The haphazard approach to the early detection of asymptomatic renal cancer: results from a contemporary executive health programme.

OBJECTIVE To compare the detection of asymptomatic renal cell carcinoma (RCC) in an executive health programme (EHP) that uses traditional methods of screening (history, physical examination and urine analysis) to programmes that screen by renal imaging. PATIENTS AND METHODS We retrospectively reviewed case records from patients undergoing executive health examinations at Mayo Clinic between 1 January 2002 and 30 September 2007. Results Of 32 310 patients, 18 RCCs were detected; of these, 13 (72%) were detected by the EHP and five (28%) were missed by the initial EHP screening process but subsequently discovered within 4-24 months. Of the 13 detected through the EHP, eight were discovered incidentally, two because of symptoms, and three because of asymptomatic microscopic haematuria (AMH). Of the 13, 12 were classified as early-stage cancers (Stage I). By contrast, of the five cancers missed by the EHP screening process, two were diagnosed because of the development of symptoms and only one was classified as Stage I. To date, two of these patients whose cancers were undetected by the EHP developed metastasis and one of them has died. Both had been followed in the EHP for years and neither had MH in multiple specimens. CONCLUSION Our EHP follows standard policy and relies on a history, physical examination and urine analysis to decide who to evaluate for asymptomatic RCC. This practice missed >70% of the potentially diagnosable cancers. The patients with RCCs that were discovered initially by the EHP fared better than those whose diagnosis was delayed. Our detection rate of four per 10 000 was only a fraction of those reported by programmes using imaging as a screening tool. The logic behind our current approach to the early detection of asymptomatic RCC needs to be reassessed. AMH is coincidental in most cases and patients could forego imaging if they are unsuitable candidates for screening. However, AMH will miss most treatable cancers and is not an appropriate screening test for an early detection programme. In the absence of reliable biomarkers, renal imaging should be the primary screening tool for detecting asymptomatic RCC in informed, clinically suitable individuals enrolled in an early detection programme.

Should the upper tracts be imaged for microscopic haematuria?

OBJECTIVE: To determine the relative prevalence of various definitions of microscopic haematuria (MH) in patients with renal neoplasms and controls, and to predict the likely outcome of renal imaging for those definitions. PATIENTS AND METHODS: In a retrospective case-control study 278 adult men and woman seen between 1998 and 2003 with untreated renal neoplasms were compared to controls matched for age and sex. All cases and controls had renal imaging within 6 months of a urine analysis. Patients were excluded for gross haematuria or other conditions associated with MH but not relevant to upper tract imaging. Adjusted odds ratios (OR) computed for 13 definitions of MH by conditional logistic regression were the primary outcome measures. Additional outcome measures were ORs in selected subsets. Hypothetical performance characteristics of a positive urine analysis were then derived to predict the likely results of detecting renal neoplasms for each definition of MH. RESULTS: The OR (95% confidence interval) for the entire series of cases and controls, both symptomatic and asymptomatic, was 2.0 (1.02-3.92, P = 0.04) for MH defined as > or = 4 red blood cells per high-power field (RBC/HPF) and 2.2 (1.09-4.52, P = 0.03) for > or = 5 RBC/HPF. No significant OR was calculated for < or = 3 RBC/HPF, nor for a subgroup of patients with MH in a routine urine analysis obtained during a periodic health examination. Symptomatic patients had an OR of 13.68 (1.6-117.1, P = 0.02) for MH defined as > or = 5 RBC/HPF. The sensitivity of a positive test decreased from 24.8% to 5.04% as the definition for MH became more stringent. The theoretical positive predictive value (assuming a prevalence of renal cell neoplasms of 0.25%) of the most stringent definition of MH was 0.58%. CONCLUSIONS: Patients with renal neoplasms have about twice the prevalence of MH with > or = 4 or 5 RBC/HPF in a single urine sample compared with matched controls, but this difference has little impact on the hypothetical detection rate of renal cancer. Imaging the kidney for low-grade MH in a routine urine analysis discovered at a periodic health examination in an otherwise asymptomatic patient is tantamount to screening without cause, and can be deferred for selected patients. The clinical context is as important as the degree of MH when deciding to image the kidneys.