Cancer mortality correlation studies. I. Statistical associations between cancers at anatomically unrelated sites and some epidemiological implications.

Reported age-corrected cancer mortalities in different countries and in the USA were systematically correlated with the female breast cancer mortalities in order to establish the extent by which cancers at other sites are affected by regional and temporal variations of exogenous factors controlling the etiology of and/or mortality from cancer of the female breast. Some of the most common human cancers are directly correlated with breast cancer, with a high degree of statistical significance. Genuine inverse associations are rare, and only a few of the major neoplastic diseases appear to be uncorrelated. The results suggest that the human cancer mortality is controlled by exogenous factors which vary over space and time. These factors are as yet unidentified but are probably related to diet.