Breast Cancer

Abstract

Breast cancer is a major health problem for women all over the world. In recent years, about half of the cases detected in Japan were below stage I. The standard care for early-stage breast cancer is breast-conserving therapy, which consists of conservative surgery and fractionated whole breast irradiation. Breast surgery followed by more than 5 weeks of radiotherapy causing adverse skin reactions is still a burden to patients. Accelerated partial breast irradiation (APBI) is an alternative to whole breast irradiation in patients with low-risk tumor, based on four randomized trials and more than 40 prospective trials. In this sense, carbon-ion radiotherapy (C-ion RT) is suitable as an effective local therapy and could be even more effective than standard radical radiotherapy. Our institute started a clinical trial of radical C-ion RT for patients with low-risk T1N0M0 invasive ductal carcinoma in 2013. The idea was to develop a short-course C-ion RT to be finished in 1 week, which we believe could replace surgery and more than 5 weeks of radiotherapy. Furthermore, it is assumed that C-ion RT may play a role in preventing regional lymph node recurrence and solitary distant metastasis.