Persistent microscopic hematuria not a risk factor for early-onset urothelial, renal cell carcinoma

The presence of persistent isolated microscopic blood in urine does not appear to convey an increased risk of early-onset urothelial or renal cell carcinoma among adolescents, a study has found.

The nationwide, population-based, retrospective cohort study included 970,366 adolescents aged 16–19 years (58.6 percent male) who underwent a fitness examination for military service between 1980 and 1997. Persistent isolated microscopic hematuria, excluding any other renal abnormalities, was diagnosed after thorough workup process.

Researchers retrieved incident cases of urothelial carcinoma and renal cell carcinoma diagnosed during the years of 1982 to 2012 from the Israeli National Cancer Registry. They used Cox proportional hazards models were used to estimate the risk of both tumours.

A total of 5,509 (0.6 percent) adolescents were diagnosed with persistent isolated microscopic hematuria over a cumulative follow-up of 22,115,629 person-years (median follow-up 22.8 years). Urothelial carcinoma occurred in 332 individuals, while renal cell carcinoma in 292 individuals, including three and two who had a previous diagnosis of microscopic hematuria, respectively.

In the analysis, isolated microscopic hematuria showed no association with either incident urothelial carcinoma (adjusted hazard ratio [HR], 1.17, 95 percent confidence interval [CI], 0.38–3.66) and incident renal cell carcinoma (adjusted HR, 1.02, 95 percent CI, 0.25–4.12).