TOPLINE:
In young women diagnosed with breast cancer, the risk for isolated locoregional recurrence was relatively low over a median follow-up of a decade and, overall, did not differ significantly by tumor subtype or surgical approach. Only mastectomy with radiation was associated with a lower risk for locoregional recurrence compared with breast-conserving therapy.
METHODOLOGY:
- Young women diagnosed with breast cancer have historically been thought to face higher rates of locoregional recurrence. However, long-term data evaluating this risk across molecular subtypes in the context of modern systemic and local therapies remain limited.
- To understand patients’ risk levels as it relates to treatment choice, researchers analyzed data from 1135 women aged 40 or younger who were diagnosed with stage I-III breast cancer and received a variety of treatment options. Patients had a median duration of follow-up from diagnosis of 10.1 years and were part of the Young Women’s Breast Cancer Study.
- The study investigators collected information on treatment and incident locoregional recurrence through patient surveys and confirmed these findings by medical record review.
- Available molecular subtypes for 1128 patients included luminal A (32.2%), luminal B (21.1%), luminal ERBB2-positive (20.4%), ERBB2-positive (7.9%), and triple-negative (17.7%) breast cancer.
- Local treatment included breast-conserving therapy (30.5%), which included lumpectomy as well as radiation for 98% of patients, unilateral mastectomy without radiation (9.7%), bilateral mastectomy without radiation (21.9%), and unilateral and bilateral mastectomies with radiation (16.4% and 21.1%, respectively). Many patients also underwent chemotherapy (82%) or endocrine therapy (78%).
TAKEAWAY:
- Overall, at 10.1 years, the cumulative incidence of isolated locoregional recurrence was 5.6%, with local recurrences occurring in 59 patients (5.2%) and regional recurrences in four patients (0.4%).
- While the cumulative incidence of locoregional recurrence varied by molecular subtype — 4.4% for luminal A, 4.7% for luminal B, 6.1% for luminal ERBB2-positive, 2.2% for ERBB2-positive, and 6.5% for triple-negative breast cancer — the differences across subtypes were not significant. Still, within each molecular category, patients who underwent a more aggressive treatment — mastectomy with radiation — had a numerically lower recurrence risk than those who had breast conserving therapy.
- The cumulative incidence of locoregional recurrence by treatment type was 6.7% after breast-conserving therapy, 6.5% after mastectomy without radiation, and 2.4% after mastectomy with radiation.
- Only mastectomy with radiation was associated with a lower risk for locoregional recurrence (hazard ratio, 0.27) compared with breast-conserving therapy. Researchers found no significant associations between locoregional recurrence and patient age, subtype, chemotherapy use, or cancer stage.
IN PRACTICE:
“In this large contemporary study of women diagnosed with breast cancer at age 40 years and undertreated with modern local and systemic therapy, we observed overall low rates of isolated [locoregional recurrence] in long-term follow-up, with no significant differences by local therapy strategy when compared within tumor subtype,” the authors of the study wrote.
The data from this study “may give breast surgeons the confidence to reassure young patients with breast cancer that outcomes remain excellent after modern multidisciplinary treatment,” Julie A. Margenthaler, MD, Washington University School of Medicine, St. Louis, said in an invited commentary. “The results do require some caution in their generalizability because the patients were not from diverse populations.”
SOURCE:
This study, led by Laura S. Dominici, MD, of Brigham and Women’s Hospital and Dana-Farber Cancer Institute, both in Boston, was published online in JAMA Surgery.
LIMITATIONS:
Predominantly White and non-Hispanic population could limit generalizability to other racial/ethnic groups. Restricting the analysis to patients who received mastectomy with radiation and remained metastasis-free could have introduced selection bias. Additionally, the small number of local recurrences potentially limited statistical power for subset analyses.
DISCLOSURES:
This study was supported by Susan G. Komen and the Breast Cancer Research Foundation. Several authors reported receiving honoraria, advisory board fees, royalties, grants, or research funding and having other ties with various sources. Additional disclosures are noted in the original article.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.