Radiation-induced heart morbidity after adjuvant radiotherapy of early breast cancer - Is it still an issue?

than in more recent trials. The heart mortality has decreased in more recent trials as demonstrated by data from the US Surveillance Epidemiology and End Results (SEER) cancer registries. They have documented in a cohort of more than 115,000 irradiated breast cancer patients with known tumour laterality that for patients treated during 1973–1982 the cardiac mortality ratio (left versus right tumour) was 1.20 (95% CI, 1.04–1.38) less than 10 years after irradiation, 1.42 (1.11–1.82) 10–14 years after irradiation, and 1.58 (1.29–1.95) after 15 years or more [5]. For women irradiated during 1983–1992 the corresponding figures were 1.04 (0.91–1.18) less than 10 years afterwards and 1.27 (0.99–1.63) 10 years or more after irradiation. The cardiac mortality ratio was 0.96 (0.82–1.12) for patients treated 1993–2001 and followed for less than 10 years. These figures thus may reflect the improvements in planning breast radiotherapy and the attempts to lower the dose to the heart. In the Danish Breast Cancer Cooperative Group (DBCG) 82 b&c post-mastectomy radiotherapy protocols no excess cardiac mortality was seen after median 12 year follow up comparing patients with left and right-sided breast cancer [6]. The patients treated according to these two protocols were irradiated with techniques designed to almost avoid doses to the heart. The patients also received systemic therapy [7].