ORIGINAL ARTICLE Phase II study of cyclophosphamide, doxorubicin, vincristine, prednisolone (CHOP) therapy for newly diagnosed patients with low- and low–intermediate risk, aggressive non-Hodgkin’s lymphoma: final results of the Japan Clinical Oncology Group Study, JCOG9508 Yoshitoyo Kagami • Kuniaki Itoh • Kensei Tobinai • Haruhiko Fukuda • Kiyoshi Mukai • Takaaki Chou • Chikara Mikuni • Tomohiro Kinoshita • Noriyasu Fukushima • Yoshio Kiyama • Takayo Suzuki • Tsuneo Sasaki • Yuko Watanabe • Kunihiro Tsukasaki • Tomomitsu Hotta • Masanori Shimoyama • Michinori Ogura • The members of the Lymphoma Study Group of the Japan Clinical Oncology Group Received: 12 September 2011 / Revised: 7 May 2012 / Accepted: 11 May 2012 / Published online: 3 June 2012 Ó The Japanese Society of Hematology 2012 Abstract The regimen of cyclophosphamide, doxorubi- cin, vincristine, and prednisolone, known as CHOP ther- apy, has been established as the standard treatment for aggressive non-Hodgkin’s lymphoma (NHL). Although patients categorized as low (L) and low–intermediate (L–I) risk using the International Prognostic Index have favor- able prognoses in Western countries, the efficacy and safety of CHOP therapy has not been prospectively eval- uated in Japan. We conducted a phase II study of CHOP in L and L–I risk Japanese patients, evaluating overall sur- vival (OS) as the primary endpoint. A total of 213 patients were enrolled and treated with eight courses of CHOP. Efficacy was evaluated in 168 eligible patients (L risk, 87; L–I risk, 81). Five-year OS rates in all eligible, L, and L–I risk patients were 68 % [95 % confidence interval (CI): 61–76 %], 73 % (95 % CI: 63–82 %), and 64 % (95 % CI: 53–74 %), respectively. The major toxicity observed was grade 4 neutropenia (64 %). Grade 4 non-hematological toxicities were observed as follows: one case each of par- alytic ileus, convulsions, hypoxemia due to interstitial pneumonia, and reactivated fulminant hepatitis B. These results show reasonable efficacy and safety of the CHOP Y. Kagami Á M. Ogura Department of Hematology and Chemotherapy, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan Present Address: Y. Kagami (&) Department of Hematology, Toyota Kosei Hospital, 500-1 Ibohara, Josui-cho, Toyota 470-0396, Japan e-mail: y-kagami@toyota.jaaikosei.or.jp K. Itoh Division of Hematology and Oncology, National Cancer Center Hospital East, 6-5-1, Kashiwanoha, Kashiwa 277-8577, Japan K. Tobinai Á M. Shimoyama Department of Hematology, and Hematopoietic Stem Cell Transplantation, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan H. Fukuda Á Y. Watanabe JCOG Data Center, Center for Cancer Control and Information Services, National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan K. Mukai Department of Clinical Pathology, Tokyo Medical University, 6-7-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo 160-0023, Japan Present Address: K. Mukai Division of Pathology, Saiseikai Central Hospital, 1-4-17 Mita, Minato-ku, Tokyo 108-0073, Japan T. Chou Department of Internal Medicine, Niigata Cancer Center Hospital, Kawagishi-cho 2-15-3, Chuo-ku, Niigata 951-8566, Japan C. Mikuni Department of Hematology, Hokkaido Cancer Center, Kikusui, 4-2-3-54, Shiroisiku, Sapporo 003-0804, Japan Present Address: C. Mikuni Sapporo Yuushoukan Hospital, Higashiibarado 50-9, Kitaku, Sapporo 002-8043, Japan 123 Int J Hematol (2012) 96:74–83 DOI 10.1007/s12185-012-1101-2