• What is already known about this topic and why is it important?

Kidney transplant recipients are more likely to be diagnosed with and die from cancer. Cancer immunotherapy, a new type of medication, has improved cancer treatment. This medication enhances the immune system by stopping it from switching off. In transplant recipients an active immune system is unwanted because it is more likely to find and attack the transplanted kidney. For this reason, people with a transplant have not been included in cancer immunotherapy trials.

When groups of people are excluded from trials, we do not know how well they respond to the treatment or what the side effects are. Despite not being included in trials, some transplant recipients after talking with their doctors, are treated with cancer immunotherapy. About 20-50% end up losing their transplant as a result.

• How will you carry out your study?

NCRAS is the cancer registry for England. This registry collects data on people in England with a cancer diagnosis. The UKRR and NHSBT are the dialysis and transplant registries for the UK. These registries hold a different part of a person’s medical journey. The information from these three registries will be joined and then made anonymous. We will compare what happens to a group of transplant recipients with cancer when they are treated with either chemotherapy or immunotherapy/chemotherapy combined.

• How will you decide which patients are included in your study?

We aim to include all dialysis and kidney transplant recipients in England with a known cancer diagnosis between 01-01-2010 and 31-12-2019.

• How many patients do you anticipate including?

We will ask the UKRR to identify all patients in England receiving dialysis between 2010 and 2019 (approximately 50,000). NHSBT will be asked to identify all kidney transplant patients between 2010 and 2019 (approximately 30,000). Of the transplant recipients, about 500-700 will have a cancer diagnosis. Only a small proportion are likely to have been treated with immunotherapy.

• For how long will you follow up these patients?

This is a retrospective study, meaning we will look back in time to see what has happened to this population.

• What value will UKRR data add to the project?

UKRR data is needed to identify dialysis recipients and the outcomes of the renal replacement therapy population, such as death. Without UKRR data we would not be able to perform the study.

• What new information will your study generate and how will this benefit patients?

The use of cancer immunotherapy is becoming more common. To ensure transplant recipients are not excluded from this treatment we need to understand:

• how many transplant recipients may need this medication,
• how many recipients treated with this medication might lose their transplant,
• why one person loses their transplant with this medication, but the other does not.

If we know this, it is easier for healthcare professionals and transplant recipients to decide if they should use this medication.