It's high time some serious research gets done to investigate cancer among flight crew. Shouldn't be too hard to look at data from crews over the past 20 years or so and compare it with the general population. We should know what the price is we pay for the conditions we work under.
I constantly fly with guys who have nasal/respiratory irritations from cabin air. This leads to long term effects - it has been proven that asthma can developed if post nasal drips constantly occur. Many friends who have low sperm counts - most likely from disrupted sleeping/eating patterns and radiation ( yep - strange things come out late at night on the flight deck ) Who knows how many of us will face cancer too eventually.