The clinical significance and diagnostic value of serum Dickkopf1 and CKAP4 levels in patients with gastric cancer: a prospective study

Objective: Gastric cancer is diagnosed at an advanced stage in most patients, and the prognosis is poor. Novel biochemical markers of high diagnostic value for the detection of the disease are therefore important. Dickkopf1 (DKK1) and cytoskeleton-associated protein 4 (CKAP4) have been extensively studied as biomarkers in cancer patients.Patients and methods: Serum DKK1 and CKAP4 levels in 58 patients with gastric cancer and 41 healthy controls were examined using an ELISA kit in this prospective study. The patients were subdivided into groups based on pathological TNM staging and histological grades. Serum levels of both proteins in the patients with gastric cancer were measured preoperatively, 10 and 30 days after surgery.Results: Serum DKK1 and CKAP4 levels were significantly higher in the gastric cancer group compared to the healthy controls (p<0.05). Serum levels of both proteins increased in line with the pathological stage and histological grade of the gastric cancer. Serum CKAP4 and DKK1 levels decreased after surgical resection. Both serum levels also decreased significantly on day 30 after surgery compared to day 10 (p<0.05). Serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) positivity rates were below 20% in the gastric cancer group, while the diagnostic value (sensitivity and specificity) of serum CKAP-4 and DKK1 exceeded 80%.Conclusions: DKK1 and CKAP4 are biomarkers of high diagnostic value that can be used to diagnose and predict the severity of gastric cancer. These proteins can also be employed for disease monitoring after surgical resection. The diagnostic value of these proteins is higher than that of biomarkers such as CEA and CA19-9, which are routinely used in clinical practice.