An increased utilisation rate and better compliance to guidelines for primary radiotherapy for breast cancer from 1997 till 2008: a population-based study in the Netherlands.

Only scarce data are available on the utilisation rate of primary radiotherapy (RT) for patients with breast cancer. In this study, we compared the use of primary RT for patients with stages I-III breast cancer in 4 of the 9 Dutch Comprehensive Cancer Centres, focussing specifically on time trends as well as age effects. From the population-based cancer registries, we selected all females diagnosed with breast cancer between 1997 and 2008 (N=65,966, about 50% of all Dutch breast cancer patients in this period). We observed an overall increase in the use of primary RT for breast cancer patients ranging from 55-61% in 1997 to 58-68% in 2008. This can be explained by a higher rate of breast-conserving surgery (BCS), which was followed by RT in 87-99% of cases, and a reduced rate of total mastectomy (TM) which was followed by RT in 26-47% of cases. Increasing age was associated with a reduced use of RT, especially for those above 75. Finally, we observed a decrease in time of observed regional variances in the use of RT after BCS as well as after TM (for stage III disease). These findings can be attributed to the development and implementation of the Dutch nationwide guidelines for treatment of breast cancer.