Background
Chemotherapy as Adjuvant for Locally Recurrent breast cancer (CALOR). Open-label, phase III RCT of 162 patients with completely excised isolated locoregional recurrence (ILRR) of breast cancer. Tested whether adjuvant chemotherapy after local excision improves outcomes. Final analysis stratified by ER status.
Interventions and follow up
Arm A: Chemotherapy (investigator’s choice) after excision of ILRR
Arm B: No chemotherapy
Primary endpoint: DFS; secondary: OS and breast cancer-free interval (BCFI)
mFollow up: 9yr
Arm B: No chemotherapy
Primary endpoint: DFS; secondary: OS and breast cancer-free interval (BCFI)
mFollow up: 9yr
Results
10-yr DFS, ER-negative: 70% (chemo) vs 34% (no chemo); HR 0.29, 95%CI 0.13–0.67
10-yr DFS, ER-positive: 50% vs 59%; HR 1.07, 95%CI 0.57–2.00 (no benefit)
10-yr OS, ER-negative: 73% vs 53%; HR 0.48, 95%CI 0.19–1.20
10-yr OS, ER-positive: 76% vs 66%; HR 0.70, 95%CI 0.32–1.55
10-yr DFS, ER-positive: 50% vs 59%; HR 1.07, 95%CI 0.57–2.00 (no benefit)
10-yr OS, ER-negative: 73% vs 53%; HR 0.48, 95%CI 0.19–1.20
10-yr OS, ER-positive: 76% vs 66%; HR 0.70, 95%CI 0.32–1.55
Adverse events
Hematologic: Grade 3–4 neutropenia (~33%) in the chemotherapy arm
Overall: Chemotherapy was generally well-tolerated; treatment-related deaths were rare
Overall: Chemotherapy was generally well-tolerated; treatment-related deaths were rare
Conclusions
Adjuvant chemotherapy after excision of isolated locoregional recurrence significantly improves DFS in ER-negative disease but provides no clear benefit in ER-positive disease. Establishes the role of chemotherapy for ER-negative ILRR.
Key Limitations
Very small (n=162) and closed early for slow accrual, limiting power, especially within ER subgroups. Open-label, investigator's-choice chemotherapy. ER-positive subgroup analyses are exploratory and underpowered. Predates modern systemic options for ILRR.
Clinical Context
The only randomized evidence supporting adjuvant chemotherapy for isolated locoregional recurrence. ASCO/ESMO guidance favors chemotherapy for ER-negative ILRR; for ER-positive ILRR, endocrine therapy is prioritized and chemotherapy is individualized given the lack of demonstrated benefit.