36TiP - A prospective study to assess response to neoadjuvant hormonal therapy in postmenopausal women with hormone-receptor positive breast cancer at a regional cancer centre in South India

Abstract

BackgroundHormonal receptor-positive breast carcinoma constitutes the most common subtype of the disease. Neoadjuvant chemotherapy is the current standard of treatment for any locally advanced breast carcinoma. However, the hormone receptor-positive, Her-2 negative cancers are less likely to respond to neoadjuvant chemotherapy than other biologic subtypes. Studies have explored the efficacy of neoadjuvant hormone treatment in this cohort of patients and efforts are ongoing to identify the subgroup of patients who can be treated with hormonal therapy alone, hence avoiding the unnecessary toxicity of chemotherapy. Our study aims to assess the response to neoadjuvant hormonal therapy (NAHT) in the postmenopausal women who are considered to be low-risk subgroup and for whom chemotherapy can be safely avoided. Trial designObjectives Primary objective: To determine the clinical tumor response rate to NAHT. Secondary Objective: To assess the number of patients undergoing surgery and pCR rates. To assess biologic changes in the tumor, including hormonal receptor status and proliferation by Ki67 staining. Methods Type of study: Phase II Prospective single-center study. Patients: Postmenopausal women diagnosed with biopsy-proven, non-metastatic and potentially operable breast cancer. Inclusion Criteria: Clinical stage T3-T4c with node-negative or clinical stage T2-T4c with node-positive disease (N1, N2) ER-positive with Allred score 6-8, Her 2 negative and Ki67 < 14%. Exclusion Criteria: Past history of treatment for any other cancer, history of having received chemotherapy or use of hormone replacement therapy previously. Sample size: 35 patients. Study site and duration: Kidwai Cancer Institute, 1.5 years. Eligible patients will receive Neoadjuvant hormonal therapy with Aromatase inhibitor and will undergo regular monitoring of objective response rate using calipers at the time of diagnosis and monthly once. The response will be noted as per the WHO criteria. Progressive disease recorded at any time will lead to exclusion from the study and the patient will be started on chemotherapy. Toxicity assessment will be done regularly. Legal entity responsible for the studyDepartment of Medical Oncology, Kidwai Cancer Institute, Bengaluru. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.