Reducing Risk of Cancer After a Kidney Transplant

Changes in your body after a transplant could increase your cancer risk

Kidneys
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While kidney transplantation is clearly the most preferred treatment of 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, to 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 kind of malignancies. The list is extensive, extending to over two dozen different varieties of cancer. However, some of the common ones are:

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, say in those with lung transplants, could be different from cancer risk in those who received 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:

  1. 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 kind of medications used for this purpose after the transplantation might increase your risk more than others.

    For instance, immunosuppressant medications which 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/level of immunosuppression induced by being on multiple different immune suppression medications, rather than the quality of one specific drug, which increases cancer risk.

    An 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 because 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.
  1. 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).

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 cancers is not typically recommended to most 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 (AST) has published guidelines for cancer screening in those with a kidney transplant.

Here is an overview of the more common screenings (some of these screening recommendations are the same as for the general population):

  1. Skin cancer: Transplant recipients are asked to examine themselves every month to look for unusual moles/spots etc. This is complemented with an annual skin exam that could be done by a dermatologist.
  2. Breast cancer: In women over 50 years of age, annual screening mammography with or without a breast exam is recommended. Similar screening could be considered in women over 40 years of age, if the physician and the patient feel it is warranted.
  3. Prostate cancer: Annual digital rectal exam and PSA testing for men over the age of 50.
  1. Colon/rectal cancer: Colonoscopy every 10 years after the age of 50, and yearly stool test to detect blood.

Do your best to plan accordingly for these screenings to reduce your risk.

Sources:

Tonelli M et al. Systematic review: kidney transplantation compared with dialysis in clinically relevant outcomes.Am J Transplant. 2011 Oct;11(10):2093-109. doi: 10.1111/j.1600-6143.2011.03686.x. Epub 2011 Aug 30.

Engels EA et al. Spectrum of cancer risk among US solid organ transplant recipients. JAMA. 2011 Nov 2;306(17):1891-901. doi: 10.1001/jama.2011.1592.

Desai R et al. Cancer transmission from organ donors-unavoidable but low risk. Transplantation. 2012 Dec 27;94(12):1200-7. doi: 10.1097/TP.0b013e318272df41.

Buell JF et al. Malignancy after transplantation. Transplantation. 2005 Oct 15;80(2 Suppl):S254-64.

Kasiske BL et al. Recommendations for the outpatient surveillance of renal transplant recipients. American Society of Transplantation. J Am Soc Nephrol. 2000 Oct;11 Suppl 15:S1-86.

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