Joyce: The good news is that the "predisposition" just means the odds are higher in your case -- it does not mean they are inevitable. Yes, if you take steps not to provoke tumors, most people can slow the progress of VHL.

Smoking accelerates the number and size of tumors
All that "nutrition for cancer prevention" does seem to help slow them
Bolstering the immune system also seems to help (conversely, if you're run down and your reserves are depleted, you may be more vulnerable)

There's no magic formula that we can rely on 100%, but there are strong indications that genistein, an element in soy, is particularly helpful. There was a study done in Heidelberg that showed that genistein inhibited vascular tumors of the retina.

Has anyone else found something to be helpful? Or have you tried any of the family recommendations on the website and had any success?

Tara: Your comments reminded me of a question my husband and I have been asking but getting no answers to, and that is the "second hit" idea. That being predisposed with the VHL gene is hit one and there is another "hit" that initiates tumor growth. Do you know what the second hit may be? I read somewhere that tumors develop following some trauma to the body 20% of the time. I tore my ACL in late November 1999, but I had headaches prior to that so I'm sure I've had the brain and spinal tumor long before then.

My husband and I hope that if we can figure out what the second hit is for me we can do what we can to avoid that. I don't doubt nutrition plays some kind of role in that. Any ideas?

Joyce: Here's the notion behind the "two-hit theory" which is now an accepted principle in cancer.

Everybody on the planet has two copies of the VHL gene. In people who have the condition called VHL, they are born with a tiny flaw in one copy of that gene. Just a tiny little misspelling is all it takes -- two letters swapped, or one letter wrong, or a few letters added or deleted -- with the result that that copy of the VHL gene doesn't know how to make the correct VHL protein. It makes some other (wrong) protein instead. It's like making pudding without sugar. The consistency is right, but it doesn't work as dessert.

ACTGACTGACTGATCG...oops...ACTG...

but that second copy of the VHL gene does make VHL protein, and works just fine.

Every day, every person on the planet sustains some kind of "event" that causes genes to change. Radiation (from sunlight and other sources), gases in the air, various pollutants, and random chance in the copying of genes as the body makes normal repairs -- any of these can cause genetic changes in any of our genes. When I was learning this for the first time from Dr. Maher in England I commented to him wryly that we needed a spelling-checker for our genes. He said that in fact we have a spelling checker! In the cell there are cells whose job it is to check the code, make sure it's right, and if a cell has been copied wrong (if it finds a spelling error) it directs the cell to self-destruct. You'll hear about these in the press. They are called "T-cells" or "killer cells". Those "oops" cells are normally deleted before they cause trouble. That's a normal part of the body's defense system, its immune system response to infection or damage.

In order for a VHL tumor to form, both copies of the VHL gene have to be inactive, and the body's spell-checker has to fail to find it and delete the faulty cell before it goes on to become a tumor. You can see that in the general population, if you have to have random occurrences hitting two copies of the same gene in one specific cell, you can see that it takes years of cumulative uncorrected damage for that to happen by chance. That's why there is more of the random cancer in older people. But in people with a "predisposition" to some kinds of tumors, one copy is already unactivated -- in other words, you have a head start in the process, and it only takes one other uncontrolled hit for a tumor to get launched.

Notice that there are "checks and balances" in your body to try to prevent it. If your spell-checker is thorough and catches the problem early, it never gets beyond one or two cells. No problem! All the sun-tanning that might have led to skin cancer gets repaired at very early stages, and most of those cells with double-hits to the VHL gene are getting deleted before they become a problem.

But if your immune system is not working at full power, then you can see that the chance that some damaged cell slips through the cracks and goes on to form a tumor are greater.

We don't know all the kinds of things that can cause that second hit, so we don't know what all to avoid. As with sunshine, the list is probably so long that it is impossible to avoid them all. So what we understand so far is that whatever we can do to keep our body's natural defenses strong, and whatever we can do to implement the suggestions from the cancer experts, all that is helpful even if it is not the only answer.

stop smoking
reduce exposure to second-hand smoke
follow suggestions for nutrition for cancer prevention
eat those fruits and veggies, washed with soap to remove pesticides
add some soy products to your diet for the genistein
watch out for exposure to harsh chemicals (there are strong suspicions about tri-chlorethylene). Use industrial rubber gloves, be sure to have adequate ventilation.
learn to manage stress in healthy ways (you can't avoid it altogether)

Sharing your stresses in a group like VHLFA is a healthy way of managing stress. Meditation, exercise, music, whatever works for you. And if you do get a tumor, it is not a failure on your part, so don't add the stress of feeling guilty. One of those random misspellings slipped past your spell-checker. There are no guarantees in nature.

The researchers are on the trail of "modifier genes" that make a person's trip with VHL easier or more difficult -- other genes in our bodies that if they are also damaged make a combination with VHL that accelerates or decelerates the process of tumor formation and growth.

If we understood some of these factors, we might be able to turn them into therapies -- maybe add some of that protector ingredient into our bodies. Over the next few years we will see many different angles on the problem. It's an exciting time!

See recipes for soy in this issue

As printed in the VHL Family Forum 8:4, December 2000. For permission to reprint, please contact VHL Family Alliance, editor@vhl.org. Further information is available from the VHL Family Alliance, info@vhl.org.