Identifying gaps in the locoregional management of early breast cancer: highlights from the Kyoto Consensus Conference.

A consensus conference was held to investigate issues related to the local management of early breast cancer. Here, we highlight the major topics discussed at the conference and propose ideas for future studies. Regarding axillary management, we examined three major issues. First, we discussed whether the use of axillary reverse mapping could clarify the lymphatic system of breast and whether the ipsilateral arm might help avoid lymphedema. Second, the use of an indocyanine green fluorescent navigation system was discussed for intraoperative lymphatic mapping. These new issues should be examined further in practice. Finally, some agreement was reached on the importance of "four-node diagnosis" to aid in the diagnostic accuracy of sentinel nodes. Regarding breast treatment, there was general agreement that the clinical value of surgical margins in predicting local failure was dependent on the tumor's intrinsic biology and subtypes. For patients treated with preoperative chemotherapy, less extensive excision may be feasible in those who respond to systemic therapy in an acceptable manner. Most trials of preoperative chemotherapy lack outcome data on local recurrence. Therefore, there is a need for such data for overview analysis. We also agreed that radiation after mastectomy may be beneficial in node-positive cases where more than four nodes are involved. Throughout the discussions for both invasive and noninvasive disease, the investigation of nomograms was justified for major issues in the decision-making process, such as the presence or absence of microinvasion and the involvement of nonsentinel nodes in sentinel node-positive patients.