Phase II clinical trial of postoperative S-1 monotherapy for gastric cancer patients with free intraperitoneal cancer cells detected by real-time RT-PCR.
BACKGROUND
We have previously reported the molecular detection of peritoneal micrometastases in patients with gastric cancer by quantifying carcinoembryonic antigen (CEA) mRNA in the peritoneal washes. Patients with CEA mRNA exceeding a cutoff value have a significant risk for developing peritoneal carcinomatosis, but optimal treatment for this population remains unknown.


METHODS
CEA mRNA (+) patients with gastric cancer were treated postoperatively with S-1 monotherapy. Overall survival, the primary endpoint of this phase II trial, was compared with the historical control, which is comprised of CEA mRNA (+) patients who were not given postoperative chemotherapy.


RESULTS
A total of 32 patients with CEA mRNA (+) gastric cancer were enrolled. Twelve patients (37.5%) relapsed; ten showed peritoneal relapse. Three-year survival was similar between the study population and the historical control (67.3% vs. 67.1%, respectively).


CONCLUSIONS
S-1 monotherapy, which significantly reduced risk for recurrence in stage II/III gastric carcinoma in another phase III trial, seems not to be as effective in eradicating free cancer cells in the abdominal cavity.
Ito
Seiji
S
Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, Nagoya, Japan. seito@aichi-cc.jp
Kodera
Yasuhiro
Y
Mochizuki
Yoshinari
Y
Kojima
Taiki
T
Nakanishi
Hayao
H
Yamamura
Yoshitaka
Y
D000230:Adenocarcinoma / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage*; D002272:Carcinoembryonic Antigen / Q000032:analysis; D017024:Chemotherapy, Adjuvant; D018572:Disease-Free Survival; D004338:Drug Combinations; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010094:Oxonic Acid / Q000008:administration & dosage*; D010533:Peritoneal Lavage; D010534:Peritoneal Neoplasms / Q000556:secondary*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018570:Risk Assessment; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D005641:Tegafur / Q000008:administration & dosage*
D000964:Antimetabolites, Antineoplastic; D002272:Carcinoembryonic Antigen; D004338:Drug Combinations; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid