Patterns Of Care In Medicare Beneficiaries Diagnosed With Acute Lymphoblastic Leukemia

ALL is the most common childhood cancer, with remission rates exceeding 90% and 5-year survival exceeding 80% in pediatric patients. However, in older adult patients, ALL is associated with high morbidity and mortality. Nonetheless, because ALL is rare in older adults, information about patterns of care and outcomes in these patients is limited.

To characterize the treatment and mortality patterns in a cohort of older adults with ALL.

Using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, we identified a cohort of Medicare beneficiaries (including patients under age 65 enrolled due to disability) with a first primary cancer of ALL diagnosed between 2000 and 2007. Patients were followed using Medicare claims from the first day of the month of diagnosis through December 31, 2009. Patients were required to be enrolled in Medicare Parts A and B for at least 4 months prior to diagnosis, and those diagnosed on autopsy were excluded. Patients were followed until the first of the following events: death, change in Part A and B Medicare coverage, or end of follow-up. Chemotherapy was identified using available diagnosis and procedure codes in the outpatient and inpatient settings.

There were 646 ALL patients who accrued 653 patient-years of observation. During the observation period, 570 (88%) died. The median survival time was 160 days, with 25% of patients surviving ≤ 41 days, and 25% surviving ≥ 472 days. In the overall cohort, within 90 days of diagnosis, 345 (53%) had at least one inpatient or outpatient claim indicating chemotherapy was provided. Older age, higher comorbidity burden, and claims-based evidence of mobility limitations were each associated with a lower probability of receiving chemotherapy (Table). Of the 345 patients with at least one claim for chemotherapy, 271 (79%) had both inpatient and outpatient chemotherapy claims, 60 (17%) had only outpatient claims, and the remaining 14 (4%) had only inpatient claims. There were 557 individuals accounting for 1,164 inpatient admissions in the first 90 days after diagnosis. Among these patients, 84 (15%) died during their first admission. The average length of stay (LOS) for the initial admission was 12.6 days, and 25% had a LOS ≥ 20 days. Among the 472 (84.7%) patients alive after their first hospitalization, 329 (69.7%) were readmitted within the first 90 days following diagnosis.

About half of Medicare beneficiaries diagnosed with ALL between 2000 and 2007 received chemotherapy, the vast majority of whom received at least one treatment in an inpatient setting. Median survival time in the cohort was short, while the hospitalization rate, duration of hospitalization, in-hospital mortality rate, re-hospitalization rate, and overall mortality rate were high. Older adults with ALL would be expected to benefit from any improvements in treatment options.

Danese:Amgen, Inc.: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; MedImmune: Consultancy, Research Funding. Cetin:Amgen, Inc.: Employment. Katz:Amgen, Inc.: Employment. Kelsh:Amgen, Inc.: Employment. Gleeson:Amgen, Inc.: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; MedImmune: Consultancy, Research Funding. Griffiths:Amgen, Inc.: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; MedImmune: Consultancy, Research Funding.