New Predictor of Survival in Blood Cancer Patients
Introduction to Gait Speed
Researchers have identified a reliable and easy-to-measure predictor of survival and unplanned hospitalizations in patients with blood cancer: gait speed, or the speed at which patients walk. This measure has been recommended as a practical assessment of functional and physical performance in older cancer patients.
Understanding Frailty and Its Implications
Gait speed, along with grip strength, serves as an indicator of frailty. Frailty has been associated with increased chemotherapy-related toxicity, a poorer response to therapy, and higher mortality rates among blood cancer patients.
Research Findings from Dana-Farber Cancer Institute
Impact of Decreased Walking Speed
A study conducted by researchers at Dana-Farber Cancer Institute and the VA Boston Healthcare System revealed that for each 0.1 m/s decrease in walking speed, the risk of dying, unexpected hospitalization, or emergency-room visits rose by 22%, 33%, and 34%, respectively. This correlation was particularly strong among patients with non-Hodgkin lymphoma. The findings were published in the journal Blood.
Study Overview
The research involved 448 patients aged 75 years and older, with an average age of 79.7 years. Participants underwent various tests assessing cognition, frailty, gait speed, and grip strength. Gait speed was measured by timing how long it took patients to walk a distance of four meters at a normal pace. Patients were classified into three groups—frail, pre-frail, or robust—based on their gait speed.
Hospitalization Rates and Frailty
Follow-Up Results
A subset of 314 patients was monitored for an average of 13.8 months post-consultation. Findings indicated that nearly 20% of this group experienced unplanned hospitalizations, and 16.8% visited the emergency department. Previous studies have shown that hospitalization can lead to increased disability and mortality in older patients, especially in those who are frail.
Expert Insights
Dr. Driver, the senior author of the study, emphasized that relying solely on performance status may be insufficient for older patients. He stated, “The standard of care is to stratify treatments based on patients’ performance status… in older people we need to do more.”
Grip Strength as an Alternative Measure
Grip Strength Findings
While grip strength was found to be a strong predictor of survival rates, it did not correlate with hospitalization or emergency room visits. It may serve as an alternative measure for patients unable to walk.
Clinical Implications of Gait Speed Measurement
Routine Assessment Recommendations
Given the significant predictive power of gait speed, regardless of cancer type or aggressiveness, researchers advocate for its inclusion in routine clinical assessments for blood cancer patients. Dr. Driver noted the need for quick screening tests for frailty that can seamlessly integrate into clinic workflows. The gait speed test can be completed in under a minute, comparable to measuring blood pressure or other vital signs.
Functional Vital Sign Potential
Gait speed reflects multiple bodily systems involved in walking, including the musculoskeletal, cardiovascular, and nervous systems. Its adoption as a measure of physical function in other medical fields supports its classification as a “functional” vital sign for blood cancer patients. Future studies could explore whether interventions like physical therapy, walking aids, and avoiding sedative medications might enhance gait speed and its positive impact on survival rates.
Conclusion
The findings from this study underscore the importance of incorporating gait speed and grip strength assessments into the care plans for older patients with blood cancer, potentially leading to improved patient outcomes.
References
Liu MA, DuMontier C, Murillo A, Hshieh T, Bean JF, Soiffer RJ, Stone RM, Abel GA, Driver JA. Gait speed, grip strength and clinical outcomes in older patients with hematologic malignancies. Blood. 2019 Jun 5. Press release available at: https://medicalxpress.com/news/2019-06-clinical-outcomes-older-adults-blood.html