Exercise May Reduce Cognitive Impairment in Cancer Patients During Chemo

The start of chemotherapy can be a daunting time for patients and emerging research suggests a simple intervention – exercise – may help mitigate one of the more debilitating side effects: cognitive impairment. A randomized phase 3 trial indicates that a home-based exercise program initiated alongside chemotherapy can lessen cognitive decline and mental fatigue experienced by those undergoing cancer treatment.

As many as 75% of patients experience cancer-related cognitive impairment during treatment, often referred to as “chemo brain.” This condition manifests as difficulties with memory, concentration, information processing, and multitasking, significantly impacting daily life. The findings, published in the Journal of the National Comprehensive Cancer Network, highlight the potential for a proactive, accessible approach to supportive cancer care.

The EXCAP Trial: Exercise and Cognitive Function

Researchers, led by Karen M. Mustian, PhD, MPH, of the University of Rochester, enrolled 687 chemotherapy-naive individuals with various cancer types – excluding leukemia – in a multicenter trial. The most common cancers represented were breast (83%), colon (5%), lymphoma (4%), and lung cancer (3%). Participants, with a good performance status (Karnofsky score of 70 or higher), were randomly assigned to either a 6-week, home-based exercise program (EXCAP) involving aerobic walking and resistance band exercises, or to usual care. The study utilized a “teach-back” method to ensure correct exercise technique, with staff providing regular check-ins and support.

All participants tracked their daily steps with a pedometer and recorded resistance training time. Cognitive impairment was assessed using the Functional Assessment of Cancer Therapy–Cognitive Function (FACT-Cog), although mental fatigue was measured with the Multidimensional Fatigue Symptom Inventory (MFSI). The researchers aimed to determine if exercise, believed to modulate inflammation, could reduce these common chemotherapy side effects.

Key Findings: Less Decline, Less Fatigue

The analysis, including 547 patients with complete data, revealed that all participants experienced some degree of cognitive decline from baseline. However, those in the exercise group showed significantly less decline, particularly those receiving chemotherapy in 2-week cycles. Specifically, the exercise intervention was associated with a 7-point difference in cognitive impairment scores (P = .04), a 4.1-point difference in perceived cognitive impairment (P = .05), and a reduction in reports of cognitive issues from others (0.6 points, P = .02).

While the benefits weren’t statistically significant for those on 3-week or 4-week chemotherapy cycles, trends toward improvement were observed across all schedules. Importantly, participants in the exercise group reported less mental fatigue overall (a –0.7 point difference, P = .02) regardless of their chemotherapy cycle length. Healio reports that participants in the exercise group maintained their pre-intervention step counts, and consistently engaged in resistance band exercises three times per week.

Inflammation and Cognitive Protection

Interestingly, blood samples collected during the trial suggested a link between a healthy inflammatory response and better cognitive outcomes. Researchers observed that increases in both anti-inflammatory and pro-inflammatory cytokines during chemotherapy were associated with higher cognitive assessment scores. This suggests that exercise may be influencing the body’s inflammatory response in a way that protects cognitive function. Previous research has also explored exercise as a therapeutic intervention for colon cancer, highlighting its potential benefits beyond symptom management.

What This Means for Patients

“This really stresses the importance that patients avoid inactivity at all costs and, if possible, try to maintain their pretreatment activity levels,” explained Dr. Mustian. “A huge increase in the volume of exercise or physical activity is not necessarily required to see terrific benefits in terms of minimizing these types of side effects.” The study underscores that even moderate, accessible exercise can have a meaningful impact on quality of life during cancer treatment.

Cognitive impairment can be a profoundly disruptive side effect, interfering with daily activities like managing finances, preparing meals, or even holding a conversation. The ability to mitigate these effects through a simple intervention like exercise offers a significant benefit to patients navigating the challenges of cancer therapy. The American Cancer Society provides comprehensive guidance on physical activity for cancer patients and survivors.

Study Limitations and Future Directions

The researchers acknowledge several limitations. The study lacked a behavioral placebo, meaning it’s difficult to determine if the benefits were solely due to exercise or also related to the attention and support provided to the intervention group. The cohort was predominantly female, non-Hispanic white, and diagnosed with breast cancer, which may limit the generalizability of the findings to other populations.

Future research will focus on identifying the optimal types and doses of exercise for cognitive protection, as well as exploring the long-term benefits of this intervention. Researchers are also investigating the potential of yoga and a multi-component approach to address cognitive impairment and treatment tolerability.

Integrating Exercise into Cancer Care

The findings reinforce existing recommendations from organizations like the American Society of Clinical Oncology (ASCO) and the American College of Sports Medicine, which advocate for exercise as standard care for managing cancer-related side effects. Clinicians are encouraged to discuss the benefits of physical activity with patients initiating chemotherapy and to connect them with resources for safe and effective exercise programs. The American College of Sports Medicine’s website offers a directory of exercise oncology specialists.

As Dr. Mustian emphasizes, the goal isn’t to turn patients into athletes, but to encourage them to remain active and avoid the detrimental effects of inactivity during a challenging time. This research offers a hopeful message: a proactive approach to physical activity can empower patients to better manage the cognitive and emotional toll of cancer treatment.