The distress thermometer predicts subjective, but not objective, cognitive complaints six months after treatment initiation in cancer patients

Objectives: Research has indicated that cancer-related cognitive impairments (CRCI) may be influenced by psychosocial factors such as distress, worry and fatigue. Therefore, we aimed to validate the distress thermometer (DT) as a screening tool to detect CRCI six months post-treatment-initiation in a group of general cancer patients. Methods: Patients (≥18 years, n = 125) with a histologically confirmed diagnosis of a solid cancer or hematological malignancy, scheduled for a curative treatment, were evaluated at baseline (T0) and six months post-treatment-initiation (T1) for CRCI by a neuropsychological assessment, including patient-reported outcome measures (PROMs). Assessed cognitive domains included premorbid intelligence, attention, processing speed, flexibility, verbal and visual episodic memory and verbal fluency. PROMs entailed distress (DT, cut-off ≥4, range 0–10), anxiety and depression, fatigue (FACIT-fatigue scale) and subjective cognitive complaints. Results: At T0, 60.4% of patients showed a DT score of ≥4, whereas 50% met this criterion at T1. According to the definition of the International Cognition and Cancer Task Force, 25.5% and 28.3% of patients presented with a CRCI at T0 and T1, respectively. When evaluating the DT as a screening tool for CRCI at T1, data showed an inverse relationship between the DT and CRCI. ROC-curve analysis revealed an AUC <0.5. ROC-curve analyses evaluating the DT and FACIT-fatigue scale as screening tools for subjective cognitive complaints showed an AUC ± SE of, respectively, 0.642 ± 0.067 and 0.794 ± 0.057. Conclusions: The DT at T0 cannot be used to screen for objective CRCI at T1, but both the DT and FACIT-fatigue scale at T0 showed potential as screening tools for subjective cognitive complaints at T1.