Overview

Tumour testing for prostate cancer patients

Tumour testing can give us more information about your cancer, and help us decide how to treat it.

Tumour testing is also called somatic testing. We do a genetic test on a sample of your cancer. This test analyses the DNA in your cancer to find changes that are non-inherited (not from your parents). Genetic changes (mutations) that have developed in your lifetime are called somatic mutations.

A non-inherited (somatic) mutation might influence how your cancer grows, and responds to treatment. This helps us decide which treatments are most likely to work for you. It might help us decide whether to use targeted medicines, precision therapies, or if you can join clinical trials.

If you are eligible for tumour testing, it will be organised automatically by your doctor as part of your cancer care. Currently, people with some types of prostate cancer are eligible for tumour testing as outlined in national guidelines.

Tumour testing is usually done on a stored sample of your cancer from a previous biopsy (tissue test) or surgery. Sometimes, a new biopsy sample is needed.

Genes

Genes are ‘coded messages’ which give instructions for how cells grow and function. Genes come in pairs. We all have 2 copies of each gene, because we inherit 1 copy from each of our parents.

Some genes give instructions about the colour of hair, or eyes. Some give the body instructions to help protect us from getting cancer.

Possible results of tumour testing

Tumour testing does not find a gene mutation

This result is still useful information for your doctor. It is unlikely that more genetic testing for inherited gene mutations is needed. You might be asked more about your family history of cancer. If there is a family history of prostate or related cancers, you might be eligible for a referral to the clinical genetics service for more tests.

Tumour testing finds a mutation

The next steps will depend on which gene the mutation was found in. You might be offered germline testing to see if the gene mutation is also present in all the cells of your body from birth. A gene mutation found from tumour testing might be useful to help us plan your cancer treatment. You might be eligible for targeted therapies or clinical trials.

Somatic testing is organised automatically as part of your cancer care. Gene mutations found in the tumour are usually non-inherited (somatic) but sometimes they are inherited (germline).

Germline testing is usually done from a blood sample. It will tell us if the gene mutation is something that you were born with, and if your family members are at risk of having the inherited gene mutation. This might mean that there is an increased risk of cancer.