Thanks to modern, multimodal breast cancer therapies, 5-year local recurrence rates following lumpectomy have dropped significantly, making breast-conserving surgery (BCS) an option for more patients with breast cancer, say researchers.
A meta-analysis of data from nine legacy trials conducted by the Alliance for Clinical Trials in Oncology shows that the 5-year rate of local recurrence was 4.2% overall in nearly 7000 breast cancer patients treated with lumpectomy as well as state-of-the-art systemic and radiation therapies.
Until now, the local recurrence rates were 5% to 10% following lumpectomy. These rates reflect historic data associated with the use of older breast cancer treatment protocols, according to a research team led by Heather B. Neuman, MD, of the University of Wisconsin School of Medicine and Public Health, Madison.
Neuman presented the study findings on May 4 at the 16th annual meeting of the American Society of Breast Surgeons (ASBS).
“Multiple randomized controlled trials have demonstrated equivalent survival between breast conservation and mastectomy, albeit with a higher local recurrence rate after breast conservation,” Neuman said during a press briefing at the conference.
“However, the absolute rates of local recurrence have been declining as a result of multimodality treatment. We sought to evaluate the local recurrence rates after breast- conserving surgery in a cohort of patients receiving modern-era therapy within the context of a clinical trial and to evaluate variation in rates of recurrence by molecular tumor subtype,” he said.
The analysis showed that the 5-year rate of local recurrence after lumpectomy was 6.9% among patients with triple-negative disease. For patients with estrogen-receptor (ER) negative, HER2-positive disease, the recurrence rate was 4.7%. For older patients with ER-positive, HER2-positive disease, the recurrence rate was 3%.
“Clearly these new data show that recurrence with breast conservation has diminished significantly overall,” Neuman said in a press release. “Additionally, in today’s age of multimodality, personalized breast cancer therapy, stratifying recurrence risk by cancer subtypes helps women and their physicians to make more informed decisions. This study absolutely has added important new information to my conversations with patients about the relative risks and benefits of lumpectomy and mastectomy.”
This study absolutely has added important new information to my conversations with patients about the relative risks and benefits of lumpectomy and mastectomy.
For the analysis, the investigators examined data from 6927 women with stage I-III breast cancer who were enrolled in nine clinical legacy trials from 1997 to 2011. All participants had undergone BCS as well as systemic and radiation therapies.
The researchers also identified factors associated with time to local recurrence. These factors included patient age, tumor size, lymph node status, and molecular tumor subtype.
Recurrence rates after mastectomy for early-stage breast cancer are 1% or less, Neuman confirmed in an interview. These new estimates of local recurrence after lumpectomy could change the way patients view their options.
“A local recurrence rate with lumpectomy of approximately 4% — and lower for certain women based on receptor status — vs 1% with mastectomy prompts a very different decision,” she told Medscape Medical News.
In a statement issued by the ASBS, Neuman noted that many women “face a difficult trade-off when making treatment decisions. These more positive, contemporary data may make their choice a little easier.”
Carla S. Fisher, MD, associate professor of surgery at Indiana University School of Medicine, in Indianapolis, agreed. This study “provides support for patients choosing breast-conserving therapy who are treated with modern, multimodal therapy,” she said in the ASBS statement.
For clinicians with patients who want unilateral or even bilateral mastectomy, this study provides evidentiary fodder to fuel treatment discussions, said an expert in breast cancer surgery when approached for comment.
“The myth that triple-negative breast cancer is a death sentence has to go away,” Henry M. Kuerer, MD, PhD, of the Department of Breast Surgical Oncology, MD Anderson Cancer Center, University of Texas, in Houston, told Medscape Medical News. “These data indicate there’s a 93% chance that it won’t recur after lumpectomy.”
The study findings will also facilitate discussion of BCS with patients who think they can avoid radiotherapy by opting for mastectomy, said Kuerer. “That’s not necessarily the case,” he pointed out.
“These discussions have to be managed very carefully so that the patient can make an informed choice, including refusing mastectomy,” he added.
Kuerer emphasized that midtherapy counseling regarding lumpectomy should be offered to patients with HER2-negative disease and lymph node involvement who have experienced significant tumor shrinkage following preoperative systemic or neoadjuvant therapy.