Evaluating Harms and Benefits of Endocrine Therapy in Patients ≥70 Years of Age With Lower Risk Breast Cancer

The current standard of care for stage 1 hormone receptor-positive (HR+) breast cancer consists of breast-conserving surgery followed by adjuvant radiotherapy (RT) and endocrine therapy (ET) for at least 5 years. The benefit of adjuvant ET for older patients is mitigated because of their increase risk of death from other causes and shorter time horizon to live. Clinical and pathological factors such as low-intermediate grade, tumor size ≤2 cm, and older age have been used in a few studies to identify patients with a lower risk of recurrence that might benefit from adjuvant therapy de-escalation, i.e. omission of RT or ET. Since there is no dedicated randomized clinical trial (RCT) conducted to evaluate the omission of ET, there is clinical equipoise as to whether we can omit adjuvant ET in older patients with lower-risk early-stage breast cancer. Therefore, we propose a randomised, multicentre trial evaluating harms and benefits of endocrine therapy in patients ≥70 years of age with lower risk breast cancer.

Sex

All

Minimum age

70 Years

Inclusion Criteria:

* New invasive estrogen and/or progesterone receptor-positive (ER+ and/or PR+), HER2-negative (HER2-) invasive breast carcinoma diagnosis as per ASCO-CAP guidelines
* The primary tumour characteristics are either: Grade 1 and ≤3 cm on microscope exam, OR Grade 2 and ≤2 cm on microscope exam, OR Grade 3 and ≤1 cm on microscope exam
* Treated with standard loco-regional therapy: breast conserving surgery followed by adjuvant radiotherapy OR total mastectomy
* Axillary node-negative (cN0 or pN0)
* Able to provide oral consent and complete questionnaires in French or English as per study protocol

Exclusion Criteria:

* Metastatic cancer

• BACKGROUNDSavard MF, Clemons M, Hutton B, Jemaan Alzahrani M, Caudrelier JM, Vandermeer L, Liu M, Saunders D, Sienkiewicz M, Stober C, Cole K, Shorr R, Arnaout A, Chang L. De-escalating adjuvant therapies in older patients with lower risk estrogen receptor-positive breast cancer treated with breast-conserving surgery: A systematic review and meta-analysis. Cancer Treat Rev. 2021 Sep;99:102254. doi: 10.1016/j.ctrv.2021.102254. Epub 2021 Jun 19. PMID 34242928
• BACKGROUNDAlzahrani M, Clemons M, Chang L, Vendermeer L, Arnaout A, Larocque G, Cole K, Hsu T, Saunders D, Savard MF. Management Strategies for Older Patients with Low-Risk Early-Stage Breast Cancer: A Physician Survey. Curr Oncol. 2021 Dec 21;29(1):1-13. doi: 10.3390/curroncol29010001. PMID 35049675
• BACKGROUNDSavard MF, Alzahrani MJ, Saunders D, Chang L, Arnaout A, Ng TL, Brackstone M, Vandermeer L, Hsu T, Awan AA, Cole K, Larocque G, Clemons M. Experiences and Perceptions of Older Adults with Lower-Risk Hormone Receptor-Positive Breast Cancer about Adjuvant Radiotherapy and Endocrine Therapy: A Patient Survey. Curr Oncol. 2021 Dec 8;28(6):5215-5226. doi: 10.3390/curroncol28060436. PMID 34940075