Early Breast Cancer: Risk-Adapted Targeted Intraoperative Radiotherapy During Lumpectomy
Posted: Friday, November 13, 2020
In terms of long-term outcomes, single-dose risk-adapted targeted intraoperative radiotherapy (TARGIT-IORT) during lumpectomy may prove to be an effective alternative to multiple sessions of external-beam radiotherapy (EBRT) in women with early breast cancer. According to Jayant S. Vaidya, MD, of the University College London, and colleagues, this targeted alternative yielded comparable long-term cancer control and lower non–breast cancer mortality. These findings from a multicenter, open-label, prospective phase III trial were published in The BMJ.
“Early results of using single-dose TARGIT-IORT during lumpectomy were promising,” the authors commented, “and the treatment was found to have advantages for the patient, such as convenience, reduced travel and personal costs, improved quality of life, and fewer side effects.”
The participants were 2,298 women, aged 45 and older, who had been diagnosed with early breast cancer via needle biopsy. They were suitable for wide local excision of invasive ductal carcinoma (cN–N1) up to 3.5 cm. Patients were then randomly assigned to receive either TARGIT-IORT immediately after lumpectomy (n = 1,140) or a standard daily fractionated course of EBRT over 3 to 6 weeks (n = 1,158).
At 5-year follow-up, local recurrences were observed in 2.4% of patients who underwent the targeted treatment versus 0.95% of those treated with EBRT. Kaplan-Meier estimates indicated that TARGIT-IORT was noninferior to EBRT (difference 1.21%, 90% confidence interval = 0.47%–1.95%). At a longer-term follow-up (median 6.5 years but up to 18.9 years), there was no difference when comparing these radiotherapy approaches in terms of in local recurrence–free survival (P = .28), mastectomy-free survival (P = .74), distant disease–free survival (P = .74), overall survival (P = .13), or breast cancer mortality (P = .54). Of note, non–breast cancer related mortality was reduced in patients who underwent the targeted approach compared with those who received EBRT (P = .005).
Disclosure: For full disclosures of the study authors, see bmj.com.