Do Ethnicity, Age, or Gender Independently Predict Overall Survival in Patients with Acute Myeloid Leukemia – a SEER Review of AML Diagnosis from 2004-2007.

Background: Acute Myelogenous Leukemia (AML) portends a poor prognosis accounting for substantial morbidity and mortality among hematologic malignancies. While studies have reported that older age, adverse cytogenetics, and molecular markers implicate survival, there is a considerable scarcity of epidemiologic literature to enhance our understanding of this disease. We aimed to study the epidemiology and survival outcome of AML and its correlation with the age, race, gender and region of diagnosis by reviewing the Surveillance, Epidemiology, and End Result Program (SEER database).

Methods: The SEER database (version 8.1.5) was reviewed for patients with histologically confirmed non APL-AML (ICD-O-3) between 2004-2007. Age of included patients ranged from 15 years to 90 years. Collected variables in the analysis included: date of diagnosis, age at diagnosis, gender, ethnicity, location of diagnosis, reported intervals of follow up and 3- year overall survival (OS). Primary outcome was 3-year median OS correlation with age, race and gender. All SEER registries were included in the analysis. Data were analyzed using Kaplan Meier and Cox proportional hazard regression model.

Results: A total of 13,238 pts with non APL-AML were included between 2004 and 2007. The mean age in was 61.6 years. The Caucasian to non-Caucasian race ratio was 5:1 and male to Female ratio was 7:6. The 3-year overall survival was statistically significant for ethnicity as non-Caucasian group had better 3 year OS (26.8%) compared with Caucasians (23.45 %, p = 0.0009). However, the association with overall survival based on ethnicity was not significant after adjusting for region, gender and age (p = 0.5881). When examining for gender, female patients demonstrated improved 3 year OS compared with male patients which held true irrespective of region, race, or age (p = 0.0036). OS was also associated with region of diagnosis as patients in East region had better survival when compared with patients in West region (HR 0.96). The patients in South and Midwest regions had poorer survival when compared with the West region (HR 1.01 and 1.13, respectively). This survival difference was statistically significant after adjusting for age, race and gender. Interestingly, when OS was analyzed according to age, the hazard ratio increased by 20% with every 5 year increment in age despite adjustments for region, race, and gender (p < 0.001).

Conclusion: Non APL-AML OS was statistically associated with gender, race, age and region of diagnosis. Non-Caucasian group had better OS compared with Caucasians. However, this association was not significant after adjusting for region, gender and age. However, female patients demonstrated improved 3 year OS compared with male patients after adjusting for confounding factors. Association with region showed statistically significant difference according to region of diagnosis favoring those diagnosed in the East. Interestingly, when OS was analyzed according to age, the hazard ratio increased by 20% with every 5 year increment in age despite adjustments for region, race, and gender. This study suggest that female gender may serve as a favorable risk factor in AML and further confirms that advancing age may confer inferior survival in this disease population.