After comparing two patient cancer registries—one featuring transplant patients and the other the general population—researchers at the University of Cincinnati (UC) have found that transplant patients experience worse outcomes from cancer.
These results will be published in the May 15, 2009, edition of the journal Transplantation
, which is currently in press.
Yun Miao, MD, PhD, Jason Everly, PharmD, Steve Woodle, MD, and colleagues at UC compared lung, colon, breast, prostate, bladder, kidney and skin cancer data in 635 adult transplant recipients from the Israel Penn International Transplant Tumor Registry with that of about 1.2 million adults from the general population in the Surveillance, Epidemiology and End Results (SEER) database.
"It has been known for some time that transplant recipients are at an increased risk of developing cancer, but the outcomes of cancers that arise in organ transplant recipients have not been defined," says Woodle, professor and chief of transplant surgery and co-author of the study.
"In this study, we wanted to examine the influence of transplantation on the outcomes of individual types of cancers arising in organ transplant recipients," adds Miao, co-author and research fellow in the division.
The Israel Penn International Transplant Tumor Registry is the largest and most comprehensive transplant tumor registry in the world and was created by doctors at the UC College of Medicine.
The SEER registry collects information on cancer incidence, survival and prevalence for roughly 26 percent of the United States population and compiles reports and statistics based on this information along with cancer mortality rates for the entire nation.
A comparison of results in transplant recipients to the general population also demonstrated that transplant patients were more likely to have early stage renal cell (kidney) cancer and more advanced colon, breast, bladder and skin cancer at the time of diagnosis.
Disease-specific survival was worse in the transplant population for each of these seven cancers analyzed and was a negative risk factor for survival.
Now, researchers want to conduct further studies to find out why this may be the case.
"Transplant patients receive immunosuppressive therapies to prevent them from rejecting transplanted organs," says Woodle. "We want to see if immunosuppressive therapies contribute to the poorer outcomes in transplant recipients."
He says the worse outcomes in transplant recipients may have occurred because this population is not as healthy as the general population or because their cancers may be more aggressive as a result of their immunosuppression treatments.
"Some of our data supports this premise, as the extent of the cancers at diagnosis were greater in the transplant recipients," Woodle continues. "This was surprising since transplant recipients are generally followed more closely than the general population."
Everly, co-author and board-certified oncology pharmacist in the division, says that this data may change the way physicians screen transplant patients for cancer.
"We found that most cancers developed within five years following transplantation," he says, noting that more frequent and detailed checks should be made in order to catch the cancer in its earliest stages. "This may alter the way doctors should screen these patients for cancer."