The use of biomarkers in advanced prostate cancer with bone tumors

The aim of this study was to determine the effect of biomarkers to tailor therapy in advanced prostate cancer in patients receiving abiraterone (Zytiga) treatment.

The authors concluded that alkaline phosphatase (ALP- protein elevated in the blood), lactate dehydrogenase (LDH – protein involved in tumor growth) and prostate specific antigen (PSA – protein elevated in the blood in the presence of prostate cancer) changes during abiraterone treatment were associated with the best clinical benefit and overall survival in men with advanced, hormone-resistant prostate cancer with evidence of bone tumors.

Advanced prostate cancer is cancer that has spread outside of the prostate gland into surrounding organs, and in some cases into the bones. Advanced cancer can become resistant to treatments, like hormone therapy (targets the male sex hormones active in prostate cancer). This is known as hormone-resistant cancer. Biomarkers are naturally occurring characteristics used to identify a disease. Biomarkers can be used to guide treatment options by identifying markers or indicators that can show the extent of the cancer. ALP, LDH and PSA are biomarkers for prostate cancer.

Treatments such as abiraterone can be used to treat advanced hormone-resistant prostate cancer. It is a hormone therapy drug used in advanced cancer when other treatments are no longer working, or in patients how have received the chemotherapy drug docetaxel (Taxotere). It is not clear whether changes in ALP, LDH, and PSA are predictive of outcome following abiraterone treatment.

The aim of this study was to determine the use of ALP, LDH and PSA biomarkers to tailor therapy in men with advanced, hormone-resistant prostate cancer that has spread to the bones who are receiving abiraterone.

84 men were included in this study with an average follow-up of 14 months. 39 men had not received previous chemotherapy and 45 men had received chemotherapy.

ALP-bouncing (immediate increases in ALP levels) was observed during the first 2-4 weeks of abiraterone treatment before PSA levels declined. ALP levels returned to normal or lower than normal levels within 8 weeks of treatment.

Failure to reduce PSA levels more than 50% and ALP-bouncing were strong predictors of cancer progression. PSA reduction of more than 50% was a strong predictor of overall survival (time from treatment until death from any cause). An increase in ALP at 12 weeks and a lack of ALP-bouncing were also predictors for poor overall survival. Patients who had a rising ALP after 12 weeks did not receive any further benefit from abiraterone treatment.

The authors concluded that ALP, LDH, and PSA changes during abiraterone treatment were associated with the best clinical benefit and overall survival in men with advanced, hormone-resistant prostate cancer with evidence of bone tumors.