Reducing Risk of Cancer After a Kidney Transplant

While kidney transplantation is clearly the most preferred treatment for kidney failure (and beats being on dialysis any day), it does not come without its risks. These range from issues like increased risk of infections and post-transplantation diabetes to an increased risk of certain kinds of cancers.

Most people considering kidney transplantation as a treatment option take a pause when they learn this fact for the first time. However, a good transplant program will usually cover the possibility of cancer as part of pre-transplant counseling.

Which Cancers Does a Kidney Transplant Recipient Receive Counseling About?

Compared to the general population, a person who receives a kidney transplant will face a higher risk of certain kinds of malignancies. The list is extensive, extending to over two dozen different varieties of cancer, including these common types:

• Skin cancers, including melanoma
• Cancers of the hematologic system/blood cancers, lymphoma
• Kidney cancer, both of the natal kidney as well as the newly transplanted kidney
• Cancers of the gastrointestinal tract (sites could include the colon, rectum, pancreas, etc.)
• Lung cancer

An important issue to appreciate here is that it's not just kidney transplantation that puts the recipient at a higher risk of cancers. Other organ transplant recipients face similar risks, but the kind of cancers seen in, for example, those with lung transplants, may differ from cancer risk in those who receive a kidney transplant.

Why Does Risk Increase?

A popular notion among recipients is that "cancer comes packaged with the transplanted organ." While this is possible, it is not the most common reason for someone to develop cancer after receiving a kidney transplant. Here are some more likely explanations.

• Immunosuppressive therapy: As you might know, getting a kidney transplant entails being on medications to suppress your immune system. Usually, these medications need to be continued indefinitely. Certain kinds of medications used for this purpose after the transplantation might increase your risk more than others. For instance, immunosuppressant medications that target certain kinds of white blood cells (e.g. OKT3 or antilymphocyte serum) will significantly increase the risk of something called post-transplant lymphoproliferative disorder, or PTLD. However, more frequently, it is the overall extent of immunosuppression induced by being on multiple different immune suppression medications, rather than the quality of one specific drug, which increases cancer risk. An easier way to understand this concept is to realize that cancer cells are constantly being produced in our bodies, in general. The reason we don't develop a new malignancy every day is that these "lone-wolf" cancer cells are identified by our immune system surveillance and destroyed at the very outset. Therefore, our immune system is not just a protective mechanism against infections, it is also a protective mechanism against aberrant cell production (which could later turn into cancer). Suppressing this very immune system will therefore increase cancer risk.
• Infections: Certain viral infections specifically increase risk of cancers. Kidney transplant recipients face a greater risk of viral infection because of an immunosuppressed status. Viruses multiply by taking over and tinkering with our cells' replication machinery (the DNA in some cases). This may be one possible explanation for why viral infection increases cancer risk. Examples of these viruses include the Epstein-Barr virus (which increases risk of lymphoma), the Human Herpes Virus-8 (associated with Kaposi sarcoma), and Human Papilloma Virus (associated with skin cancers and cervical carcinoma).

What Can You Do to Reduce Your Cancer Risk?

Learning that you're at increased risk for cancer is frightening and may make you want to reconsider getting a transplant, but refusing an organ transplant because it increases future risk of cancer is not typically recommended, since risk of dying from kidney failure in the short term would usually outweigh the cancer risk. Therefore, after proper pre-transplant counseling, and once you receive a kidney transplant, cancer screening is recommended as part of the usual post-transplant care routine to reduce risk.

The American Society of Transplantation has published guidelines for cancer screening in those with a kidney transplant.

 Transplant recipients are asked to examine themselves every month to look for unusual moles, spots, and other skin changes that could suggest skin cancer. This is complemented with an annual skin exam that could be done by a dermatologist.

For solid organ cancer screenings, patients should follow guidelines from The American Cancer Society.