Phase II study of oral S-1 and concurrent radiotherapy in patients with unresectable locally advanced pancreatic cancer.
OBJECTIVE
S-1 is an oral fluoropyrimidine derivative that has demonstrated favorable antitumor activity in patients with metastatic pancreatic cancer. The aim of this study was to evaluate safety and efficacy of S-1 and concurrent radiotherapy in patients with unresectable locally advanced pancreatic cancer.


METHODS
Patients with histopathologically proven, unresectable, locally advanced pancreatic cancer were eligible. Radiotherapy was delivered in 1.8 Gy daily fractions to a total dose of 50.4 Gy over 5.5 weeks. S-1 was administered orally twice a day at a dose of 80 mg/m(2)/day from day 1 to 14 and 22 to 35. Two weeks after the completion of chemoradiotherapy, maintenance chemotherapy with S-1 was administered for 28 days every 6 weeks until progression.


RESULTS
Thirty-four patients were enrolled in this study. The most common Grade 3 toxicities during chemoradiotherapy were anorexia (24%) and nausea (12%). The overall response rate was 41% (95% confidence interval, 25%-58%) and overall disease control rate (partial response plus stable disease) was 97%. More than 50% decrease in serum CA 19-9 was seen in 27 of 29 evaluable patients (93%). The median progression-free survival was 8.7 months. The median overall survival and 1-year survival rate were 16.8 months and 70.6%, respectively.


CONCLUSIONS
Oral S-1 and concurrent radiotherapy exerted a promising antitumor activity with acceptable toxicity in patients with locally advanced pancreatic cancer. This combination therapy seems to be an attractive alternative to conventional chemoradiotherapy using 5-fluorouracil infusion.
Sudo
Kentaro
K
Department of Gastroenterology, Chiba Cancer Center, Chiba, Japan. kentarosudo9@yahoo.co.jp
Yamaguchi
Taketo
T
Ishihara
Takeshi
T
Nakamura
Kazuyoshi
K
Hara
Taro
T
Denda
Tadamichi
T
Tawada
Katsunobu
K
Imagumbai
Toshiyuki
T
Araki
Hitoshi
H
Sakai
Mitsuhiro
M
Hatano
Kazuo
K
Kawakami
Hiroyuki
H
Uno
Takashi
T
Ito
Hisao
H
Yokosuka
Osamu
O
D000328:Adult; D000368:Aged; D000855:Anorexia / Q000209:etiology; D000964:Antimetabolites, Antineoplastic / Q000009:adverse effects / Q000627:therapeutic use*; D018395:CA-19-9 Antigen / Q000097:blood; D003131:Combined Modality Therapy / Q000009:adverse effects / Q000379:methods; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000627:therapeutic use; D018450:Disease Progression; D004334:Drug Administration Schedule; D004338:Drug Combinations; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009325:Nausea / Q000209:etiology; D010094:Oxonic Acid / Q000009:adverse effects / Q000627:therapeutic use*; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D005641:Tegafur / Q000009:adverse effects / Q000627:therapeutic use*; D000093542:Gemcitabine
D000964:Antimetabolites, Antineoplastic; D018395:CA-19-9 Antigen; D004338:Drug Combinations; D003841:Deoxycytidine; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid; D000093542:Gemcitabine