In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 31, No. 15_suppl ( 2013-05-20), p. 4049-4049
Abstract:
4049 Background: We previously demonstrated correlation between hypoxia and aggressive tumor biology in orthotopic, patient-derived pancreatic xenografts (Chang et al. Cancer Res 2011). With the development of hypoxia-directed therapies, there is a need to understand the range and relevance of hypoxia in PDAC patients. We therefore launched two complementary clinical trials using 2-nitroimidazole-based hypoxia probes. Methods: PIMO-PANC involves pre-operative administration of pimonidazole to patients (pts) undergoing PDAC resection. Hypoxic percent (HP) of tumors is determined by semi-automated image analysis (on Aperio’s Genie) of multiple histological sections stained for pimonidazole by immunohistochemistry (IHC). FAZA-PANC uses the positron emission tomography (PET) tracer fluoroazomycin arabinoside ( 18 F-FAZA) to evaluate hypoxia by functional imaging. 2 hours post-injection of (5.2 MBq/kg) 18 F-FAZA, static scans are acquired followed by computed tomography for anatomic registration. Skeletal muscle is a non-hypoxic reference tissue to define standardized uptake values (SUV), tumor to muscle uptake ratios (T/M’s) and a threshold for hypoxia. Results: PIMO-PANC has enrolled 29 pts and FAZA-PANC 16. IHC analysis of the first 10 pt tumors demonstrates considerable intra- and inter-tumoral heterogeneity of hypoxia (HP: 1 to 26% across pt tumors); minimal hypoxia ( 〈 5%) was observed in 3 pts. 18 F-FAZA-PET in the first 11 pts demonstrates SUV max from 1.02 to 1.83, median T/M's from 0.84 to 1.31. A threshold of 1.27 SUV max defines HP of 0 to 60% with minimal hypoxia ( 〈 10%) in 5 pts. Conclusions: There is significant heterogeneity of hypoxia across the spectrum of clinical PDAC (local to metastatic disease) using the 2-nitroimidazole hypoxia probes pimonidazole and 18 F-FAZA. Given the intra-tumoral heterogeneity of hypoxia by histopathology, functional imaging is the preferred method to assess hypoxia in PDAC patients. Importantly, both methods identified a group of PDAC tumors with low levels of hypoxia. This is relevant to the on-going development of hypoxia-targeting strategies. Accrual to PIMO-PANC is on-going and will address the prognostic relevance of hypoxia in PDAC. Clinical trial information: NCT01542177 and NCT01248637.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/jco.2013.31.15_suppl.4049
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2013
detail.hit.zdb_id:
2005181-5
detail.hit.zdb_id:
604914-X
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