Muscle wasting shortens postsurgery survival in older CRC patients

Muscle wasting is a risk factor for death in older patients undergoing colorectal cancer (CRC) surgery, a recent study has found.

The study included 233 patients (aged ≥70 years, 40 percent women) who underwent surgery for nonmetastatic CRC. Muscle mass was measured using cross-sectional area scans of skeletal muscle at the level of the third lumbar vertebra; those with >1 standard deviation decrease in muscle mass were deemed to have muscle wasting. The primary outcome was overall survival (OS).

The cohort showed a mean relative change in muscle mass of 1.6±5.7 percent. Thirty-four patients qualified for muscle wasting, with a median decline in muscle mass of 8.1 percent.

Over a median follow-up of 4.7 years, 53 patients died, yielding a mortality rate of 22.7 percent. CRC was the cause of death in 22 patients (41.5 percent). Multivariable Cox regression analysis, adjusted for age, recurrence, and baseline skeletal muscle index, found that patients qualifying for muscle wasting were nearly three times as likely to die from all causes (adjusted hazard ratio [HR], 2.8, 95 percent confidence interval [CI], 1.5–5.4; p=0.002).

Incorporating rectal cancer and adjuvant therapy in the model did not meaningfully alter the principal findings. Moreover, muscle wasting remained a significant risk factor for mortality in the subgroup of patients with no evidence of recurrent cancer (adjusted HR, 2.7, 95 percent CI, 1.2–2.6; p=0.02).

“Measuring changes in muscle mass on follow-up computed tomography scans may improve risk prediction in this patient group. Future studies should address the aetiology of muscle wasting in older CRC patients,” the researchers said.