OPTimizing Irradiation through Molecular Assessment of Lymph node (OPTIMAL): a randomized open label trial

Abstract

Background Conservative surgery followed by breast and nodal irradiation is the standard loco-regional early breast cancer (BC) treatment for patients with four or more involved lymph nodes. However, the treatment strategy when fewer nodes are involved remains unclear, especially when lymphadenectomy has not been performed. Sensitive nodal status assessment molecular techniques as the One-Step Nucleic Acid Amplification (OSNA) assay can contribute to the definition and standardization of the treatment strategy. Therefore, the OPTIMAL study aims to demonstrate the feasibility of incidental irradiation of axillary nodes in patients with early-stage BC and limited involvement of the SLN. Methods BC patients who underwent conservative surgery and whose SLN total tumour load assessed with OSNA ranged between 250–15,000 copies/µL will be eligible. Patients will be randomized to receive irradiation on the breast, tumour bed, axillary and supraclavicular lymph node areas (intentional arm) or only on the breast and tumour bed (incidental arm). All areas, including the internal mammary chain, will be contoured. The mean, median, D5% and D95% doses received in all volumes will be calculated. The primary endpoint is the non-inferiority of the incidental irradiation of axillary nodes compared to the intentional irradiation in terms of 5-year disease free survival. Secondary endpoints comprise the comparison of acute and chronic toxicity and loco-regional and distant disease recurrence rates. Discussion Standardizing the treatment and diagnosis of BC patients with few nodes affected is crucial due to the lack of consensus. Hence, the quantitative score for the metastatic burden of SLN provided by OSNA can contribute by improving the discrimination of which BC patients with limited nodal involvement can benefit from incidental radiation as an adjuvant treatment strategy. Trial registration ClinicalTrial.gov, NCT02335957; https://clinicaltrials.gov/ct2/show/NCT02335957

Survival and recurrence with or without axillary dissection in patients with invasive breast cancer and sentinel node metastasis

“…The authors concluded that even without the routine use of nodal radiotherapy, complete dissection could be avoided with excellent regional control 45 . Hopefully, we will have answers about the real influence of radiotherapy in regional control with the results of the ongoing trials [46][47][48][49] .…”

Implementation of the Findings from The American College of Surgeons Oncology Group Z0011 Study in Axillary Management in Patients with Invasive Breast Cancer: A Cohort Study in A Brazilian Public University Hospital

“…45 Hopefully, we will have answers about the real in uence of radiotherapy in regional control with the results of the ongoing trials. [46][47][48][49] .…”