Variations in excision biopsy rates for women with B3/C3 results do not account for high benign open biopsy rates in the NHS Breast Screening Programme: a regional study

Introduction

Since 2000 the South West Region has shown a benign open biopsy rate higher than the national average, often failing to meet the guideline targets.

Methods

Information from the nine screening units in the South West Region of all women having a B3 or C3 diagnosis as their final result following screening assessment during the period 2003 to 2005 was reviewed.

Results

Of 374 women with a B3/C3 result, 89 (23%) had no further investigations. Between individual units, the proportion of women undergoing surgical biopsy ranged from 55% (18/33) (95% CI = 37% to 71%) to 89% (72/81) (95% CI = 80% to 94%). Of 285 women undergoing open biopsy, 75 (26%) had malignant disease. The range between units was 13% (5/38) to 36% (26/81). There was no correlation between the rate of open biopsy for B3/C3 lesions and the overall benign biopsy rates, which ranged from 0.76 to 2.74 per 1,000 women screened.

Conclusion

B3/C3 results following screening assessment are associated with a significant risk of malignancy. Variations in rates of surgical biopsy following an indeterminate result do not account for differences in overall benign open biopsy rates. Further studies are required to determine the indications for open biopsy in these cases and to evaluate the outcome in women who do not undergo open biopsy.