1448P - Evaluation of human circulating tumor cells by hTERT-specific replication-selective adenovirus in soft tissue sarcoma

Date 29 September 2014
Event ESMO 2014
Session Poster Display session
Topics Soft Tissue Sarcomas
Translational Research
Presenter Toshihiro Matsuo
Citation Annals of Oncology (2014) 25 (suppl_4): iv494-iv510. 10.1093/annonc/mdu354
Authors T. Matsuo1, N. Hamada1, H. Hachisuka1, T. Hamasaki1, Y. Izuta2, R. Mori1, S. Okawa1, T. Harada1, Y. Urata3, T. Sugita1
  • 1Orthopaedic Surgery, National Hospital Organization Kure Medical Center, Chugoku Cancer Center, 7370023 - Kure/ Hiroshima/JP
  • 2Orthopaedic Surgery, National Hospital Organization Kure Medical Center, Chugoku Cancer Center, 7370023 - Kure/JP
  • 3Head Office, Oncolys Biopharma Inc., 1050001 - Tokyo/JP

Abstract

Aim

Circulating tumor cells (CTCs) in peripheral blood are a useful prognostic factor and a tool for measuring the treatment effects in various carcinomas. We attempted to detect viable CTCs in the peripheral blood of sarcoma patients using a telomerase-specific viral agent. We then investigated whether there was a correlation between numbers of CTCs and other clinical features of sarcomas to determine whether these factors can be used as parameters of aggressiveness or prognosis.

Methods

Seventeen blood samples were obtained from 12 soft tissue sarcoma patients with soft tissue sarcoma of trunk or extremity before and/or after surgery. The samples were collected from 7 males and 5 females with an average age of 73 years. Four patients presented with myxoidfibrosarcoma, 2 with pleomorphic sarcoma, 2 with liposarcoma histology and others. Histological grades were assigned according to the French Federation of Cancer Centers Sarcoma Group (FNCLCC) system. One patient was diagnosed with grade 1, 2 with grade 2, and 9 with grade 3 sarcoma. The average duration of postoperative observation was 18.1 months (range: 3 to 40 months). Four patients developed a lung metastasis without local recurrence after surgery. We detected viable CTCs in the 7.5ml blood samples after incubating them with a telomerase-specific, replication-selective, oncolytic adenoviral agent carrying the green fluorescent protein (GFP) gene (OBP-401). GFP-positive cells were counted under a fluorescence microscope.

Results

The average number of CTCs was 6.5 (range: 0-65). There was a significant difference in number of CTCs between the patients with grade 3 (average 7.2) and those with grade 1 and 2 (average 2.8) (p=0.045). A decrease in the number of postoperative CTCs compared to number of preoperative CTCs was significantly related to lung metastasis (p=0.046). The number of CTCs was not related to gender, age, tumor location, and tumor size.

Conclusions

A significant relationship emerged among the number of CTCs, histological grade, and occurrence of lung metastasis in patients with sarcoma. The detection of CTCs using OBP-401 may be useful for prognostic evaluation.

Disclosure

All authors have declared no conflicts of interest.