Predictive value of different proportion of lesion HLA-G expression in colorectal cancer

Differential expression of HLA-G has been observed among cancer types and tumors from individuals with the same type of cancer; however, its clinical significance is rather limited. In this study, expression and predictive relevance of HLA-G expression in 457 primary colorectal cancer (CRC, ncolon = 232, nrectal = 225) patients was investigated. Data showed 70.7% (323/457) of the CRC were HLA-G expression when the above 5% (HLA-GLow) was considered as positive, which wasn't associated with patient survival (p = 0.109). However, HLA-G expression above 55% (HLA-GHigh) was associated with a worse prognosis of CRC patients (p = 0.042). Furthermore, a shorter survival was found for the female (p = 0.042) and elder (p = 0.037) patients whose HLA-G expression was above HLA-GLow level. HLA-G expression above HLA-GHigh level showed a worse prognosis for female (p = 0.013), elder (p = 0.023), colon cancer (p = 0.016), advanced tumor burden (T3+4, p = 0.018), regional lymph node status (N1+2, p = 0.044), and advanced clinical stage patients (AJCC III+IV, p = 0.037). In conclusion, our results demonstrated for the first time that combination of differential lesion HLA-G expression notably improved the value of traditional survival prediction for CRC patients.