Adolescent, Young Adult Leukemia Survivors Face Higher Long-term Mortality Rates

The short-term survival of adolescent and young adult (AYA) leukemia survivors has improved over time, but long-term mortality outcomes are not as clear. A recent study published in Cancer Epidemiology, Biomarkers & Prevention aimed to provide insight into long-term outcomes and found that these patients have higher mortality rates than the general population, even decades after diagnosis.

The population of AYA (aged 15-39 years) cancer survivors has grown in the last few decades due to increased rates of cancer in AYAs and better 5-year survival rates as treatments have improved. Two of the most common cancer diagnoses in AYAs are acute lymphocytic leukemia (ALL) and acute myeloid leukemia (AML), and 5-year survival for these cancer types decreases with age.

The current study explored the long-term survival patterns of AYA leukemia survivors and assessed demographic factors that may contribute to long-term survival based on data from the Surveillance, Epidemiology, and End Results (SEER) registry. A total of 1938 ALL 5-year survivors and 2350 AML 5-year survivors diagnosed between 1980 and 2009 were included in the study, with a median diagnosis age of 23 years in ALL and 28 years in AML. Median follow-up times from diagnosis were 12.3 years in ALL and 12.7 years in AML, and an accelerated failure time model was used to determine the effect of age at diagnosis, patient characteristics, and decade of diagnosis on long-term survival.

Overall, AML and ALL patients had similar survival, but both cohorts had lower survival compared with the general population. While the 10-year survival rate in the general population was 99%, AML survivors and ALL survivors has 10-year survival rates of 89% and 87%, respectively. At 30 years of follow-up, AYA leukemia survivors still showed lower survival rates than the general population.

Older age at diagnosis was associated decreased long-term survival in both groups, and male AML survivors survived 61% as long as females (95% CI, 0.45-0.82). The same difference between male and female survivors was not seen in ALL.

Over time, the length of survival for AYA leukemia survivors more than doubled, with patients diagnosed in the 1990s and 2000s living twice as long compared with patients diagnosed in the 1980s. In earlier decades, the leading cause of death in early survivorship was acute leukemia in both ALL and AML patients. But deaths due to acute leukemia eventually plateaued, and non-leukemia deaths in AYA leukemia survivors became more common than acute leukemia deaths at approximately 20 years of follow-up.

“Importantly, treatment advances leading to increased cure rates and improvements in supportive care, specifically for patients receiving stem cell transplants, have improved survival for AYA patients with leukemia diagnosed in more recent decades,” the authors wrote.

The authors noted that while past research has identified ethnic and socioeconomic status (SES) disparities in survival, this study did not produce statistically significant findings in that regard. Adjusting for SES and a limited cohort size may have to do with the lack of findings regarding either SES or ethnic disparities in this study, the authors wrote.

Overall, the findings suggest there is still work to do to improve long-term survival in AYA leukemia patients.

“While there have been improvements in late mortality, long-term survival for AYA leukemia survivors remains below that of the general population,” the authors concluded.“ Studies investigating risk factors for mortality and disparities in late effects among long-term AYA leukemia survivors are needed.”

Reference

Berkman AM, Andersen CR, Cuglievan B, et al. Long-term outcomes among adolescent and young adult survivors of acute leukemia: a surveillance, epidemiology, and end results analysis. Cancer Epidemiol Biomarkers Prev. Published online May 13, 2022. doi:10.1158/1055-9965.EPI-21-1388