Impact of telomere length on survival in classic and variant hairy cell leukemia

• Telomeres protect the ends of chromosomes but are sometimes shortened in leukemias.
• Short telomeres in hairy cell leukemia are associated with decreased overall survival.
• Short telomere length correlates with other poor prognosis factors in hairy cell leukemia.
• Low telomere length should be studied further in this disease.

Telomeres, which protect the ends of chromosomes, are shortened in several hematologic malignancies, often with adverse prognostic implications, but their effect on prognosis of classic and variant hairy cell leukemia (HCL and HCLv) has not been reported. HCL/HCLv genomic DNA from 46 patients was studied by PCR to determine the ratio of telomere to single copy gene number (T/S). T/S was unrelated to diagnosis of HCL or HCLv (p = 0.27), but shorter T/S was associated with unmutated immunoglobulin rearrangements (p = 0.033) and age above the median at diagnosis (p = 0.017). Low T/S was associated with shorter overall survival from diagnosis (OS), particularly T/S <0.655 (p = 0.0064, adjusted p = 0.019). Shorter OS was also associated with presence of unmutated (p < 0.0001) or IGHV4-34+ (p < 0.0001) rearrangements, or increasing age (p = 0.0002). Multivariable analysis with Cox modeling showed that short T/S along with either unmutated or IGHV4-34+ rearrangements remained associated with reduced OS (p = 0.0071, p = 0.0024, respectively) after age adjustment. While T/S is relatively long in HCL and the disease usually indolent with excellent survival, shortened telomeres in HCL/HCLv are associated with decreased survival. Shortened T/S could represent a risk factor needing further investigation/intervention to determine if non-chemotherapy treatment options, in addition to or instead of chemotherapy, might be particularly useful.