Analysis of the local recurrence and the feasibility of partial breast radiotherapy for early breast cancer treated by conservative surgery

Objective: To study the local recurrence and the role of Whole breast radiotherapy for early breast cancer treated by conservative surgery. Methods: From April 1990 to December 2000, 134 patients with early primary breast cancer were treated by conservative surgery. It consisted of stage 0 1, stage I 78 and stage II a 55. 125 patients underwent quadrantectomy plus axillary lymph node dissection and the other 9 patients had lumpectomy alone. Irradiation, which was received by 102 patients, was administered by using low tangential half fields with 6 MV X-ray to lower pulmonary irradiative volume. The dose of whole breast was 45 Gy/22-23f/4.5w, then 15 Gy boost dose was delivered to tumor bed by electron beam, the others were irradiated regional field according to postoperative pathologic findings. Results: All patients were followed for 5 years or more. The 5-year local recurrence rates, distant metastasis rates, survival rates were 3.7%, 2.2%, 95.5% respectively. All 5 patients who had had local recurrence had infiltrative carcinoma and negative lymph node. The 5-year local recurrence rate was higher(9.4% vs 2.0% ) in non-post- operative whole breast radiotherapy. But the statistical difference was insignificant because there were too few patients. Primary site recurrences were observed in 4 patients. Conclusions: Primary. site recurrence is the main type of local recrudescence. Radiation therapy after conservative surgery is very essential. It is feasible that irradiation with enough dose may be administered alone to the neighboring region of tumor bed after conservative surgery. (authors)