What is the Best Approach for Breast Conserving Therapy?

Abstract

Since the introduction of breast conserving therapy (BCT) in Japan about 10 years ago, many researchers have published their experiences in the Japanese Breast Cancer Society congresses, and the results have been gathered successfully, on the whole. It is now recognized that in Japan, there is no difference in survival rates between breast conserving therapy and mastectomy, and the goal of conserving therapy has shifted from survival rate to inhibition of local recurrence and cosmesis. Recently, the indications for BCT have been expanding and individualized applications dependent on breast cancer characteristics are being tried. With such a history and trends as background, the Symposium was planned by the Chairman to discuss ideal breast conservation therapy. The rate of intra-mammary recurrence after this operative procedur is 3-10%, though it depends on the duration and accuracy of observation. Positive surgical margin, diffuse ductal spread, lymphatic invasion, negative estrogen receptor, etc are risk factors for recurrence, while irradition is considerd to inhibit recurrence. It was demonstrated, however, that in some cases, depending on the oprative procedure, irradiation is not needed, if an accurately defined negative surgical margin is secured. It is thus important to establish a pathological exploratory method to assess surgical margins and diagnostic criteria. Problems to be solved include identification of subgroups which do not require radiation, further inhibiting local recurrence, decreasing radiationassociated complications by improving irradiation techniques, and realizing that irradiation should be substituted for axillary dissection in NO cases. It was discussed how the positive rate for surgical margin can be decreased and in what way multiple cancer can be excluded preoperatively. When conservative therapy was used correctly in accordance with therapeutic criteria, the results were regarded as rather satisfactory. However, the therapy had poor results and required reconstruction by plastic surgeons in some cases. It should be noted that quality of life (QOL) assessment by patients does not necessarily agree with the assessment of physicians, demonstrating the importance of informed consent. When we consider the radicability, function and cosmesis of breast conservation therapy, the former two have been quite favorble in the past 10 years. However, for the improvement of QOL including cosmesis, patients in whom this procedure is indicated should be stratified, and individualized therapy should be conducted multidisciplinary point of view. For that purpose, further standardization by establishing criteria for the therapy as well as technical improvement through research should be performed.