The paper presents a study on the changes in cognitive functioning in patients undergoing chemotherapy with diagnosed multiple myeloma (MM). The aim of the study was to answer the following two main research questions: Does the treatment stage differentiate the functioning of cognitive processes in patients with diagnosed MM and to what extent? Is it possible to treat biological factors (TNF-α, IL-6, IL-10, and BDNF) as predictors of patients’ cognitive functioning? The patients were examined twice, before the treatment and after 4–6 cycles of chemotherapy. Selected neuropsychological research methods as well as experimental and clinical trials were employed to diagnose the patients’ general cognitive state, attention, memory, and executive functions. The level of biological factors was assessed with the ELISA test. The results show that the patients’ cognitive functioning was worse before the treatment than during the cytostatic therapy. It was also possible to predict the cognitive state of patients suffering from multiple myeloma based on a selected biological parameter (neurotrophin BDNF).

Introduction: The aim of the study was to illustrate the difference in how multiple myeloma and its treatment affect the cognitive functioning of both older and younger patients. Material and methods: The study involved the use of selected neuropsychological methods, i.e., experimental trials based on the Battery of Tests for Assessing Cognitive Functions PU1 and the Choynowski’s Memory Scale. Results: The interaction of health status and age appeared to be a differentiating factor between subjects under and over 65 years of age. Younger people with multiple myeloma displayed poorer performance in direct auditory memory compared to subjects of the same age without a cancer diagnosis. Similarly, regarding long-term verbal memory, patients in middle adulthood showed inferior performance in verbal memory as compared to those without multiple myeloma. Phonemic and semantic verbal fluency levels were also lower across some indicators in younger patients compared to older people with plasma cell myeloma. Better task performance by younger patients subjects with cancer was only noticeable in terms of short-term visual memory. Discussion and conclusions: Decreased cognitive functioning in the middle adulthood group was associated with a worse disease course. Although the disease progresses rapidly and is detected at an advanced stage, but this does not translate negatively into patient survival, which results from a good response to treatment, mainly bone marrow transplantation. The younger age group is also subjected to more aggressive forms of treatment, known as high-dose chemotherapy, which may be associated with their poorer condition and diminished mental and physical condition.