Purpose: We conducted a randomized controlled study to evaluate the safety and usefulness of a combined treatment of radiotherapy and chemotherapy with doxifluridine (5'-DFUR) plus tamoxifen (TAM) as an adjuvant therapy for breast cancer patients after conservative surgery. The complications observed in this trial are reported herein.
Methods: A total of 550 patients were registered and randomized (based on factors such as T, N, with/without radiotherapy) to groups A and B. Drug regimens were: group A, 5'-DFUR 600 mg/body/day for 6 months and TAM 20 mg/body/day for 2 years; group B, 5'-DFUR 600 mg/body/day for 2 years and TAM 20 mg/body/day for 2 years. Radiotherapy (2 Gy x 5 times/week, for 5 weeks) was administered to 88.6% of evaluable patients (481/543). Radiation-related acute adverse reactions occurred in 28.5% of the 481 patients and moderate to severe reactions occurred in 1.5% of the patients. Delayed radiation-related adverse reactions occurred in 23.8% of the patients but none were severe. Chemo-endocrine therapy-related adverse reactions occurred in 17.9% of group A patients and 25.6% of group B patients. Grade 3 reactions occurred in 6 of the group A patients (2.4%) and in 5 of the group B patients (1.9%); all adverse reactions subsided after dose reduction or discontinuation. These findings suggest that the combination therapy of irradiation and 5'-DFUR with TAM is safe for patients after breast conserving surgery.