Top Line: What is the risk of local recurrence for luminal A breast cancer when adjuvant radiation is omitted?
The Study: LUMINA was a single-arm prospective cohort study of 500 patients with low risk breast cancer treated with breast conservation without adjuvant radiation. Compared to other trials of RT omission that relied primarily on clinical factors, LUMINA also used molecular classification of low risk disease. To be eligible, patients had to be 55 or older with a grade 1 or 2, T1N0 (<2cm) tumor of luminal A subtype. Luminal A tumors have ER >1%, PR >20%, HER2 negative, and Ki67 ≤13.25%. Before lumping all grade 1-2 ER/PR positive tumors into the luminal A category, recognize that of 740 initially eligible patients, 30% had a Ki67 >13.25% and were not included in the study. All patients received adjuvant endocrine therapy for at least 5 years. At 5 years, the cumulative incidence of local recurrence was 2.3%. The cumulative incidence of contralateral breast cancer was 1.9%. The risk of recurrence when omitting RT in this cohort is obviously low, but LUMINA failed to answer the more relevant questions of whether recurrence risk is just as low with radiation and no endocrine therapy or with neither RT nor endocrine therapy. The authors, who show such concern about the inconvenience, cost, and long term toxicity of radiation, fail to acknowledge the cost, inconvenience, and cumulative toxicity of 5-10 years of endocrine therapy. Many patients in LUMINA could have received just 5 days of radiation at low cost with minimal short and long-term toxicity.
TBL: In the LUMINA trial, the risk of local recurrence was 2.3% at 5 years after breast conservation surgery and endocrine therapy for luminal A breast cancer. | Whelan, N Engl J Med 2023
The Study: LUMINA was a single-arm prospective cohort study of 500 patients with low risk breast cancer treated with breast conservation without adjuvant radiation. Compared to other trials of RT omission that relied primarily on clinical factors, LUMINA also used molecular classification of low risk disease. To be eligible, patients had to be 55 or older with a grade 1 or 2, T1N0 (<2cm) tumor of luminal A subtype. Luminal A tumors have ER >1%, PR >20%, HER2 negative, and Ki67 ≤13.25%. Before lumping all grade 1-2 ER/PR positive tumors into the luminal A category, recognize that of 740 initially eligible patients, 30% had a Ki67 >13.25% and were not included in the study. All patients received adjuvant endocrine therapy for at least 5 years. At 5 years, the cumulative incidence of local recurrence was 2.3%. The cumulative incidence of contralateral breast cancer was 1.9%. The risk of recurrence when omitting RT in this cohort is obviously low, but LUMINA failed to answer the more relevant questions of whether recurrence risk is just as low with radiation and no endocrine therapy or with neither RT nor endocrine therapy. The authors, who show such concern about the inconvenience, cost, and long term toxicity of radiation, fail to acknowledge the cost, inconvenience, and cumulative toxicity of 5-10 years of endocrine therapy. Many patients in LUMINA could have received just 5 days of radiation at low cost with minimal short and long-term toxicity.
TBL: In the LUMINA trial, the risk of local recurrence was 2.3% at 5 years after breast conservation surgery and endocrine therapy for luminal A breast cancer. | Whelan, N Engl J Med 2023