What is achieved by mammographic surveillance after breast conservation treatment for breast cancer?

Background: After breast conservation surgery for breast cancer, patients a re followed up by regular clinical examination and mammography, at interval s which vary according to local practice. However, the optimum interval rem ains unclear with current guidelines suggesting mammography should be carri ed out every 1 to 2 years. This study has investigated this aspect and, in particular, whether mammography or clinical examination or both allowed an early detection of recurrence of the disease in the conserved breast. Methods: A total of 695 patients who had undergone breast conservation surg ery were identified from a database of prospectively recorded data during t he period 1990 to 1995. Clinical examination and annual mammography were pe r-formed in accordance with local protocol. The results of clinical examina tion, mammography, and local recurrence rates were evaluated. Results: A total of 2,181 mammograms were undertaken in the 695 patients st udied. Local recurrence of disease in the conserved breast occurred in 21 p atients (3%), at a mean follow-up of 3.5 years. The first identification of tumor recurrence was by clinical examination in 11 patients with local rec urrence, and by the surveillance mammography in the other 10 patients with local recurrence. Overall, mammography detected the local recurrence in 13 of 20 (65%) patients who underwent this examination. In the other patients, the recurrence was detected on clinical examination only. In addition, in 52 patients, mammography was falsely positive, giving a false positive rate of 2.3%. Contralateral cancers in the opposite breast were detected in 2 p atients. Conclusions: The detection of local disease after breast conservation surge ry requires both clinical examination and mammography. In the context of ou r follow-up policy, in 52% of patients with local recurrence, this was firs t identified by clinical examination. Disease recurrence was identified in the other 48% of patients by mammographic surveillance. Overall, mammograph y will identify or confirm local recurrence in two thirds of women. However , in a small number of cases (2.3% in our series) mammography will give fal se positive results. New imaging modalities to assist in the diagnosis of l ocal recurrence of disease after breast conservation surgery are required. (C) 2001 Excerpta Medica, Inc. All rights reserved.