Ethnic Disparities in Survival of Chronic Myeloid Leukemia

Introduction:

Development of tyrosine kinase inhibitors has led to significant improvement in survival of chronic myeloid leukemia (CML) patients. We conducted this study to evaluate any ethnic disparity in CML survival.

Methods:

We analyzed surveillance, Epidemiology, and End Results, SEER 18 registry to compare 1 and 3 years relative survival rates of CML patients diagnosed between 2001- 2008 by ethnicity - Caucasian, African American (AA), Others (O). We analyzed survival rates by age (≤65, >65), and time periods: (2001-2004) and (2005-2008). We used SEER*Stat software to calculate Z value.

Results:

There were 6,306 CML patients during (2001-2008); 3,111 during (2001-2004) and 3,195 during (2005-2008). The 1-year relative survival rates among Caucasians (n=6,306), AA (n=790), and Others (n=532) were 80.0±0.5%, 83.8 ±1.4%, and 84.0±1.7% [Z value 2.43 (AA vs Caucasian), 2.15 (O vs Caucasian)] respectively. The 3 years RS rates were 65.6±0.7%, 70.2±1.8%, and 70.9 ±2.1% respectively with Z value 2.49 (AA vs Caucasian) and 2.42 (Caucasian vs O).

Among younger patients (age ≤65 years, n=4,245) Caucasians had better RS compared to AA (83.1±0.7% vs 78.7±1.8%, Z value 2.24) at 3 years. There was no difference survival at 1and 3 years in older patients (age >65 years, n= 3,383).

The survival rates of patients diagnosed during 2001-2004 were similar for all ethnic groups. Among patients diagnosed during 2005-2008, survival rates were significantly higher for AA versus Caucasians (1 year RS 86.6±1.8% vs 81.3±0.7%, Z value 2.45, and 3 year RS 73.8±2.4% vs 68.3±0.9%, Z value 2.20). Others also had better RS compared to Caucasians (87.1±2.1% vs 81.3±0.7%, Z value 2.22) at 1 year.

There was no racial disparity in survival rates when analyzed by age (≤65 and >65) and sex at 1 and 3 years during 2001-2004 and 2005-2008.

Conclusions:

Our study showed that there is ethnic disparity in CML survival. Among CML patients diagnosed during 2005-2008, AA and Other races had superior survival rates compared to Caucasians.