Any organ transplant increases your risk for developing skin cancer, but people receiving kidney transplants have the highest rate - with up to 70 percent of renal transplant recipients developing skin cancer after 20 years. 
After an organ transplant, patients are given immunosuppressant medications to reduce the chance of rejecting the new organ. Without these medications your body would attack the new organ as it does bacteria and other germs that cause illness. Your body, in its effort to save you, rejects the very thing that has saved you.
Because we need our immune system to fight off infection, your doctor must find the correct balance. You need enough of the immunosuppression drugs to stop your body from rejecting the new organ, but if you completely stop your immune system from working, you risk developing infections and not having the ability to fight that infection. Knowledge we have today helps doctors find that balance but immunosuppression still leaves you at a higher risk of developing many types of cancer.
Kidney Transplants and Skin Cancer
A number of studies have shown that patients who received a kidney transplant have a high risk of developing skin cancer, with squamous cell carcinoma being the most common among transplant recipients. "Cancer, especially skin squamous cell carcinoma, is a leading cause of mortality and morbidity in long-surviving kidney transplant recipients,"  according to Cai Bin Cui, M.D. and David Berber, M.D., School of Medicine at the University of North Carolina at Chapel Hill.
While most research shows a clear link between immunosuppression therapy and increased skin cancer, a recent study found that in some patients, the skin cancer contains the same genotype as the donor, raising questions about whether the donor kidney may, at least in some cases, contribute to the risk of cancer.
A previous study, completed in 2005, also showed an increased risk of melanoma. According to researchers, people with kidney transplants were 4 times more likely to develop melanoma than the general population.  This study also pointed to long-term immunosuppression therapy as a cause for the increased cancer risk. The risk for melanoma was higher in men than in women.
Taking Steps to Prevent Skin Cancer
Early detection and treatment is important. "Kidney transplant patients - especially men - should have a regular, complete skin examination as part of their routine health care. In addition kidney transplant recipients should be educated about melanoma and instructed on the importanceof routine self-examination." 
Because skin cancer in transplant patients can be more aggressive and invasive, seeing your doctor for any spots or lesions that appear, change or grow is important. Regular preventive measures, such as using sunscreen, wearing protective clothing and staying out of the sun between 10:00 AM and 4:00 PM is also important.
"Human Skin Carcinoma Arising From Kidney Transplant - Derived Tumor Cells," 2013, Laurence Verneuil et al, Journal of Clinical Investigation
  'Kidney Transplant Patients Face Higher Skin Cancer Risk," 2005, Sept. 29, Staff Writer, ScienceDaily.com
 "Kidney Transplants Linked to Invasive Skin Cancer," 2013, Sept. 5, Fran Lowry, Medscape.com
 "Skin Cancer in Renal Transplant Recipients," 2010, M. Mangino, FP Schena, G Ital Nefrol
Eileen Bailey is a freelance health writer. She is the author of What Went Right: Reframe Your Thinking for a Happier Now, Idiot’s Guide to Adult ADHD, Idiot’s Guide to Cognitive Behavioral Therapy, Essential Guide to Overcoming Obsessive Love, and Essential Guide to Asperger’s Syndrome. She can be found on Twitter @eileenmbailey and on Facebook at eileenmbailey.