Cardiorespiratory fitness in long-term lymphoma survivors after high-dose chemotherapy with autologous stem cell transplantation

Background: Cardiorespiratory fitness as measured by peak oxygen consumption (VO2peak) is a strong predictor of longevity and may be compromised by anticancer therapy, inactivity, and smoking. We compared VO2peak among lymphoma survivors (LSs) with reference data from healthy sedentary subjects, after a 10.2-year (mean) follow-up post high-dose chemotherapy with autologous stem cell transplantation (HDT-ASCT). We further examined the association between VO2peak and treatment, physical activity, smoking, pulmonary, and cardiac function. Methods: Lymphoma survivors treated with HDT-ASCT in Norway 1987-2008 were eligible. VO2peak was assessed by cardiopulmonary exercise testing. Pulmonary function testing and echocardiography were also conducted. Data on treatment, physical activity, and smoking were collected from hospital records and questionnaires. VO2peak was compared with age-sex predicted reference data. Linear regression was used to associate clinical factors with VO2peak cross-sectionally. Results: A total of 194 LSs without heart failure were studied. Mean VO2peak was 4.5% and 7.7% below norms in females and males, respectively. Twenty-two percent had impaired (<80% predicted) VO2peak. Decreasing VO2peak was associated with impaired diffusion capacity and current smoking, while physical activity level and VO2peak were positively associated. Conclusion: We suggest increased attention towards physical activity counseling and smoking cessation advice to preserve cardiorespiratory fitness in LSs after HDT-ASCT. Patients with impaired diffusion capacity may benefit from subsequent monitoring to detect pulmonary vascular diseases.