[Trends and variation in breast conserving surgery in the southeast and east of the Netherlands over the period 1990-2002].

Objective: To give an overview of the trends and variation in breast-conserving surgery in patients with a breast tumour < or = 2 cm (pT1) or > 2 and < or = 5 cm (pT2), treated in general hospitals in the southeast and east of the Netherlands.

Design: Descriptive.

Method: Data from the regional cancer registries of the Comprehensive Cancer Centre South (CS) and the Comprehensive Cancer Centre Stedendriehoek Twente (CST) were used to study trends and variations in the use of breast-conserving surgery in 12,985 pT1 tumours and 8,893 pT2 tumours in the period 1990-2002.

Results: The mean percentage of patients that underwent breast-conserving surgery from 1990-2002 was 54 in the CS region and 43 in the CST region. In patients < 50 years old with a pT1 tumour a decrease in the percentage of breast-conserving surgery from 73 to 64 was seen in the CS region, and in the CST region this percentage decreased from 72 to 51. In pT2 tumours a decrease from 47 to 37 was seen in the CS region and from 34 to 31 in the CST region. In patients of 50 to 69 years of age with a pT1 tumour, the percentage of breast-conserving surgery increased in the CS region from 67 to 74 and in the CST region from 54 to 61. In pT2 tumours it increased from 40 to 44 and from 25 to 37. In patients > or = 70 years the percentage of breast-conserving surgery in pT1 tumours increased from 37 to 59 in the CS region and in the CST region from 42 to 50. In pT2 tumours it increased from 20 to 31 in the CS region whereas it remained 17 in the CST region. The variation in breast-conserving surgery between hospitals in the period 1999-2002 was large. The percentage of breast-conserving surgery in patients with pT1 tumours varied between 47 and 86 in the hospitals in the CS region and between 54 and 71 in the CST region. In patients with a pT2 tumour the percentages varied between 25 and 43 in the CST region and between 16 and 64 in the CS region.

Conclusion: More than 20 years after the introduction of breast-conserving surgery a large regional variation still exists in the use of this treatment, in the CS region in particular. There is also wide inter-hospital variation.