Hi OKOC -
Sorry to hear of your entry into the one kidney owners' club, but I admire your upbeat approach to dealing with it.
I'm a research scientist (PhD, not MD) who is currently studying the health of aircrews. In preparation for this I have reviewed a massive amount of research literature on quite a number of topics. Cancer incidence is one of those topics -- esp. the kinds related to crews' increased exposure to high altitude (galactic) radiation. I have not seen renal cancer mentioned in relation to this exposure.
To the best of my knowledge, renal cancer is linked most frequently to exposure to various chemicals, especially occupational exposure. People who work with chemicals (ranging from housepainters to hairdressers), have a higher incidence of renal/bladder cancer than the general population.
Smoking has been linked to renal cancer, so if you have a history of smoking -- or of being around a lot of smoke -- that may have been a contributing factor.
Awhile back, epidemiologists discovered a link for renal cancer with chronic use of certain analgesics, particularly phenacetin, which was contained in many over-the-counter remedies for headache, muscle aches, and so on. Phenacetin has since been removed for the market in most countries.
Other over-the-counter medications are suspected as well, including certain laxatives and the analgesic acetaminophen (AKA paracetamol). Mind you, small, irregular doses are probably not damaging. It is chronic, frequent use over a long period of time which may do the harm.
Here is a link to a recent study carried out in Germany on these topics.
http://ndt.oupjournals.org/cgi/content/full/14/12/2892
There is possibly a hereditary component in some of these cancers, as well. By that I do not mean that you inherit cancer. Rather it is some factor in cell function which either protects/does not protect the cells in the presence of certain carcinogens or mutagens which is heritable.
I know this post is a little long-winded, but the topic is important -- esp. if you are indeed in the OKOC.
Good luck to you.
I wish you well.
Bobbie Sullivan, PhD
Principal Researcher
http://AirCrewStudy.com