Lowered expression level of INSC predicts poor prognosis in patients with colon cancer.

The aim of this study was to investigate the prognostic value of inscuteable spindle orientation adaptor protein (INSC) in colon cancer (CC). Firstly, transcriptional change of INSC was analysed using the data from public databases. Next, INSC protein expression was assessed by immunohistochemistry. Its correlation with clinicopathological features and the prognostic values of patients were also investigated. Then, an INSC-based nomogram was built to predict CC prognosis. Compared to normal tissues, INSC was significantly downregulated at the transcriptional level in CC tissues. A low INSC mRNA level not only positively correlated with TNM stage (tumour-nodus-metastases), advanced T stage, and N stage, but also with the shorter 5- and 8-year overall survival (OS) and disease-specific survival. Concerning protein level, INSC downregulation was confirmed in CC samples. In terms of the correlation with N stage and 5- and 8-year OS, it was also consistent with mRNA levels. Cox regression analysis indicated that INSC protein expression was an independent prognostic factor for OS. The nomogram showed better prognostic accuracy and clinical net benefit for 5-year OS than TNM staging. Altogether, downregulation of INSC is related to inferior clinicopathological features and patient outcomes, and it may be a novel independent prognostic biomarker in CC.