Risk of additional cancers in untreated and treated hairy cell leukemia patients

Abstract

Importance of the field: One of the feared events encountered in hairy cell leukemia (HCL) survivors is the subsequent development of a malignant neoplasm. The increased incidence of second cancers in HCL has been documented in large epidemiologic studies conducted in various locations on the globe.

Areas covered in this review: The authors explore the current clinico-epidemiologic evidence, as well as the immune alterations, that link HCL and its therapies to the development of second cancers. Most relevant publications have been identified through the PubMed/Medline database search.

What the reader will gain: Although HCL patients could develop both HCL and secondary malignancies because of a shared genetic predisposition, a common environmental carcinogen, or not yet identified infectious agents, multiple immune defects documented in HCL might play an important role in second carcinogenesis. Furthermore, the ‘gold standards’ of HCL therapy – cladribine and pentostatin – are associated with profound and prolonged suppression of the CD4⁺ T-lymphocyte counts, often in excess of 2 – 3 years. And while there is no clear-cut evidence that pentostatin or interferon-alpha play an established role in generation of an excess of second cancers in HCL, the safety of cladribine, the preferred agent by a majority of clinicians worldwide, in this regard is a still largely unsettled issue.

Take-home message: Therefore, it remains to be seen if the immune deficiencies induced by the HCL therapies and their consequences can be offset by the benefit conferred by controlling the leukemic process.

Keywords::

• additional malignancies
• cladribine
• hairy cell leukemia
• immune defects
• pentostatin
• second cancers

Notes

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