The Association between Neighborhood Socioeconomic Status and Posttransplant Cancer Outcomes among Kidney Transplant Recipients in the United States.

Background: Cancer is a leading cause of death among kidney transplant recipients (KTRs) and may disproportionately affect disadvantaged individuals. We assessed the association between neighborhood socioeconomic status and cancer outcomes among KTRs in the US.

Methods: We evaluated first-time KTRs through a linkage between US transplant and cancer registries (2000-2019). The Yost index, which incorporates neighborhood measurements of income, educational level, housing, and employment, was categorized into quintiles, with the lowest quintile (Q1) corresponding to the most disadvantaged neighborhood. We used Poisson regression to compare the association of Yost quintiles with cancer incidence overall and with seven common cancer types (colorectum, lung, female breast, prostate, kidney, melanoma, and non-Hodgkin lymphoma) as well as to compare the Yost index with cancer stage at diagnosis. Cox regression was used to evaluate cancer-specific mortality.

Results: We included 168,028 KTRs. Overall cancer incidence was 12.3 per 1,000 person-years (n=11,146 cases) with no overall difference across Yost quintiles (p-trend=0.893). However, KTRs from the most disadvantaged neighborhoods had higher lung cancer incidence (adjusted incidence rate ratio [IRR] 1.44, 95% confidence interval [95%CI] 1.19-1.73, Q1 vs. Q5; p-trend=0.001) and lower prostate cancer incidence (IRR 0.76, 95%CI 0.63-0.92, Q1 vs. Q5; p-trend=0.022). KTRs in more disadvantaged areas who were diagnosed with melanoma were more likely to present with regional or distant stage cancer (p-trend=0.022). After a cancer diagnosis, cancer-specific mortality was higher among KTRs in lower Yost quintiles (adjusted hazard ratio 1.18, 95%CI 1.05-1.32 for Q1 vs. Q5; p-trend=0.004), although trends were not significant for individual cancer types.

Conclusions: KTRs from disadvantaged neighborhoods have increased lung cancer risk and reduced prostate cancer risk, and are more likely to present with advanced-stage melanoma. After a cancer diagnosis, KTRs from disadvantaged neighborhoods are also more likely to die from their cancer. These results point to important disparities among KTRs in cancer screening and treatment.