Study shows risk for cancer increases for relatives of patients with leukemia

Relatives of patients with myelodysplastic neoplasia (MDS), acute myeloid leukemia (AML), or acute lymphoblastic leukemia (ALL) have an increased risk for cancer, according to a study published in the February issue of Cancer Epidemiology.

Nikolaj Juul Nitschke, from Copenhagen University Hospital in Denmark, and colleagues estimated the relative risk for cancer among relatives of patients with MDS/AML/ALL using linked data from the Danish Civil Registration System and the Danish Cancer Registry, the Danish National Acute Leukemia Registry, and the Danish Myelodysplastic Syndrome Database. Standardized incidence ratios (SIRs) were calculated as a measure of relative risk.

A total of 13,010 first-degree relatives (FDRs) and 22,051 second-degree relatives (SDRs) of 8,386 patients with MDS/AML/ALL were identified.

The researchers found that the relative risk for cancer overall, excluding basal cell carcinoma (BCC), was increased among FDRs and SDRs (SIRs, 1.3 and 1.5), respectively.

Among FDRs, SIRs were significantly increased for malignant melanoma, BCC, and the combined group of cancers of the male genital organs, urinary tract, and MDS/AML/ALL.

SIRs were significantly increased for malignant melanoma, BCC, and cancers in the digestive organs and peritoneum among SDRs.

"We speculate that to some extent the increased cancer risk reflects polygenic cancer predisposition possibly interacting with environmental factors," the authors write.