Advertisement


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

2022 ASCO Annual Meeting

Advertisement

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).



Transcript

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

Breast Cancer

Lisa A. Carey, MD, and Hope S. Rugo, MD, on Advanced Breast Cancer: New Data on Sacituzumab Govitecan-hziy vs Treatment of Physician’s Choice

Lisa A. Carey, MD, of the University of North Carolina Lineberger Comprehensive Cancer Center, and Hope S. Rugo, MD, of the University of California, San Francisco, Helen Diller Family Comprehensive Cancer Center, discuss phase III results from the TROPiCS-02 trial. This study showed that sacituzumab govitecan-hziy was more beneficial than single-agent chemotherapy in terms of progression-free survival in heavily pretreated patients with hormone receptor–positive/HER2-negative and unresectable advanced breast cancer (LBA1001).

Bladder Cancer

Sumanta K. Pal, MD, on Urothelial Carcinoma: New Results on Cabozantinib Plus Atezolizumab

Sumanta K. Pal, MD, of City of Hope National Medical Center, discusses findings from the COSMIC-021 study, which showed that cabozantinib plus atezolizumab demonstrated encouraging clinical activity with manageable toxicity in patients with inoperable locally advanced or metastatic urothelial carcinoma. The combination was administered as first-line therapy in cisplatin-based chemotherapy–eligible and –ineligible patients and as second- or later-line treatment in those who received prior immune checkpoint inhibitors (Abstract 4504).

Prostate Cancer

Alicia K. Morgans, MD, MPH, and Ian D. Davis, PhD, MBBS, on Prostate Cancer: Updated Overall Survival Outcomes With Enzalutamide

Alicia K. Morgans, MD, MPH, of Dana-Farber Cancer Institute, and Ian D. Davis, PhD, MBBS, of Monash University and Eastern Health, discuss the latest findings from ANZUP Cancer Trials Group’s ENZAMET cooperative group trial of enzalutamide in patients with metastatic hormone-sensitive prostate cancer. The results corroborate the benefit of enzalutamide with improved overall survival, and involve some exploratory subgroup analyses (Abstract LBA5004).

Leukemia

Courtney D. DiNardo, MD, MSCE, and Stéphane de Botton, MD, PhD, on AML: New Data on IDH2-Mutant Alleles, Enasidenib, and Conventional Care

Courtney D. DiNardo, MD, MSCE, of The University of Texas MD Anderson Cancer Center, and Stéphane de Botton, MD, PhD, of Institut Gustave Roussy, discuss phase III findings from the IDHENTIFY trial, which showed that mutational burden and co-mutational profiles differed between patients with relapsed or refractory acute myeloid leukemia that exhibited IDH2-R140 and IDH2-R172 mutations. Enasidenib improved survival outcomes for patients with IDH2-R172 mutations: median overall survival and 1-year survival rates were approximately double those in the conventional care arm (Abstract 7005).

Pancreatic Cancer

Alfredo Carrato, MD, PhD, on Pancreatic Cancer: Nab-Paclitaxel, Gemcitabine, and FOLFOX for Metastatic Disease

Alfredo Carrato, MD, PhD, of Alcala de Henares University in Spain, discusses phase II results from the SEQUENCE trial, which showed that nab-paclitaxel, gemcitabine, and modified FOLFOX showed significantly higher clinical activity than the standard nab-paclitaxel and gemcitabine in the first-line setting of patients with untreated metastatic pancreatic ductal adenocarcinoma (Abstract 4022).

Advertisement

Advertisement




Advertisement