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

Issues in Oncology
Global Cancer Care

Clifford A. Hudis, MD, and Karen E. Knudsen, PhD, MBA, on How ASCO and the American Cancer Society Are Collaborating to Help Patients With Cancer

Clifford A. Hudis, MD, of the American Society of Clinical Oncology, and Karen E. Knudsen, PhD, MBA, of the American Cancer Society, discuss their collaboration, pooling their research and education resources to help empower patients with cancer and their families. Within 48 hours, Drs. Hudis and Knudsen were able to gear up a rapid response to the crisis in Ukraine, forming a clinical corps of volunteers to post information online in multiple languages, which helped patients navigate their care in the war-torn region. To date, 300 European cancer organizations have joined their efforts.

Leukemia

Eunice S. Wang, MD, on AML: Long-Term Results With Crenolanib Plus Chemotherapy

Eunice S. Wang, MD, of Roswell Park Comprehensive Cancer Center, discusses long-term phase II findings of a trial evaluating crenolanib plus chemotherapy in newly diagnosed adults with FLT3-mutant acute myeloid leukemia. The study showed a composite complete remission rate of 86%. With a median follow-up of 45 months, median overall survival has not been reached. A phase III trial is ongoing (Abstract 7007).

Breast Cancer
Immunotherapy

Erika Hamilton, MD, on Metastatic Breast Cancer: Safety Follow-up Data on T-DXd vs T-DM1

Erika Hamilton, MD, of Sarah Cannon Research Institute at Tennessee Oncology, discusses phase III data from the DESTINY-Breast03 study, which reinforced the consistent safety profile of fam-trastuzumab deruxtecan-nxki (T-DXd) vs ado-trastuzumab emtansine (T-DM1) in patients with HER2-positive unresectable and/or metastatic breast cancer. The findings also support T-DXd’s risk benefit over that of T-DM1 (Abstract 1000).

Pancreatic Cancer

Pamela L. Kunz, MD, on Pancreatic Neuroendocrine Tumors: A Final Analysis of Temozolomide or Temozolomide Plus Capecitabine

Pamela L. Kunz, MD, of the Yale University School of Medicine, discusses new findings from the ECOG-ACRIN E2211 trial, which showed the longest progression-free survival and highest response rates with temozolomide plus capecitabine reported to date for patients with pancreatic neuroendocrine tumors. The presence of a deficiency of MGMT, the drug-resistance gene, was associated with greater odds of an objective response (Abstract 4004).

Michael J. Overman, MD, and Takayuki Yoshino, PhD, MD, on Colorectal Cancer: Phase III Data on Panitumumab or Bevacizumab Plus mFOLFOX6

Michael J. Overman, MD, of The University of Texas MD Anderson Cancer Center, and Takayuki Yoshino, PhD, MD, of the National Cancer Center Hospital East, Japan, discuss results from the PARADIGM trial, the first prospective study to test the superiority of panitumumab vs bevacizumab in combination with standard doublet first-line chemotherapy for patients with RAS wild-type and left-sided metastatic colorectal cancer. The study showed that panitumumab improved overall survival in combination with mFOLFOX6, which may establish a standard first-line combination regimen for this population (Abstract LBA1).

Advertisement

Advertisement




Advertisement