The association of fat and other macronutrients with breast cancer: a case-control study from Greece.

The Greek diet is characterized by a high total fat but low saturated fat intake. In a hospital-based case-control study of female breast cancer conducted in Athens (1989-91), 820 patients with confirmed cancer of the breast were compared with 795 orthopaedic patient controls and 753 hospital visitor controls, matched to the cases by age and interviewer. Diet was ascertained through a semiquantitative food frequency questionnaire; macronutrient intakes were estimated from the nutrient content of a selected typical portion size for each specified food item, summed for all items. Logistic regression was used to analyse the data, controlling for demographic and reproductive risk factors for breast cancer as well as for total energy intake and mutual confounding influences among nutrients. There was no significant or suggestive association of total protein, total fat, categories of fat or total carbohydrates with breast cancer risk. Thus, the mutually adjusted relative risk per quintile and (in parenthesis) 95% confidence interval were: for protein, 1.06 (0.94-1.20); saturated fat, 0.99 (0.89-1.11); monounsaturated fat, 0.97 (0.88-1.07), polyunsaturated fat, 1.05 (0.97-1.13); and total carbohydrates, 1.03 (0.94-1.12). In alternative analytical approaches only total protein appeared to be positively associated to the occurrence of breast cancer with some consistency, but the results were far from statistically significant. These findings do not support a role for fat or other energy-generating nutrients in the aetiology of breast cancer.

Maternal age, parity, and pregnancy estrogens.

Total estrogens (TE), estradiol (E2), estriol (E3), and human placental lactogen (hPL) were determined by radioimmunoassay in the blood of 126 pregnant women during their 26th and 31st weeks of pregnancy and the results were studied in relation to maternal age and parity. Total estrogens and E2 were lowest among the youngest women (less than 20 years) and highest among women aged 20-24 years, whereas older women (25+ years) had, on the average, intermediate values. For E3 the pattern was qualitatively similar to that of TE and E2 but less striking, and no maternal age pattern was evident with respect to hPL. Within maternal age groups, TE and E2 were higher among women in the first, than among those in their second, full-term pregnancy; the difference was about seven percent for TE (P = 0.14) and about 14 percent for E2 (P = 0.05). No parity patterns were evident with respect to E3 and hPL. There were fairly strong correlations between the determinations of the same hormone in the same woman during the 26th and 31st weeks of pregnancy; Pearson correlation coefficients were 0.60 for TE, 0.78 for E2, 0.60 for E3, and 0.72 for hPL. Since the risk of breast cancer increases apparently monotonically with maternal age at birth, the present data are equivocal with respect to the hypothesis linking levels of pregnancy estrogens to risk of breast cancer in the offspring. However, the data are compatible with hypotheses linking excessive pregnancy-estrogen exposure to conditions more common among first-born individuals, including testicular cancer and cryptorchidism.