Absence of association between reproductive variables and the risk of breast cancer in young women in Sweden and Norway.

摘要: A population-based case-control study was conducted in Sweden and Norway to analyse possible associations between breast cancer occurring before the age of 45 several different characteristics women's reproductive life. total 422 (89.2%) all eligible patients, 527 (80.6%) controls were interviewed. In univariate analyses, child-bearing (parity, at first birth, years last birth diagnosis, duration breast-feeding, number induced spontaneous abortions), measures fertile or ovulating period (age menarche, menarche pregnancy, estimates menstruation span) symptoms anovulatory cycles infertility seemingly unrelated to, most weakly associated with cancer. Adjustment for confounding factors multivariate analyses resulted largely unaltered risk odds ratios close unity without any significant trends when exposure variables studied categorised continuous form. We conclude that did not explain occurrence this population.