Context
Non-visible haematuria (NVH)is a common finding and may indicate undiagnosed urological cancer. The optimal investigation of NVH is unclear, given the incidence of cancer and the public health implications of testing all individuals with this finding.
Objective
We review contemporary literature to determine the association of NVH with the diagnosis of bladder cancer (BC), upper tract urothelial carcinoma (UTUC), and kidney cancer (KC).
Evidence acquisition
A systematic review of original articles in English was completed in May 2019. Meta-analyses for the diagnostic accuracy of NVH and urine cytology were performed.
Evidence synthesis
We screened 1529 articles and selected 78 manuscripts that fulfilled our inclusion criteria for narrative synthesis. Forty manuscripts were eligible for a metaanalysis (reporting 19 193 persons). The likelihood of a urological cancer in patients with NVH increased with age (<1% in those aged <40 yr), male sex, and cigarette smoking. Less than 1% of patients are found to have a urological cancer after a negative NVH evaluation. Cancer detection rates in individuals evaluated for NVH ranged from 0% to 16% for BC in 37 studies, 0% to 3.5% for UTUC in 30 studies, and 0% to 9.7% for KC in 29 studies. Substantial statistical heterogeneity was present for the meta-analysis of detection rates.
Conclusions
We present an up-to-date review of the association of NVH with the diagnosis of BC, UTUC, and KC. Individuals with dipstick positive haematuria aged ≥40 yr, who have had potential precipitating causes excluded, should undergo an evaluation. Re-evaluation of patients with unremarkable initial investigations should be performed in high-risk patients or if new symptoms occur.
By Dr. Soria
The aim of this systematic review and meta-analysis was to evaluate the association between non-visible hematuria (NVH) and the presence of urological malignancies in order to assess the need of urological work-up among different patients’ categories of risk. After the articles’ selection process, 78 full-text manuscripts were included in the systematic review and 40 in the meta-analysis (reporting on 19.193 patients). The most common urological cancer found in patients with NVH was bladder cancer (0-16%), followed by renal cancer (0-9%), and upper tract urothelial carcinoma (0-3.5%). The likelihood of having a urological cancer increased with age, male gender and cigarette smoking, being less than 1% in patient younger than 40 years. Of importance, the likelihood to present a urological cancer after a negative evaluation for NVH resulted to be less than 1%, and usually related to the presence of persistent or new symptoms.
By Dr. Soria
NVH is a frequent clinical condition in the general population, with a reported prevalence of about 20% in men over 60 years. However, and differently from gross hematuria, the role of NVH in indicating the presence of urological cancer and, consequently, the need of urological evaluation, remains debatable. Actually, historical series reported a likelihood of harboring urological cancer of around 20% in case of gross hematuria and less than 5% in case of NVH. Therefore, the combination of the high prevalence of NVH together with the relatively low chance to be a sign of cancer presence underlines the need of developing a risk-based algorithm to identify which patients need a complete urological evaluation. This is even more true in an optic of resource allocation, where a urological work-up consisting in cystoscopy and abdomen computed tomography scan or ultrasound to be performed in every case of NVH may negatively impact on healthcare system costs and be a cause of the progressive enlargement of waiting lists.