Intraoperative Blood Loss is Associated with Shortened Postoperative Survival of Patients with Stage II/III Gastric Cancer: Analysis of a Multi-institutional Dataset

Background The influence of intraoperative blood loss (IBL) on postoperative long-term outcomes of patients with gastric cancer is controversial. Here, we used a large multicenter dataset from nine institutes to evaluate the prognostic impact of IBL on patients with stage II/III gastric cancer. Methods The study analyzed 1013 patients with stage II/III gastric cancer who underwent gastrectomy without preoperative treatment and intraoperative transfusion. Patients were equally divided into learning and validation cohorts using a table of random numbers. The optimal cutoff value of IBL to predict recurrence was determined using the learning cohort, and the prognostic significance of the proposed cutoff was validated using the second cohort. Results The optimal cutoff value of IBL determined with the learning cohort using the receiver operating characteristic curve analysis was 330 ml. In the validation cohort, IBL > 330 ml was significantly associated with high body mass index, total gastrectomy, and postoperative complications, but not disease stage and the frequency of adjuvant chemotherapy. The disease-free and disease-specific survival rates of patients in the IBL > 330 ml (IBL-high) group were significantly shorter compared with those in the IBL ≤ 330 ml group. IBL-high was identified as an independent prognostic factor of disease recurrence (hazard ratio 1.45, 95% confidence interval 1.01–2.09, P = 0.0420). The hazard ratio of the IBL-high group was greater in the surgery-alone subgroup compared with that of the postoperative adjuvant-chemotherapy subgroup. Conclusions Our analysis of a multicenter dataset indicates that IBL adversely influenced long-term outcomes of patients with stage II/III gastric cancer.