Treatment of locally advanced breast cancer using primary induction chemotherapy with hormonal synchronization followed by radiation therapy with or without debulking surgery.

Fifty-one patients with stage IIIA or IIIB locally advanced breast cancer received primary induction chemotherapy (hormonal synchronization, 46 patients) to a maximum objective clinical response before proceeding to local therapy. Patients achieving a pathological complete response (CR) received radiation therapy, while patients with residual disease, partial response (PR), or stable disease (NC) received debulking surgery prior to radiation therapy; in all patients, 6 additional months of chemotherapy were administered. Chemotherapy consisted of cyclophosphamide (500 mg/m2 iv) and doxorubicin (30 mg/m2 iv) on day 1; tamoxifen (40 mg/m2 orally) on days 2-6; Premarin (0.625 mg/m2 orally) every 12 hours for three doses, beginning on day 7; and methotrexate (300 mg/m2 iv) followed in 1 hour by 5-fluorouracil (500 mg/m2 iv) on day 8 and leucovorin rescue (10 mg/m2 orally) every 6 hours for six doses, beginning 24 hours after methotrexate. Fifty patients are evaluable with respect to response, time to disease progression, and survival. The rate of objective response to chemotherapy was 90%; 52% of the patients had CR, 38% had PR, and 10% had NC. The median numbers of chemotherapy cycles to achieve CR, PR, and NC were five, four, and four, respectively. Twenty-four patients with CR to chemotherapy were pathologically assessed, 22 by multiple biopsies and 2 by mastectomy. Seventy-one percent of the patients were proven to have pathological CR. All patients completing combined therapy thus far are disease free. Nine of 29 patients with stage IIIB disease have relapsed; 7 of 23 with inflammatory histology have relapsed; and 2 of 20 with stage IIIA disease have relapsed.(ABSTRACT TRUNCATED AT 250 WORDS)