[Dutch Institute for Healthcare Improvement guideline, "Treatment of breast cancer"].

The first Dutch evidence-based guideline for the treatment of breast cancer has been developed to realise the optimal care of breast cancer patients in the Netherlands. This was possible due to the close cooperation of the Dutch Institute for Healthcare Improvement [Dutch acronym: CBO] and the Dutch Consultative Committee on Breast Cancer [Dutch acronym: NABON]. A broad, multidisciplinary working group was appointed to develop the guideline. This group consisted of surgeons, radiotherapists, internists, pathologists, a radiologist, a nuclear medicine specialist, a plastic surgeon and a clinical geneticist, all of whom had been given a mandate to represent their respective professional societies. In addition to these medical specialists, there were physiotherapists, oncology nurses, psychologists, staff from comprehensive cancer centres and the Dutch Institute for Healthcare Improvement and representatives from the Dutch Breast Cancer Association. This CBO guideline is divided into seven chapters: local treatment of operable breast cancer, systemic adjuvant treatment, locoregionally advanced disease, follow-up, locoregional recurrence, metastasised disease, and the psychosocial aspects of breast cancer. Although the guideline is not intended as a set of instructions that must be rigidly adhered to, deviations from the guideline must be motivated, principally on the basis of published scientific information. To obtain insight into the actual use of the guidelines 'Screening and diagnostics' and 'Treatment of breast cancer' the work group advocates a nationwide prospective registration of all breast cancer patients, including follow-up. Steps to this end have been undertaken. In this way, the CBO guideline will contribute to a further optimisation of breast cancer care in the Netherlands.