Chemosensitivity test for 5-fluorouracil and 5-chloro-2, 4-dihydroxypyridine predicts outcome of gastric cancer patients receiving S-1 postoperatively.
BACKGROUND
Chemosensitivity tests have long been discussed but remain a topic of research. In this study, we investigated the correlation between the results of a chemosensitivity test for 5-fluorouracil and 5-chloro-2, 4-dihydroxypyridine and the clinical outcomes of gastric cancer patients treated with S-1, an oral fluoropyrimidine, as adjuvant chemotherapy.


METHODS
For gastric cancer patients, we performed surgical treatment and a lymph node dissection of D2 or more. Afterwards, a chemosensitivity test for 5-fluorouracil and 5-chloro-2, 4-dihydroxypyridine was performed, using the collagen gel droplet embedded culture drug-sensitivity test (CD-DST), in surgical specimens. All the patients received postoperative adjuvant chemotherapy with S-1 for 1 year, and the overall survival (OS), relapse-free survival (RFS), and adverse events were investigated.


RESULTS
The chemosensitivity test was performed for 27 patients. The growth inhibition rate (IR) was 50% or more (high-sensitivity group) in 59.3% (16 cases) and it was under 50% (low-sensitivity group) in 40.7% (11 cases). The 3-year OS rate was 100% in the high-sensitivity group and 62.34% in the low-sensitivity group. The 3-year RFS rate was 83.33% in the high-sensitivity group and 24.24% in the low-sensitivity group. Thus, the 3-year OS rate and the 3-year RFS rate were higher in the high-sensitivity group than in the low-sensitivity group. No adverse events of grade 3 or greater severity were observed.


CONCLUSIONS
The results of the chemosensitivity test were correlated with the patient outcome. Therefore, such results might be useful for individualizing cancer chemotherapy and for determining future indications for postoperative adjuvant chemotherapy.
Institute of Gastroenterology, Nippon Medical School Musashi Kosugi Hospital, Nakahara-ku, Kawasaki, Kanagawa, Japan.
Kentaro
K
Maejima
Akira
A
Tokunaga
Teruo
T
Kiyama
Hitoshi
H
Kanno
Hideki
H
Bou
Masanori
M
Watanabe
Hideyuki
H
Suzuki
Eiji
E
Uchida
D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D004338:Drug Combinations; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D010094:Oxonic Acid / Q000008:administration & dosage; D011182:Postoperative Care; D011237:Predictive Value of Tests; D011725:Pyridines / Q000008:administration & dosage; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D016019:Survival Analysis; D005641:Tegafur / Q000008:administration & dosage; D016896:Treatment Outcome
D004338:Drug Combinations; D011725:Pyridines; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid; D005472:Fluorouracil; C104201:gimeracil