Based on the information reported by 10 included studies [17, 18, 21–28], we explored the association of PIK3CA gene mutation with the sex (male vs. female), age (≥60 vs. <60), lymph node metastasis (+ vs. -), TNM stage (advanced vs. limited), and smoking history (yes vs. no). This evidence concerns the gene PIK3CA and metastatic malignant neoplasm in the lymph nodes.