How women with a family history of breast cancer and their general practitioners act on genetic advice in general practice: prospective longitudinal study

The most important risk factor for breast cancer, besides advanced age, is a family history of breast cancer. General practitioners play an important role in identifying women who are at increased risk of breast cancer,¹ especially women who are too young to be eligible for population screening. In a prospective longitudinal study with three years of follow up, we studied women's compliance with advice provided by their general practitioner that was based on assessment of genetic risk and whether this genetic advice was in line with the advice of a clinical geneticist.

Participants, methods, and results

The women were patients at a primary healthcare centre linked to a university in the Netherlands. The centre, whose six general practitioners serve 11 500 patients, uses only computerised medical records. This system allows records of patients with specific risk factors and diseases to be marked and selected. A total of 2000 of the 2220 patients aged between 25 and 50 consulted their general practitioner between April 1994 and July 1995, and of these 81 sought advice on their familial risk of breast cancer.² These women were subsequently interviewed twice. In summer 1995, 67 of the 81 women were interviewed about their family history of breast cancer. A clinical geneticist reviewed each family history, calculated a relative risk of breast cancer for each woman (from <2, representing a normal or slightly increased risk, to ⩾3, a highly increased risk) and gave genetic advice to the general practitioner (table). The genetic advice was in line with Dutch national guidelines as developed in 1999-2000. In autumn 1995 the general practitioners discussed this advice and the risk assessment with each woman in a single consultation (n=63; four women had moved). In autumn 1998, 42 of the women were asked about their reasons for their compliance (or non-compliance) with the genetic advice and with advice on breast self examination. Data on the genetic advice given by the general practitioner to each patient, the surveillance given by the general practitioner (annual palpation by the general practitioner and annual mammography), and patients' visits to family cancer clinics were extracted from the medical records (n=63). The medical ethics committee of the Leiden University Medical Centre approved the study protocol.

The clinical geneticist's advice was not followed by the general practitioner in 30% of the individual consultations; the general practitioners advised surveillance more frequently than did the geneticist (table). Women appreciated surveillance more than reassurance or referral to a family cancer clinic. Nearly 25% of the women reported that they performed breast self examination at least monthly. One third of the women were compliant with the advice on surveillance. The main reasons given for non-compliance were not remembering to do preventive activities and a lack of confidence in the value of surveillance.

Comment

The value of giving genetic advice on breast cancer in primary care is questionable, for three reasons. Firstly, women showed a low level of compliance with genetic advice as given by general practitioners. This is in line with results from other studies on the effectiveness of annual mammography in general practice for asymptomatic women with a family history of breast cancer.³ Secondly, there was a low level of compliance among general practitioners with the clinical geneticist's advice. Thirdly, there is no evidence that surveillance is effective in women under 50.⁴,⁵ Breast self examination in women under 50 has not been shown to reduce mortality, not even when combined with palpation by a general practitioner,⁴ and the sensitivity of mammography in women without breast symptoms is lower when the women are under 50.⁵ Nevertheless, we believe that there is a place for genetic advice in general practice and that further research could improve its effectiveness.

Table.

Genetic advice given by clinical geneticist to general practitioner, based on relative risk of breast cancer calculated for each woman, and advice given by general practitioner to patient. Values are numbers of women

Genetic advice given by general practitioner*	Relative risk and genetic advice of clinical geneticist
	<2; reassurance	2-3; surveillance†	⩾3; referral to family cancer clinic	Total
Reassurance	19	0	0	19
Surveillance†	8	17	11	36
Referral to a family cancer clinic	0	0	8	8
Total	27	17	19	63

^*All women received advice on breast self examination. 

^†Surveillance=annual palpation by the general practitioner and annual mammography.