Cancer patient

receiving chemotherapy

Photo by Rhoda Baer

A study published in the British Journal of Hematology has revealed factors that appear to affect survival in patients with acute myeloid leukemia (AML).

The research showed that death was more likely among AML patients treated at centers not affiliated with the National Cancer Institute (NCI).

Death was also more likely for black patients, older patients, those without health insurance, and those who lived in poorer neighborhoods.

“Our study reveals that survival inequalities persist among vulnerable patients with acute myeloid leukemia, such as the uninsured, those of black race/ethnicity, and adolescents and young adults,” said study author Renata Abrahão, MD, of Cancer Prevention Institute of California.

“This study can serve as a baseline to compare changes in survival that may result from potential improvements in health insurance coverage following the implementation of the Affordable Care Act.”

Dr Abrahão and her colleagues analyzed 3935 AML patients who were 39 or younger between 1988 and 2011. The team used data from the California Cancer Registry, which participates in the Surveillance, Epidemiology and End Results program of the NCI.

The data revealed an increase over time in the 5-year survival rate, from 32.9% in 1988–1995 to 50% in 2004–2011. However, 58% of the patients (n=2272) died during follow-up. The overall median follow-up was 10 years, and the median time to death was 0.9 years.

A multivariate analysis revealed several subgroups of patients with worse survival.

Older patients had a greater risk of death when compared to patients ages 0 to 9. The hazard ratio (HR) was 1.23 for patients ages 10 to 19, 1.34 for patients ages 20 to 29, and 1.55 for patients ages 30 to 39.

Black patients had an increased risk of death as well. When compared with white patients, the HR was 1.27 for black patients, 1.05 for Hispanic patients, and 0.98 for Asian/Pacific Islanders.

Patients living in the neighborhoods with the lowest socioeconomic status had an HR of 1.14. And patients who received their initial care at a hospital not affiliated with the NCI had an HR of 1.18.

Health insurance information was only available for patients diagnosed from 1996 to 2011. Among these patients, the risk of death was higher among uninsured patients (HR=1.34) than among privately insured patients, but there was no difference between privately and publicly insured patients.

Explaining the findings

The researchers said AML diagnosis in older children, adolescents, and young adults may require more intensive treatment than in young children, which may lead to a higher probability of treatment-related complications. And recent studies have shown the biology of pediatric AML differs from adult AML, which may lead to a favorable prognosis in younger patients.

In addition, older children, adolescents, and young adults are less likely to participate in clinical trials and more likely to receive treatment at hospitals not affiliated with the NCI, when compared to younger children.

The researchers said it is not clear what factors accounted for the inferior survival observed among black patients. The team speculated that genetics may contribute to the difference in chemotherapy response or that black patients had less access to chemotherapy and other treatments such as hematopoietic stem cell transplant.

The association between lower socioeconomic status and death suggests a lack of access to treatment. The same can be said for the association between death and a lack of insurance.

“[T]his study showed that survival after AML remains low among young patients and highlights the need for new therapeutic regimens to treat this disease with various subtypes,” Dr Abrahão said.

“We emphasized the importance of linking population-based data with genetic and clinical information contained in the patients’ medical records in order to better understand the causes of survival inequalities.”

Factors appear to confer poor survival in AML