Preoperative prediction of peritoneal metastasis in gastric cancer as an indicator for neoadjuvant treatment.

Abstract

14 Background: Although Gastric cancer (GC) mortality has been reduced by advances in new treatments and in chemotherapy, it still has a poor prognosis and high mortality. One of the reasons for poor prognosis is that at the time of diagnosis advanced GC with metastatic disease is often detected and it is frequently accompanied by peritoneal metastasis. Imaging studies are frequently used to predict peritoneal metastasis, however, these modalities did not obtain consistently high sensitivity and specificity in assessing peritoneal metastasis. Therefore, we investigated whether the combination of several serum markers and clinical factors could be used for preoperative prediction of peritoneal metastasis in GC as an indicator for neoadjuvant treatment. Methods: A total of 493 patients with GC were enrolled in our Hospital. Preoperative serum tumor markers [carcinoembryonic antigen (CEA) and carbohydrate antigen (CA)19-9], systemic inflammatory marker C-reactive protein (CRP), host immune markers [neutrophil and lymphocyte counts and their ratio (NLR)], albumin as a nutritional marker, and objective preoperative clinical factors were available as indicators of postoperative peritoneal metastasis. Results: This study included a total of 344 men and 149 women who were classified according to UICC TNM Classification: 264 patients had stage I disease, 79 stage II, 78 stage III and 72 stage IV. Specific clinical factors, including tumor size, histopathology of biopsy sample, and tumor morphology, were significantly correlated with peritoneal metastasis. CA19-9, lymphocyte count and NLR were also predictive factors for peritoneal metastasis. Multivariate analysis identified the clinical factors tumor morphology and histopathology, and laboratory markers CA19-9 and lymphocyte count as independent factors predictive for peritoneal metastasis. Next, a combination of independent predictive factors achieved high predictive accuracy (0.882) for peritoneal metastasis preoperatively. Conclusions: A combination of preoperative tumor features and serum parameters is an alternative method to preoperatively discriminate patients with GC with peritoneal metastasis from those without.