Study Type – Therapy (case series)
Level of Evidence 4
What’s known on the subject? and What does the study add?
Recent studies suggest that the incidence of RCC is increasing among early-stage, incidentally discovered tumours, presumably detected because of the increased use of soft tissue imaging for evaluating a wide variety of abdominal and pelvic symptoms. This study did not show migration towards earlier stage and smaller RCCs.
• To verify whether migration towards earlier-stage renal cell carcinoma (RCC), which has been observed in the USA over the last decade, also applies to Australia.
PATIENTS AND METHODS
• Between January 1993 and December 2007, 547 nephrectomies performed in public and private hospitals in western Sydney were analysed from a retrospectively collected database.
• Data were divided into three consecutive time groups.
• Tumour-node-metastasis (TNM) stage as well as patient demographics, size, grade and histology of tumours and proportion of benign tumours were also assessed.
• In all, 499 nephrectomies were performed for RCC. The median age was 62 years, with a male:female ratio of 1.9 : 1. Similarly sized tumours were identified in each time group [group 1 (1993–1997), 54.8 mm; group 2 (1998–2002), 52.0 mm; group 3 (2003–2007), 52.2 mm, P= 0.6].
• Pathological stage II disease decreased from 18.1 to 11.1%, but stage III disease showed an increase from 13.9 to 21.5% over that time period (P= 0.02).
• The proportion of stage I and stage IV disease has remained relatively the same. There has been a statistically significant upward histological migration for the papillary subtype from 1.3 to 10.2% (P= 0.01).
• There has also been an increasing representation of Fuhrman grade III tumours over time, from 17.6 to 30.8%, and a decreasing proportion of Fuhrman grade I tumours from 16.2 to 7.1% (P= 0.03).
• There was a decrease in the incidence of benign tumours originally thought to be malignant on preoperative investigations, from 10% in group 1 to 4% in group 3 (P= 0.03).
• The recent US phenomenon of migration towards earlier-stage, smaller RCCs as well as increased representation of benign tumours was not observed in the present study. The results of the present study, however, show an upward histological migration for papillary RCCs and an increasing representation of more aggressive Fuhrman grade III tumours.