Tetsuo Saito1, Takashi Kosugi2, Naoki Nakamura3, Hitoshi Wada4, Ayako Tonari5, Hirofumi Ogawa6, Norio Mitsuhashi7, Kazunari Yamada8, Takeo Takahashi9, Kei Ito10, Shuhei Sekii11, Norio Araki12, Miwako Nozaki13, Joichi Heianna14, Kenta Murotani15, Yasuhiro Hirano16, Atai Satoh17, Tsuyoshi Onoe6, Takahiro Watakabe18, Naoto Shikama19. 1. Department of Radiation Oncology, Arao Municipal Hospital, 2600, Arao, Arao-shi, Kumamoto, 864-0041, Japan. tetsuosaito1977@gmail.com. 2. Department of Radiation Oncology, Fujieda Municipal General Hospital, Shizuoka, Japan. 3. Department of Radiology, St. Marianna University School of Medicine, Kanagawa, Japan. 4. Department of Radiation Oncology, Southern TOHOKU Proton Therapy Center, Fukushima, Japan. 5. Department of Radiation Oncology, Kyorin University Hospital, Tokyo, Japan. 6. Division of Radiation Therapy, Shizuoka Cancer Center, Shizuoka, Japan. 7. Radiation Therapy Center, Hitachi, Ltd., Hitachinaka General Hospital, Ibaraki, Japan. 8. Department of Radiation Oncology, Seirei Mikatahara General Hospital, Shizuoka, Japan. 9. Department of Radiation Oncology, Saitama Medical Center, Saitama Medical University, Saitama, Japan. 10. Division of Radiation Oncology, Department of Radiology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan. 11. Department of Radiation Oncology, Kita-Harima Medical Center, Hyogo, Japan. 12. Department of Radiation Oncology, National Hospital Organization Kyoto Medical Center, Kyoto, Japan. 13. Department of Radiation Oncology, Saitama Medical Center, Dokkyo Medical University, Saitama, Japan. 14. Department of Radiology, Nanbu Tokushukai Hospital, Okinawa, Japan. 15. Biostatistics Center, Kurume University, Fukuoka, Japan. 16. Division of Radiation Oncology and Particle Therapy, National Cancer Center Hospital East, Chiba, Japan. 17. Department of Surgery, Southern TOHOKU General Hospital, Fukushima, Japan. 18. Department of Radiation Oncology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan. 19. Division of Radiation Oncology, Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan.
Abstract
BACKGROUND: Palliative radiotherapy seems to be rarely performed for incurable gastric cancer. In this first multicenter study, we examined the effectiveness of palliative radiotherapy and investigated whether biologically effective dose (BED) is associated with survival, response, or re-bleeding. METHODS: Eligibility criteria included blood transfusion or hemoglobin levels < 8.0 g/dL. The primary endpoint was the intention-to-treat (ITT) bleeding response rate at 4 weeks. Response entailed all of the following criteria: (i) hemoglobin levels ≥ 8.0 g/dL; (ii) 7 consecutive days without blood transfusion anytime between enrollment and blood sampling; and (iii) no salvage treatment (surgery, endoscopic treatment, transcatheter embolization, or re-irradiation) for bleeding gastric cancer. Re-bleeding was defined as the need for blood transfusion or salvage treatment. RESULTS: We enrolled 55 patients from 15 institutions. The ITT response rates were 47%, 53%, and 49% at 2, 4, and 8 weeks, respectively. The per-protocol response rates were 56%, 78%, and 90% at 2, 4, and 8 weeks, respectively. Neither response nor BED (α/β = 10) predicted overall survival. Multivariable Fine-Gray model showed that BED was not a significant predictor of response. Univariable Cox model showed that BED was not significantly associated with re-bleeding. Grades 1, 2, 3, and, ≥ 4 radiation-related adverse events were reported in 11, 9, 1, and 0 patients, respectively. CONCLUSIONS: The per-protocol response rate increased to 90% during the 8-week follow-up. The frequent occurrence of death starting shortly after enrollment lowered the ITT response rate. BED was not associated with survival, bleeding response, or re-bleeding.
BACKGROUND: Palliative radiotherapy seems to be rarely performed for incurable gastric cancer. In this first multicenter study, we examined the effectiveness of palliative radiotherapy and investigated whether biologically effective dose (BED) is associated with survival, response, or re-bleeding. METHODS: Eligibility criteria included blood transfusion or hemoglobin levels < 8.0 g/dL. The primary endpoint was the intention-to-treat (ITT) bleeding response rate at 4 weeks. Response entailed all of the following criteria: (i) hemoglobin levels ≥ 8.0 g/dL; (ii) 7 consecutive days without blood transfusion anytime between enrollment and blood sampling; and (iii) no salvage treatment (surgery, endoscopic treatment, transcatheter embolization, or re-irradiation) for bleeding gastric cancer. Re-bleeding was defined as the need for blood transfusion or salvage treatment. RESULTS: We enrolled 55 patients from 15 institutions. The ITT response rates were 47%, 53%, and 49% at 2, 4, and 8 weeks, respectively. The per-protocol response rates were 56%, 78%, and 90% at 2, 4, and 8 weeks, respectively. Neither response nor BED (α/β = 10) predicted overall survival. Multivariable Fine-Gray model showed that BED was not a significant predictor of response. Univariable Cox model showed that BED was not significantly associated with re-bleeding. Grades 1, 2, 3, and, ≥ 4 radiation-related adverse events were reported in 11, 9, 1, and 0 patients, respectively. CONCLUSIONS: The per-protocol response rate increased to 90% during the 8-week follow-up. The frequent occurrence of death starting shortly after enrollment lowered the ITT response rate. BED was not associated with survival, bleeding response, or re-bleeding.