Preliminary Results from a Multi-center Prospective Study (JROSG 05-5) on Postoperative Radiotherapy for Patients with High-risk Ductal Carcinoma in situ with Involved Margins or Margin Widths 1 mm or less than

Abstract Purpose: This prospective study aimed to evaluate the effectiveness of postoperative radiotherapy (PORT) consisting of whole breast irradiation followed by boost irradiation in patients with high-risk ductal carcinoma in situ (DCIS) with margin widths less than 1 mm. Materials and Methods: A multi-center phase II study (Japanese Radiation Oncology Study Group: JROSG 05-5) was conducted to evaluate the effectiveness of PORT. PORT consisted of whole breast irradiation (50 Gy/25 fractions) followed by boost irradiation (10 Gy/5 fractions) using electron beams for patients with high-risk DCIS. Eligibility criteria were as follows: 1) DCIS without an invasive carcinoma component, 2) age between 20 and 80 years, 3) involved margins or margin widths less than 1 mm, 4) refusal of re-resection, 5) performance status of 0−2, and 6) written informed consent. The primary endpoint was ipsilateral breast tumor recurrence (IBTR), and secondary endpoints were overall survival, relapse-free survival, recurrence patterns, and adverse events. Conclusions: Our preliminary results suggest that this PORT schedule may be promising for patients with high-risk DCIS. However, to make any definitive conclusions, a longer follow-up time is required

Preliminary Results from a Multi-center Prospective Study (JROSG 05-5) on Postoperative Radiotherapy for Patients with High-risk Ductal Carcinoma in situ with Involved Margins or Margin Widths 1 mm or less than

Purpose: This prospective study aimed to evaluate the effectiveness of postoperative radiotherapy (PORT) consisting of whole breast irradiation followed by boost irradiation in patients with high-risk ductal carcinoma in situ(DCIS) with margin widths less than 1mm.Materials and Methods:A multi-center phase II study (Japanese Radiation Oncology Study Group: JROSG 05-5) was conducted to evaluate the effectiveness of PORT. PORT consisted of whole breast irradiation (50Gy/25 fractions) followed by boost irradiation (10Gy/5 fractions) using electron beams for patients with high-risk DCIS. Eligibility criteria were as follows:1)DCIS without an invasive carcinoma component, 2)age between 20 and 80 years, 3) involved margins or margin widths less than 1 mm, 4) refusal of re-resection, 5) performance status of 0−2, and 6) written informed consent. The primary endpoint was ipsilateral breast tumor recurrence (IBTR), and secondary endpoints were overall survival, relapse free survival, recurrence patterns, and adverse events