Disparities in chronic myeloid leukemia survival by age, gender, and ethnicity in pre- and post-imatinib eras in the US.

BACKGROUND

Since May 2001, imatinib mesylate has become the first-line therapy for chronic myeloid leukemia (CML) but the survival pattern by age, sex, and ethnicity is not clear.

MATERIAL AND METHODS

We analyzed the Surveillance, Epidemiology, and End Results (SEERStat) database to compare survival rates in CML among Caucasians, African-Americans (AA), and other races, and also within each race to see survival differences from the pre-imatinib (1973-2000) to post-imatinib eras (2002-2008). We used Z-tests in SEERStat to compare relative survival rates categorized by race, gender, and age groups (all ages, < 50, 50+ years).

RESULTS

The three-year relative survival rates among Caucasians, AA, and other races in the pre-imatinib era were 44.9 ± 0.6%, 46.8 ± 1.8%, and 48.0 ± 2.2%, respectively, and in the post-imatinib era 64.4 ± 0.8%, 67.3 ± 2.4%, and 69.6 ± 1.6%, respectively. The relative survival increased from the pre-to post-imatinib era for all ethnic groups. In the post-imatinib era, three-year relative survival rates among young AA women were significantly lower (Z-value = -2.54, p = 0.011) than young Caucasian women, 80.5 ± 4.5% (n = 105) vs. 90.3 ± 1.4% (n = 589).

CONCLUSIONS

The relative survival rates of CML patients have improved in the post-imatinib era. However, the improvement in survival rates has been modest in this population-based data compared to those reported from randomized trials. Improvement in survival among older patients is lower than in younger patients. Young (<50 years) AA women with CML had lower relative survival rates compared to young Caucasian women in the post-imatinib era.