Cancer risks after solid organ transplantation and after long‐term dialysis

Abstract

Immunosuppression involves an inability to control virus infections and increased incidence of virus-associated cancers. Some cancers without known viral etiology are also increased, but data on exactly which cancer forms are increased has been inconsistent. To provide a reliable and generalizable estimate, with high statistical power and long follow-up time, we assessed cancer risks using comprehensive, population-based registries in two different countries and from two different immunosuppressed patient groups (solid organ transplant recipients (OTRs) and long-term dialysis patients (LDPs)). National registries in Denmark and Sweden identified 20,804 OTRs and 31,140 LDPs that were followed up using national cancer registries. Standardized incidence ratios (SIR) compared to the general population were estimated. We found highly similar results, both for the two different countries and for the two different immunosuppressed cohorts, namely an increased incidence for the following specific cancer forms: Non-melanoma skin cancer (NMSC), non-Hodgkin's lymphoma and cancers of the lip, kidney, larynx and thyroid. The SIR for overall cancer among OTRs was 3.5 [n = 2,142, 95% CI, 3.4-3.7] in Sweden, 2.9 [n = 1,110, 95% CI, 2.8-3.1] in Denmark and 1.6 [n = 1,713, 95% CI, 1.5-1.6] among LDP. The SIR for NMSC among OTRs was 44.7 [n = 994, 95% CI, 42-47.5] in Sweden and 41.5 [n = 445, 95% CI, 37.8-45.5] in Denmark. The increased SIR for NMSC among LDPs was 5.3 [n = 304, 95% CI, 4.7-5.9]). In summary, an increased SIR for a specific, similar set of cancer forms is consistently found among the immunosuppressed. Conceivable explanations include surveillance bias and immunosuppression-related susceptibility to viral infections.

Oncology in nephrology comes of age: A focus on chronic dialysis patients

“…The elevated cancer risk was greatest in Australia and New Zealand (SIR 1.8) when compared with the United States (SIR 1.2) and Europe (SIR 1.1) . Similar increased cancer risk was also found in chronic dialysis patients in different geographical areas including Australia (SIR 1.35; 95% CI 1.27–1.45), Hong Kong (SIR 1.44; 95% CI 1.26–1.65), Taiwan (SIR 1.4; 65% CI 1.3–1.4), the United States (SIR 1.42; 95% CI 1.41–1.43) and Denmark (SIR 1.6; 95% CI 1.5–1.6) . A meta‐analysis of cohort studies could not demonstrate any significant difference in the overall cancer risk between Asian and non‐Asian populations .…”

Gynecologic cancers and solid organ transplantation

“…Likewise, 2 studies of kidney transplant recipients reported in Nordic countries reported 2-fold increases in cervical cancer risk among kidney transplant recipients, with no increase in uterine or ovarian cancers. 17,18 In contrast, a report of a US study of 187 649 SOT recipients, including 119 756 kidney transplant recipients (64%), did not report an increase in invasive cervical cancers after transplantation (SIR 1.0, 95% CI 0.8-3.3), although it did report an increased incidence of in situ cervical cancer (SIR 3.3, 95% CI 2.6-4.2). 6 The increase in this study of in situ (high-grade cervical intraepithelial neoplasia grade 3, CIN3) but not invasive cervical cancer may be explained by increased medical visits leading to earlier detection of noninvasive cervical lesions.…”

Viruses in cancers among the immunosuppressed

“…Solid organ transplantation is accompanied with immunosuppression and a surge in incidence in immunosuppression‐associated cancers after transplantation , . Several cancer forms with greatly increased incidences after transplantation are not known to have a viral etiology.…”

“…Solid organ transplantation is accompanied with immunosuppression and a surge in incidence in immunosuppression-associated cancers after transplantation. 3,[6][7][8]10 Several cancer forms with greatly increased incidences after transplantation are not known to have a viral etiology. Nonmelanoma skin carcinoma (NMSC) and lip cancer have a highly increased incidence among the immunosuppressed (up to 100-fold), but cancers of the kidney, thyroid, esophagus, larynx, eye, bladder, lung, and colon, as well as endocrine cancers, multiple myeloma, leukemia, and melanoma are also increased.…”

“…Nonmelanoma skin carcinoma (NMSC) and lip cancer have a highly increased incidence among the immunosuppressed (up to 100-fold), but cancers of the kidney, thyroid, esophagus, larynx, eye, bladder, lung, and colon, as well as endocrine cancers, multiple myeloma, leukemia, and melanoma are also increased. 3,[6][7][8]10 As was pointed out by the 2008 Nobel Laureate Harald zur Hausen, exploration of any further role of infections in cancer is likely to be particularly rewarding if focused on the cancer forms that are increased among the immunosuppressed, but that do not have an established microbiological etiology. 2 However, progress in tumor microbiology has been slow as most studies have typically only focused on one candidate infection or one cancer type at a time.…”