Objective physical and mental markers of self-reported fatigue in women undergoing (neo)adjuvant chemotherapy for early-stage breast cancer

Abstract

BACKGROUND: Objective, treatment-independent markers of cancer-related fatigue are needed to advance clinical trials. In the current study, the authors evaluated physical, neurocognitive, and serologic markers for correlation with self-reported fatigue before and after (neo)adjuvant chemotherapy for patients with early-stage breast cancer. METHODS: Women with AJCC TNM Stage I-III breast cancer consented to assessment before and after the completion of 4 cycles of dose-dense doxorubicin and cyclophosphamide. Assessment included self-reported fatigue (using the Brief Fatigue Inventory), depression (using the Center for Epidemiologic Studies–Depression Scale [CES-D]), Pittsburgh Sleep Quality Index, and 28 objective measures (grip strength in dominant and nondominant hands, 6-minute walk, daily total energy expenditure, 14 neurocognitive tests, and 10 serologic markers). Generalized linear regression models of fatigue were constructed (1 model per marker), and adjusted for depression, timing before/after chemotherapy, menopausal status, obesity, and educational level. P values were adjusted to control the False Discovery Rate. RESULTS: Of 28 subjects, 3 withdrew without completing baseline assessments. Prechemotherapy and postchemotherapy data were available for the evaluation of physical measures (25 subjects aged 50.6 ± 9.5 years), neurocognitive tests (22 subjects), and serologic markers (10 subjects). On covariate-adjusted analysis, interleukin (IL)-12 was found to be associated with fatigue at both assessments (P