Early Breast Cancer: 5 Years Versus 3 Years of Adjuvant Bisphosphonate Treatment
Posted: Monday, August 30, 2021
The optimal duration of treatment using bisphosphonate for patients with early breast cancer is still unclear. In the phase III SUCCESS trial, Thomas W.P. Friedl, PhD, and colleagues from University Hospital Ulm, Prittwitzstr, Ulm, Germany, found there was no statistically significant difference in survival outcomes between 5 and 2 years of adjuvant zoledronate treatment. Their results were reported in JAMA Oncology.
“Extending the zoledronate treatment beyond 2 years does not improve the prognosis of high-risk patients with early breast cancer receiving chemotherapy,” noted the study authors.
The randomized clinical trial enrolled a total of 3,754 patients with either node-positive or high-risk node-negative primary invasive breast cancer. Patients were randomly assigned to receive adjuvant chemotherapy consisting of three cycles of fluorouracil, epirubicin, and cyclophosphamide followed by three cycles of docetaxel with or without gemcitabine. Following chemotherapy, patients were then randomly assigned to receive 2 or 5 years of 4 mg zoledronate treatment intravenously.
Disease-free survival based on the duration of zoledronate treatment revealed no significant difference between patients receiving 5 versus 2 years (hazard ratio [HR] = 0.97; 95% confidence interval [CI] = 0.75–1.25; P = .81). Similarly, overall survival (HR = 0.98; 95% CI = 0.67–1.42; P = .90) and distant disease–free survival (HR = 0.87; 95% CI = 0.65–1.18; P = .38) did not differ significantly between the two treatment arms. The most common adverse events were skeletal-related events bone pain (5 years = 8.3% vs. 2 years = 3.7%) and arthralgia (5 years = 5.1% vs. 2 years = 3.1%).
Based on the results, the study authors commented: “The recommended 3 to 5 years of adjuvant bisphosphonate treatment for patients with high-risk early breast cancer as published in current guidelines could be reduced.”
Disclosure: For full disclosures of the study authors visit jamanetwork.com.
