Taro Shibuki: Department of Hepatobiliary and Pancreatic Oncology, National Cancer Center Hospital East, Kashiwa, Japan; Department for the Promotion of Drug and Diagnostic Development, Division of Drug and Diagnostic Development Promotion, Translational Research Support Office, National Cancer Center Hospital East, Kashiwa, Chiba, Japan. Electronic address: tshibuki@east.ncc.go.jp.
Masafumi Ikeda: Department of Hepatobiliary and Pancreatic Oncology, National Cancer Center Hospital East, Kashiwa, Japan.
Masayuki Yokoyama: JCOG Data Center/Operations Office, National Cancer Center Hospital, Tokyo, Japan.
Yusuke Sano: JCOG Data Center/Operations Office, National Cancer Center Hospital, Tokyo, Japan.
Junji Furuse: Department of Gastroenterology, Kanagawa Cancer Center, Yokohama, Japan; Department of Medical Oncology, Kyorin University Faculty of Medicine, Mitaka, Japan.
Satoshi Kobayashi: Department of Gastroenterology, Kanagawa Cancer Center, Yokohama, Japan.
Akihiro Ohba: Department of Hepatobiliary and Pancreatic Oncology, National Cancer Center Hospital, Tokyo, Japan; Division of Gastrointestinal Oncology, Shizuoka Cancer Center, Shizuoka, Japan.
Akiko Todaka: Division of Gastrointestinal Oncology, Shizuoka Cancer Center, Shizuoka, Japan; Department of Medical Oncology and Hematology, Oita University Faculty of Medicine, Yufu, Japan.
Yoshiki Horie: Department of Clinical Oncology, St. Marianna University School of Medicine, Miyamae-ku, Kawasaki, Japan.
Kazuhiko Shioji: Department of Internal Medicine, Niigata Cancer Center Hospital, Niigata, Japan.
Masashi Kanai: Department of Therapeutic Oncology, Kyoto University Graduate School of Medicine, Kyoto, Japan; Department of Clinical Oncology, Kansai Medical University Hospital, Osaka, Japan.
Tomohiro Nishina: National Hospital Organization Shikoku Cancer Center, Matsuyama, Japan.
Yusuke Kumamoto: Department of General, Pediatric, and Hepatobiliary-Pancreatic Surgery, Kitasato University, Kanagawa, Japan.
Nao Fujimori: Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Akio Katanuma: Center for Gastroenterology, Teine-Keijinkai Hospital, Sapporo, Japan.
Yukiko Takayama: Department of Medicine, Institute of Gastroenterology, Tokyo Women's Medical University, Tokyo, Japan.
Hidetaka Tsumura: Department of Gastroenterology and Hepatology, Hyogo Cancer Center, Akashi, Japan.
Haruo Miwa: Department of Gastroenterology, Yokohama City University Medical Center, Yokohama, Japan.
Masato Ozaka: Department of Gastroenterology, Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan.
Makoto Ueno: Department of Gastroenterology, Kanagawa Cancer Center, Yokohama, Japan.
BACKGROUND/OBJECTIVES: Depth of response (DpR; maximum % reduction from baseline in sum of the target lesion diameters) has demonstrated potential in predicting prognosis in several malignancies. However, its role in locally advanced pancreatic cancer (LAPC) is still unclear. In JCOG1407, modified FOLFIRINOX (mFOLFIRINOX) and gemcitabine plus nab-paclitaxel (GnP) exhibited comparable efficacy for LAPC. In this exploratory analysis using the data of JCOG1407, we focused on the association between DpR and prognosis. METHODS: DpR was classified into three groups at the tertile point and patients' backgrounds and survival were compared. The impact of DpR on survival outcomes was evaluated using the multivariable Cox proportional hazard model. RESULTS: Of the 126 patients enrolled in JCOG1407, 109 patients were included, categorized into three DpR groups: T1 (<-37.2 %), T2 (-37.2 to -13.6 %), and T3 (>-13.6 %). The median DpR was significantly greater in the GnP arm than in the mFOLFIRINOX arm (-28.9 vs. -22.7 %, P = 0.041). Median duration of response tended to be shorter in the GnP arm than in the mFOLFIRINOX arm, although the difference was not significant (5.3 vs. 8.2 months, P = 0.132). Greater DpR (T1) had a significantly larger impact on better progression-free survival (PFS) and overall survival (OS) than T3, with the hazard ratio of 0.469 (95 % confidence interval [CI] 0.268-0.821, P = 0.008), and 0.398 (95 % CI 0.217-0.728, P = 0.003), respectively. CONCLUSIONS: mFOLFIRINOX and GnP had similar OS, it is noteworthy that the regimens exhibited differences in DpR, with GnP leading to greater DpR. Greater DpR are associated with improved survival in patients with LAPC.
