Biphenotypic acute leukemia following intensive adjuvant chemotherapy for breast cancer: case report and review of the literature.

The risk of secondary leukemia in breast cancer patients who receive adjuvant chemotherapy is an open question. We describe the case a 38-year-old woman who developed acute leukemia 18 months after completion of intense adjuvant chemotherapy with prophylactic granulocyte colony-stimulating factor (G-CSF) support and chest wall irradiation. The diagnosis of biphenotypic T-cell acute myeloid leukemia (AML) was based on morphologic and immunophenotypic criteria. Chromosomal analysis of blasts revealed multiple trisomies and tetrasomies. The patient failed to respond to induction and salvage chemotherapy and died 4 months later. This case of acute leukemia occurred in a cohort of 65 high-risk breast cancer patients who were given intense adjuvant chemotherapy during the last 5 years in our hospital. This is the first case reported in the literature of acute leukemia following intense adjuvant chemotherapy with continuous prophylactic G-CSF, which is an actively investigated therapeutic strategy. Vigilance and investigation are needed to determine the leukemogenic potential of intense adjuvant chemotherapy plus radiotherapy in breast cancer patients. A brief review of the literature that deals with acute leukemia that develops after adjuvant chemotherapy for breast cancer and with secondary biphenotypic acute leukemia is presented.