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There has been considerable debate about the potential role of general practitioners in genetic screening programmes. Doubts have been raised, for example, about their degree of interest and about their level of genetic knowledge. Leggatt et al have carried out a pilot study in which a postal questionnaire was used to identify people in one general practice who were at a significantly higher risk of breast or colorectal cancer on the basis of their family history [Leggatt, V. et al. (1999) BMJ 319, 757-758 (18 Sept issue general practice section)]. Of 2265 people aged between 35 and 65, 1460 responded to the initial letter but 500 did not wish to take part. 666 completed the questionnaire and of these 29 were assessed by the GP as being at high risk on the basis of criteria in use in local cancer genetics clinics. Around half of these people (14) had received genetic advice already. Among the remaining 15, who were referred to a cancer genetics clinic, one was found to have early signs of breast cancer. The paper does not report whether genetic testing was offered to any of the referred patients.

Comment: The results of the study indicate that screening for a high genetic risk of breast or colorectal cancer is possible within general practice. However the uptake was quite low (29%) and a significant percentage of patients (22%) actively declined to take part (rather than simply not responding).The authors suggest that uptake might have been higher if the invitation were made in another setting, such as in initial consultations with new patients. Looking beyond these specific points, however, from a public health perspective many important questions remain to be answered. What is the balance between benefit and harm in a screening programme such as this? (see item on population screening elsewhere in this Newsletter for a discussion of the twin problems of undue anxiety and false reassurance). What would be the costs of extending such a programme nationally, both in the administration and evaluation of the family-history questionnaire, and in the surveillance of those identified as being at high risk? Would GPs who do not have a personal interest in genetics be willing to take on such a programme? Would such screening divert patients' attention from the large environmental component of cancer risk?