DDR2 and IFITM1 Are Prognostic Markers in Gallbladder Squamous Cell/Adenosquamous Carcinomas and Adenocarcinomas

This study was conducted to investigate the expressions of DDR2 and IFITM1 and their clinical and pathological significances in the rare type squamous cell/adenosquamous carcinomas (SC/ASC) and ordinary adenocarcinomas (AC) of gallbladder cancers. DDR2 and IFITM1 expression was examined in 69 SC/ASCs and 146 ACs using EnVision immunohistochemistry. Results showed that the percentage of positive DDR2 and IFITM1 expression was significantly higher in SC/ASC patients with high TNM stage, lymph node metastasis, invasion, and no resection surgery compared to patients with low TNM stages, no lymph node metastasis, no invasion, and resection surgery (P < 0.05 or P < 0.01). The positive rate of DDR2 was significantly higher in SC/ASC patients with large tumor sizes than patients with small tumor sizes (p < 0.05). The percentage of positive DDR2 and IFITM1 expressions was significantly higher in AC patients with high TNM stages that didn't receive resection surgery compared to patients with low TNM stages that did receive resection surgery (P < 0.05 or P < 0.01). The positive rate of IFITM1 was significantly higher in AC patients with lymph node metastasis and invasion than in patients without metastasis and invasion (p < 0.05). Positive DDR2 and IFITM1 expression was closely associated with a decreased overall survival in SC/ASC and AC patients (P < 0.05 or P < 0.01). AUC analysis showed that DDR2 and IFITM1 was sensitive and specific for the diagnosis of SC/ASC (AUC = 0.740 and AUC =0.733, respectively) and AC (AUC = 0.710 and AUC =0.741, respectively). In conclusion, positive DDR2 and IFITM1 expression is a marker for the clinical severity, poor prognosis, and diagnosis of gallbladder SC/ASC and AC.