Sugar and ovarian cancer risk.

To the Editors: The recent article reporting no association of consumption of animal foods with risk of ovarian cancer (1) was based on an incomplete study (2). Whereas ecologic studies can find animal products as an important risk factor for breast cancer (2, 3), a more recent ecologic study based on ovarian cancer mortality rates for European countries for 1989 to 1991 and dietary data for the period 1974 to 1976 found that sugar is the most important dietary component (4). This study also found that ovarian cancer rates correlated directly with latitude, an index inversely correlated with solar UVB doses and vitamin D production, in a multiple linear regression analysis. A recent cohort study found high glycemic index and glycemic load to be important risk factors for ovarian cancer (5). Countries with high animal product consumption often have high sugar consumption as well, but it is easy to separate the two in ecologic studies. If the data for sugar consumption and/or glycemic load are readily available for the data set in ref. 1, it would be worthwhile to reprocess the data to check this link. Copyright D 2007 American Association for Cancer Research.