Molecular biomarker study in randomized phase II trial of capecitabine plus cisplatin versus S-1 plus cisplatin as a first-line treatment for advanced gastric cancer: XParTS IIb

Date

19 Dec 2015

Session

Poster presentation 1

Presenters

Akira Tsuburaya

Citation

Annals of Oncology (2015) 26 (suppl_9): 42-70. 10.1093/annonc/mdv523

Authors

A. Tsuburaya¹, K. Nishikawa², M. Kobayashi³, J. Kawada⁴, T. Namikawa³, R. Fukushima⁵, H. Kojima⁶, K. Tanabe⁷, K. Yamaguchi⁸, S. Yoshino⁹, M. Takahashi¹⁰, N. Hirabayashi¹¹, S. Sato¹², H. Nemoto¹³, Y. Rino¹⁴, T. Yoshikawa¹⁵, J. Nakajima¹⁶, P. Tan¹⁷, S. Morita¹⁸, J. Sakamoto¹⁹

Author affiliations

¹ Gastroenterological Center, Yokohama City University Medical Center, 2320024 - Yokohama/JP
² Surgery, National Hospital Organization Osaka National Hospital, 540-0006 - Osaka/JP
³ Human Health And Medical Sciences, Kochi Medical School Hospital, Nangoku/JP
⁴ Surgery, Osaka General Medical Center, Osaka/JP
⁵ Surgery, Teikyo University, Tokyo/JP
⁶ Gastroenterological Surgery, Aichi Cancer Center - Aichi Hospital, Okazaki/JP
⁷ Gastroenterological And Transplant Surgery, Hiroshima University, Hiroshima/JP
⁸ Surgical Oncology, Gifu University, Graduate School of Medicine, 5011194 - Gifu/JP
⁹ Department Of Digestive Surgery And Surgical Oncol, Yamaguchi University Graduate School of Medicine, 755-8505 - Ube/JP
¹⁰ Surgery, Yokohama Municipal Citizen's Hospital, Yokohama/JP
¹¹ Surgery, Hiroshima City Asa Hospital, 731-0223 - Hiroshima/JP
¹² Gastroenterological Surgery, Saga-Ken Medical Center Koseikan, Saga/JP
¹³ Gastroenterological And General Surgery, Showa University Fujigaoka Hospital, Yokohama/JP
¹⁴ Surgery, Yokohama City University, Yokohama/JP
¹⁵ Gastrointestinal Surgery, Kanagawa Cancer Center, Yokohama/JP
¹⁶ Surgery, Obihiro Kousei Hospital JA Hokkaidoukouseiren, Obihiro/JP
¹⁷ Cancer And Stem Cell Biology, Duke-NUS Graduate Medical School Singapore, Singapore/SG
¹⁸ Biomedical Statistics And Bioinformatics, Kyoto University-Graduate school of medicine, Kyoto/JP
¹⁹ Hospital Director, Tokai Central Hospital, Kakamigahara/JP

Resources

Abstract 1070

Aim/Background

Among standard chemotherapy regimens for advanced gastric cancer; capecitabine plus cisplatin (XP) and S-1 plus cisplatin (SP) were comparable in a multicenter randomized phase II trial, XParTS II. This study was designed to identify molecular biomarkers for XP and SP in the trial.

Methods

Paraffin-embedded primary tumor specimens were collected in 98 of 116 randomized patients in XParTS II. The mRNA was measured with a real-time PCR for thymidine phosphorylase (TP), dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyltransferase (OPRT), and thymidylate synthase (TS), and categorized at median into low or high subgroups in order to analyze their association with efficacy endpoints.

Results

Baseline demographic and clinical characteristics of the subjects were similar to the results of the original trial. There was no significant difference in each marker between XP and SP groups; while TP was higher in samples from patients with measurable lesions, and TS was higher in patients with intestinal type and measurable tumors. In comparison for efficacy between XP and SP groups, there was no interaction for PFS and TTF for each marker. While for OS, OPRT was associated with efficacy of the treatment regimens; for XP vs. SP, hazard ratios were 2.0 and 0.73 for low and high mRNA, respectively (P = 0.098 for interaction).

Conclusions

OPRT is suggested to be a candidate predictive biomarker for the first-line treatment of advanced gastric cancer by XP or SP. Further examination is warranted to confirm these results in other clinical trials and/or cohort studies.

Clinical trial identification

NCT0140624

Disclosure

All authors have declared no conflicts of interest.

Resources from the same session

19 Dec 2015