Study leader Vicki Freedman of the University of Michigan at Ann Arbor says older people -- whether Caucasian or African-American -- living in racially segregated neighborhoods with high crime rates had a much higher chance of developing cancer than older people with similar health histories and income levels but who live in safer, less segregated neighborhoods.
The study, published in the American Journal of Public Health, found the chance of developing cancer is 31 percent higher for older men living in these kinds of neighborhoods and 25 percent higher for older women.
"The remarkable similarity in the size and strength of this relationship for both men and women is quite surprising given differences in the types of cancer each gender develops," Freeman said in a statement. "This suggests that a non-specific biological mechanism may be involved, possibly a stress response that interrupts the body's ability to fight the development of cancer cells."
Freeman and colleagues analyzed detailed measures of self-reported individual health histories of 20,000 Americans age 50 and older taking part in a nationally representative, longitudinal survey.