Progressive sarcopenia, or loss of muscle mass, occurring after the diagnosis of colorectal cancer has a significantly negative impact on the overall and progression-free survival in patients, according to a study published in the American Journal of Roentgenology.

To evaluate the relationship between progressive sarcopenia’s impact on the prognostic association with patient survival, researchers retrospectively studied more than 100 patients with colorectal cancer who underwent CT at the time of diagnosis and six to 18 months after diagnosis. They were monitored for at least five years after diagnosis.

Changes in muscle mass were determined using the skeletal muscle index (SMI) and mean muscle attenuation of the psoas and paraspinal muscles at L4 vertebral level. Measurements combining psoas and paraspinal muscles were calculated and univariate and multivariate Cox proportional hazard analysis was performed to assess the link between survival and changes in SMI and attenuation. The researchers also ran the Kaplan-Meier analysis.

“The hypothesis of this study was that changes in CT measures of sarcopenia within the six to 18-month interval after diagnosis of cancer would have an association with overall and progression-free survival,” wrote lead author Kun-Yun Yeh, MD, PhD, Chang Gung Memorial Hospital, Keelung and Chang Gung University, College of Medicine in Taiwan, and colleagues. “Overall, a significant relationship between the change in muscle quantity (measured as SMI) and overall survival was established.”

The calculated hazard ratios for overall survival survival for changes in SMI and attenuation of the psoas muscle, paraspinal muscle and total muscle were significant. The hazard ratios for progression-free survival were 1.33, 1.41, and 1.23 for changes in SMI of the psoas muscle, paraspinal muscle, and total muscle. This was not significant. The Kaplan-Meier analysis illustrated significant difference in overall and progression-free survival based on sex-specific quartiles of muscle quantity and quality.

“One surprising result of our study was the lack of significant association of baseline SMI and attenuation with patient prognosis, which is at odds with prior reports,” the authors wrote. “We observed a trend toward worse overall and progression- free survival with lower baseline and follow-up SMI that did not reach statistical significance, but this may simply have been a result of the size of our patient population.”

The authors concluded preventing cancer-related sarcopenia is challenging, but additional research is needed.

“Additional investigation is warranted of the relationship of changes over time of CT-measured muscle quantity and quality to prognosis for patients with other cancers,” the authors wrote. “As the importance of these measures in informing the clinical status of patients becomes more recognized, practical implementation of time-efficient means of deriving these data will be crucial to mainstream clinical utilization.”