Purpose: To assess long-term cause-specific mortality in breast cancer patients. Patients and Methods: We studied mortality in 7425 patients treated for early breast cancer between 1970 and 1986. Follow-up was 94% complete until January 2000. Treatment-specific mortality was evaluated by calculating standardized mortality ratios (SMRs) based on comparison with general population rates and by using Cox proportional hazards regression. Results: After a median follow-up of 13.8 years, 4160 deaths were observed, of which 76% were due to breast cancer. Second malignancies showed a slightly increased SMR of 1.2 (95% confidence interval [CI], 1.0-1.3). Radiotherapy (RT) as compared with surgery was associated with a 1.7-fold (95% CI, 1.2-2.5) increased mortality from cardiovascular disease (CVD). After postlumpectomy RT, no increased mortality from CVD was observed (hazard ratio, 1.0; 95% CI, 0.5-1.9). Postmastectomy RT administered before 1979 and between 1979 and 1986 was associated with a 2-fold (95% CI, 1.2-3.4) and 1.5-fold (95% CI, 0.9-2.7) increase, respectively. Patients treated before age 45 experienced a higher SMR (2.0) for both solid tumors (95% CI, 1.6-2.7) and CVD (95% CI, 1.3-3.1). Conclusion: Currently, a large population of breast cancer survivors is at increased risk of death from CVDs and second cancers, especially when treated with RT at a young age. Patients irradiated after 1979 experience low (postmastectomy RT) or no (postlumpectomy RT) excess mortality from CVD.

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doi.org/10.1016/j.ijrobp.2005.10.022, hdl.handle.net/1765/68775
International Journal of Radiation: Oncology - Biology - Physics
Department of Medical Oncology

Hooning, M., Aleman, B., van Rosmalen, A., Kuenen, M., Klijn, J., & van Leeuwen, F. (2006). Cause-specific mortality in long-term survivors of breast cancer: A 25-year follow-up study. International Journal of Radiation: Oncology - Biology - Physics, 64(4), 1081–1091. doi:10.1016/j.ijrobp.2005.10.022