“However, the absolute risk of those second cancers is small,” Dr. Michie Hisada from the National Cancer Institute, Bethesda, Maryland, said.

“It translates into a total excess of about 34 cancers — 21 non-Hodgkin’s lymphomas, 2 Hodgkin’s lymphomas, and 7 solid tumors (including two thyroid cancers) might be observed per year among hairy cell leukemia survivors,” she explained.

The findings are based on information from the Surveillance, Epidemiology and End Results (SEER) program for 3104 patients with hairy cell leukemia who survived for at least two months after diagnosis and were followed for a mean of 6.5 years.

The cumulative probability of all second cancers 25 years after hairy cell leukemia diagnosis is estimated to be 31.9%, the team reports in the February 7 issue of the Journal of the National Cancer Institute.

In addition to statistically significant higher risks of Hodgkin’s and non-Hodgkin’s lymphoma, and thyroid cancer, relative to the general population, hairy cell leukemia survivors are also at increased risk of death from leukemia and lymphoma, the team’s analyses suggest.

“In contrast, hairy cell leukemia survivors are at slightly decreased risk of lung cancer incidence,” Dr. Hisada reports. “Risks of deaths from cardiovascular and cerebrovascular diseases are also lower among the survivors when compared to the general population.”

“Future studies,” she said, “should address the influence of such factors as changes in treatment regimens, immunologic impairment, natural history, diagnostic misclassification, and tobacco use on risk of second cancers in hairy cell leukemia patients.”