Table 1 clinicopathologic characteristics and PD-L2 expression in 70 patients
2, correlation between PD-L2 expression and clinicopathologic characteristics
Table 2 shows the clinicopathologic characteristics stratified by PD-L2 and PD-L2 scores stratified by clinicopathologic characteristics. The PD-L2 expression was significantly associated WHO histology of type B2 and B3 thymoma (p=0.008). And the PD-L2 scores were significantly higher in patients with WHO type B2 and B3 (98.9 vs 33.4, p=0.007). The PD-L2 positive group also had a significantly higher proportion of the status of MG than without MG (p=0.002). The PD-L2 scores were significantly higher in MG positive group (124.1 vs 23.3, p=0.001). In addition, PD-L2 positive tumors showed a significantly smaller tumor size than the PD-L2 negative group (P=0.017). Ectopic thymus has been significantly more often seen in the PD-L2 positive group than the negative group (p=0.035). However, no significantly difference considering PD-L2 expression was observed in the age (p=0.275), gender (p=0.621) or Masaoka-Koga stage (p=0.791). The PD-L2 scores were not significantly different in gender (p=0.736), age (p=0.23), Masaoka-Koga stage (p=0.26), tumor size (p=0.111) or ectopic thymus (p=0.115). We conducted a logistic regression model to investigate PD-L2 expression (Table 3). The status of MG (OR 12.601, 95%CI 2.406-65.995, p=0.02) and age (OR 0.199, 95%CI 0.046-0.863, p=0.031) were significantly associated with the expression of PD-L2. WHO histology type, Masaoka-Koga stage, tumor size or ectopic thymus were not associated with PD-L2 expression.