Postsurgical concurrent letrozole plus radiotherapy safe for early stage breast cancer

Concurrent and sequential adjuvant letrozole and radiotherapy after breast-conserving surgery was safe in postmenopausal women with early stage breast cancer. Grade-2 skin-related adverse events were similar between both methods.

Researchers conducted the CO-HO-RT (Concomitant Hormono-radiotherapy) trial, a phase-2 trial at two centers in France and one center in Switzerland. They randomly assigned postmenopausal women with early-stage breast cancer who had breast conserving surgery to concurrent radiotherapy and letrozole (n=75) or sequential radiotherapy and letrozole (n=75). The primary endpoint was acute or late grade-2 skin toxicities.

During radiotherapy and within the first 12 weeks after, any adverse skin-related toxicity grade-2 or worse was observed in 31 patients in the concurrent group and 31 patients in the sequential group. Grade-3 acute skin dermatitis and was noted in four patients in the concurrent group and six patients in the sequential group during radiotherapy.

At a median follow-up of 26 months, late effects grade-2 or worse were observed in two patients from each group. The median time to subcutaneous fibrosis was 14 months. In the sequential group, there was an increase in pain (P=.02) and dyspnoea (P=.04).

Long-term follow-up is needed to examine cardiac- and cancer-specific outcomes, according to researchers.

The findings of this trial contribute to understanding how best to integrate radiotherapy and antihormonal therapy, according to Abram Recht, MD, professor in the department of radiation oncology at Harvard Medical School, Boston.

“At present, starting treatment with aromatase inhibitors either after or before radiation therapy seems reasonable,” he wrote in an accompanying editorial.

Azria D. Lancet Oncol. 2010;doi:10.1016/S1470-2045(10)70013-9.