Cancer Mortality Among Solid Organ Transplant Recipients in the United States During 1987-2018.

BACKGROUND: Solid organ transplant recipients (ie, "recipients") have elevated cancer risk and reduced survival after a cancer diagnosis. Evaluation of cancer mortality among recipients can facilitate improved outcomes from cancers arising before and after transplantation. METHODS: We linked the US transplant registry to the National Death Index to ascertain the causes of 126 474 deaths among 671 127 recipients (1987-2018). We used Poisson regression to identify risk factors for cancer mortality and calculated standardized mortality ratios to compare cancer mortality in recipients with that in the general population. Cancer deaths verified with a corresponding cancer diagnosis from a cancer registry were classified as death from pretransplant or posttransplant cancers. RESULTS: Thirteen percent of deaths were caused by cancer. Deaths from lung cancer, liver cancer, and non-Hodgkin lymphoma (NHL) were the most common. Heart and lung recipients had the highest mortality for lung cancer and NHL, whereas liver cancer mortality was highest among liver recipients. Compared with the general population, cancer mortality was elevated overall (standardized mortality ratio 2.33; 95% confidence interval, 2.29-2.37) and for most cancer sites, with large increases from nonmelanoma skin cancer (23.4, 21.5-25.5), NHL (5.17, 4.87-5.50), kidney cancer (3.40, 3.10-3.72), melanoma (3.27, 2.91-3.68), and, among liver recipients, liver cancer (26.0, 25.0-27.1). Most cancer deaths (93.3%) were associated with posttransplant cancer diagnoses, excluding liver cancer deaths in liver recipients (of which all deaths were from pretransplant diagnoses). CONCLUSIONS: Improved posttransplant prevention or screening for lung cancer, NHL, and skin cancers and management of liver recipients with prior liver cancer may reduce cancer mortality among recipients.

Risk of Rare Cancers Among Solid Organ Transplant Recipients.

BACKGROUND: Immunosuppressed solid organ transplant recipients (SOTRs) have elevated rates of certain rare cancers caused by viruses. Evaluating risk of rare cancers among SOTRs may provide etiological clues for additional cancers linked to poor immunity and viral infections. METHODS: We performed a cohort study of 262 455 SOTRs (1987-2014) from the US SOTR registry linked to 17 population-based cancer registries. First cancers in SOTRs were categorized using an established classification scheme based on site and histology. Standardized incidence ratios (SIRs) compared risk in SOTRs with the general population. We used Poisson regression to calculate incidence rate ratios according to immune-related SOTR characteristics, including time since transplant (ie, duration of immunosuppression). All statistical tests were 2-sided. RESULTS: We examined 694 distinct cancer subtypes, with 33 manifesting statistically significantly elevated SIRs (Bonferroni P < 7.2 × 10-5). All 33 are rare (incidence <6 per 100 000 person-years) and several have known viral etiology (eg, Merkel cell carcinoma: SIR = 24.7, 95% confidence interval [CI] = 20.8 to 29.1). Additional cancers that were increased include squamous cell carcinomas of the lip (SIR range = 18.3-19.8), eye and adnexa (SIR = 13.8, 95% CI = 7.9 to 22.3), salivary gland (SIR = 9.3, 95% CI = 6.1 to 13.5), and nasal cavity and sinuses (SIR = 4.5, 95% CI = 2.8 to 6.8); sebaceous adenocarcinoma (SIR = 34.3, 95% CI = 26.3 to 44.0); malignant fibrous histiocytoma (15.4); and subtypes of bladder, kidney, lung, and colon cancer (SIR range = 3.2-13.3). Incidence of several cancers increased over time since transplant (Ptrend < .05), including squamous cell carcinomas of the lip, salivary gland, and anogenital sites. CONCLUSIONS: SOTRs experience elevated rates of several rare cancers. Because some of these cancers exhibit aggressive behavior with poor outcomes, it is important to further characterize the role of immunity and the potential involvement of oncogenic viruses to improve prevention and treatment.

Risk of lung cancer in lung transplant recipients in the United States.

Lung transplant recipients have an increased risk of lung cancer that is poorly understood. Prior studies are largely descriptive and single-center, and have not examined risk factors or outcomes in this population. This registry-linkage study utilized matched transplant and cancer registry data from 17 US states/regions during 1987-2012. We used standardized incidence ratios (SIRs) to compare incidence with the general population, Poisson models to identify lung cancer risk factors, and Cox models to compare survival after diagnosis. Lung cancer risk was increased among lung recipients (SIR 4.8, 95% confidence interval [CI] 4.1-5.5). Those with single lung transplant had 13-fold (95% CI 11-15) increased risk in the native lung. Native lung cancer risk factors included age, prior smoking, time since transplant, and idiopathic pulmonary fibrosis. Compared with cases in the general population, lung cancers in recipients were more frequently localized stage (P = .02) and treated surgically (P = .05). However, recipients had higher all-cause (adjusted hazard ratio 1.90, 95% CI 1.52-2.37) and cancer-specific mortality (adjusted hazard ratio 1.67, 95% CI 1.28-2.18). In conclusion, lung cancer risk is increased after lung transplant, especially in the native lung of single lung recipients. Traditional risk factors are associated with lung cancer in these patients. Lung cancer survival is worse among lung recipients despite earlier diagnosis.

Melanoma Outcomes in Transplant Recipients With Pretransplant Melanoma.

BACKGROUND: There are limited data on outcomes in transplant recipients with a history of pretransplant melanoma. OBJECTIVE: To determine whether pretransplant melanoma is associated with differences in survival or posttransplant melanoma risk. MATERIALS AND METHODS: We evaluated the outcomes of 185,039 US transplant recipients from the Transplant Cancer Match Study. We also evaluated the impact of transplantation on 141,441 patients with melanoma identified in cancer registries. RESULTS: There were 336 transplant recipients (0.18%) with pretransplant melanoma; they had increased risk of melanoma-specific mortality (hazard ratio [HR], 27; 95% confidence interval [CI], 11-64, p < .0001), overall mortality (HR, 1.3; 95% CI, 1.0-1.5, p = .02), and incident melanoma (HR, 5.4; 95% CI, 2.9-9.8, p < .0001) after transplant, compared with recipients without pretransplant melanoma. The 10-year absolute risk difference was 2.97% for melanoma-specific mortality, 3.68% for incident melanoma, and 14.32% for overall mortality. Among the 141,441 patients with melanoma in the general population, 68 (0.05%) subsequently received a transplant. Transplantation increased melanoma-specific mortality, but not significantly (HR, 1.7; 95% CI, 0.61-4.5, p = .32). CONCLUSION: Pretransplant melanoma is associated with increased melanoma-specific mortality, overall mortality, and incident melanoma after transplant. Nonetheless, the rarity of melanoma-related events supports the current practice for listing transplant candidates with a history of melanoma.

Spectrum of cancer risk among US solid organ transplant recipients.

CONTEXT: Solid organ transplant recipients have elevated cancer risk due to immunosuppression and oncogenic viral infections. Because most prior research has concerned kidney recipients, large studies that include recipients of differing organs can inform cancer etiology. OBJECTIVE: To describe the overall pattern of cancer following solid organ transplantation. DESIGN, SETTING, AND PARTICIPANTS: Cohort study using linked data on solid organ transplant recipients from the US Scientific Registry of Transplant Recipients (1987-2008) and 13 state and regional cancer registries. MAIN OUTCOME MEASURES: Standardized incidence ratios (SIRs) and excess absolute risks (EARs) assessing relative and absolute cancer risk in transplant recipients compared with the general population. RESULTS: The registry linkages yielded data on 175,732 solid organ transplants (58.4% for kidney, 21.6% for liver, 10.0% for heart, and 4.0% for lung). The overall cancer risk was elevated with 10,656 cases and an incidence of 1375 per 100,000 person-years (SIR, 2.10 [95% CI, 2.06-2.14]; EAR, 719.3 [95% CI, 693.3-745.6] per 100,000 person-years). Risk was increased for 32 different malignancies, some related to known infections (eg, anal cancer, Kaposi sarcoma) and others unrelated (eg, melanoma, thyroid and lip cancers). The most common malignancies with elevated risk were non-Hodgkin lymphoma (n = 1504; incidence: 194.0 per 100,000 person-years; SIR, 7.54 [95% CI, 7.17-7.93]; EAR, 168.3 [95% CI, 158.6-178.4] per 100,000 person-years) and cancers of the lung (n = 1344; incidence: 173.4 per 100,000 person-years; SIR, 1.97 [95% CI, 1.86-2.08]; EAR, 85.3 [95% CI, 76.2-94.8] per 100,000 person-years), liver (n = 930; incidence: 120.0 per 100,000 person-years; SIR, 11.56 [95% CI, 10.83-12.33]; EAR, 109.6 [95% CI, 102.0-117.6] per 100,000 person-years), and kidney (n = 752; incidence: 97.0 per 100,000 person-years; SIR, 4.65 [95% CI, 4.32-4.99]; EAR, 76.1 [95% CI, 69.3-83.3] per 100,000 person-years). Lung cancer risk was most elevated in lung recipients (SIR, 6.13 [95% CI, 5.18-7.21]) but also increased among other recipients (kidney: SIR, 1.46 [95% CI, 1.34-1.59]; liver: SIR, 1.95 [95% CI, 1.74-2.19]; and heart: SIR, 2.67 [95% CI, 2.40-2.95]). Liver cancer risk was elevated only among liver recipients (SIR, 43.83 [95% CI, 40.90-46.91]), who manifested exceptional risk in the first 6 months (SIR, 508.97 [95% CI, 474.16-545.66]) and a 2-fold excess risk for 10 to 15 years thereafter (SIR, 2.22 [95% CI, 1.57-3.04]). Among kidney recipients, kidney cancer risk was elevated (SIR, 6.66 [95% CI, 6.12-7.23]) and bimodal in onset time. Kidney cancer risk also was increased in liver recipients (SIR, 1.80 [95% CI, 1.40-2.29]) and heart recipients (SIR, 2.90 [95% CI, 2.32-3.59]). CONCLUSION: Compared with the general population, recipients of a kidney, liver, heart, or lung transplant have an increased risk for diverse infection-related and unrelated cancers.

Hepatitis C virus infection and risk of posttransplantation lymphoproliferative disorder among solid organ transplant recipients.

Posttransplantation lymphoproliferative disorder (PTLD) is a serious complication of solid organ transplantation. Hepatitis C virus (HCV) infection has been linked to increased risk of lymphoma among immunocompetent individuals. We therefore investigated the association between HCV infection and PTLD in a retrospective cohort study of all individuals in the United States who received their first solid organ transplant from 1994 to 2005 (N = 210 763) using Scientific Registry of Transplant Recipients data. During follow-up, 1630 patients with PTLD were diagnosed. HCV prevalence at transplantation was 11.3%. HCV infection did not increase PTLD risk in the total cohort (Cox regression model, hazard ratio [HR] = 0.84; 95% confidence interval [CI] 0.68-1.05), even after adjustment for type of organ transplanted, indication for transplantation, degree of HLA mismatch, donor type, or use of immunosuppression medications. Additional analyses also revealed no association by PTLD subtype (defined by site, pathology, cell type, and tumor Epstein-Barr virus [EBV] status). HCV infection did increase PTLD risk among the 2.8% of patients (N = 5959) who were not reported to have received immunosuppression maintenance medications prior to hospital discharge (HR = 3.09; 95% CI, 1.14-8.42; P interaction = .007). Our findings suggest that HCV is not a major risk factor for PTLD, which is consistent with the model in which an intact immune system is necessary for development of HCV-related lymphoproliferation.