Study on Multi-Gene Classifier for Identifying Indolent Tumours
Introduction to Breast Cancer and Recurrence
Breast cancer poses a significant health threat, leading to a variety of outcomes for those diagnosed. The recurrence of tumours after an initial diagnosis can occur within months or span several years. To combat this issue, molecular profiling is increasingly employed to detect early recurring tumours. Failure to accurately identify these recurring cases often results in over-treatment, which can have repercussions including increased costs, resource utilization, and negative impacts on patient health and overall well-being.
Research Overview
A recent study published in the Journal of the American Medical Association investigates the efficacy of the 70-gene MammaPrint Assay in identifying “very low risk” tumours. The research involved a cohort of 652 postmenopausal women diagnosed with breast cancer, with a median age of 62.8 years. All participants underwent treatment via lumpectomy or mastectomy and radiation. The study divided the patients into two groups: one receiving tamoxifen treatment and the other not receiving any systemic therapy.
Ultralow Risk Threshold Findings
The study established an ultralow risk threshold. Notably, above this threshold, there were no breast cancer-related deaths reported after 15 years among patients who did not receive systemic therapy. Statistical models were utilized to assess survival rates concerning variables such as age, hormone receptor status, and time of diagnosis.
Results of the MammaPrint Assay
The findings indicated that 58% of the participants were classified as low risk according to the MammaPrint Assay, while 42% were deemed high risk. Among all participants, 15% fell into the ultralow risk category. After 15 years, the tamoxifen-treated group with ultralow risk showed no breast cancer-associated deaths. Furthermore, at the 20-year milestone, the survival rate was 97% for tamoxifen-treated patients compared to 94% for those who did not receive treatment.
Conclusion and Implications
The study concludes that the gene signature associated with the ultralow-risk threshold can effectively identify patients with an extremely low long-term risk of death from breast cancer. These results are crucial for addressing the issue of over-treatment in breast cancer, a significant concern in healthcare. By utilizing the ultralow-risk threshold, healthcare professionals can better identify patients whose long-term prognosis is excellent, allowing for reassurance regarding their outcomes regardless of whether they pursue follow-up therapy.
Reference
Esserman L, Yau C, Thompson C, van ‘t Veer L, Borowsky A, Hoadley K et al. Use of Molecular Tools to Identify Patients With Indolent Breast Cancers With Ultralow Risk Over 2 Decades. JAMA Oncology. 2017.