Meta-analysis of the prevalence of renal cancer detected by abdominal ultrasonography

BackgroundThe potential for an ultrasound-based screening programme for renal cell carcinoma (RCC) to improve survival through early detection has been the subject of much debate. The prevalence of ultrasound-detected asymptomatic RCC is an important first step to establishing whether a screening programme may be feasible. MethodsA systematic search of MEDLINE and Embase was performed up to March 2016 to identify studies reporting the prevalence of renal masses and RCC. Two populations of patients were chosen: asymptomatic individuals undergoing screening ultrasonography and patients undergoing ultrasonography for abdominal symptoms not related to RCC. A random-effects meta-analysis was performed. Study quality was evaluated using a validated eight-point checklist. ResultsSixteen studies (413551 patients) were included in the final analysis. The pooled prevalence of renal mass was 036 (95 per cent c.i. 023 to 052) per cent and the prevalence of histologically proven RCC was 010 (006 to 015) per cent. The prevalence of RCC was more than double in studies from Europe and North America than in those from Asia: 017 (009 to 027) versus 006 (003 to 009) per cent respectively. Data on 205 screen-detected RCCs showed that 844 per cent of tumours were stage T1-T2N0, 137 per cent were T3-T4N0, and only 20 per cent had positive nodes or metastases at diagnosis. ConclusionAt least one RCC would be detected per 1000 individuals screened. The majority of tumours identified are early stage (T1-T2). 1:1000