Timothy J. Whelan, MD: When Can Radiotherapy Be Avoided After Breast-Conserving Surgery?

2022 ASCO Annual Meeting


Timothy J. Whelan, MD, of McMaster University and Hamilton Health Sciences, discusses findings from the LUMINA study, which found that women aged 55 or older who had grade 1–2 T1N0 luminal A breast cancer following breast-conserving surgery and were treated with endocrine therapy alone had very low rates of local tumor recurrence at 5 years. These patients, the research suggests, may be able to forgo radiotherapy (Abstract LBA501).


Disclaimer: This video transcript has not been proofread or edited and may contain errors.
Women with breast cancer, early stage breast cancer, are primarily treated with lumpectomy, often endocrine therapy and radiation. And for many years now we've realized that the risk of local recurrence after lumpectomy has been steadily decreasing, and this has been attributed to smaller screen detected cancers, better surgical therapies and better systemic therapy. And radiation itself is associated with significant side effects, both early, such as fatigue and skin irritation, and late side effects such as breast distortion, which can affect cosmesis and quality of life. And rare life threatening side effects such as cardiac disease and second cancers. The question is arisen, can we avoid radiotherapy in women who are already going to have lumpectomy and endocrine therapy? We've done a number of studies which have evaluated clinical pathological factors alone, but haven't been able to identify a very low risk group of patients after lumpectomy and endocrine therapy alone. But over the last two decades, we realized a better understanding of the molecular biology of breast cancer and have identified four major intrinsic subtypes of breast cancer. Luminal A being the most common subtype and also the lowest risk subtype. The objective of our study was to determine women with clinical pathological factors, low risk and the Luminal A subtype who were treated with lumpectomy and endocrine therapy alone. Could they avoid radiotherapy? The Luminal was a prospective cohort study where we followed 500 women who had low clinical risk factors and Luminal A subtype determined by ER, PR, HER2 and a low Ki-67, less than 13.25%, which was measured centrally in three labs using the international working group methods. And we found over five years that women had a very low rate of local recurrence, only 2.3% with the upper border of the 90% confidence interval being 3.8%, which was well below the 5% limit that we had set for ourselves. We believe that this rate is very low and constitutes that we could omit radiotherapy in this low risk subtype. Should point out that the risk of contralateral breast cancer in this group of women was only 1.8%. Very similar to the risk of local recurrence and the risk of any recurrence was only 2.7%. Again, a low risk group of patients. Based on these results in women who meet the clinical criteria for the study, and I'll mention again, they were women less than or equal to 50 or greater than or equal to 55 years of age who had a T1 N0 cancer, grades 1 and 2, and the luminal A subtype as we determined who were treated with endocrine therapy, they can avoid radiotherapy. Now, although Luminal A is a common subtype, we estimate that this group of women probably constitutes about 10 to 15% of all women with breast cancer. Given that the risk of invasive breast cancer is about 300,000 annually per year in North America, we estimate that this would relate to about 30 to 40,000 women per year.

Related Videos

Head and Neck Cancer
Supportive Care

Carryn M. Anderson, MD, on Head and Neck Cancer: New Data on Avasopasem Manganese for Oral Mucositis

Carryn M. Anderson, MD, of the University of Iowa Hospital, discusses phase III results of the ROMAN trial of avasopasem manganese for patients with severe oral mucositis who are receiving chemoradiotherapy for locally advanced, nonmetastatic head and neck cancer. Compared with placebo, avasopasem manganese improved severe oral mucositis (Abstract 6005).

Supportive Care
Symptom Management

Sriram Yennu, MD, on Cancer-Related Fatigue: Is Open-Labeled Placebo an Effective Treatment?

Sriram Yennu, MD, of The University of Texas MD Anderson Cancer Center, discusses the placebo response in patients with advanced cancer and cancer-related fatigue. His latest findings show that open-labeled placebo was efficacious in reducing cancer-related fatigue and improving quality of life in fatigued patients with advanced cancer at the end of 1 week. The improvement in fatigue was maintained for 4 weeks (Abstract 12006).

Gynecologic Cancers

Benoit You, MD, PhD, on Ovarian Cancer: Who Benefits From Bevacizumab in the First-Line Setting

Benoit You, MD, PhD, of Lyon University hospital (HCL, France) and GINECO group (France), discusses findings from the GOG-0218 trial of patients with ovarian cancer, which appears to confirm earlier data on the link between poor tumor chemosensitivity and benefit from concurrent plus maintenance bevacizumab. In Dr. You’s validation study, patients who derived the most progression-free and overall survival benefit from bevacizumab were those with high-risk disease (stage IV or incompletely resected stage III) associated with an unfavorable KELIM score (CA-125 kinetic elimination rate constant, calculable online) (Abstract 5553).


Courtney D. DiNardo, MD, MSCE, and Jorge E. Cortes, MD, on CML: New Efficacy and Safety Results for Asciminib

Courtney D. DiNardo, MD, MSCE, of The University of Texas MD Anderson Cancer Center, and Jorge E. Cortes, MD, of Georgia Cancer Center at Augusta University, discuss phase III results from the ASCEMBL trial, which showed that after more than 2 years of follow-up, asciminib continued to yield superior efficacy and better safety and tolerability vs bosutinib in patients with chronic myeloid leukemia (CML) in chronic phase. These results continue to support the use of this kinase inhibitor as a new CML therapy, says Dr. Cortes, with the potential to transform the standard of care (Abstract 7004).

Breast Cancer

Lisa A. Carey, MD, and Shanu Modi, MD, on Breast Cancer: Is T-DXd a Potential New Standard of Care for HER2-Low Disease?

Lisa A. Carey, MD, of the University of North Carolina Lineberger Comprehensive Cancer Center, and Shanu Modi, MD, of Memorial Sloan Kettering Cancer Center, discuss the phase III findings from the DESTINY-Breast04 trial, which compared fam-trastuzumab deruxtecan-nxki (T-DXd) vs treatment of physician’s choice (TPC) in patients with HER2-low unresectable and/or metastatic breast cancer. T-DXd is the first HER2-targeted therapy to demonstrate clinically meaningful improvement in progression-free and overall survival compared with TPC in this patient population, regardless of hormone receptor or immunohistochemistry status or prior use of CDK4/6 inhibitors (Abstract LBA3).