Long-term outcomes of patients with metastatic gastric cancer after initial S-1 monotherapy.
BACKGROUND
S-1, an oral fluoropyrimidine, has been shown to have excellent activity against gastric cancer in two phase II studies and is widely used in Japan. However, the long-term outcomes of patients after S-1 monotherapy for metastatic gastric cancer are unclear. The aim of this study was to investigate the long-term outcomes in metastatic gastric cancer patients who had initially received S-1 monotherapy.


METHODS
Ninety-two previously untreated patients with advanced gastric cancer received S-1 monotherapy as first-line chemotherapy at the National Cancer Center Hospital East, Kashiwa, Japan, and then the long-term outcomes and characteristics of long-term survivors were analyzed retrospectively. Multivariate analysis of prognostic factors was performed by the Cox proportional hazard method.


RESULTS
With a median follow-up of 3.1 years, the median progression-free survival time was 4.6 months. The median survival time was 11.9 months, with 1-, 2- and 3-year survival rates of 49.1%, 22.8%, and 9.8%, respectively. Multivariate analysis showed that good performance status (P = 0.0004) and only one metastatic site (P = 0.0048) were significant independent prognostic factors. Among 48 patients with a single metastatic site, 22 with peritoneal metastasis had longer survival times (median survival, 24 months) than patients with metastasis at other sites. Among the nine 3-year survivors, six had peritoneal metastases alone.


CONCLUSIONS
The survival outcomes after S-1 monotherapy are promising, especially in patients with good performance status and a single metastatic site. Our findings suggest that, among patients with a single metastatic site, those with peritoneal metastases alone have a chance for long-term survival.
Hosokawa
Ayumu
A
Department of Internal Medicine, Faculty of Medicine, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan.
Sugiyama
Toshiro
T
Ohtsu
Atsushi
A
Doi
Toshihiko
T
Hattori
Santa
S
Kojima
Takashi
T
Yano
Tomonori
T
Minashi
Keiko
K
Muto
Manabu
M
Yoshida
Shigeaki
S
D000328:Adult; D000368:Aged; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use*; D018450:Disease Progression; D018572:Disease-Free Survival; D004338:Drug Combinations; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D010094:Oxonic Acid / Q000627:therapeutic use*; D010534:Peritoneal Neoplasms / Q000556:secondary; D011379:Prognosis; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000473:pathology; D015996:Survival Rate; D005641:Tegafur / Q000627:therapeutic use*
D000964:Antimetabolites, Antineoplastic; D004338:Drug Combinations; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid