Environmental factors and cancer mortality in Italy: correlational exercise

Mortality rates for 21 cancer sites in 20 Italian regions have been correlated with several economic and dietary variables (including alcohol and coffee consumption), patterns of cigarette smoking and reproductive habits. In both sexes, a large number of strong correlations emerged, the most notable ones being the strong positive coefficients between cigarettes sold in the early 1950s and lung cancer mortality in middle-aged males in the early 1970s, between gross internal product or meat consumption and cancer of the intestines in both sexes, between total per caput consumption and cancer of the prostate and between mean age at first birth, gross internal product and milk consumption and cancer of the breast. Cancer of the ovary was positively correlated with mean age at the first birth, and negatively with average number of births. Among the unexpected correlations observed, the most remarkable ones were the strong positive coefficient between skin cancer mortality and latitude (which can however be explained in terms of different constitutional characteristics of skin color in various Italian regions), and the pattern of coefficients emerging for gastric cancer, showing positive correlations with gross internal product or meat and negative ones with bread, pasta or fish. These and other results (including the analysis of several first-order partial correlation coefficients) are discussed with regard to their limitations and major points of interest, and in comparison with similar studies conducted on different populations.