NCT02624115

FAZA PET as Biomarker for Hypoxia in Rectal Cancer

Completed Last updated 16 August 2019

What this trial tests

trial in Colon Rectal Cancer Adenocarcinoma in 8 participants. Completed in 9 June 2019.

Timeline

1 May 2016

Primary endpoint
9 June 2019

9 June 2019

Quick facts

Lead sponsor	University Health Network, Toronto
Status	Completed
Study type	OBSERVATIONAL
Enrollment	8
Start date	1 May 2016
Primary completion	9 June 2019
Estimated completion	9 June 2019
Sites	1 location across Canada

Conditions studied

• Colon Rectal Cancer Adenocarcinoma — all drugs for Colon Rectal Cancer Adenocarcinoma →

Sponsor

University Health Network, Toronto

Who can join

18 and older, any sex, with Colon Rectal Cancer Adenocarcinoma. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

Colorectal cancer (CRC) is one of the leading causes of cancer mortality in Canada. Rectal cancers are now known to be hypoxic which is a negative prognostic factor and predictive of metastatic spread and poor responsiveness to treatment. This has also been shown in preclinical xenograft models. Hence there is a need for identification of hypoxic rectal cancers.

In this pilot study the investigators intend to non-invasively assess the tumor and nodal metastasis using an integrated Positron Emission Tomography-Magnetic Resonance Imaging scanner (PET/MRI) with 18F-Fluoroazomycin Arabinoside (18F-FAZA) a radiopharmaceutical for assessing tumor hypoxia. The hypoxic rectal tumors will show an increased uptake of 18F-FAZA on PET which will have morphological correlation on MRI. The patient will then undergo neoadjuvant chemoradiation therapy (CRT) followed by repeat 18F-FAZA PET/MRI and rectal cancer surgery with pimonidazole staining. Pimonidazole is an extrinsic marker of hypoxia that is selectively reduced and covalently bound to intracellular macromolecules in areas of hypoxia within normal and tumor tissue with current approval for use in humans for research studies.

The primary goal of this pilot trial is to validate FAZA-PET as a biomarker of hypoxia by correlating its uptake in rectal tumors to pimonidazole staining in histopathology specimens. If the investigators pilot study successfully demonstrates the uptake and correlation of pimonidazole and FAZA-PET, the investigators would like to initiate a larger study examining hypoxia in rectal cancer. The investigators aims would be to image patients with locally advanced rectal cancer before CRT to ascertain whether high FAZA-PET uptake correlates with poor outcome to CRT. The ability to preoperatively predict the patient sub-population that will respond best to CRT, will help to identify the "complete pathological" responders and avoid unnecessary surgery. Furthermore, the FAZA-PET high subset of patients may benefit from other treatment strategies including clinical trials of anti-hypoxic agents.

Publications & conference data

2 peer-reviewed publications reference this trial (live from Europe PMC):

1. Hypoxia imaging with ¹⁸F-FAZA PET/CT predicts radiotherapy response in esophageal adenocarcinoma xenografts.
   Melsens E, De Vlieghere E, Descamps B, Vanhove C, et al · · 2018 · cited 21× · PMID 29514673 · DOI 10.1186/s13014-018-0984-3
2. <sup>18</sup>F-Fluoroazomycin Arabinoside (FAZA) PET/MR as a Biomarker of Hypoxia in Rectal Cancer: A Pilot Study.
   Metser U, Kohan A, O'Brien C, Wong RKS, et al · · 2024 · PMID 39330748 · DOI 10.3390/tomography10090102