Serum pepsinogen combined with computed tomography imaging for diagnosing recurrence of gastric cancer after total gastrectomy

Figure 1 Representative cases with elevated serum pepsinogen levels in the early postoperative period and negative concurrent computed tomography imaging, with recurrence subsequently confirmed on follow-up imaging. A: A 73-year-old male with an early postoperative serum pepsinogen (PG) I concentration of 30.97 ng/mL and a PG II concentration of 2.25 ng/mL. Concurrent computed tomography (CT) imaging revealed no evidence of metastasis. At 6 months post-surgery, CT imaging showed multiple liver metastases (orange arrows); B: An 80-year-old female with an early postoperative serum PG I concentration of 27.10 ng/mL and a PG II concentration of 1.83 ng/mL. Concurrent CT imaging was negative for metastasis. At 7 months post-surgery, CT imaging revealed widespread lymph node metastases, including left axillary lymph node metastasis (orange arrow).

Figure 2 Receiver operating characteristic curves of serum pepsinogen levels, computed tomography imaging, and the combined logistic regression model for diagnosing recurrence after total gastrectomy for gastric cancer. The combined model was constructed using the predicted probability from multivariate logistic regression. CT: Computed tomography; PG: Pepsinogen.

Figure 3 Representative immunohistochemical staining for pepsinogen in different histological types of gastric cancer. A: Pepsinogen (PG) I staining; B: PG II staining. Positive immunoreactivity appeared as brown cytoplasmic staining. Original magnification: 10 × and 40 × (objective). DGC: Differentiated gastric cancer; UGC: Undifferentiated gastric cancer; PDA: Poorly differentiated adenocarcinoma; MADC: Mucinous adenocarcinoma; SRCC: Signet ring cell carcinoma.