Background: The results of BCT in Japanese women have not been fully evaluated. The Tokyo Women's Medical University Breast Cancer Society initiated BCT protocols in 1987. Here, we present a retrospective analysis of BCT outcomes and identify prognostic factors.
Methods: The study population comprised 348 patients (353 breasts) with UICC clinical stage 0,I or II breast cancer, for whom wide excision (n= 294), quadrantectomy (n= 56) and tumorectomy (n= 3) were performed. The final pathological margin states were positive in 102 breasts (cancer cells remained within 5 mm of the surgical margin). The whole breast was irradiated to a total dose with 44 Gy/20 fractions or 46 Gy/23 fractions in the patients with negative surgical margins. The patients with positive or close margins received 48.4 Gy/22 fractions or 50 Gy/25 fractions irradiation to the whole breast. All but 2 patients received a radiation boost to the tumor bed and all tumor beds were irradiated to more than 53 Gy. Adjuvant therapy was administered in 240 cases. The median follow-up time was 4.3 years.
Results: The 5-year overall, cause-specific and disease-free survival rates were 95.8%, 97.3% and 92.5%, respectively. Recurrence was observed in 29 patients including 11 patients with loco-regional recurrence. Local recurrence was observed in 6 patients, 5 of whom were premenopausal. The 5-year local control and loco-regional control rates were 98.9% and 96.6%, respectively. T status (T1 to T2) was the only significant prognostic factor for disease-free survival. No severe morbidity has been observed. Cosmetic results were excellent or good in 73% of patients.
Conclusion: Our BCT protocols provide a high rate of local control and good cosmetic outcome. Pathologic margin status was not a major prognostic factor for local recurrence. Long term follow-up is required to reach a definite conclusion on optimal BCT protocols.