The assessment of genetic risk of breast cancer: a set of GP guidelines

Background. Assessing a genetic risk for developing breast cancer is not an easy task for a GP. Current expert guidelines for referring and counsellin g women with a family history positive for breast cancer are complex and di fficult to apply in general practice, and have only two strategies (to refe r or not to refer for genetic counselling), giving no guidance for the GP o n the management of women with a moderately increased risk of familial brea st cancer. Objectives. We aimed to develop a set of simple practical guidelines for us e in primary care for assessing risk and advising women with a positive fam ily history in general practice and aimed to explore its performance. Methods. Based on a consensus meeting of the Leiden working party of heredi tary tumours, the GPs of a university-related health care centre developed a set of GP guidelines to assess risk and advise women with a family histor y positive for breast cancer in general practice. The GP guidelines include four therapeutic strategies (reassuring, starting surveillance, starting s urveillance and contacting a family cancer clinic, referring to a family ca ncer clinic). Its performance was tested in 67 patients whose pedigrees wer e available together with the risk assessment of a clinical geneticist usin g Claus' tables as a gold standard. The gold standard was dichotomized rega rding (i) referral to a family cancer clinic and (ii) surveillance. Two exi sting expert guidelines were similarly compared. Results. Regarding referral to a family cancer clinic, the GP guidelines we re very specific, whereas the expert guidelines were more sensitive. Regard ing surveillance, the GP guidelines were very sensitive, whereas the expert guidelines were very specific. The total number of misclassified patients was lowest when using the GP guidelines, and higher when using the expert g uidelines. Conclusions. The GP guidelines provide a simplification of current guidelin es. Before using them on a larger scale, more testing and refining are need ed to increase their sensitivity regarding a referral to a family cancer cl inic and their specificity regarding surveillance. They incorporate a role for the GP in the care for women with a family history positive for breast cancer with a moderately increased risk.