Development of renal cell carcinoma (RCC) diagnostics and impact on prognosis

To evaluate imaging methods and prognoses between small renal cell carcinomas (RCCs) and larger tumours according to the era of diagnostics.

In all, 784 consecutive patients diagnosed with RCC between 1964 and 1997 at the Pirkanmaa Hospital District in Finland were included. Patients were divided into two groups: tumours of ≤3.0 and >3.0 cm in diameter. Prognosis was analysed according to the era of diagnostics: (i) pre-computed tomography (CT) and pre-ultrasound (US), (ii) US era and (iii) CT era.

Small tumours became more common: in the pre-CT and pre-US era, only 4.4% of tumours were small; however, in the CT era 16% were small tumours. More diagnostic methods were used in studying small tumours. CT proved to be the most reliable method, although it was actually better at diagnosing large tumours. Relapses occurred less frequently among patients with small tumours; more than half of the tumours that developed distant metastases (16.0%) already evinced them at the time of diagnosis. There were no relapses after 14 years of follow-up among small tumours, whereas large tumours relapsed within that time. RCC was the cause of death in 14.9% of patients with small tumours vs 50.7% with large tumours. The best prognosis was among patients with small tumours diagnosed with CT.

Among patients with small tumours, prognosis has improved along with better diagnostics, although some showed relapse during a surveillance period of up to 14 years.