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A review of the physiology behind letrozole applications in infertility: are current protocols optimal?
Letrozole is a targeted aromatase inhibitor which has primarily been used in post-menopausal women with breast cancer. Recently, it has been utilized in infertile pre-menopausal women because of its ability to enhance FSH production for ovulation induction. However, the ovarian follicle’s response t...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Springer US
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7492298/ https://www.ncbi.nlm.nih.gov/pubmed/32712844 http://dx.doi.org/10.1007/s10815-020-01892-6 |
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author | Rose, Bruce I. Brown, Samuel E. |
author_facet | Rose, Bruce I. Brown, Samuel E. |
author_sort | Rose, Bruce I. |
collection | PubMed |
description | Letrozole is a targeted aromatase inhibitor which has primarily been used in post-menopausal women with breast cancer. Recently, it has been utilized in infertile pre-menopausal women because of its ability to enhance FSH production for ovulation induction. However, the ovarian follicle’s response to FSH is only a part of the endocrine events occurring in a developing follicle. The health of the small antral follicles is driven primarily by androgens, which contribute to granulosa cell mitosis, sensitivity to FSH, and resistance to atresia. In contrast, elevated androgens in the late antral to pre-ovulatory follicle have a negative impact on follicle health and lead to atresia and cystic follicle formation. This ovarian physiologic data suggests that current applications of letrozole to infertility may be squandering some of the primary benefits available in using letrozole to promote follicle development. Four applications of letrozole to infertility that have appeared in the medical literature are reviewed. Androgen-related benefits are reviewed and various questions put forward about how letrozole could be more effectively used to help patients in these settings. |
format | Online Article Text |
id | pubmed-7492298 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | Springer US |
record_format | MEDLINE/PubMed |
spelling | pubmed-74922982020-09-28 A review of the physiology behind letrozole applications in infertility: are current protocols optimal? Rose, Bruce I. Brown, Samuel E. J Assist Reprod Genet Review Letrozole is a targeted aromatase inhibitor which has primarily been used in post-menopausal women with breast cancer. Recently, it has been utilized in infertile pre-menopausal women because of its ability to enhance FSH production for ovulation induction. However, the ovarian follicle’s response to FSH is only a part of the endocrine events occurring in a developing follicle. The health of the small antral follicles is driven primarily by androgens, which contribute to granulosa cell mitosis, sensitivity to FSH, and resistance to atresia. In contrast, elevated androgens in the late antral to pre-ovulatory follicle have a negative impact on follicle health and lead to atresia and cystic follicle formation. This ovarian physiologic data suggests that current applications of letrozole to infertility may be squandering some of the primary benefits available in using letrozole to promote follicle development. Four applications of letrozole to infertility that have appeared in the medical literature are reviewed. Androgen-related benefits are reviewed and various questions put forward about how letrozole could be more effectively used to help patients in these settings. Springer US 2020-07-26 2020-09 /pmc/articles/PMC7492298/ /pubmed/32712844 http://dx.doi.org/10.1007/s10815-020-01892-6 Text en © The Author(s) 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. |
spellingShingle | Review Rose, Bruce I. Brown, Samuel E. A review of the physiology behind letrozole applications in infertility: are current protocols optimal? |
title | A review of the physiology behind letrozole applications in infertility: are current protocols optimal? |
title_full | A review of the physiology behind letrozole applications in infertility: are current protocols optimal? |
title_fullStr | A review of the physiology behind letrozole applications in infertility: are current protocols optimal? |
title_full_unstemmed | A review of the physiology behind letrozole applications in infertility: are current protocols optimal? |
title_short | A review of the physiology behind letrozole applications in infertility: are current protocols optimal? |
title_sort | review of the physiology behind letrozole applications in infertility: are current protocols optimal? |
topic | Review |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7492298/ https://www.ncbi.nlm.nih.gov/pubmed/32712844 http://dx.doi.org/10.1007/s10815-020-01892-6 |
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