Prognostic value of paravertebral muscle density in patients with spinal metastases from gastrointestinal cancer.

PURPOSE: Morphometric analyses have shown that trunk muscle mass and density are associated with mortality in cancer patients. Because of the low incidence of spinal metastasis from gastrointestinal cancer and the limited life expectancy of these patients, few studies have been reported in this population. We evaluated the prognostic value of trunk muscle area and density in predicting overall survival.

METHODS

The data from 78 patients with spinal metastases from gastrointestinal cancer, collected from February 2009 to July 2016, were evaluated. Psoas muscle and paravertebral muscle area and density were measured at the L3 level on CT scans taken at the time nearest to the diagnosis of spinal metastasis. Cox proportional hazards analysis was performed to evaluate the factors independently associated with overall survival.

RESULTS

The mean patient age was 68.3 years (range, 42-88 years). The overall median survival time was 4.8 months: 2.2 months in the extremely rapid growth group (stomach, biliary tract, and pancreas) and 7.6 months in the rapid growth group (esophagus, liver, and colorectum). Multivariate analyses showed that lower paravertebral muscle density (HR 2.23 [95% CI 1.24-3.99], p = 0.007), extremely rapid growth group, presence of abnormal laboratory data, poor performance status, and chemotherapy after spinal metastasis were independent prognostic factors.

CONCLUSIONS

Median overall survival was poor among patients with spinal metastases from gastrointestinal carcinoma, especially among those with gastric, biliary tract, or pancreatic cancer. Lower paravertebral muscle density was an independent poor prognostic factor in patients with spinal metastases from gastrointestinal cancer.