Background: The aim of the study was to determine the value of synchronous liver resection in patients with oligo-metastatic gastric cancer and the prognostic factors in these patients. Patients and methods: We compared the results of 21 gastric patients with liver metastases and synchronous liver resection (LMR) to 21 propensity score-matched patients with gastric cancer and liver metastases in whom liver resection was not performed (LM0) and to a propensity score-matched control group of 21 patients without liver metastases and stage III and IV resectable gastric cancer (CG). Results: The overall 5-year survival of LMR, LM0 and CG were 14.3%, 0%, and 19%, respectively (p = 0.002). Five-year survival was 47.5% for well-differentiated tumour compared to 0% in patients with moderate or poor tumour differentiation ( p = 0.006). In addition, patients with R0 resection and TNM stage N0–1 had a significantly better survival compared to patients with TNM N stage N2–3 (5-year survival: 60% for N0–1 vs . 7.7% for N2–3; p = 0.007). Conclusions: The results presented in the study support synchronous liver resections in gastric patients and provide additional criteria for patient selection.

Background: We explored the prognostic value of the up-regulated carbohydrate antigen (CA19-9) in node-negative patients with gastric cancer as a surrogate marker for micrometastases.Patients and methods: Micrometastases were determined using reverse transcription quantitative polymerase chain reaction (RT-qPCR) for a subgroup of 30 node-negative patients. This group was used to determine the cut-off for preoperative CA19-9 serum levels as a surrogate marker for micrometastases. Then 187 node-negative T1 to T4 patients were selected to validate the predictive value of this CA19-9 threshold.Results: Patients with micrometastases had significantly higher preoperative CA19-9 serum levels compared to patients without micrometastases (p= 0.046). CA19-9 serum levels were significantly correlated with tumour site, tumour diameter, and perineural invasion. Although not reaching significance, subgroup analysis showed better five-year survival rates for patients with CA19-9 serum levels below the threshold, compared to patients with CA19-9 serum levels above the cut-off. The cumulative survival for T2 to T4 node-negative patients was significantly better with CA19-9 serum levels below the cut-off (p= 0.04).Conclusions: Preoperative CA19-9 serum levels can be used to predict higher risk for haematogenous spread and micrometastases in node-negative patients. However, CA19-9 serum levels lack the necessary sensitivity and specificity to reliably predict micrometastases.