Clonal Hematopoiesis is a Risk Factor for Chemotherapy-Related Complications

'CHIP' stands for Clonal Hematopoiesis of Indeterminate Significance (1-4). Up to 20% of individuals in the general population acquire mutations in their bone marrow stem cells as they age that give that population of cells a survival or 'clonal' advantage for growth. The frequency of CHIP may be higher in patients with other cancers. CHIP increases with age, and has been shown to be a risk factor associated with cardiovascular disease and a tendency to the development of bone marrow cancers at a rate of 1% per year (1,2,5). CHIP is also associated with the development of bone marrow cancers that occur after chemotherapy. The investigators want to investigate whether CHIP is also a risk factor for chemotherapy-related complications like low blood counts, infections, cardiac events, hospitalizations, dose delays and dose reductions. They are also interested in determining if CHIP may explain why some patients do not recover normal blood counts after chemotherapy finishes.

The results from this study may help physicians better understand why some people have difficulty with chemotherapy (in the short and long-term) while others do not. Screening for CHIP in older patients may become a recommended standard that allows physicians to tailor anti-cancer treatment to the patient.

Inclusion criteria

• Diagnosis of a lymphoma (ex: diffuse large B cell lymphoma (DLBCL), follicular lymphoma, marginal zone lymphoma, small lymphocytic lymphoma/chronic lymphocytic leukemia, Hodgkin's lymphoma, peripheral T cell lymphoma, anaplastic large cell lymphoma, angioimmunoblastic lymphoma, hairy cell leukemia, Waldenstrom's macroglobulinemia, anaplastic large cell lymphoma, small lymphocytic lymphoma/chronic lymphocytic leukemia, and mantle cell lymphoma).
• Commencing first or second-line cytotoxic chemotherapy for lymphoma with or without rituximab [ex: cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), cyclophosphamide, vincristine and prednisone (CVP), Fludarabine, fludarabine cyclophosphamide (FC), Bendamustine, cisplatin, cytarabine, dexamethasone (DHAP), etoposide, cytarabine, cisplatin, prednisone (ESHAP), gemcitabine, cisplatin and dexamethasone (GDP), Cladribine, Cyclophosphamide, Epirubicin, Vincristine, Prednisone (CEOP), dose-adjusted Dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin (DA-EPOCH)]

Exclusion criteria

• Pre-existing diagnosis of myeloid neoplasm
• Circulating lymphocyte count > 10 x 109/L
• Significant uncontrolled renal or hepatic impairment [>1.5 x upper limit of normal (ULN) bilirubin, >1.5 x ULN Alanine aminotransferase (ALT), >1.5 x ULN creatinine]
• HIV
• Active infection