Clinical outcome and service implications of screening women at increased breast cancer risk from a family history

The value of special screening for women at moderate breast cancer risk with a family history of breast cancer remains controversial. Little is known about recall rates, false negative outcomes and the impact on clinical service. Despite this, surveillance programmes within breast units have been established in the United Kingdom. In our institution, screening of women at moderate (lifetime risk, 17–30%) and high risk (>30%) consisted of annual clinical examination and mammography from the age of 35 years. The active study period ran for four months and each patient was followed through a further screening cycle (whole study period), providing information on interval cancers and detection at the subsequent screen. One thousand one hundred and thirty-two women attended for their incident screen: 137 at high risk, 803 at moderate risk and 192 at standard risk. The median age at cancer diagnosis in the moderate risk group was 54 (range, 45–68) years and the high-risk group 51 (46–52) years, compared to 63 (45–69) years in the standard risk group. Seven cancers were diagnosed during the four-month active study period. Two patients were diagnosed with interval cancers and eight at the next screen, giving a cancer incidence in the whole study period of 17/1132 (1.5%). Thirteen patients had invasive cancer and four had ductal carcinoma in situ (DCIS) The median invasive tumour size was 15 had (range, 7–28) mm and the median DCIS size was 4 (2–30) mm. 10/13 (76.9%) invasive cancers were ≤20 mm and 2/13 patients (15.4%) with invasive cancer were lymph node positive. The sensitivity and specificity of mammography were 85.7% and 98.8%, respectively. The mammogram recall rate was 27.6 per 1000. The benign to malignant surgery ratio was 8:17. Screening women at increased breast cancer risk is effective. Early detection and recall rates are comparable to that of older women attending the British National Breast Screening Programme.