What should you know about PSMA immunohistochemistry?

Immunohistochemistry uses an antibody to attach to a chosen marker in tissue. A laboratory dye then makes the marked areas visible under a microscope. PSMA is associated with prostate tissue and is often assessed when a pathologist is investigating a prostate-related tumour or a tumour whose origin is uncertain.

A positive stain does not, by itself, prove prostate cancer, determine stage or show how a person will respond to treatment. Some non-cancerous tissues and cancers outside the prostate can show PSMA expression. The pathologist combines the stain with cell appearance, other markers, imaging and clinical history.

Ask for the complete pathology report rather than focusing only on the word positive or negative. Discuss the intensity and distribution of staining, the other markers tested, and whether the findings support a prostate origin. If tissue was obtained through a Biopsy, ask whether the sample was adequate for the planned interpretation.

Your oncology team may use the result alongside scans and other tests when considering diagnosis or management. Do not change treatment based on a single immunohistochemistry marker.

Arrange a results appointment when PSMA staining appears in a report, particularly if the tumour origin or treatment plan is still unclear. Seek urgent care for heavy bleeding after a procedure, fever, worsening pain, difficulty passing urine, shortness of breath or sudden weakness.

Ask what PSMA staining means in your tissue, which other markers were used, whether the findings change the suspected diagnosis, whether more tissue is needed, and how the result affects the next scan or treatment discussion.