Abstract P2-11-06: Mortality among offspring of women diagnosed with breast cancer; a population based study

Abstract

Abstract Introduction: Survival after breast cancer has improved substantially over the past decades. As a result, an increasing number of breast cancer survivors is starting or extending their family post-diagnosis. We evaluated mortality risks of offspring from women with a history of breast cancer. Methods: From the Swedish Multi-Generation Register and the Cancer Register we identified all 63,205 children whose mother had ever been diagnosed with invasive breast cancer. For these children, we calculated relative mortality risks as compared to the background population (Standardized Mortality Ratios [SMRs]). We compared SMRs according to the mother's parity status at diagnosis and timing of birth in relation to time of diagnosis, i.e. before (>1 year before), around (between 1 year before and 1 year after) and after (>1 year after) diagnosis. Results: Children born around their mother's breast cancer diagnosis had an increased mortality risk as compared to the background population (SMR 2.70 95% CI [1.64–4.44]). This risk was particularly high for first-born children (SMR 11.07 (95% CI [2.09–27.13]), who had an absolute excess risk of 6.4% to die before the age of 5 years. Children born more than one year before or after their mother's breast cancer diagnosis had similar mortality risks as the background population. Conclusion: Children born around their mother's breast cancer diagnosis have significantly increased mortality risks. Offspring of nulliparous women have a particularly high relative mortality risk, suggesting that pregnant breast cancer patients may be keen to keep their first child in spite of potential treatment toxicity. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-11-06.