Most causes of microscopic hematuria (MH) are benign but may indicate an underlying malignancy. Current MH evaluation guidelines are reflective of male urologic malignancy risks. The objective of this systematic review was to evaluate whether the finding of MH predicts subsequent urologic malignancy in women.
MEDLINE was searched between January 1990 and June 8, 2018. The positive predictive value (PPV) of MH as a screening tool for urologic malignancy was calculated for each study individually and collectively. The pooled relative risk of urologic malignancy associated with MH was calculated.
Seventeen studies were included. Eight studies included only women. In total, 300 urinary tract cancers were identified in 110,179 women with MH. The PPV of MH as a screening tool for cancer ranged from approximately 0.6% to 2.8%; confidence intervals (CIs) suggested this is a relatively unstable performance indicator because of small sample sizes. Average PPV across all studies was 2.13%, but the weighted average PPV was 0.24%. The risk of urologic malignancies among women with relative those without MH was 2.01 (95% CI, 1.61–2.51). Based on these limited data, we estimate that 859 (95% CI, 654–1250) women with MH would require complete evaluation to identify 1 urinary tract malignancy.
A very small proportion of women with MH are likely to have a urologic malignancy. Approximately 859 women require full screening to identify 1 malignancy. Current evidence is limited, and further studies, specifically in women, are needed.