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

Multiple Myeloma

Paul G. Richardson, MD, on Multiple Myeloma: New Data on Lenalidomide, Bortezomib, and Dexamethasone, With or Without ASCT

Paul G. Richardson, MD, of Dana-Farber Cancer Institute, discusses phase III findings from the DETERMINATION trial, which showed that, for patients with newly diagnosed multiple myeloma, lenalidomide, bortezomib, and dexamethasone (RVd) with or without autologous stem cell transplant (ASCT) and lenalidomide maintenance to disease progression resulted in the longest median progression-free survival reported for each approach, and a highly significant difference in progression-free survival in favor of early transplant. While overall response rates were similar, rates of MRD favored early transplant also, but toxicity was greater and quality of life was transiently but significantly diminished. No overall survival advantage has been observed to date (Abstract LBA4).

Colorectal Cancer
Genomics/Genetics

Michael J. Overman, MD, and Smitha Krishnamurthi, MD, on RAS Wild-Type Metastatic Colorectal Cancer: Refining Treatment Strategy

Michael J. Overman, MD, of The University of Texas MD Anderson Cancer Center, and Smitha Krishnamurthi, MD, of the Cleveland Clinic, review three abstracts, all of which enrolled patients with newly diagnosed RAS and BRAF wild-type metastatic colorectal cancer with left-sided primary tumors. The discussion centers on what the study results indicate about the use of an EGFR therapy and weighing the risk to quality of life from rash, in particular (Abstracts LBA3503, LBA3504, LBA3505).

Neuroendocrine Tumors

Mairéad G. McNamara, PhD, MBBCh, on Neuroendocrine Carcinoma: Findings on Liposomal Irinotecan Plus Fluorouracil and Folinic Acid or Docetaxel

Mairéad G. McNamara, PhD, MBBCh, of The Christie NHS Foundation Trust, discusses phase II findings of the NET-02 trial, which explored an unmet need in the second-line treatment of patients with progressive, poorly differentiated extrapulmonary neuroendocrine carcinoma. In the trial, the combination of liposomal irinotecan, fluorouracil, and folinic acid, but not docetaxel, met the primary endpoint of 6-month progression-free survival rate (Abstract 4005).

Breast Cancer

Richard Finn, MD, on Advanced Breast Cancer: New Data on Palbociclib Plus Letrozole From PALOMA-2

Richard Finn, MD, of the Geffen School of Medicine at UCLA and the Jonsson Comprehensive Cancer Center, discusses analyses from the PALOMA-2 trial on overall survival with first-line palbociclib plus letrozole vs placebo plus letrozole in women with ER-positive/HER2-negative advanced breast cancer. The study met its primary endpoint of improving progression-free survival but not the secondary endpoint of overall survival. Although patients receiving palbociclib plus letrozole had numerically longer overall survival than those receiving placebo plus letrozole, the results were not statistically significant (Abstract LBA1003).

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).

Advertisement

Advertisement




Advertisement