis. Both
were very favorable. In the first, "cell invasion also was
decreased (by 72% after IP6 treatment, p = 0.001) in a dose-dependent
fashion." in a breast cancer cell model.  The second study
focused on explaining the mechanism by which IP-6 inhibits metastasis,
concluding ": The results of this study indicate that IP6-induced
inhibition of cancer cell adhesion, migration and invasion may be mediated
through the modulation of integrin dimerization, cell surface expression
and integrin-associated signaling pathway." 
(If that means anything to you?)
All of these studies continue to be either in vitro (test tube) or in
vivo (in living subjects) but at this point not humans yet they are starting
to add up, especially when talking about breast cancer. Inhibition
of growth, synergistic effects with chemotherapy, effect on drug resistant
strains and slowing metastasis are all, each on their own, good reasons
to take this supplement seriously.
1. Anticancer Res. 2001 Jul-Aug;21(4A):2393-403 G0/G1 arrest
and S phase inhibition of human cancer cell lines by inositol hexaphosphate
(IP6). El-Sherbiny YM, Cox MC, Ismail ZA, Shamsuddin AM, Vucenik I.
2. Breast Cancer Res Treat. 2003 Jun;79(3):301-12. Inositol
hexaphosphate (IP6) enhances the anti-proliferative effects of adriamycin
and tamoxifen in breast cancer. Tantivejkul K, Vucenik I, Eiseman J, Shamsuddin
3. Anticancer Res. 2003 Sep-Oct;23(5A):3671-9 Inositol hexaphosphate
(IP6) inhibits key events of cancer metastasis: I. In vitro studies of
adhesion, migration and invasion of MDA-MB 231 human breast cancer cells.
Tantivejkul K, Vucenik I, Shamsuddin AM.
4. Anticancer Res. 2003 Sep-Oct;23(5A):3681-9 Inositol hexaphosphate
(IP6) inhibits key events of cancer metastasis: II. Effects on integrins
and focal adhesions.Tantivejkul K, Vucenik I, Shamsuddin AM.
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