Andrea Carter

Nonadherence to Oral Mercaptopurine and Risk of Relapse in Hispanic and Non-Hispanic White Children With Acute Lymphoblastic Leukemia: A Report From the Children's Oncology Group

PURPOSE Systemic exposure to mercaptopurine (MP) is critical for durable remissions in children with acute lymphoblastic leukemia (ALL). Nonadherence to oral MP could increase relapse risk and also contribute to inferior outcome in Hispanics. This study identified determinants of adherence and described impact of adherence on relapse, both overall and by ethnicity. PATIENTS AND METHODS A total of 327 children with ALL (169 Hispanic; 158 non-Hispanic white) participated. Medication event-monitoring system caps recorded date and time of MP bottle openings. Adherence rate, calculated monthly, was defined as ratio of days of MP bottle opening to days when MP was prescribed. RESULTS After 53,394 person-days of monitoring, adherence declined from 94.7% (month 1) to 90.2% (month 6; P < .001). Mean adherence over 6 months was significantly lower among Hispanics (88.4% v 94.8%; P < .001), patients age ≥ 12 years (85.8% v 93.1%; P < .001), and patients from single-mother households (80.6% v 93.1%; P = .001). A progressive increase in relapse was observed with decreasing adherence (reference: adherence ≥ 95%; 94.9% to 90%: hazard ratio [HR], 4.1; 95% CI,1.2 to 13.5; P = .02; 89.9% to 85%: HR, 4.0; 95% CI, 1.0 to 15.5; P = .04; < 85%: HR. 5.7; 95% CI, 1.9 to 16.8; P = .002). Cumulative incidence of relapse (± standard deviation) was higher among Hispanics (16.5% ± 4.0% v 6.3% ± 2.2%; P = .02). Association between Hispanic ethnicity and relapse (HR, 2.6; 95% CI, 1.1 to 6.1; P = .02) became nonsignificant (HR, 1.8; 95% CI, 0.6 to 5.2; P = .26) after adjusting for adherence and socioeconomic status. At adherence rates ≥ 90%, Hispanics continued to demonstrate higher relapse, whereas at rates < 90%, relapse risk was comparable to that of non-Hispanic whites. CONCLUSION Lower adherence to oral MP increases relapse risk. Ethnic difference in relapse risk differs by level of adherence-an observation currently under investigation.

Health Care Utilization by Adult Long-term Survivors of Hematopoietic Cell Transplant: Report from the Bone Marrow Transplant Survivor Study

The high intensity of therapy and prolonged immune suppression after hematopoietic cell transplantation (HCT) increase the risk of long-term complications and health care needs among survivors. The aim of this study was to evaluate the current status of health care utilization by long-term HCT survivors and to identify factors associated with lack of utilization. A total of 845 individuals who had undergone HCT between 1974 and 1998 at age 21 years or older and survived 2 or more years after HCT participated in the study. Health care utilization was assessed through a mailed questionnaire in three domains: general contact with health care system, general physical examination, and cancer/HCT–related visit. The median age at HCT was 38.2 years, and the median length of follow-up was 6.4 years. Overall, 98% of allogeneic and 94% of autologous HCT survivors reported medical contact 11+ years after HCT. Cancer/HCT–related visits decreased with increasing time from HCT (allogeneic HCT, 98-57%; autologous HCT, 94-63%). The prevalence of general physical examination increased with time (allogeneic HCT, 56-74%; autologous HCT, 72-81%). Primary care physicians provide health care for an increasing number of adult long-term survivors of HCT, emphasizing the need for increased awareness of the long-term follow-up needs of the HCT survivors by the health care providers. (Cancer Epidemiol Biomarkers Prev 2007;16(4):834–9)