Abstract 5107: Development of modified telomerase-specific adenovirus-based identification for viable-peritoneal tumor cells in peritoneal lavage fluid in resectable pancreatic cancer

Abstract

Abstract Pancreatic cancer (PC) is a highly aggressive disease with dismal prognosis. Although only a surgical resection can offer the chance of a cure, the 5-year survival rate after a potentially curative resection have been reported to be a low as 10-30%. Peritoneal recurrence is a major recurrence pattern after surgery for PC. Peritoneal lavage cytology (CY) is employed widely in the diagnosis and staging of PC to rule out patients with occult peritoneal metastasis. However, the prognostic significance of CY+ in potentially resectable PC is still controversial. We rise the question of whether CY+ status in PC has predictive value for survival and early peritoneal recurrence. We conducted this study to evaluate use of a new genetically modified telomerase-specific replication-selective adenovirus, expressing GFP (TelomeScan F35) in rapid detection of viable peritoneal tumor cell (v-PTC) dissemination of PC. This human clinical trial sought to determine if the presence of virally-detected, rare v-PTC predict peritoneal recurrence and patient outcome. This study was approved by the IRB in Osaka Police Hospital and Rinku General Medical Center. Patients with resectable cytologically or histologically proven ductal adenocarcinoma of the pancreas were enrolled. 100ml of saline as peritoneal lavage fluid was harvested just after a laparotomy in 53 patients with PC. Half of the fluid was examined by cytology with papanicolau staining and MOC-31 immunostaining and the remaining half was analyzed to detect v-PTC with TelomeScan F35. To distinguish between leucocyte and cells with epithelial origin, cells were stained with anti-CD45 Ab. To further distinguish cells with primary tumor origin, cells were labeled with anti-CEA, anti-CA19-9 and EpCAM Abs. GFP-positive and CD45-negative, and either CEA-, CA19-9- or EpCAM-positive cells were counted as v-PTC by automatic detection system using NIS Elements imaging software. Patients were followed after surgery to evaluate its clinical significance. Among 53 patients aged 53-87 years (30 males and 23 females), 6 were cytologically positive (CY+), other 12 were virally positive by TelomeScan F35 (v-PTC+). All 53 patients underwent a surgical resection (PD/DP/TP=32/14/7). 2 patients were double positive (CY+/v-PTC+), and peritoneal recurrence early occurred at 7 month after surgery despite adjuvant chemotherapy. 4 were CY+, but v-PTC-, and no peritoneal recurrence were observed (0%). On the other hand, other 10 were CY-, but v-PTC+, and 4 of these 10 patients occurred peritoneal recurrence (40%). Remaining 37 patients were double negative (CY-/v-PTC-), peritoneal recurrence were observed in only 4 patients. In conclusion, the TelomeScan F35-based v-PTC detection may be an independent prognostic factor in patients with resectable PC and had close association with peritoneal recurrence. Citation Format: Masahiro Tanemura, Kenta Furukawa, Manabu Mikamori, Tadafumi Asaoka, Yasuo Urata, Kentaro Kishi, Daisaku Yamada, Shogo Kobayashi, Hidetoshi Eguchi. Development of modified telomerase-specific adenovirus-based identification for viable-peritoneal tumor cells in peritoneal lavage fluid in resectable pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5107.