The Impact of Improved Treatments on Survival of Adult U.S. Leukemia Patients: 1990-2018.

INTRODUCTION

Molecularly targeted therapies such as tyrosine kinase inhibitors (TKI) are effective treatments for B-cell receptor (BCR)-ABL-bearing leukemias. We evaluated the impact of TKIs on historical chronic myeloid leukemia (CML) mortality trends compared with acute lymphoblastic leukemia (ALL) and chronic lymphoblastic leukemia (CLL).

METHODS

Because mortality trends reflect combined effects of leukemia incidence and survival, we also evaluated the contribution of incidence and survival trends to mortality trends by subtypes. We used data from 13 U.S. (SEER) registries (1992-2017) among U.S. adults. We utilized histology codes to identify cases of CML, ALL, and CLL and death certificate data to calculate mortality. We used Joinpoint to characterize incidence (1992-2017) and mortality (1992-2018) trends by subtype and diagnosis year.

RESULTS

For CML, mortality rates started declining in 1998 at an average rate of 12% annually. Imatinib was approved by the FDA for treating CML and ALL in 2001, leading to clear benefits for patients with CML. Five-year CML survival increased dramatically over time, especially between 1996 to 2011, 2.3% per year on average. ALL incidence increased 1.5% annually from 1992 to 2017. ALL mortality decreased 0.6% annually during 1992 to 2012 and then stopped declining. CLL incidence fluctuated during 1992 to 2017 while mortality decreased 1.1% annually during 1992 to 2011 and at a faster rate of 3.6% per year from 2011. Five-year survival increased 0.7% per year on average during 1992 to 2016.

CONCLUSIONS

Survival benefit from TKIs and other novel therapies for treating leukemia subtypes has been demonstrated in clinical trials.

IMPACT: Our study highlights the impact of molecularly targeted therapies at the population level.