Non-surgical care for locally advanced breast cancer: radiologically assessed therapeutic outcome of a new enzyme-targeting radiosensitization treatment, Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, Type II (KORTUC II) with systemic chemotherapy.

We have previously developed a new enzyme-targeting radiosensitization treatment named Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, Type II (KORTUC II), which markedly enhances radiotherapeutic effects on various types of locally advanced malignant neoplasms. KORTUC II was approved by our local ethics committee for use against various types of malignant neoplasms. A maximum of 6 ml of radiosensitizer was injected into tumor tissue under ultrasonographic guidance just before each administration of radiotherapy. Seventeen patients with locally advanced breast cancer were enrolled to receive KORTUC II with systemic chemotherapy without surgical care. Patients were eligible if they had declined surgical treatment. Median observation period was 13.4 months (range, 1-26 months). This therapy was well tolerated. Contrast-enhanced magnetic resonance imaging revealed complete response in all primary breast tumors, and no patients displayed local recurrence during the follow-up period. Ultrasonography depicted tumor-like findings in 9 of 17 cases after therapy. The existence rate of posterior shadow artifacts behind the tumor was 2/17 before therapy, increasing to 8/17 after therapy. Intratumoral flow signals on color Doppler sonography were seen in 16/17 cases before therapy, but had disappeared from all cases after therapy. The increased rate of posterior shadow artifacts and absence of flow signals after therapy suggest that the tumor-like finding on ultrasonography represents scar tissue. Computed tomography revealed positive axillary nodes metastases in 16/17 and 2/17 cases before and after therapy, respectively. Nodal metastatic failure affected only 1 patient, who refused adjuvant systemic chemotherapy at the end of the observation period. Abnormal lymph node findings on computed tomography remained stable in the other patient. Excellent locoregional control based on accurate radiological evaluation implies that KORTUC II with chemotherapy has the potential to replace surgery in therapy for locally advanced breast cancer.