Lysophosphatidic Acid is a Biomarker for Peritoneal Carcinomatosis of Gastric Cancer and Correlates with Poor Prognosis.

BACKGROUND

Peritoneal carcinomatosis (PC) is an important cause of morbidity and mortality among patients with gastric cancer. Thus, it is important to identify an ideal biomarker for PC.

METHODS

Plasma and ascites samples were collected from gastric cancer patients with PC and a control group. Lysophosphatidic acid (LPA) levels were tested and analyzed.

RESULTS

The plasma LPA levels of gastric cancer patients with PC were significantly higher than those in gastric cancer patients after radical resection (p = 0.046) and healthy volunteers (p < 0.001). Besides, plasma LPA levels were statistically lower after chemotherapy in gastric cancer patients with PC (p = 0.028). Furthermore, the ascites LPA levels were significantly higher in gastric cancer patients with peritoneal carcinomatosis than those in liver cirrhosis patients (p < 0.001). Moreover, ascites LPA levels were statistically lower after intraperitoneal chemotherapy injection than before (p < 0.001). In addition, the plasma LPA levels were significantly associated with serum CA125 levels (p = 0.032) and TNM stage in gastric cancer patients (p = 0.009). Individuals with plasma LPA levels >20,000 ng/mL had significantly worse overall survival (OS) than those with plasma LPA levels <20,000 ng/mL group (p = 0.006). In addition the group with ascites LPA levels >24,000 ng/mL showed significantly worse progression-free survival (PFS) and OS (p < 0.001 in PFS and OS).

CONCLUSIONS

This study demonstrated that LPA levels in plasma and ascites may be useful diagnostic biomarkers for PC of gastric cancer and that higher levels are associated with poor prognosis.