Cognitive function following cancer and cancer treatment has been an area of accelerated research over the last 20-30 years, explains Zev Nakamura, MD. “Most recently, there has been increasing appreciation of the importance of inquiring about patients’ own evaluation of these cognitive difficulties,” Dr. Nakamura says. “Up until our study, however, there has never been research describing how these cognitive difficulties, as described by patients with multiple myeloma (MM), change over time.”

For a study published in Clinical Lymphoma, Myeloma & Leukemia, Dr. Nakamura and colleagues aimed to evaluate how common and how severe cognitive problems are in this population. They also sought to identify risk factors for these cognitive difficulties. “We enrolled patients with MM who were receiving treatment in our cancer center clinics and asked them to answer questions about their memory and concentration,” Dr. Nakamura says. “We then repeated these questions at 3 months and 6 months after they enrolled. To evaluate potential risk factors for cognitive problems, we also asked them to complete assessments related to aspects of psychological, social, and physical function.”

Patient-Reported CRCI Observed in 30% of Participants at 6 Months

A total of 104 adults with MM with a mean age of 67 were included in the study. The European Organization for Research and Treatment of Cancer Quality of Life of Cancer Patients Core 30 (EORTC QLQ-C30) tool was used to assess cognitive function, with cancer-related cognitive impairment (CRCI) defined as scores of less than 75. To investigate differences by group and differences in changes over time by group, generalized estimate equation models were used. Patient-reported CRCI was observed in 18% at enrollment, 21% at 3 months, and 30% at 6 months. Patients with impairments in physical function (P=0.002), performance status (P=0.04), and instrumental activities of daily living (P=0.02) reported worse cognitive function, as well as those who were pre frail/frail (P=0.02) and depressed (P=0.049).

Clinicians Should Inquire About Patients’ Cognitive Symptoms Regularly

Dr. Nakamura and colleagues observed three key findings from their study. “The most important points to emphasize are 1) patent reported cognitive difficulties are common in MM, 2) they become more common over time
as patients live with their cancer, and 3) patients with lower levels of education are most at risk for cognitive decline over time,” Dr. Nakamura notes. During a 6-month period, patients’ self-reported cognitive function declined over time, the study team observed (Figure). “While on average, patients’ cognition was within the normal range, a substantial minority—30%—reported impairments by the completion of our study,” Dr. Nakamura adds. “Our findings emphasize the importance of physicians inquiring about their patients’ cognitive symptoms and doing so
regularly over time as patients progress through various treatments for their cancer.”

The study team concurs that future studies are needed to identify risk factors for adverse cognitive outcomes to identify patents who are most at risk and, by extension, help physicians recognize which patients would benefit most from close monitoring of their symptoms. “Identification of risk factors that are modifiable would facilitate future research on ways to prevent to treat these cognitive problems,” Dr. Nakamura says.