Radiation Therapy Based on LUMINA Trial | Cynthia Ma, MD, PhD | ASCO22 Breast Cancer Updates

Dr. Cynthia Ma, breast cancer care expert from Washington University, reviews the following case question, incorporating updates from the 2022 ASCO annual conference that have changed the standard of care.

You are seeing a 65-year old woman, who is s/p breast conservation therapy for a stage I (1.2cm N0), ER strongly positive 100%, PR strongly positive 80%, HER2 1+ on IHC. Grade 1, Ki67 10%. Negative margin. She is healthy otherwise. What is your recommendation for her adjuvant therapy:
a. She will not need radiation therapy. She will proceed with adjuvant aromatase inhibitor, may consider adjuvant denosumab.
b. She needs radiation therapy.
c. She needs adjuvant chemotherapy, followed by radiation therapy, then aromatase inhibitor
The correct answer is a. Rationale: LUMINA trial was a prospective trial that enrolled early stage breast cancer patients ≥ 55 years, with T1N0 breast cancer, grade 1-2, ER≥1%, PR greater than 20%, HER2-ve, Ki67 ≤ 13.25%, post breast conservation therapy, margin ≥1mm, treated with adjuvant aromatase inhibitor, to omit radiation. The local recurrence rate was found to be very low at 5 years, 2.3% (90%CI 1.3 to 3.8%). The study supports the omission of radiation I this patient population.