Secondary hematological malignancies after treatment of non-metastatic breast cancer.

ABSTRACT

PURPOSE: To determine the frequency of secondary hematological malignancies in non-metastatic breast cancer (BC) patients who received adjuvant chemotherapy and radiotherapy. METHODS: Data of BC patients followed at Hacettepe University Institute of Oncology, Department of Medical Oncology between 2004 and 2010 were retrospectively analysed. RESULTS: There were 1,475 BC patients followed between 2004 and 2010 at our department; 1,319 (89.4%) of them had not metastatic disease. One thousand, one hundred eighty three (89.7%) early-stage BC patients received at least one treatment modality (radiotherapy and/or chemotherapy). The number of patients receiving only chemotherapy or only radiotherapy were 228 (17.3%) and 117 (8.9%), respectively. Eleven (1%) out of 1,066 BC patients receiving adjuvant/neoadjuvant chemotherapy were also treated with granulocyte colony stimulating factor (G-CSF). The frequency of secondary hematological malignancies among adjuvant or neoadjuvant chemotherapy BC patients was 0.56% (6/1,066); it was 0.59% (7/1,183) among radiotherapy and/or chemotherapy treated non-metastatic BC patients. Five patients developed acute myeloid leukemia (AML); 3 of them were AML-FAB M3 and 2 could not be subclassified. The 6th patient had multiple myeloma and the 7th had diffuse large B cell lymphoma (DLBCL). However, the latter did not receive cytotoxic chemotherapy for BC. CONCLUSION: Treatment-associated secondary hematological malignancies, especially myeloid leukemias, are a growing problem due to high prevalence of BC and the dismal outcome of secondary leukemias. Further studies are needed to determine the risk for other hematological malignancies, possible responsible agents, and mechanisms.