Single Dose Radiotherapy as Effective as Conventional Therapy for Patients with Breast Cancer

For women with early breast cancer, a single dose of targeted radiotherapy is just as effective as conventional radiotherapy, which requires several visits to the hospital after surgery, according to a study published by The BMJ.¹

Intraoperative radiotherapy, the combination of targeted therapy given after surgery, is associated with about an 80% chance of avoiding a full course of conventional therapy, fewer side effects, and no difference in survival or likelihood of cancer recurrence.

“Early results of using single dose TARGIT-IORT during lumpectomy were promising, 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,” wrote the researchers.²

The research analyzed almost 2300 women, aged 45 years or older, eligible for breast conservation surgery. Between March 2000 and June 2012, 1140 women were randomized to receive targeted intraoperative radiotherapy (TARGIT-IORT) and 1158 received external beam radiotherapy (EBRT).

The results suggested that TARGIT-IORT was no worse than EBRT. Specifically, after 5 years of monitoring, local recurrence risk was 2.11% for TARGIT-IORT compared with 0.95% for EBRT, but the difference was no considered statistically significant.

More, in the first 5 years after surgery, the data found 13 additional local recurrences (24 out of 1,140 vs 11 out of 1,158) but 14 fewer deaths (42 out of 1,140 vs 56 out of 1,158) with TARGIT-IORT compared to EBRT. The researchers also found that deaths from other causes were significantly lower (45 vs 74 events) with TARGIT-IORT than with EBRT.

“We believe that the long term data presented in this paper, together with many benefits for the patient, provide compelling evidence in favour of TARGIT-IORT as an effective alternative for this large group of patients with early breast cancer who are suitable for breast conservation,” wrote the researchers.²

The strengths of the study included the randomized design style, large sample population with a long duration and high complete follow up level. This typically suggests the results are reliable and robust.

As for the study’s limitations, the results may include a possible overdiagnosis of non-invasive local recurrence, and not collecting the background risk factors for deaths from non-breast cancer causes.

“Ultimately the treatment patients receive should be their choice and they should be provided with the data in a format which is transparent, straightforward, and easily understood,” wrote the researchers.²

References:

1. Single dose radiotherapy as good as conventional therapy for most women with early breast cancer [news release]. Published August 19, 2020. https://www.eurekalert.org/pub_releases/2020-08/b-sdr081720.php. Accessed September 14, 2020.

2. Vaidya JS, Bulsara M, Baum M, et al. Long term survival and local control outcomes from single dose targeted intraoperative radiotherapy during lumpectomy (TARGIT-IORT) for early breast cancer: TARGIT-A randomised clinical trial. BMJ. doi: https://doi.org/10.1136/bmj.m2836.