Does drinking 2 cups or less of coffee a day present any risks of
developing cancer for a 'normal' individual with a 'normal' immune
system? I was surprised to read various web sites claiming that coffee
contains several carcinogens.

I think it might be impossible to answer this... Coffee can contain
acrylamide and other suspected carcinogenic substances; but it also
contains antioxidants that might counter the possible carcinogenic
effects, and perhaps even lower the risk of cancer. Coffee (and
caffeine) have also been linked to a reduced risk of developing
several other diseases, like Parkinsons. It's perhaps not just the
coffee's "fault" either, consuming very hot drinks have been linked to
esophageal cancer. (Castellsague et al.; Int. Journ. Cancer, Nov. 15,
2000;88:658-664. )

:-) As2O3

Thanks for the comment. It probably is a difficult question to answer.
I am interested in any conclusions by recent credible research on the
subject. Given that a significant percentage of society (in North
American at least) has been drinking coffee for many, many years, I
would imagine that if coffee was a significant carcinogen, we would
know about it.

I am still surprised to read material such as the following from
credible sources however (from
http://interactive.usask.ca/ski/agriculture/food/foodnut/constit/constit_add5.html):

"...a cup of coffee is estimated to contain over 2,000 natural
occurring chemical components some of which are highly mutagenic
(causes changes in the cell genes). Many mutagens are also
carcinogens. One cup of coffee has the equivalent of fifty times the
mutagenic activity of smoke absorbed from smoking a single cigarette."

It is necessary to put this into perspective though: there are varying
degrees of toxic substances and even "natural carcinogens" in just
about everything we consume. As this web site (above) states: "Almost
every food we consume contains some type of harmful substance;
naturally or produced during food preparation".

I've always been fascinated by the fact that any molecule that mimics
the structure of of a DNA base (A,T,G,C)is usually cacinogenic,
presumably due to its messing-up of DNA assembly.  If you look at the
structure of caffeine, it is almost IDENTICAL in size and structure to
two of the bases ... the pyrimidine ones I think.  If you buy a 500g
jar of reagent-grade highly-purified caffeine powder from Fisher
Scientific ... the warnings on the label will knock your socks off.  I
don't have it memorized but it goes on for about 20 sentences re:
"mutagenic studies have shown ... causes cancer in ... WARNING:do not
inhale" ... and so-forth, for a product that is present at about 0.1 g
in every cup of coffee, 0.35 g in every can of Coke.  Always has had
me fascinated, That !