Acute myeloid leukemia and myelodysplastic syndrome following breast cancer: increased frequency of other cancers and of cancers in multiple family members.

Adjuvant chemotherapy and radiation therapy for breast cancer are associated with therapy-related acute myeloid leukemia (AML)/myelodysplastic syndromes (MDS), but little is known about additional risk factors. Thirty-four patients with AML (n=26)/MDS (n=8) following breast cancer (cases) were compared with 2029 breast cancer patients without AML/MDS (controls). Cases were older at breast cancer diagnosis (mean 60.2 years versus 54.5 years; p=0.01) and more commonly had additional cancers (29% versus 4.9%; p<0.0001) and >or=4 first-degree relatives with any type of cancer (OR: 5.37, CI: 1.44-19.9). Thus risk factors for AML/MDS following breast cancer include older age, other cancers and multiple first-degree relatives with cancer.