Does family history of breast cancer improve survival among patients with breast cancer?

Overall cancer mortality to December 1985 among 291 patients whose breast cancer was diagnosed between 1971 and 1974 and who were interviewed shortly after diagnosis was 39.9% (116 deaths). In this study population a positive maternal family history was strongly associated with breast cancer: The odds ratio for patients versus controls of having a mother with breast cancer was 3.32 (95% confidence limits 1.64 and 6.72); the odds ratio of having a mother, sister, or maternal aunt with breast cancer was 1.92 (95% confidence limits 1.27 and 2.91). However, family history was not associated with stage at diagnosis, which is the most important survival factor (53.6% of patients with a family history and 51.7% without were at a local stage at diagnosis). Survival was better, although not significantly so, among women with maternal relatives with breast cancer. The relative risk of dying of cancer, adjusted for confounding factors, was 1.40 for women without versus with a family history; the difference in survival was not statistically significant.