The association between breast cancer and physiological, reproductive, clinical, behavioral, and dietary factors

Other possible factors that might be related to breast cancer, including physiological, reproductive, clinical, behavioral, and dietary factors, were also analyzed. We did not find any significant differences between the breast-cancer case and control groups for menstrual history, including age at menarche (χ² = 1.496, P = 0.221), menstrual pattern (χ² = 2.446, P = 0.118), dysmenorrhea (χ² = 0.382, P = 0.536), or menopausal status (χ² = 0.643, P = 0.423); reproductive history, including age at first birth (χ² = 1.613, P = 0.204), number of births (χ² = 1.433, P = 0.231), or breastfeeding status (χ² = 0.057, P = 0.811); or history of hypertension (χ² = 1.246, P = 0.264), cardiovascular disease (χ² = 1.712, P = 0.191), nephritis (χ² = 0.333, P = 0.564), or gynecologic tumors (χ² = 0.914, P = 0.339). However, significant differences between the case and control groups were found for number of miscarriages (χ² = 8.660, P = 0.003), history of benign breast tumor (χ² = 12.075, P = 0.001) and presence of DM (χ² = 4.459, P = 0.035).

No significant differences were found for other factors including oral contraception (χ² = 0.000, P = 0.997), inverted nipple (χ² = 1.731, P = 0.188), nipple discharge (χ² = 0.150, P = 0.699), orgalactophore hyperplasia (χ² = 0.441, P = 0.507), or for dietary habits, including intake of bean products (χ² = 2.578, P = 0.108), fresh beans (χ² = 0.022 P = 0.883), red meat (χ² = 0.010, P = 0.919), milk products (χ² = 0.422, P = 0.516), corn (χ² = 543, P = 0.461), carrots (χ² = 0.319, P = 0.572), fried food (χ² = 0.721, P = 0.396), vegetables or fruit (χ² = 0.630, P = 0.427), garlic (χ² = 3.316, P = 0.069), hams (χ² = 0.763, P = 0.383), or pickled foods (χ² = 0.583, P = 0.445).