Stage at Diagnosis and Prognosis of Colorectal, Stomach, Lung, Liver, Kidney, and Bladder Cancers in Dialysis Patients: A Multicenter Retrospective Study Using Cancer Registry Data and Administrative Data

Abstract

Background: Cancer is an important comorbidity that can affect survival in dialysis patients. However, it is unclear if dialysis patients who develop cancer are disadvantaged by later detection and poorer prognosis. This study comparatively examined the stage at diagnosis and prognosis of several common cancer types in dialysis and nondialysis patients. Methods: In this retrospective cohort study, cancer registry data were linked with administrative data to identify dialysis and nondialysis patients with any new diagnosis of cancer between 2010 and 2015 at 36 hospitals in Osaka Prefecture, Japan. In these patients, we identified the cancer stage at diagnosis for patients with colorectal, stomach, lung, liver, kidney, and bladder cancers. The association between dialysis and survival time (up to 3 years of follow-up) was examined for each cancer type using Cox proportional hazards models that adjusted for age, sex, and cancer stage. Results: We analyzed 2,161 dialysis patients and 158,964 nondialysis patients with cancer. Dialysis patients had a higher prevalence of colorectal, liver, and kidney cancers than nondialysis patients. Colorectal, stomach, lung, liver, and kidney cancers were diagnosed earlier in dialysis patients, whereas bladder cancer was diagnosed at an advanced stage. The Cox proportional hazards models revealed that mortality was significantly higher in dialysis patients with colorectal, stomach, lung, and bladder cancers than in nondialysis patients (all p < 0.05). Conclusions: Dialysis patients had higher mortality for several common cancers despite their earlier detection. This poorer prognosis may be influenced by the unavailability and complications of cancer treatment for these patients.