The pooled HR = 0.47 (95% CI 0.36–0.62, P < 0.00001), which indicated that higher HCP5 expression in the tumor tissues of patients with non-small cell lung cancer, colorectal cancer, oral squamous cell carcinoma, clear cell renal cell carcinoma, gastric cancer and osteosarcoma were associated with a poor OS. This evidence concerns the gene HCP5 and oral cavity squamous cell carcinoma.