Cancer and PIDs
People affected by primary immunodeficiency disorders (PIDs) may have an increased risk of developing some kinds of cancer compared with people who do not have a PID. Cancer affects only a small number of people with a PID, and your doctor will look out for any early signs so it can be detected and treated early.
What is cancer?
In normal health, how quickly cells in the body divide and multiply is closely controlled. In cancer these normal control processes are lost. This leads to cells becoming abnormal and unregulated in their growth and the rate at which they divide. These cancerous cells can grow into visible tumours and may spread into other nearby tissues. If left unchecked, these cells can also spread, through the blood and other body fluids, to other areas of the body.
Most cancers arise through a combination of genetic and environmental factors. Environmental factors include things like cigarette smoke, radiation (including ultraviolet radiation causing sunburn), chemicals and some viruses. These are sometimes called carcinogens (car-sin-o-gens).
Cancer is not just one disease – there are many different kinds of cancer. Most are named after the area in the body in which they arise (e.g. breast cancer). They may also be named after the particular kind of cell that they grow from, for example, melanoma, which is a kind of skin cancer that comes from skin cells called melanocytes.
The language doctors use to describe cancer
Doctors use many different terms when they talk about cancer. These might include words such as ‘neoplasia’ (nee-oh-play-zee-ah) or ‘malignant disease’ or ‘tumour’, as well as ‘cancer’ itself. This terminology can be very confusing at times but these terms essentially all mean the same thing.
Which PIDs are particularly associated with developing cancer?
The evidence shows there is an increased risk of developing some kinds of cancer in people with PIDs compared with people who have healthy immune systems. This said, having a PID does not mean you will definitely develop cancer. Many people with a PID will remain unaffected by cancer throughout their lives.
Conditions that have an increased risk of cancer are common variable immune deficiency (CVID), ataxia telangiectasia, Wiskott–Aldrich syndrome and X-linked lymphoproliferative disease, which is also called Duncan’s syndrome. However, the great majority of people with CVID, for instance, will never have a problem with cancer.
What types of cancer are associated with PIDs?
Studies, to date, show that people with a PID do not appear to have an increased risk of developing more common kinds of cancers found in the population, e.g. lung, breast, ovary, prostate, large bowel. However, they may be more at risk of developing cancers of white blood cells, known as lymphomas, cancer of the stomach and some kinds of cancer of the skin.
Why is cancer more common in PID?
This is not fully understood. Clinicians and researchers think this happens because the faulty immune response in PID fails to get rid of potentially cancerous cells before they grow into an established cancer or because these particular kinds of cancer may be caused, at least in part, by infections with viruses or bacteria which are not killed off effectively in someone who has a PID.
Can the development of cancers in PID be avoided?
In general no, because it isn’t possible to tell in advance with any certainty who will, and who will not, get cancer. Your immunologist may discuss with you ‘risk factors’ that are thought to have a role in cancer development and try to address these issues, but the value of doing this is not yet known. Some of these so-called ‘risk factors’ include getting rid of specific bugs from the stomach that might be associated with stomach cancer and avoiding exposure to large amounts of radiation in X-rays and scans, which is particularly relevant to conditions like ataxia telangiectasia.
Remember you can also do your bit to decrease your general cancer risk by not smoking, eating a healthy diet and avoiding sunburn.
How do doctors check for cancer?
There are a number of good reasons why your immunologist or immunology nurse sees you regularly to examine you and to perform routine ‘monitoring’ tests of your blood, stools, etc. One of these reasons is to detect cancer, or any risk factors for cancer, at as early a stage as is possible.
How are cancers treated?
If a cancer is detected your immunologist will work with specialists from another health team. This may be an oncologist or a haematologist depending on the type of cancer involved. They will ensure that timely and appropriate treatment options are discussed, agreed with you and started.
Useful resource:
This page was reviewed by the Medical Advisory Panel, April 2018.
