Abstract

Despite therapeutic advances, cancer patients demonstrate an increased risk of developing disease- and treatment-related cardiovascular (CV) and metabolic morbidity, as compared to their peers. In light of emerging evidence, cancer- and treatment-related damage to the autonomic nervous system (ANS) may play a role in the development of the aforementioned morbidity risks. This assertion needs to be verified. The purpose of this study was to assess the feasibility of conducting concurrent ANS and CV evaluations in adolescent and young adult (AYA) cancer patients undergoing treatment for various cancers by defining the i) methodological pitfalls and best-practice criteria for ANS testing in cancer, and ii) provide initial physiologic evidence of autonomic perturbations in cancer patients using the composite autonomic scoring scale (CASS). Thirteen patients were assessed, pre-treatment (T1) and following 4 cycles of chemotherapy (T2), using CASS and a modified Astrand-Rhyming cycle ergometer protocol, and their results compared to 13 sex and age-match controls. Overall, the average success rate in achieving the targeted feasibility criteria (FC) was 98.5%. Additionally, according to the CASS, there was evidence of ANS impairment at T1 in 5 of 13 patients, which persisted in 4 of 12 patients at T2, compared to 0 of 13 controls at T1 and 1 of 12 controls at T2. Using a 2 x 2 repeated measures ANOVA, treatment led to a significant improvement in patient heart rate (HR) recovery [F=6.188, p=0.027]. Results from this feasibility study suggest the investigation of ANS function in AYA cancer patients undergoing chemotherapy is possible, provided the proper precautions are taken. Furthermore, to the best of our knowledge, this is the first study to report evidence of ANS impairment using CASS and sudomotor dysfunction in this population.