Susan A. McCloskey, MD
Postoperative radiation in breast cancer has become a personalized process, even enabling physicians to identify patients with ductal carcinoma in situ (DCIS) who have smaller incremental benefits and can potentially omit radiotherapy, says Susan A. McCloskey, MD.
Two studies published in the New England Journal of Medicine
(NEJM) that addressed the use of postoperative radiation in patients with breast cancer have been instrumental to the implementation of this personalized approach.
The first trial randomized women with early-stage breast cancer to whole-breast or thoracic-wall irradiation and regional nodal irradiation or whole-breast or thoracic-wall irradiation alone. Approximately 4000 patients enrolled on the trial, 76.1% of whom received breast-conserving surgery. Following mastectomy, 73.4% of patients in both arms received chest-wall irradiation. Ten-year follow up showed overall survival of 82.3% and 80.7% in the nodal-irradiation arm and control arms, respectively. Additionally, disease-free survival (DFS) was 72.1% and 69.1% in the nodal-irradiation group and control group, respectively (HR, 0.89; 95% CI, 0.80-1.00; P
A second trial similarly randomized women with early-stage breast cancer to whole-breast irradiation and regional nodal irradiation or whole-breast irradiation alone. A total of 1832 women participated in the study. Neither arm showed a significant difference in survival, and 10-year follow-up showed respective DFS rates of 82.0% in the nodal-irradiation group and 77.0% in the control arm (HR, 0.76; 95% CI, 0.61-0.94; P
In an interview during the 2018 OncLive®
State of the Science SummitTM
on Breast Cancer, McCloskey, assistant professor of radiation oncology, University of California, Los Angeles (UCLA), Jonsson Comprehensive Cancer Center, discussed the use of postoperative radiation in patients with breast cancer.
OncLive: Please provide an overview of your presentation.
: Postoperative radiation is a large topic, and we use radiation in different clinical circumstances—be it after lumpectomy, mastectomy for DCIS, or for more locally advanced invasive disease. I wanted to cover a little bit about all of those clinical scenarios to inform the audience of situations in which radiation is appropriate to consider, when it may be appropriate to forego, and how we can tailor our radiation recommendations to the population at hand. I also spoke about some technological advances that make radiation a much better experience than it has historically been for women.
Can you elaborate on some of these data?
The thing that is striking to me is that there have been many recent advances, across the spectrum of clinical scenarios, in which we give radiation. Physicians have identified the subsets of women with early-stage disease with DCIS who have smaller incremental benefits and can potentially benefit from the omission of radiation therapy.
Physicians have come a long way in informing postmastectomy radiation recommendations. If anything, physicians are using radiation a bit more commonly, but they are also aiming to tailor it more to risk factors, individualized decision making, and patient preferences so that we can inform our patients, help them weigh the pros and cons, and come to a decision.
Several studies have helped tailor recommendations. Two NEJM articles were published looking at regional nodal radiation. It's unusual for us; we are a small field, so to make it into NEJM and have those articles come out has helped physicians tailor how much radiation to give and which areas are treated; it’s been a big advance. Technologically, there have been so many advances.