Five-year outcomes of a randomized phase III trial comparing adjuvant chemotherapy with S-1 versus surgery alone in stage II or III gastric cancer.
OBJECTIVE
The first planned interim analysis (median follow-up, 3 years) of the Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer confirmed that the oral fluoropyrimidine derivative S-1 significantly improved overall survival, the primary end point. The results were therefore opened at the recommendation of an independent data and safety monitoring committee. We report 5-year follow-up data on patients enrolled onto the ACTS-GC study.


METHODS
Patients with histologically confirmed stage II or III gastric cancer who underwent gastrectomy with D2 lymphadenectomy were randomly assigned to receive S-1 after surgery or surgery only. S-1 (80 to 120 mg per day) was given for 4 weeks, followed by 2 weeks of rest. This 6-week cycle was repeated for 1 year. The primary end point was overall survival, and the secondary end points were relapse-free survival and safety.


RESULTS
The overall survival rate at 5 years was 71.7% in the S-1 group and 61.1% in the surgery-only group (hazard ratio [HR], 0.669; 95% CI, 0.540 to 0.828). The relapse-free survival rate at 5 years was 65.4% in the S-1 group and 53.1% in the surgery-only group (HR, 0.653; 95% CI, 0.537 to 0.793). Subgroup analyses according to principal demographic factors such as sex, age, disease stage, and histologic type showed no interaction between treatment and any characteristic.


CONCLUSIONS
On the basis of 5-year follow-up data, postoperative adjuvant therapy with S-1 was confirmed to improve overall survival and relapse-free survival in patients with stage II or III gastric cancer who had undergone D2 gastrectomy.
Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo, 663-8501, Japan. msasako@hyo-med.ac.jp
Mitsuru
M
Sasako
Shinichi
S
Sakuramoto
Hitoshi
H
Katai
Taira
T
Kinoshita
Hiroshi
H
Furukawa
Toshiharu
T
Yamaguchi
Atsushi
A
Nashimoto
Masashi
M
Fujii
Toshifusa
T
Nakajima
Yasuo
Y
Ohashi
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D004338:Drug Combinations; D005743:Gastrectomy; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D010094:Oxonic Acid / Q000008:administration & dosage; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D005641:Tegafur / Q000008:administration & dosage
D004338:Drug Combinations; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid