Sarcopenia is associated with higher toxicity and poor prognosis of nasopharyngeal carcinoma

Abstract

Background: Given the growing evidence that sarcopenia is associated with toxicity and survival in various cancers, we investigated its significance in patients with nasopharyngeal carcinoma (NPC) receiving concurrent chemoradiotherapy (CCRT).

Methods: In this retrospective analysis, we studied 862 NPC patients who had received CCRT between 2010 and 2014. Sarcopenia was determined using routine pre-radiotherapy computed tomography (CT) simulation scans at the third cervical vertebral level. Receiver-operating characteristic curve analyses were used to determine the optimal cutoff values. Propensity score matching (PSM) was applied to develop comparable cohorts of patients with or without sarcopenia.

Results: A total of 862 patients were included as the primary cohort, and 308 patients were matched and regarded as the matched cohort. In the primary cohort, the 5-year overall survival (OS), locoregional recurrence-free survival, and distant metastasis-free survival (DMFS) rates for the sarcopenia group versus non-sarcopenia group were 78.2% versus 93.6% (p < 0.001), 89.4% versus 87.9% (p = 0.918), and 82.5% versus 89.0% (p = 0.007), respectively. Univariate and multivariate survival analyses revealed that sarcopenia was an independent predictor of OS (p < 0.001 and p < 0.001) and DMFS (p = 0.009, p = 0.034). Patients with sarcopenia experienced significantly higher rates of treatment-related toxicities compared with patients without sarcopenia (p = 0.032). In addition, patients with sarcopenia also experienced significantly worse treatment response than those without sarcopenia (p = 0.004). Similar results were found in a PSM cohort.

Conclusion: The current findings support that sarcopenia is a promising indicator for predicting clinical outcomes in NPC patients receiving CCRT. A simple and rapid analysis on CT simulation images can provide information about the therapeutic toxicity and survival prognosis, consequently guiding personalized multi-modality interventions during CCRT.

Keywords: concurrent chemoradiotherapy; nasopharyngeal carcinoma; sarcopenia; survival; toxicity; treatment response.

Figure 1.

Slice of computed tomography (CT) simulation images of skeletal muscle at the level of the third cervical vertebra (C3). We measured the cross-sectional area of the sternocleidomastoid and paravertebral muscles on an axial slice at the level of C3 vertebrae; the CT Hounsfield unit thresholds were −29 to +150 for skeletal muscle.

Figure 2.

Predictive ability of sarcopenia by receiver-operating characteristic curve (ROC) analysis. ROC curve analyses by overall survival status were used to determine the optimal cutoff points for the skeletal muscle index. Area under the ROC curve of sarcopenia was 0.631 (95% confidence interval: 0.55–0.72; p = 0.001).

Figure 3.

Kaplan–Meier survival curves for overall survival (OS), locoregional recurrence-free survival-free survival (LRFS), and distant metastasis-free survival (DMFS) in the primary cohort and the propensity score matching (PSM) cohort. Kaplan-Meier curves for: (A) OS in the primary cohort; (B) OS in the PSM cohort; (C) LRFS in the primary cohort; (D) LRFS in the PSM cohort; (E) DMFS in the primary cohort; (F) DMFS in the PSM cohort. Survival curves were calculated using the Kaplan–Meier method and compared using the log-rank test.