Sarcopenia and its relation to response on the first CT scan
The number of patients who developed sarcopenia during chemotherapy treatment was 34 (30.3%). After treatment with pembrolizumab after the first CT scan evaluation, these patients were subdivided as follows: 15 were HPs, 4 were PPs, 7 were Ps, and 8 were NPs. There was a significant relationship between the presence of sarcopenia and the response on the first CT scan (Table 1).
The Kruskal-Wallis one-way analysis of variance showed that there were significant differences in ∆PMMA only between HPs and Ps (16.2±4.8 vs 8.3±8.1; p=0.009) and NPs and HPs (5.8±13.8 vs 16.2±4.8; p<0.0001). The Mann-Whitney U test showed that patients with sarcopenia had significantly higher NLR2 and PLR2 values than patients without sarcopenia (7.9±3.2 vs 3.6±2.3 and 315.9±157.9 vs 168.7±93.8, respectively; both p<0.0001). ROC analysis revealed that at the cutoff value of ΔPMMA≥10% could distinguish between patients with or without HPD with an AUC=0.89 (95% CI, 0.82-0.96; p<0.0001), and with a sensitivity of 93.8% and specificity of 79.2% (Figure 1C). After adjustment for age, sex, PD-L1 expression, number of metastatic sites, NLR, PLR and their derivations, higher levels of ∆PMMA were associated with a decreased likelihood of being a P vs an HP (OR, 0.81; 95% CI, 0.65-0.99; p=0.047) and being an NP vs an HP (OR, 0.76; 95% CI, 0.62-0.94; p=0.012).
A significant but weak correlation was detected between ∆PMMA and NLR2 (rho=0.365), ∆PMMA and PLR2 (rho=0.279), and ∆PMMA and age (rho=0.292).