Alkaline phosphatase and metastatic prostate cancer

Alkaline phosphatase is an enzyme made mainly in the liver and bones. Bone-forming cells release more of it when bone is being remodelled. Prostate cancer that has spread to bone may increase this activity, so clinicians may follow the blood result alongside imaging and prostate-specific antigen testing.

A raised result does not identify the cause by itself. Liver or bile-duct problems, healing bone, and other conditions can also affect it. A normal result cannot by itself exclude cancer in bone. Your doctor may review the separate liver and bone-related results and compare changes over time.

Take the result to the clinician managing your prostate cancer and ask how it fits with your scan findings, symptoms, and treatment plan. Keep a record of new bone pain, weakness, numbness, or changes in bladder or bowel function. Treatment may include cancer-directed medicines, radiotherapy, targeted radioisotope therapy, or bone-strengthening therapy, depending on where disease is found and your overall health.

For background, read [Prostate Cancer](/conditions/prostate-cancer/) and ask whether [Radiotherapy](/treatments/radiation-oncology/radiotherapy/) or [Bone-Strengthening Therapy](/treatments/supportive-and-palliative-care/bone-strengthening-therapy/) is relevant to you.

Contact your cancer team promptly for worsening back or neck pain, new leg weakness, numbness, trouble walking, or loss of bladder or bowel control. These symptoms can signal pressure on the spinal cord and need urgent assessment. Seek immediate help for inability to pass urine, severe sudden pain, or a new inability to move safely.

Ask: Could this result come from bone, liver, or another cause? What do my scans show? Should the test be repeated or separated into liver and bone sources? Which symptoms should trigger an urgent call? Would [Targeted Radioisotope Therapy](/treatments/radiation-oncology/targeted-radioisotope-therapy/) or another treatment be appropriate?