Radiotherapy of left-sided breast cancer tied to elevated high-grade coronary artery stenosis risk
WEDNESDAY, Dec. 28 (HealthDay News) -- Women with irradiated left sided breast cancer (BC) have an increased risk of high-grade coronary artery stenosis in the mid and distal left anterior descending artery and distal diagonal (mdLAD + dD), according to a study published online Dec. 27 in the Journal of Clinical Oncology.
Greger Nilsson, M.D., from the University Hospital in Upsala, Sweden, and colleagues evaluated the distribution of coronary artery stenoses among 199 patients with BC, and investigated the association between radiotherapy (RT) and the location of stenoses. Participants were identified from a BC cohort diagnosed from 1970 to 2003, which was linked to coronary angiography registers from 1990 to 2004. Coronary artery stenoses were graded from 0 to 5, with 0 indicating a normal vessel and 5 indicating occlusion. For radiation, two hotspot areas were defined: the proximal right coronary artery and the mdLAD + dD. According to the hotspot areas irradiated, RT regimens were categorized as high or low risk.
The investigators found that, for irradiated left- versus right-sided BC, the odds ratio (OR) for stenoses in the mdLAD + dD was 4.38 for grade 3 to 5 stenosis and 7.22 for grade 4 to 5 stenosis. The OR for grade 3 to 5 stenosis in hotspot areas was 1.9 for high-risk RT versus low-risk or no RT.
"When women with RT-treated left-sided BC were compared with those with right sided, a significant increase of stenosis in mdLAD + dD was seen, and the risk was higher for more severe stenosis," the authors write.
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