The outcome of gastric cancer patients with peritoneal metastasis remains poor. We treated these patients with intraperitoneal and intravenous administration of paclitaxel plus oral tegafur/gimeracil/oteracil (S-1), followed by gastrectomy in responders. However, it remains to be determined whether gastrectomy contributes significantly to the survival benefit in good responders. It is also unclear how and when gastrectomy should be performed. Therefore, reliable biomarkers are urgently needed to predict the outcome of gastrectomy. Herein, we evaluated the clinical significance of carcinoembryonic antigen (CEA) mRNA levels in peritoneal lavage as a biomarker for the indication of conversion gastrectomy.
The peritoneal lavage of 68 patients who received the above regimen as induction chemotherapy was repeatedly collected via intraperitoneal access ports. Gastrectomy was considered when improvement of peritoneal metastasis was confirmed by a second laparoscopic examination with negative peritoneal cytolog. CEA and porphobilinogen deaminase (PBGD) mRNAs were chronologically quantified using the transcription reverse-transcription concerted reaction method. The CEA-mRNA Index (CmRI) was calculated as CEA mRNA/PBGD mRNA x 10,000.
Thirty-nine patients received gastrectomy and 29 patients did not (median survival time (MST): 27.8 vs. 10.7 months, P
The CmRI reflects the response of peritoneal metastases to induction intraperitoneal chemotherapy. It may be a useful biomarker to determine gastrectomy in gastric cancer patients with peritoneal metastasis.
Clinical trial identification
Legal entity responsible for the study
Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science
All authors have declared no conflicts of interest.