A study looking at a blood test to help doctors decide the best treatment for prostate cancer (VARIANT)

Study design
The team had hoped to find 70 people to take part in the study. 14 people were screened and 12 people agreed to take part. 

A computer put them into a treatment group at random. There were 2 groups:

• 6 people had treatment guided by the results of the blood test (group 1)
• 6 people had treatment in the usual way (group 2)

Group 1 - treatment guided by the AR-V7 test 
Everyone had a blood test to look for the AR-V7 protein. 

One person had AR-V7 in their blood. This meant they were AR-V7 positive. They had cabazitaxel chemotherapy. This was a standard treatment  for prostate cancer that had spread to other parts of the body. 

5 people didn’t have AR-V7 in their blood. They were AR-V7 negative. They had abiraterone or enzalutamide hormone therapy. 

Group 2 - treatment as usual (standard of care) 
Everyone had a blood test to look for the AR-V7 protein. Neither those taking part nor their doctor knew the result of the test. Their doctor decided the best treatment:

• 1 person had cabazitaxel chemotherapy 
• 2 people had enzalutamide hormone therapy 
• 3 people had abiraterone hormone therapy 

Results
This study closed earlier than planned due to the COVID-19 pandemic.

The study team found that some men were willing to join the study and doctors were willing to put men into it. 

It wasn’t possible to draw firm conclusions about the AR-V7 blood test. There were a few reasons for this. These included the following: 

• there was a problem with the way the AR-V7 test was done so the team couldn’t be confident that the results were correct 
• there were a low number of people in the study 
• standard treatment for metastatic prostate cancer changed during the course of the study 
• the study closed earlier than planned due to the COVID-19 pandemic 

Conclusions
In this small study it wasn’t possible to draw firm conclusions about the AR-V7 blood test for prostate cancer. But the study team found that men were willing to take part to allow their treatment to be guided by a blood test. 

The study team hope that researchers doing other similar trials can use these findings. 

All trial results help doctors and researchers understand more about different cancers and the best way to treat them. 

More detailed information
There is more information about this research in the reference below. 

Please note, this article is not in plain English. It has been written for healthcare professionals and researchers.

Using the AR-V7 biomarker to determine treatment in metastatic castrate resistant prostate cancer, a feasibility randomised control trial, conclusions from the VARIANT trial
P Gravestock and others 
NIHR Open Research, 2023. 2:49

Where this information comes from    
We have based this summary on the information in the article above. This has been reviewed by independent specialists (peer reviewed ) and published in a medical journal. We have not analysed the data ourselves. As far as we are aware, the link we list above is active and the article is free and available to view.