FROM CANCER
Solid organ transplant recipients contribute a disproportionate fraction of pediatric non-Hodgkin lymphoma (NHL) cases, especially diffuse large B-cell lymphoma cases (DLBCL), according to an analysis of data drawn from transplant and cancer registries.
Investigators calculated that the incidence of NHL for the pediatric transplant population was 257 times higher than the general population, after analysis from the U.S. transplant registry and 16 cancer registries from around the country between 1990 and 2012. The incidence of NHL for the pediatric transplant population was 306 cases per 100,000 person-years (95% CI, 271-344), compared to 1.19 cases per 100,000 person-years (95% CI, 1.12-1.27) in the general population. Furthermore, transplant recipients made up a much larger proportion of general population DLBCL cases (7.62%; 95% CI, 6.35%-8.88%).
In the general population, the most common subtypes were DLBCL (25% of cases), Burkitt lymphoma (24%), and precursor cell lymphoblastic lymphoma (20%). Among NHLs diagnosed in transplant recipients, 65% were DLBCL, and 9% were Burkitt lymphoma, whereas there were no cases of precursor cell lymphoblastic lymphoma, reported Elizabeth L. Yanik, PhD, of Washington University, St. Louis, and her associates (Cancer. 2017 Jul 31. doi: 10.1002/cncr.30923 ).
The increased risk of NHL and other cancers for organ transplant recipients is primarily the result of the immunosuppressant medications administered after transplantation, leading to an increased risk of infection-related cancers, the authors said.
“NHL cases are largely attributable to EBV [Epstein-Barr virus] infections that occur while recipients are immunosuppressed, as evidenced by the high prevalence of EBV detectable in NHL tumors and particularly in cases diagnosed during the heavily immunosuppressed period early after transplantation,” wrote Dr. Yanik and her colleagues. “Patients who experience a primary EBV infection after transplantation are particularly susceptible because transplant recipients have a higher NHL risk if they are seronegative for EBV before transplantation.”
Among those at risk, Dr. Yanik and fellow investigators found transplant patients younger than 5 years were the most susceptible to NHL, making up 19.79% of those diagnosed with DLBCL.
The proportion of NHL in solid organ transplant recipients within the entire pediatric NHL population has risen over time, from 1.66% of the NHL population during 1990-1994 to 3.73% during 2010-2012.
“This trend is driven by the rising prevalence of transplant recipients in the general population and not by increases in NHL risk among transplant recipients,” noted Dr. Yanik and her coauthors. “The proportion of NHL diagnoses attributable to transplant recipients has grown over time, and it is likely that this population will be an important source of pediatric NHL cases in the future.”
This study was partially funded by the National Cancer Institute. One coauthor reported being an employee at GRAIL Inc. No other relevant financial disclosures were reported.
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