Although Cancer kills more citizens per year than total soldiers killed in combat since the end of WWI, the US government spends 1/1000th of what it spends on the Dept. of Defense on the National Cancer Institute.
Thats 1 penny for every $10.00 spent on taxes every year.
A complete scientific understanding of the exact biochemical mechanism(s) which account for increased risk for disease are not a necessary prerequisite for the introduction of interventive and preventative measures
e.g. John Snow stopping a cholera epidemic in London by recognizing that the water supply was associated with the spread of the disease, despite not knowing about the germ theory and the fact the organism was not isolated until the 1950s
Factors Affecting Cancer Risk
do NOT prove cause and effect
lifestyle choices
EtOH and smoking have consequences
diet
fat consumption is linked strongly to the incidence of breast, colon, and prostate cancers
changes in the dietary practices of various race/ethnicity/culture groups has lead to changes in their cancer risks
e.g. Japanese living in Hawaii lose some of the predisposition to stomach and liver cancer that their Japanese mainland counterparts experience, but at the expense of becoming more susceptible to colon and prostate cancer like Caucasian Hawaiians
age
in general, solid tumor cancer risks increase with advancing age
some cancers strike at specific ages (e.g. testicular cancer strikes young men)
sex
there is a 10:15 ratio of women to men in overall cancer mortality
the slight increase in men dying of cancer could be due to a variety of reasons (not the least of which is the smoking rates of men and women forty years ago, etc)
environment
what area of the world a person is from influences their cancer risks:
Ý
stomach and Liver cancer but ß colon and prostate cancer in Japan, China, and Costa Rica as compared to US. Is it genetic or due to diet and lifestyle? (thought to be linked to diet)
race/ethnicity/culture
in the US, African Americans present with more advanced stage cancers than whites, but have similar survival rates as similarly staged cancers in whites.
other confounders
level of education (more education = less cancer), income level (more $ = less cancer)