Tomohiro Nishina1, Mizutomo Azuma2, Kazuhiro Nishikawa3, Masahiro Gotoh4, Hideaki Bando5, Naotoshi Sugimoto6, Kenji Amagai7, Keisho Chin8, Yasumasa Niwa9, Akihito Tsuji10, Hiroshi Imamura11, Masahiro Tsuda12, Hirofumi Yasui13, Hirofumi Fujii14, Kensei Yamaguchi15, Hisateru Yasui16, Shuichi Hironaka17, Ken Shimada18, Hiroto Miwa19, Terukazu Mitome20, Hiroki Kageyama20, Ichinosuke Hyodo21. 1. Department of Gastrointestinal Medical Oncology, National Hospital Organization Shikoku Cancer Center, 160 Kou, Minamiumemotomachi, Matsuyama, 791-0280, Japan. tnishina@shikoku-cc.go.jp. 2. Department of Gastroenterology, Kitasato University East Hospital, 2-1-1 Asamizodai, Minami-ku, Sagamihara, 252-0380, Japan. 3. Department of Surgery, National Hospital Organization Osaka National Hospital, 2-1-14 Hoenzaka, Chuo-ku, Osaka, 540-0006, Japan. 4. Cancer Chemotherapy Center, Osaka Medical College Hospital, 2-7 Daigakumachi, Takatsuki, 569-8686, Japan. 5. Division of Gastrointestinal Oncology and Digestive Endoscopy, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, 277-0882, Japan. 6. Department of Clinical Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, 1-3-3 Nakamichi, Higashinari-ku, Osaka, 537-8511, Japan. 7. Department of Gastroenterology, Ibaraki Prefectural Central Hospital, 6528 Koibuchi, Kasama, 309-1703, Japan. 8. Department of Gastroenterology, Cancer Institute Hospital of JFCR, 3-8-31 Ariake, Tokyo, 135-8550, Japan. 9. Department of Endoscopy, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, 464-8681, Japan. 10. Department of Medical Oncology, Kochi Health Sciences Center, 2125-1 Ike, Kochi, 781-8555, Japan. 11. Department of Surgery, Sakai City Hospital, 1-1-1 Minamiyasui-cho, Sakai, 590-0064, Japan. 12. Department of Gastroenterological Oncology, Hyogo Cancer Center, 13-70 Kitaoji-cho, Akashi, 673-8558, Japan. 13. Division of Gastrointestinal Oncology, Shizuoka Cancer Center, 1007 Nagaizumi-cho, Shimonagakubo, Sunto-gun, 411-8777, Japan. 14. Department of Clinical Oncology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, 329-0498, Japan. 15. Division of Gastroenterology, Saitama Cancer Center, 780 Inamachi Oaza Komuro, Kita-adachi-gun, 362-0806, Japan. 16. Department of Medical Oncology, National Hospital Organization Kyoto Medical Center, 1-1 Fukakusamukaihata-cho, Fushimi-ku, Kyoto, 612-0861, Japan. 17. Clinical Trial Promotion Department, Chiba Cancer Center, 666-2 Nitona-cho, Chuo-ku, Chiba, 260-8717, Japan. 18. Department of Internal Medicine, Showa University Northern Yokohama Hospital, Chigasakichuo, Tsuzuki-ku, Yokohama, 224-0032, Japan. 19. Division of Gastroenterology, Department of Internal Medicine, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, 663-8131, Japan. 20. Pharmaceutical Research and Development Department, Yakult Honsha Co., Ltd., 16-21 Ginza 7-chome, Chuo-ku, Tokyo, 104-0061, Japan. 21. Division of Gastroenterology, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8575, Japan.
Abstract
BACKGROUND: We investigated early tumor shrinkage (ETS) and depth of response (DpR) using data from the G-SOX study comparing S-1 plus oxaliplatin with S-1 plus cisplatin as the first-line treatment for advanced gastric cancer (AGC). METHODS: ETS was determined as % decrease in the sum of the longest diameters of the target lesions at the first evaluation of week 6 compared to baseline. DpR was the maximum % shrinkage during the study treatment. The impact of ETS (cutoff value 20%) and DpR (continuous value) on progression-free survival (PFS) and overall survival (OS) were assessed by the log-rank test and Cox regression analysis including prognostic factors obtained in the G-SOX study; ECOG performance status, baseline sum of tumor diameters, disease status (recurrent/unresectable), and histology (diffuse/intestinal). RESULTS: Among 685 patients enrolled in the G-SOX study, 632 patients who had the first tumor evaluation were analyzed. Patients with ETS ≥ 20% had longer PFS (median 4.5 vs. 2.8 months, p < 0.0001) and OS (median 14.8 vs. 10.5 months, p < 0.0001) than those with ETS < 20%. Adjusted hazard ratios of ETS < 20 vs. ≥ 20% were 0.606 (95% confidence interval (CI) 0.506-0.725) for PFS and 0.589 (95% CI 0.492-0.704) for OS. DpR was also significantly associated with PFS and OS (both p < 0.0001). These results were similar between the SOX and CS groups. CONCLUSIONS: In AGC patients receiving the first-line therapy, ETS and DpR might be predictors for PFS and OS.
RCT Entities:
BACKGROUND: We investigated early tumor shrinkage (ETS) and depth of response (DpR) using data from the G-SOX study comparing S-1 plus oxaliplatin with S-1 plus cisplatin as the first-line treatment for advanced gastric cancer (AGC). METHODS:ETS was determined as % decrease in the sum of the longest diameters of the target lesions at the first evaluation of week 6 compared to baseline. DpR was the maximum % shrinkage during the study treatment. The impact of ETS (cutoff value 20%) and DpR (continuous value) on progression-free survival (PFS) and overall survival (OS) were assessed by the log-rank test and Cox regression analysis including prognostic factors obtained in the G-SOX study; ECOG performance status, baseline sum of tumor diameters, disease status (recurrent/unresectable), and histology (diffuse/intestinal). RESULTS: Among 685 patients enrolled in the G-SOX study, 632 patients who had the first tumor evaluation were analyzed. Patients with ETS ≥ 20% had longer PFS (median 4.5 vs. 2.8 months, p < 0.0001) and OS (median 14.8 vs. 10.5 months, p < 0.0001) than those with ETS < 20%. Adjusted hazard ratios of ETS < 20 vs. ≥ 20% were 0.606 (95% confidence interval (CI) 0.506-0.725) for PFS and 0.589 (95% CI 0.492-0.704) for OS. DpR was also significantly associated with PFS and OS (both p < 0.0001). These results were similar between the SOX and CS groups. CONCLUSIONS: In AGC patients receiving the first-line therapy, ETS and DpR might be predictors for PFS and OS.
Entities:
Keywords:
Chemotherapy; Depth of response; Early tumor shrinkage; Gastric cancer; Oxaliplatin