No Increase in Leukemia or Myelodysplastic Syndrome With Adjuvant Chemotherapy for Breast Cancer

According to a study from the US Oncology Network, breast cancer patients treated with adjuvant chemotherapy have no increased risk for acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS), at least within the first 3 years of treatment. The study was presented at the American Society of Clinical Oncology 2012 Breast Cancer Symposium by Neelima Denduluri, MD, of Virginia Cancer Specialists.¹

“The rates of AML/MDS were found to be low after adjuvant chemotherapy, and similar to those noted in non–chemotherapy-treated patients,” Denduluri reported.

Previous estimates have placed the risk of developing AML/MDS after breast cancer therapy at around 1%, with the greatest risk seen among older patients and those who receive anthracyclines, higher cumulative doses of cyclophosphamide, and radiotherapy. It has not been established whether granulocyte colony-stimulating factors are correlated with increased risk, nor are incidence rates with taxane combinations well characterized.

Denduluri and colleagues explored the oncology-specific electronic health record, iKnowMed, which contains nearly 1.3 million patient records. The base population included 20,900 breast cancer patients, of whom 11,295 received chemotherapy.

At a median follow-up time of about 3 years, 12 cases were identified among chemotherapy recipients (0.106%), including 1 case among 2466 patients receiving pegfilgrastim and 11 cases among 8829 patients not receiving pegfilgrastim. Among breast cancer patients not receiving chemotherapy, there were 16 cases (0.167%). The median time to onset of AML/MDS was 22 months.

Risk was increased 7-fold among patients aged ≥70 years and nearly 4-fold among those who received anthracyclines. These were statistically significant effects, whereas the almost 3-fold increase with pegfilgrastim use was numerically higher but not statistically significant, she said.

“With the recent news that Robin Roberts with Good Morning America developed MDS after beating breast cancer, many of my patients were concerned about the risk,” Denduluri said. “This study can reassure patients who receive adjuvant chemotherapy that their risk of a secondary AML/MDS is very low within the first 3 years.”

Reference

1. Denduluri N, Espirito JL, Turnwald B, et al. Risk of acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) after adjuvant chemotherapy (CT) for early breast cancer (BC) in the community setting. Presented at: American Society of Clinical Oncology 2012 Breast Cancer Symposium; September 13-15, 2012; San Francisco, CA. Abstract 62.