RT Journal Article SR Electronic T1 Rare Nivolumab-associated Super Hyper Progressive Disease in Patients With Advanced Gastric Cancer JF In Vivo JO In Vivo FD International Institute of Anticancer Research SP 1865 OP 1875 DO 10.21873/invivo.12449 VO 35 IS 3 A1 YUTARO KUBOTA A1 KIYOSHI YOSHIMURA A1 KAZUYUKI HAMADA A1 YUYA HIRASAWA A1 MIDORI SHIDA A1 MAKOTO TANIGUCHI A1 HIROTO MATSUI A1 HIROTSUGU ARIIZUMI A1 TOMOYUKI ISHIGURO A1 NORIHIRO SUZUKI A1 RYOTARO OHKUMA A1 TAKEHIKO SAMBE A1 HIROO ISHIDA A1 ATSUSHI HORIIKE A1 SATOSHI WADA A1 JUNJI TSURUTANI A1 SANJU IWAMOTO A1 NAOKI UCHIDA A1 YUJI KIUCHI A1 SHINICHI KOBAYASHI A1 TAKUYA TSUNODA YR 2021 UL http://iv.iiarjournals.org/content/35/3/1865.abstract AB Background/Aim: Rapid tumor growth after administration of immune checkpoint inhibitors is designated hyper progressive disease (HPD). In this study, besides the conventional HPD category, we proposed the “super HPD” category where the disease is naturally rapidly growing. Patients and Methods: Patients treated for advanced gastric cancer with irinotecan or nivolumab as a third-line treatment were retrospectively compared. Results: Eighteen and 26 patients were treated with irinotecan or nivolumab, respectively. There were 3 HPD cases (16.7%) in the irinotecan group, 6 cases (23.1%) in the nivolumab group, and the frequency of HPD was not significantly different. Two cases satisfied the super HPD definition only in the nivolumab group. When one of them was analyzed immunologically, the number of regulatory T cells was found to be increased, resulting in a low neutrophil-to-lymphocyte ratio. Conclusion: Our proposed super HPD was likely to represent a true HPD, with a frequency of 7.7%.