Decreased prevalence of immediate hypersensitivity (atopy) in a cancer population.

It has been suggested that the atopic population has decreased risk of cancer. This investigation examined the cumulative prevalence of atopy in a population with neoplastic disease and compared this with the prevalence of atopy in an age-matched control group and with published estimates of atopy in the general peopulation. Seventy-four patients with neoplastic disease and 86 patients without cancer were evaluated. The subjects were given a standard allergic questionnaire which evaluated them with regard to a history of allergic symptoms, hives, eczema, frequent colds, frequent unexplained rashes, hay fever, and asthma. All were skin tested with a representative group of regionally significant allergens. There was a 15-fold decrease in prevalence of atopy in the cancer population, compared with the control group and compared with published estimates of atopy in the general population.