Feasibility and low toxicity of early radiotherapy after high-dose chemotherapy and autologous stem cell transplantation for patients with high-risk stage II-III and locally advanced breast carcinoma.

BACKGROUND

This prospective trial examined the feasibility, toxicity, and effectiveness of early locoregional radiotherapy after high-dose chemotherapy and autologous stem cell transplantation in patients with high-risk American Joint Committee on Cancer (AJCC) Stage II-III and locally advanced breast carcinoma.

METHODS

One hundred forty-seven consecutive patients with high-risk and locally advanced breast carcinoma were included in the current study. All patients received induction chemotherapy with a doxorubicin-based therapy, which was consolidated with high-dose cyclophosphamide, carboplatin, and thiotepa followed by autologous stem cell support. Within 50 days of the transplant, the patients were treated with locoregional radiotherapy that included the chest wall or breast, the axilla and supraclavicular area, and the internal mammary chain. The volume of lung included in the treatment volume was kept to a minimum. The central lung distance of the tangential fields ranged from 0.6-2.0 cm (mean, 1.1 cm). Tamoxifen was given based on receptor status.

RESULTS

One hundred forty-six of 147 patients received the planned treatment. Only six patients had a delay in the initiation of radiotherapy, and another 16 patients had delays during radiotherapy. Leukocyte and platelet toxicities during radiotherapy were not life-threatening and blood counts thereafter returned to normal. Grade 2 (according to National Cancer Institute Common Toxicity Criteria) skin toxicity occurred in 22% of patients and Grade 3 skin toxicity occurred in 6% of patients. Radiation pneumonitis was reported to occur in 5 patients (< 4%). After a median follow-up of 36 months from diagnosis (range, 6-64 months), there were no long-term organ toxicity and no secondary malignancy reported. No treatment-related deaths were reported. Three patients (< 3%) developed locoregional recurrence.

CONCLUSIONS

Locoregional radiotherapy after high-dose chemotherapy and autologous stem cell transplantation appears to be feasible and can be delivered safely within 10 weeks of transplantation. The short-term and long-term toxicity are reported to be low, with good local control.