Urinary N1, N12-diacetylspermine as a potential tumor biomarker for gastric and colorectal cancer

Figure 1 Study flowchart. RT: Room temperature; BGD: Benign gastrointestinal diseases; GC: Gastric cancer; CRC: Colorectal cancer.

Figure 2 The levels of urinary N1, N12-diacetylspermine concentrations. A: Gastric cancer patients vs healthy controls and patients with benign gastrointestinal diseases; B: Colorectal cancer patients vs healthy controls and patients with benign gastrointestinal diseases. ^aP < 0.05, ^bP < 0.01, ^cP < 0.001. BGD: Benign gastrointestinal diseases; GC: Gastric cancer; CRC: Colorectal cancer.

Figure 3 Diagnostic values of urinary N1, N12-diacetylspermine, serum carcinoembryonic antigen, and carbohydrate antigen 199 for gastric cancer and colorectal cancer, and their correlation. A: Receiver operating characteristic curves of urinary N1, N12-diacetylspermine (DiAcSpm), serum carcinoembryonic antigen (CEA) and carbohydrate antigen 199 for gastric cancer patients; B: Receiver operating characteristic curves of urinary DiAcSpm, serum CEA and carbohydrate antigen 199 for colorectal cancer patients; C: Correlation of urinary DiAcSpm and serum CEA levels in gastric cancer patients; D: Correlation of urinary DiAcSpm and serum CEA levels in colorectal cancer patients. TPR: True positive rate; AUC: Area under the curve; FPR: False positive rate; CEA: Carcinoembryonic antigen; CA199: Carbohydrate antigen 199; DiAcSpm: N1, N12-diacetylspermine.

Figure 4 Receiver operating characteristic curves of urinary N1, N12-diacetylspermine combined with serum carcinoembryonic antigen for gastric cancer and colorectal cancer. A: In gastric cancer patients; B: In colorectal cancer patients. TPR: True positive rate; AUC: Area under the curve; FPR: False positive rate; DiAcSpm: N1, N12-diacetylspermine; CEA: Carcinoembryonic antigen; CI: Confidence interval.

Figure 5 Changes of urinary N1, N12-diacetylspermine concentrations in patients with chemotherapy. A: The changes of N1, N12-diacetylspermine in 9 colorectal cancer patients with chemotherapy; B: The changes of N1, N12-diacetylspermine in 5 gastric cancer patients with chemotherapy. ^aP < 0.05.