Surveillance of women at increased risk of breast cancer using mammography and clinical breast examination: further evidence of benefit.

Abstract

Women with a significant family history of breast cancer are generally offered early surveillance by mammography and often clinical breast examination (CBE). The evidence base for surveillance has been questioned. We reviewed its effectiveness in terms of tumour size, lymph node status and survival in 7,475 women seen over a 22-year period in the Manchester Family History Clinic. We diagnosed 139 invasive and 26 in situ breast cancers. Seventy-six percent of the invasive cancers were screen detected, 65% node negative and 71% <2 cm in diameter at diagnosis. Twenty-one tumours were BRCA1 positive and were significantly more likely to be grade 3, ER/PR negative (p < 0.0001) and have a poorer survival. CBE contributed to 30% of cancer diagnoses and was responsible for discovery of nine mammographically occult tumours. The cost per quality life year was estimated at £13,080 for tumours detected by CBE and not by mammography. We conclude that screening by annual mammography and CBE between age 35-50 years and 18 monthly from 50 to 60 years may diagnose breast cancer in a less advanced state in terms of size and node status compared with symptomatic cancers and, apart from BRCA1 carriers, is likely to contribute to improved long-term outcome compared with no surveillance.