The HMGA2 positive expression ratio of cases with well-differentiated adenocarcinoma, with the largest tumor diameter <2 cm, lymph node without metastasis and with organs which did not invade surrounding tissues was significantly lower than that of cases with poorly differentiated adenocarcinoma, the largest tumor diameter ≥2 cm, lymph node with metastasis and organs invading surrounding tissues. This evidence concerns the gene HMGA2 and adenocarcinoma.