Seonmi Hwangbo, MD, Oh Kyoung Kwon, MD, Wansik Yu, MD, FACS. Gastric Cancer Center, Kyungpook National University Medical Center
INTRODUCTION: The aim of this study is to investigate the predictive factors of macroscopic serosal invasion in gastric cancer and to determine suitable candidates for intraperitoneal chemotherapy. Macroscopic serosal invasion is one of the most important risk factors for the peritoneal recurrence of gastric cancer and is a good criterion for the use of adjuvant intraperitoneal chemotherapy. However, in clinical practice, many patients still hesitate or refuse to receive intraperitoneal chemotherapy despite the reported survival benefit.
METHODS AND PROCEDURES: The clinical data of 680 patients who underwent surgery with clinical diagnosis of advanced gastric cancer between January 2011 and December 2014 were reviewed. Multiple stepwise logistic regression analysis was used to determine factors associated with macroscopic serosal invasion.
RESULTS: Macroscopic serosal invasion was found in 223 (32.8 %) patients during laparotomy. The patients with macroscopic serosal invasion had significantly worse outcomes than those without macroscopic serosal invasion (overall survival (OS): 36.5 vs. 47.2 months, p<0.001; disease-free survival (DFS): 37.0 vs. 48.3 months, p<0.001). In univariate analyses, macroscopic serosal invasion were significantly associated with CEA level (p<0.001), CA 19-9 level (p<0.001), macroscopic type (p<0.001), differentiation (p=0.001), longitudinal location (p<0.001), and circumferential location (p<0.001). Multivariate analysis showed that CEA level >7 ng/mL [hazard ratio (HR) 4.018; 95 % confidence interval (CI) 2.089-7.728; p<0.001), CA 19-9 level >37 U/mL (HR 1.906; 95% CI 1.076-3.375; p=0.027), macroscopic type 3 or 4 (HR 2.193; 95% CI 1.481-3.247; p<0.001), undifferentiated histology (HR 1.456; 95% CI 1.001-2.118; p=0.049), tumors involving more than 2 portions in longitudinal location (HR 2.771; 95% CI 1.538-4.991; p=0.001), and tumors with circumferential involvement (HR 2.618; 95% CI 1.319-5.197; p=0.006) were significant predictive factors for macroscopic serosal invasion.
CONCLUSION: Patients with CEA level >7 ng/mL, CA 19-9 level >37 U/mL, macroscopic type 3 or 4, tumors involving more than 2 portions in longitudinal location, and tumors with circumferential involvement may be suitable candidates for intraperitoneal chemotherapy because of the high possibility of macroscopic serosal invasion. Physicians need to make efforts to improve the compliance to intraperitoneal chemotherapy through adequate education of those patients.