Abstract
Background The function of ASXL1 protein in colorectal cancer has not been investigated yet. The purpose of this study was to investigate the clinicopathological and prognostic impact of ASXL1 protein expression on colorectal cancer.Methods We performed immunohistochemical staining of ASXL1 protein using tissue microarrays of 408 colorectal cancers, 46 normal colonic mucosae, 48 adenomas, and 92 metastatic lymph nodes. The intensity of expression was scored as 0–3, and the extent of staining was scored as 0–4, based on the percentage of positive cells. The immunoreactivity score (IRS) was calculated by multiplying the two scores.Results ASXL1 protein expression rates were 89.1% in normal mucosae, 72.9% in tubular adenomas, 44.4% in adenocarcinomas, and 28.3% in metastatic lymph nodes ( p < 0.001). With respect to the IRS cut-off score, the mean tumor size was smaller in the IRS 0–6 group than in the IRS 8–12 group (4.9 ± 2.1 vs. 6.3 ± 2.7 cm, p = 0.002). Lymph node metastasis was more frequent in the IRS 0–6 group than in the IRS 8–12 group (56.3% vs. 33.3%, p = 0.034). Lymphatic invasion was more frequent in the 0–6 group than in the IRS 8–12 group (56.0% vs. 33.3%, p = 0.035). The 5-year disease-free survival rate did not differ between two groups at stage II and stage III.Conclusions ASXL1 protein might act as a tumor suppressor in colorectal cancer. The loss of ASXL1 expression might be associated with metastasis via the lymphatic system to the lymph nodes.
MA12.09 Comparative Histological Subtype Analysis of Lung Adenocarcinoma Tumor and Metastatic Lymph Nodes and the Prognostic Impact
