Prognosis of Patients With Early Breast Cancer Receiving 5 Years vs 2 Years of Adjuvant Bisphosphonate Treatment

TY - JOUR

T1 - Prognosis of Patients With Early Breast Cancer Receiving 5 Years vs 2 Years of Adjuvant Bisphosphonate Treatment

T2 - A Phase 3 Randomized Clinical Trial

AU - Friedl, Thomas W P

AU - Fehm, Tanja

AU - Müller, Volkmar

AU - Lichtenegger, Werner

AU - Blohmer, Jens

AU - Lorenz, Ralf

AU - Forstbauer, Helmut

AU - Fink, Visnja

AU - Bekes, Inga

AU - Huober, Jens

AU - Jückstock, Julia

AU - Schneeweiss, Andreas

AU - Tesch, Hans

AU - Mahner, Sven

AU - Brucker, Sara Y

AU - Heinrich, Georg

AU - Häberle, Lothar

AU - Fasching, Peter A

AU - Beckmann, Matthias W

AU - Coleman, Robert E

AU - Janni, Wolfgang

AU - Rack, Brigitte

PY - 2021/8/1

Y1 - 2021/8/1

N2 - Importance: Bisphosphonate treatment in patients with early breast cancer has become part of care, but the optimal treatment duration is still unclear.Objective: To compare 2 vs 5 years of zoledronate treatment following adjuvant chemotherapy in patients with early breast cancer.Design, Setting, and Participants: The SUCCESS A phase 3 multicenter randomized open-label clinical trial with a 2 × 2 factorial design enrolled 3754 patients from September 21, 2005, to March 12, 2007 (last patient out, May 7, 2014). Final data analysis was conducted from September 2019 to October 2020. In 250 German study centers, patients were eligible for participation in the SUCCESS A trial if they had either node-positive or high-risk node-negative (defined as at least 1 of the following: tumor size ≥ pT2, histologic grade 3, negative hormone receptor status, or age ≤35 years) primary invasive breast cancer.Interventions: Patients were first randomized to adjuvant chemotherapy with 3 cycles of fluorouracil, epirubicin, and cyclophosphamide followed by 3 cycles of docetaxel with or without gemcitabine (not presented in this report). After chemotherapy, patients underwent a second randomization of 5 years of zoledronate treatment (4 mg intravenously every 3 months for 2 years, followed by 4 mg intravenously every 6 months for 3 years) vs 2 years of zoledronate treatment (4 mg intravenously every 3 months for 2 years).Main Outcomes and Measures: The primary end point of the study was disease-free survival; secondary end points were overall survival, distant disease-free survival, and the incidence of skeletal-related adverse events. Survival times were measured from 2 years after the start of zoledronate treatment (landmark analysis).Results: Overall, data on 2987 patients were available for analysis; median age was 53 (range, 21-86) years. Disease-free survival, overall survival, and distant disease-free survival did not differ significantly between the 2 treatment arms (5 vs 2 years) as shown by adjusted multivariable Cox proportional hazards regression models (disease-free survival: hazard ratio [HR], 0.97; 95% CI, 0.75-1.25; P = .81; overall survival: HR, 0.98; 95% CI, 0.67-1.42; P = .90; distant disease-free survival: HR, 0.87; 95% CI, 0.65-1.18; P = .38). Adverse events were observed more often in the 5-year (46.2%) vs 2-year (27.2%) zoledronate treatment arm, which was particularly true for the 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%).Conclusions and Relevance: The results of this phase 3 randomized clinical trial indicate that extending the zoledronate treatment beyond 2 years does not improve the prognosis of high-risk patients with early breast cancer receiving chemotherapy, suggesting that the currently recommended bisphosphonate treatment duration of 3 to 5 years could be reduced.Trial Registration: ClinicalTrials.gov Identifier: NCT02181101.

AB - Importance: Bisphosphonate treatment in patients with early breast cancer has become part of care, but the optimal treatment duration is still unclear.Objective: To compare 2 vs 5 years of zoledronate treatment following adjuvant chemotherapy in patients with early breast cancer.Design, Setting, and Participants: The SUCCESS A phase 3 multicenter randomized open-label clinical trial with a 2 × 2 factorial design enrolled 3754 patients from September 21, 2005, to March 12, 2007 (last patient out, May 7, 2014). Final data analysis was conducted from September 2019 to October 2020. In 250 German study centers, patients were eligible for participation in the SUCCESS A trial if they had either node-positive or high-risk node-negative (defined as at least 1 of the following: tumor size ≥ pT2, histologic grade 3, negative hormone receptor status, or age ≤35 years) primary invasive breast cancer.Interventions: Patients were first randomized to adjuvant chemotherapy with 3 cycles of fluorouracil, epirubicin, and cyclophosphamide followed by 3 cycles of docetaxel with or without gemcitabine (not presented in this report). After chemotherapy, patients underwent a second randomization of 5 years of zoledronate treatment (4 mg intravenously every 3 months for 2 years, followed by 4 mg intravenously every 6 months for 3 years) vs 2 years of zoledronate treatment (4 mg intravenously every 3 months for 2 years).Main Outcomes and Measures: The primary end point of the study was disease-free survival; secondary end points were overall survival, distant disease-free survival, and the incidence of skeletal-related adverse events. Survival times were measured from 2 years after the start of zoledronate treatment (landmark analysis).Results: Overall, data on 2987 patients were available for analysis; median age was 53 (range, 21-86) years. Disease-free survival, overall survival, and distant disease-free survival did not differ significantly between the 2 treatment arms (5 vs 2 years) as shown by adjusted multivariable Cox proportional hazards regression models (disease-free survival: hazard ratio [HR], 0.97; 95% CI, 0.75-1.25; P = .81; overall survival: HR, 0.98; 95% CI, 0.67-1.42; P = .90; distant disease-free survival: HR, 0.87; 95% CI, 0.65-1.18; P = .38). Adverse events were observed more often in the 5-year (46.2%) vs 2-year (27.2%) zoledronate treatment arm, which was particularly true for the 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%).Conclusions and Relevance: The results of this phase 3 randomized clinical trial indicate that extending the zoledronate treatment beyond 2 years does not improve the prognosis of high-risk patients with early breast cancer receiving chemotherapy, suggesting that the currently recommended bisphosphonate treatment duration of 3 to 5 years could be reduced.Trial Registration: ClinicalTrials.gov Identifier: NCT02181101.

U2 - 10.1001/jamaoncol.2021.1854

DO - 10.1001/jamaoncol.2021.1854

M3 - SCORING: Journal article

C2 - 34165508

VL - 7

SP - 1149

EP - 1157

JO - JAMA ONCOL

JF - JAMA ONCOL

SN - 2374-2437

IS - 8

ER -