Abstract
Background: Chronic Lymphocytic Leukemia (CLL) is the most common type of leukemia diagnosed in the United States and accounts for about one-quarter of the newly diagnosed cases while it is one of the least common leukemias in India (< 5% of all leukemias) with incidence rates ten times lesser than in the US. There is a dearth of data on regional characteristics and treatment outcomes of the disease; especially from India
Methods: This is a retrospective single centre study conducted among 63 newly diagnosed CLL patients at a tertiary cancer care centre in India from January 2020 to December 2023. The various demographic, clinicopathological characteristics and response to various treatment regimens were recorded. Relapse-free survival, Time to next treatment and Overall survival were the end points studied. The median follow up period was 17 months.
Results: In contrast to the Western data, majority of our patients presented in the younger cohort, with patients aged<= 55 years comprising 36.5% of the total patient population, with a median age of 60 years (about a decade lesser than our Western counterparts). Majority of our patients (88.9%) were symptomatic for the disease at presentation and required initiation of treatment.
Deletion 13q(del 13q) was the most common genetic abnormality seen in our population and deletion 11q(del 11q ) the least. Deletion 17p(del 17p) was positive in 30.2% cases upfront and the hazard ratio for relapse was found to be 11.26(95% CI: 2.9,42.7; p=0.0001) in those patients.
The various regimens used in the study were primarily Bruton Tyrosine Kinase inhibitors (BTKis), Bendamustine-Rituximab regimen (BR)and Chlorambucil-Wysolone combination.
All the patients treated with Ibrutinib (BTKi) achieved a complete response (CR) at the end of 6 months, with no documented relapses. BR regimen was the most common regimen found to have been used among the relapsed cases and the hazard ratio for relapse in patients treated with BR regimen was found to be 3.37(95% CI: 0.90,12.5; p=0.069) with a trend towards statistical significance.
Median relapse free survival was found to be 17.6 months & median time to next treatment was found to be 10.9 months. The Median Overall survival was not reached in this study.
This study concludes that Chronic Lymphocytic Leukemia seems to be more aggressive in Indian patients with younger age of presentation, higher disease burden, higher incidence of del 17p, shorter time to first treatment, more frequent relapses and lesser time to next treatment. BTKis seem to be the best treatment regimen for CLL patients. Chlorambucil-wysolone regimen was found to have better survival benefit as compared to the BR regimen.