ABSTRACT
BACKGROUND: For postmenopausal women with hormone-receptor-positive breast cancer, the most effective duration for adjuvant therapy with an aromatase inhibitor remains unclear. METHODS: In this prospective, phase 3 trial, we randomly assigned postmenopausal women with hormone-receptor-positive breast cancer who had received 5 years of adjuvant endocrine therapy to receive the aromatase inhibitor anastrozole for an additional 2 years (2-year group, receiving a total of 7 years) or an additional 5 years (5-year group, receiving a total of 10 years). The primary end point was disease-free survival. The primary analysis included all the patients who were still participating in the trial and who had no recurrence 2 years after randomization (i.e., when treatment in the 2-year group had ended). Secondary end points were overall survival, contralateral breast cancer, second primary cancer, and clinical bone fracture. RESULTS: Among the 3484 women who were enrolled in the trial, 3208 remained in the trial without disease progression after the first 2 years of extended anastrozole treatment following randomization. Among these women, disease progression or death occurred in 335 women in each treatment group in the primary-analysis set at 8 years (hazard ratio, 0.99; 95% confidence interval [CI], 0.85 to 1.15; P = 0.90). No between-group differences occurred in most secondary end points, and subgroup analyses did not indicate differences in any particular subgroup. The risk of clinical bone fracture was higher in the 5-year group than in the 2-year group (hazard ratio, 1.35; 95% CI, 1.00 to 1.84). CONCLUSIONS: In postmenopausal women with hormone-receptor-positive breast cancer who had received 5 years of adjuvant endocrine therapy, extending hormone therapy by 5 years provided no benefit over a 2-year extension but was associated with a greater risk of bone fracture. (Funded by AstraZeneca and the Austrian Breast and Colorectal Cancer Study Group; ABCSG-16/SALSA ClinicalTrials.gov number, NCT00295620.).
Subject(s)
Anastrozole/administration & dosage , Aromatase Inhibitors/administration & dosage , Breast Neoplasms/drug therapy , Neoplasm Recurrence, Local/prevention & control , Administration, Oral , Aged , Anastrozole/adverse effects , Antineoplastic Agents, Hormonal/administration & dosage , Antineoplastic Agents, Hormonal/therapeutic use , Aromatase Inhibitors/adverse effects , Breast Neoplasms/mortality , Breast Neoplasms/surgery , Chemotherapy, Adjuvant , Disease-Free Survival , Fractures, Bone/epidemiology , Fractures, Bone/etiology , Humans , Kaplan-Meier Estimate , Middle Aged , Postmenopause , Prospective Studies , Receptors, Estrogen , Receptors, Progesterone , Tamoxifen/therapeutic useABSTRACT
BACKGROUND: Conflicting evidence exists regarding the value of surgical resection of the primary in stage IV breast cancer patients. OBJECTIVE: The prospective randomized phase III ABCSG-28 POSYTIVE trial evaluated median survival comparing primary surgery followed by systemic therapy to primary systemic therapy in de novo stage IV breast cancer. METHODS: Between 2011 and 2015, 90 previously untreated stage IV breast cancer patients were randomly assigned to surgical resection of the primary tumor followed by systemic therapy (Arm A) or primary systemic therapy (Arm B) in Austria. Overall survival (OS) was defined as the primary study endpoint. RESULTS: The trial was stopped early due to poor recruitment. Ninety patients (45 arm A, 45 arm B) were included; median follow-up was 37.5 months. Patients in the surgery arm had more cT3 breast cancer (22.2% vs 6.7%) and more cN2 staging (15.6% vs 4.4%). Both groups were well balanced with respect to the type of first-line systemic treatment. Median survival in arm A was 34.6 months, versus 54.8 months in the nonsurgery arm [hazard ratio (HR) 0.691, 95% confidence interval (95% CI) 0.358-1.333; P = 0.267]; time to distant progression was 13.9 months in the surgery arm and 29.0 months in the nonsurgery arm (HR 0.598, 95% CI 0.343-1.043; P = 0.0668). CONCLUSION: The prospective phase III trial ABCSG-28 (POSYTIVE) could not demonstrate an OS benefit for surgical resection of the primary in breast cancer patients presenting with de novo stage IV disease.
