Clinical Significance Of CA125in Gastric Cancer With Peritoneal Dissemination

Background Peritoneal metastasis is the most frequent and life-threatening form ofmetastasis in patients with gastric cancer. Currently, the preoperative diagnosis ofperitoneal metastasis mainly depends on radiological exams which are not sensitiveenough to detect tiny lesions. Recent studies have revealed a significant relationshipbetween preoperative serum CA125levels and gastric cancer with peritonealdissemination.Methods We used survival analysis to discover the diagnostic and prognostic valueof serum tumor markers in a retrospective cohort of751patients with gastric cancer,who received operation in the Ruijin Hospital Affiliated to The Shanghai Jiao TongUniversity Medical School from January2008to June2009.Results Peritoneal metastasis in gastric cancer was correlated with preoperativeserum level of CA125(P<0.001), CA724(P<0.001), Borrmann type IV(P<0.001),tumor differentiation(P=0.002), tumor infiltration depth(P=0.008) andascites(P<0.001). The serum CA125level yielded a ROC value of0.848in thepreoperative diagnosis of gastric cancer, with sensitivity and specificity of48.9%and96.5%, respectively. The CA125level was significantly correlated with the degrees ofperitoneal dissemination(R=0.254, P<0.001) as well as the amount ofascites(R=0.401,P=0.011). The sensitivity and specificity of combined use of CA125and ascites increased to59.8%and95.3%. In the follow-up study, non-radical tumorresection (P=0.005), degree of peritoneal metastasis (P<0.001), ascites (P<0.001), andpreoperative serum CA125level (P=0.006) were associated with increased mortalityrisk in patients with peritoneal metastasis, while P3peritoneal metastasis was theindependent risk factor after adjustment (hazard ratio [HR],3.296;95%confidence interval [CI],1.9.6to5.699). In patients with P1or P2peritoneal metastasis, elevatedCA125and non-radical tumor resection were independently associated with poorerprognosis, while the median survival time was3.98months for patients with elevatedCA125and23.92months for those with normal CA125(HR,3.407;95%CI1.449to8.011).Conclusions Peritoneal dissemination is one of the most lethal events in patientswith gastric carcinoma. Serum CA125is a clinically useful marker in preoperativediagnosis of peritoneal metastasis as well as evaluating the degrees of peritonealdissemination in patients with gastric cancer. We suggest that patients with elevatedCA125should refer to laparoscopic exploration to verify peritoneal metastasis, thus toavoid the damage from unnecessary laparotomy.