Predictive Value Of Serum Tumor Markers In Peritoneal Implantation Metastasis Of Patients With Gastric Cancer

1.Background and ObjectiveWith high incidence and mortality rate, some patients with advanced gastric carcinoma can’t receive radical resection because of peritoneal implantation metastasis,which is related with the prognosis and recurrence. As the common used tumor markers for digestive system, serum sialic acid (SA) and CEA, CA-125, CA19-9, CA72-4, AFP have certain relationships with the growth, invasion and metastasis of gastric cancer. At present, due to the lack of effective evaluative means, parts of patients with gastric cancer had suffered from unnecessary exploratory laparotomy because the invasion and peritoneal implantation metastasis, that can’t perform radical resection. The current study aimed to summarize and discuss the predictive value of serum tumor markers in peritoneal implantation metastasis of patients with gastric cancer.2.Methods127 cases of gastric cancer who were diagnosed by pathology in Shandong University Qilu Hospital from 2012.07 to 2015.02 were retrospectively reviewed. The patients were divided into two groups by operation exploration:67 patients with peritoneal implantation metastasis and 60 patients without patients. The relationship between serum SA and CEA, CA-125, CA19-9, CA72-4, AFP and other clinicopathological characteristics with peritoneal implantation metastasis of gastric cancer were analyzed.3.Results3.1 The group with peritoneal implantation metastasis had lower ALB level, bigger tumor size, higher incidence of ascites,higher rates of invasion of vessels and hepatoduodenal ligament(p<0.05),while the age, sex, symptom, time, the location of tumor, pathological type, lymph node metastasis, liver and diaphragm invasion, HGB had no statistically significant difference(p>0.05).3.2 The serum levels of SA,CEA,CA125 and CA19-9 in the group with peritoneal implantation metastasis were much higher than those without peritoneal implantation metastasis (p<0.05),while that of AFP and CEA had no statistically significant difference(p>0.05).3.3 Regarded as positive value with higher level than upper limit (CEA>5ng/ml,CA-125>35U/ml,CA19-9>39U/ml, SA>75.4mg/dl),SA and CA-125 had higher sensitivity(40.30%,40.30% vs.28.36%,31.34%), specificity (90.00%,100%vs.88.33%,80.00%), positive predictive value(81.82%,100% vs. 73.08%,63.64%), negative predictive value(57.45%,60.00% vs.52.48%,51.06%)and accuracy(63.87%,68.50 vs.56.69%,54.33%) than CA19-9 and CEA in predicting peritoneal implantation metastasis of patients with gastric carcinoma.3.4 The area under the ROC curve was:SA=0.717,CA-125=0.856,CEA=0.595 and CA19-9=0.584,which also showed that the SA and CA-125 were more valuable than CA19-9 and CEA. The Optimal Operating Point determined by Youden index,which SA=66.4 mg/dl,CA-125=20.99U/ml, would increase the sensitivity(64.18% vs.64.18%), specificity(64.18% vs.78.33%), positive predictive value(95.56%,76.79%), negative predictive value (70.73%vs.66.20%) and accuracy(79.52% vs.70.87%).SA combined with CA-125 would increase the sensitivity (88.06%), accuracy (82.68%) and negative predictive value(85.19%) and would decrease the misdiagnosis rate (11.94%).3.5 The Logistic analysis revealed that CA-125,size of tumor and pancreatic invasion was an independent predictive factor of peritoneal implantation metastasis of patients with gastric carcinoma, and the CA-125 had higher relative risk.4.ConclusionThe preoperative levels of serum SA and CEA, CA-125, CA19-9 play a significant role in predictive value of peritoneal implantation metastasis of patients with gastric carcinoma. Furthermore, the levels of SA and CA-125,specially determined by ROC curve,are more significant, and SA combined with CA-125 would increase the predictive value.CA-125 has higher relative risk than size of tumor and pancreatic invasion as independent predictive factors of peritoneal implantation metastasis of patients with gastric carcinoma.