Phase II multicenter study of adjuvant S-1 for colorectal liver metastasis: survival analysis of N-SOG 01 trial.
OBJECTIVE
We previously showed that S-1 after curative resection of colorectal liver metastasis had acceptable toxicity and a high rate of completion of therapy in a prospective phase II trial. We here reported the primary endpoint of disease-free survival (DFS).


METHODS
Between October 2008 and August 2010, 60 patients were eligible for this study and received S-1 for 28 days followed by a 2-week rest period. Treatment was started within 8 weeks after surgery and repeated for eight cycles.


RESULTS
Median follow-up was 41 months. Among 60 patients, 45 had solitary metastasis, and the median maximum tumor diameter was 2.6 cm. The 3-year DFS and overall survival were 47.4 and 80.0 %, respectively. Recurrences developed in 31 patients, with the remnant liver the most common site (19 patients). Multivariate analysis showed that positive lymph node metastasis around the primary site (p = 0.013) and early liver metastasis (synchronous disease or metachronous disease within 12 months) (p = 0.041) were independent poor prognostic factors for DFS. Patients having both risk factors had a significantly worse DFS than those without these risk factors (p < 0.001). Early liver metastasis was an independent indicator of early recurrence within 1 year.


CONCLUSIONS
S-1 after curative liver resection yielded promising survival in patients with a low tumor burden. Outcome in patients having both positive lymph node metastasis around the primary site and early liver metastasis was much worse than in patients without these conditions; therefore, they might warrant more aggressive therapy.
Division of Surgical Oncology, Department of Surgery, Nagoya University Graduate School of Medicine, 65, Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
Takehiro
T
Kato
Keisuke
K
Uehara
Atsuyuki
A
Maeda
Eiji
E
Sakamoto
Kazuhiro
K
Hiramatsu
Eiji
E
Takeuchi
Hidenari
H
Goto
Yuichiro
Y
Tojima
Hiroshi
H
Yatsuya
Masato
M
Nagino
D000328:Adult; D000368:Aged; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant / Q000379:methods; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D018572:Disease-Free Survival; D004338:Drug Combinations; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000556:secondary; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy; D010094:Oxonic Acid / Q000627:therapeutic use*; D011379:Prognosis; D011446:Prospective Studies; D016019:Survival Analysis; D005641:Tegafur / Q000627:therapeutic use*
D000964:Antimetabolites, Antineoplastic; D004338:Drug Combinations; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid