leukemia risk higher in olde bc patients treated w chemo (1.8% vs 1.2%--53% increase)

[Lani]

(sorry I meant older)

shows how statistics can put a different slant on things 1.8% does not sound that much more than 1.2%--but 53% higher risk sounds awful!



Leukemia Risk Increases After Breast Cancer Therapy in Older Women

NEW YORK (Reuters Health) Sept 24 - Older breast cancer patients who receive adjuvant chemotherapy have a small but significantly elevated risk of developing acute myeloid leukemia (AML) relative to peers not receiving this treatment, new research shows.

Moreover, the authors note, it is possible that their study may have underestimated this risk, since they could not determine the occurrence of myelodysplastic syndrome through the medical claims that were analyzed.

The findings, which appear in the September 1st issue of the Journal of Clinical Oncology, stem from an analysis of data for women diagnosed with nonmetastatic breast cancer from 1992 to 2002 and entered in the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database.

The study focused on the treatments received by women with or without a claim listing a diagnosis of AML, explain senior author Dr. Sharon H. Giordano and colleagues from the University of Texas, M. D. Anderson Cancer Center in Houston.

Of the 64,715 women included in the study, 10,130 had received adjuvant chemotherapy and 54,585 had not. Patients ranged in age from 66 to 104 years and the average follow-up period was 54.8 months.

Women treated with adjuvant chemotherapy had a 1.8% absolute risk of developing AML at 10 years. The risk in other patients was significantly lower -- 1.2%. On multivariate analysis, this translated into a 53% increased risk of AML that was associated with adjuvant chemotherapy.

Contrary to some prior reports, treatment with granulocyte colony-stimulating factor (G-CSF) within the first year of diagnosis did not significantly increase the risk of AML.

"Decisions regarding adjuvant chemotherapy in older women must incorporate both short- and long-term risks of chemotherapy as well as potential benefits, so that patients can make informed decisions," the authors conclude.

J Clin Oncol 2007;25:3871-3876.