Objective: To evaluate changes in the pathological characteristics, stage of primary renal tumours and their surgical management in the Netherlands during the period 1995-2005.
Methods: Extracts from the records of all patients who had surgery for primary renal tumours in the Netherlands during the period 1995-2005 were reviewed. Data were collected from PALGA, the nationwide network and archive of histocytopathology. The 2002 Tumour-Node-Metastasis and the three-tier Fuhrman grade were used for staging and grading.
Results: In all there were 12 471 operations for primary renal masses during the study period. The incidence of surgically removed renal cancers increased from 6.2 in 1995 to 7.5 cases per 100 000 inhabitants (P = 0.005) in 2005. The mean (sd, median) age of the patients was 63.3 (11.9, 65.0) years, with a male-to-female ratio of 3:2. The mean (sd) tumour size of malignant tumours decreased from 7.3 (3.6) to 6.9 (3.7) cm (P = 0.301). The percentage of benign removed tumours remained relatively stable (P = 0.056), with a mean of 5.4% of all resected tumours. There was an increase of grade 1 tumours; the incidence of T1 tumours increased from 36.6% to 44.2%, and advanced tumours decreased from 46.4% to 33.7%, respectively. The percentage of nephron-sparing surgery increased from 3.5% in 1995 to 10.1% (P = 0.003) in 2005, mainly in the T1a tumours.
Conclusions: During the last decade there was an increase in the incidence of surgically treated renal tumours in the Netherlands. Tumours with favourable histopathological characteristics, low stage and grade, accounted for most of this increase. The percentage of surgically removed benign tumours remained stable. The use of nephron-sparing surgery increased during the last decade, especially in T1a tumours.