Existing cancer screening guidelines for solid organ transplant recipients fall short in several key ways, according to a new review.
Cancer development and deaths are higher among transplant recipients than the general population, Nancy N. Baxter, MD, and Sergio A. Acuna, MD, of St. Michael’s Hospital in Toronto, and colleagues explained in an online report in the American Journal of Transplantation. Cancer screening of these patients remains controversial, however, because they often have multiple comorbidities and lower life expectancy.
“Transplant recipients should be aware they have a heightened risk of developing and dying from cancer and should advocate with their health-care providers to be screened for cancer,” Dr Baxter commented in a press release. “Even though transplant recipients often have other serious medical conditions that could shorten their life expectancy, they also need to be screened for cancer to ensure early detection.”
Dr Baxter and her team conducted an international, systematic review of clinical practice guidelines on cancer screening for solid organ transplant recipients and found varying recommendations for screening of breast, cervical, colorectal, and other cancers. Among 13 guidelines, only annual skin cancer screening with clinical skin exam was endorsed routinely. Consistent evidence of increased cancer incidence and mortality existed solely for colorectal cancer.
In addition, many of the screening recommendations were based on elevated risks of cancer rather than evidence of benefits from screening. Randomized clinical trials on screening might clarify matters, but require large numbers of participants, and the numbers of transplant recipients are relatively small. There are ethical considerations, as well. The risk and benefit profile of specific cancer screening modalities for this population are largely unknown.
Screening recommendations also varied considerably by transplanted organ. Five guidelines specifically addressed kidney transplant recipients, and they showed some consistency, although screening frequency differed. The risks of developing and dying from breast and cervical cancers are similar to those observed in the general population. “For these cancers, similar screening to that recommended for the general population would be adequate,” Dr Acuna told Renal & Urology News. Screening for lung and renal cancer was not recommended. But low-dose computed tomography scan for lung cancer is an option that may warrant re-evaluation, the researchers suggested.
Subgroups of transplant recipients, such as those with pre-transplant malignancies or hepatitis B or C infection, would likely benefit from tailored screening advice, they added. Individual risk factors based on family or smoking history, for example, also should be considered.
Concerted research efforts still are needed to define optimal approaches to cancer screening and aid decision making, the researchers emphasized. For example, most of the guidelines were written by transplant specialists without the benefit of other perspectives. “Involvement of relevant stakeholders such as oncologists, primary care physicians, public health officials and patients, could lead to changes in the strength of these recommendations and may help improve screening practices,” Dr Acuna said.
1. Acuna SA, Huang JW, Scott AL, et al. Cancer Screening Recommendations for Solid Organ Transplant Recipients: A Systematic Review of Clinical Practice Guidelines. Am J Transplant. 2016 Aug 30. doi: 10.1111/ajt.13978.
2. Inconsistent guidelines for screening transplant recipients at higher cancer risk: Study. St. Michael’s Hospital. August 30, 2016. [press release]