Dose Delays, Dose Reductions, and Relative Total Dose Intensity in Patients with Advanced Cancer Who Exercised During Neoadjuvant Chemotherapy Treatment

SIGNIFICANCE & BACKGROUND: When it comes to chemotherapy, maintaining the dose and schedule of treatment are of vital importance, as clinical evidence suggests that this is associated with optimal treatment outcomes. Yet, dose delays and reductions are common methods of mitigating the chemotherapy-induced side effects of treatment. Despite the fact that maintaining RDI is important to achieve improved outcome, a substantial proportion of patients are given less than 85% of the suggest dose. Exercise has been successfully shown to attenuate chemotherapy-related symptoms that frequently cluster together. PURPOSE: In light of importance of maintaining dose intensity, we conducted a retrospective analysis in patients with advanced disease treated with adjuvant or neoadjuvant chemotherapy regimens and who completed exercise training during treatment. INTERVENTIONS: After obtaining IRB approval, data were collected retrospectively in a chart review of 184 patients, aged 18 years or older and treated for Stage IIIA-IV cancer. Data collection included baseline patient demographics and clinical characteristics, including age at diagnosis, cancer stage at initial diagnosis, chemotherapy regimen, and planned dose and schedule. Specific variables that were collected include: cardiovascular changes, treatment-related side effects, treatment compliance, and medications. All patients completed at least 12 weeks of prescribed, individualized exercise. Each program included cardiovascular, resistance training, and flexibility components, and were completed under the supervision of a certified exercise oncology trainer once a week. EVALUATION: RDI was measured for each myelosuppressive agent in a regimen over the entire chemotherapy course and then averaged across the myelosuppressive agents in a regimen. An RDI of less than 85% was designated as the clinically meaningful threshold for reduction in RDI based on previously published studies. DISCUSSION: A considerable proportion of patients across regimens had dose delays (18.3%-74.3%) and dose reductions (18.1%-84.6%). Further between 12% and 83.9% of patients missed at least one dose of a myelosuppressive agent that was part of their standard regimen. Overall, 50.8% of patients received less than 85% of the RDI. INNOVATION: Patients with advanced cancer who adhered to their exercise regimen, chemotherapy dose delays and dose reductions were relatively common among tumor types and treatment regimens. However, these delays and reductions occurred significantly less frequently than previously published data