Maternal breast cancer risk after the death of a child.

The possible association between a severe traumatic life event (death of a child) and breast cancer risk was examined in a case-control study nested within a nation-wide cohort in Sweden. Our study population included 27,571 women with breast cancer and 141,798 control women born between 1925-1976. After adjustment for age, parity, age at first birth and education, the overall risk estimate for breast cancer among all women that had experienced the death of a child was 1.05 (95% confidence interval [CI] = 0.96-1.15). Among uniparous women the corresponding odds ratio (OR) was 1.27 (95% CI = 0.98-1.64). When stratifying for child's age at death a significant risk increase was detected among women that had lost their only child when the child was between 1-4 years of age (OR = 2.65; 95% CI = 1.06-6.60). These findings do not support an overall increase in breast cancer risk after the death of a child, a severe traumatic life event. Based on a small number of subjects, our finding of an increased risk in a subgroup of uniparous women losing their only child could be due to chance. Copyright 2004 Wiley-Liss, Inc.