Surgical intervention in screen-detected patients versus symptomatic patients with breast cancer

The impact of population-based screening for breast cancer on the rate of breast-conserving surgery has not been established. We sought to evaluate whether surgical intervention in patients with screen-detected breast cancer differed from those with clinically detected tumours.

St Vincent's University Hospital and the BreastCheck Merrion Unit, part of the Irish National Breast Screening Programme, were the setting for the study.

A total of 902 patients referred for surgery to St Vincent's University Hospital over a four-year period (2000-2003) were studied. Patients with breast cancers detected during the prevalent round of screening (n=325) were compared with patients presenting with symptomatic disease (n=577). The operative procedure, nature of axillary surgery and histopathological findings were recorded in each case.

There was an increase in breast-conserving therapy in the screened population compared with symptomatic cases (68% screened versus 53% symptomatic; p<0.0001), with a corresponding reduction in axillary clearance rates (65% screened versus 81% symptomatic; p<0.0001). Nodal positivity was similar following correction for size in all tumours >1 cm, regardless of method of detection. Sentinel node biopsy was successfully undertaken in 39% of tumours <2 cm (T1 tumours) [corrected] in the screening population.

The screened population was statistically more likely to have breast-conserving therapy than the symptomatic group. Sentinel node biopsy has evolved into an acceptable alternative to axillary clearance in T1 cancers, particularly in screen-detected cases.