1. Academic Validation
  2. Constitutively active ESR1 mutations in gynecologic malignancies and clinical response to estrogen-receptor directed therapies

Constitutively active ESR1 mutations in gynecologic malignancies and clinical response to estrogen-receptor directed therapies

  • Gynecol Oncol. 2019 Jul;154(1):199-206. doi: 10.1016/j.ygyno.2019.04.010.
Stéphanie L Gaillard 1 Kaitlyn J Andreano 2 Laurie M Gay 3 Meghan Steiner 2 Matthew S Jorgensen 4 Brittany Anne Davidson 2 Laura J Havrilesky 2 Angeles Alvarez Secord 2 Fidel A Valea 2 Gerardo Colon-Otero 4 Deborah A Zajchowski 5 Ching-Yi Chang 2 Donald P McDonnell 2 Andrew Berchuck 2 Julia A Elvin 2
Affiliations

Affiliations

  • 1 Duke University Medical Center, Durham, NC, United States of America; Johns Hopkins Sidney Kimmel Cancer Center, Baltimore, MD, United States of America. Electronic address: stephanie.gaillard@jhmi.edu.
  • 2 Duke University Medical Center, Durham, NC, United States of America.
  • 3 Foundation Medicine, Inc., Cambridge, MA, United States of America.
  • 4 Mayo Clinic, Jacksonville, FL, United States of America.
  • 5 The Clearity Foundation, San Diego, CA, United States of America.
Abstract

Objective: Endocrine therapy is often considered as a treatment for hormone-responsive gynecologic malignancies. In breast Cancer, activating mutations in the Estrogen Receptor (mutESR1) contribute to therapeutic resistance to endocrine therapy, especially aromatase inhibitors (AIs). The purpose of this study was to evaluate the frequency and clinical relevance of ESR1 genomic alterations in gynecologic malignancies.

Methods: DNA from FFPE tumor tissue obtained during routine clinical care for 9645 gynecologic malignancies (ovary, fallopian tube, uterus, cervix, vagina, vulvar, and placenta) was analyzed for all classes of genomic alterations (base substitutions (muts), insertions, deletions, rearrangements, and amplifications) in ESR1 by hybrid capture next generation Sequencing. A subset of alterations was characterized in laboratory-based transcription assays for response to endocrine therapies.

Results: A total of 295 ESR1 genomic alterations were identified in 285 (3.0%) cases. mutESR1 were present in 86 (0.9%) cases and were more common in uterine compared to other cancers (2.0% vs <1%, respectively p < 0.001). mutESR1 were enriched in carcinomas with endometrioid versus serous histology (4.4% vs 0.2% respectively, p < 0.0001 in uterine and 3.5% vs 0.3% respectively, p = 0.0004 in ovarian carcinomas). In three of four patients with serial sampling, mutESR1 emerged under the selective pressure of AI therapy. Despite decreased potency of Estrogen Receptor (ER) antagonists in transcriptional assays, clinical benefit was observed following treatment with selective ER-targeted therapy, in one case lasting >48 months.

Conclusions: While the prevalence of ESR1 mutations in gynecologic malignancies is low, there are significant clinical implications useful in guiding therapeutic approaches for these cancers.

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