Source: Cancer  |  Posted 8 years ago

Concurrent administration of cyclophosphamide/methotrexate/5-fluorouracil (CMF) and reduced-dose radiotherapy appears to result in a low level of late toxicity and good local tumour control, a new study suggests.

Concurrent chemotherapy and radiotherapy allows more immediate use of both treatments and may provide radiation sensitisation. However, the most effective way to use concurrent treatment in women with early-stage breast carcinoma is unclear.

In their report, Jennifer R. Bellon, MD, with the Department of Radiation Oncology, at the Brigham and Women's Hospital Boston, Massachusetts, United States, and colleagues present updated results of a prospective protocol of concurrent CMF and reduced-dose radiotherapy.

The researchers enrolled 112 women with AJCC Stage I or Stage II breast carcinoma with 0-3 positive axillary lymph nodes. Patients were treated in a prospective single-arm study with concurrent CMF and 39.6 Gy radiotherapy to the whole breast with a 16-Gy boost.

Notably, many of the women had risk factors associated with an increased risk of local disease recurrence: age less than 40 (32%), close or positive margins (37%), and lymphatic/vascular invasion (51%).

Patients were followed for a median of 94 months; 94% survived for 5 years. After 60 months, 4% of the patients experienced local disease recurrence, and 17% experienced distant metastasis.

No recurrences in isolated regional lymph nodes were observed. Local disease recurred in 4% of patients with positive margins, 6% in patients with close (<1 mm) margins, and 4% of those with negative margins. One patient developed Grade 2 pneumonitis, and 1 patient developed acute myelogenous leukaemia.

"Concurrent CMF and reduced-dose radiotherapy is a well tolerated regimen with a low risk of long-term toxicity," Dr. Bellon and colleagues conclude. "Despite the inclusion of patients at high risk for local disease recurrence, a low risk of local disease recurrence was observed at 5 years."

"It remains to be seen whether novel treatment planning strategies such as intensity modified radiotherapy, which can improve the homogeneity of radiation delivery, can reduce the toxicity of concurrent regimens," suggest the researchers.