IMP3 expression in biopsy specimens of colorectal cancer predicts lymph node metastasis and TNM stage

IMP3 is associated with lymph node metastasis and TNM stage and is a good independent prognostic biomarker for colorectal cancer (CRC). However, the expression status and clinical implication of IMP3 in biopsy specimens have not yet been studied. We aim to address whether the presence of IMP3 expression in preoperative biopsies of CRC could predict lymph node metastasis and TNM stage. In this study, we examined IMP3 expression in paired biopsy and resection specimens of 71 CRC and analyzed the correlation of IMP3 expression with clinicopathological parameters. In the biopsy specimens, IMP3 positive expression was observed in 56 of 71 cases (78.9%) whereas negative expression was observed in 15 of 71 cases (21.1%). In the resection specimens, IMP3 positive expression was detected in 83.1% cases (59/71) whereas negative expression was detected in 16.9% cases (12/71). The absolute concordance rate between biopsy and resection specimens was 90.1% (64/71). The Spearman correlation test documented the existence of a strong linear correlation between the percentage of IMP3-positive cells in the biopsy and resection specimen (r = 0.629; P < 0.001). IMP3 expression in resection specimens was significantly related to histological grade (P = 0.043), T classification (P = 0.035), lymph node metastasis (P = 0.023), TNM stage (P = 0.007), tumor border (P = 0.049) and tumor budding (P = 0.012). IMP3 expression in biopsy specimens was significantly related to lymph node metastasis (P = 0.004), TNM stage (P = 0.005) and tumor budding (P = 0.001). In conclusion, IMP3 expression in biopsy specimens could be used to predict lymph node metastasis and TNM stage in CRC patients.