Reduction in tumor grade and Ki-67 in postmenopausal patient with node-positive invasive ductal carcinoma following combination hormone replacement therapy cessation: a case report

• Published in: Translational breast cancer research 2022-07, Vol.3, p.29-29
• Main Authors: King, Caroline A, Masanam, Monika K, Maini, Aneesha S, Merritt, Clint M, Fan, Kenneth L, Greenwalt, Ian T
• Format: Article
• Language: English
• Subjects: Case Report
• ISSN: 2218-6778; 2218-6778
• DOI: 10.21037/tbcr-22-26

While praised for its benefits in treating symptoms related to menopausal changes, hormone replacement therapy (HRT) has been associated with an increased risk for hormone-dependent cancer development, particularly endometrial and breast. Few studies have elucidated the relationship between HRT cessation and hormone receptor-positive breast cancer proliferation. We report herein, to the best of our knowledge, the first case of 28.6% relative reduction in proliferation index marker Ki-67 in node-positive hormone receptor-positive breast cancer following HRT cessation. We report an unusual case of a 64-year-old female patient with longstanding HRT for fifteen years who underwent immediate discontinuation after diagnosis of poorly differentiated invasive ductal carcinoma. We observed a reduction in tumor grade from poorly differentiated at time of biopsy to moderately differentiated at time of surgery following cessation of HRT, as well as a reduction in the tumor proliferation index (Ki-67) from 70% to 50%. The patient has remained recurrence-free at the one-year mark postoperatively with continued follow-up. This case highlights potential clinical benefits associated with HRT discontinuation in the postmenopausal population with preexisting hormone-dependent cancers with high proliferation index, as well as the usefulness of Ki-67 in measuring response to aromatase inhibition in this subpopulation of patients. Hormone replacement therapy (HRT); breast cancer; tumor grade; Ki-67; case report.