A Phase III clinical study has identified a blood test that can be used to monitor the effectiveness of chemotherapy in metastatic, castration-resistant prostate cancer (mCRPC) patients.
Conducted by Chris O’Brien Lifehouse and Garvan Institute of Medical Research, the study involved the analysis of blood samples for a methylated copy of the glutathione S-transferase gene (mGSTP1) both before and during treatment.
At the beginning of the study, the blood test identified the biomarker in 81% of patients. The tests were then repeated after two cycles of chemotherapy with docetaxel and revealed the absence of the biomarker in 53% of participants.
Based on these results, the researchers concluded that the absence of detectable mGSTP1 is a reliable indicator of longer overall survival and slower disease progression.
Chris O’Brien Lifehouse’s medical oncology director Lisa Horvath said: “This significant advance in personalised cancer treatment can provide clinicians with reliable information for making decisions that ensure the patient is getting the most effective treatment for them and potentially avoiding unnecessary treatment.”
Prostate cancer is one of the most commonly diagnosed in Australia.
The institute’s genomics and epigenetics head Susan Clark said: “I am immensely proud of this collaborative Australian discovery which will allow us to tailor the most appropriate treatment to a patient, based on the genetic makeup of cancer.”
The research team is planning to further investigate the blood biomarker in additional clinical trials.