Needle biopsy in the NHS breast screening programme 1996/97: how much and how accurate?

We have shown that 62% of cancers detected in the National Health Service Breast Screening Programme are diagnosed preoperatively by needle biopsy. Although still short of the 70% national target there is a year on year improvement in the pre-operative diagnosis rate and further increases should be achievable with greater experience. The numbers of core biopsies being performed is increasing although fine needle aspiration cytology remains the mainstay biopsy technique in the UK. Core biopsy (CB) shows distinct advantages over fine needle aspiration cytology in terms of absolute ability to diagnose malignancy and benignity. There is also a much lower inadequate rate with CB. Importantly, however, we have found that the false negative rate is higher with CB. Various reasons have been advanced to explain this and with greater experience and close attention to biopsy technique this level of false negatives may fall. These data emphasize that, whichever needle biopsy technique is used, the results should not be interpreted in isolation but considered in conjunction with clinical and radiological findings for best and safest practice.