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Su Y, Dang NM, Depypere H, Santucci-Pereira J, Gutiérrez-Díez PJ, Kanefsky J, Janssens JP, Russo J. Recombinant human chorionic gonadotropin induces signaling pathways towards cancer prevention in the breast of BRCA1/2 mutation carriers. Eur J Cancer Prev 2023; 32:126-138. [PMID: 35881946 PMCID: PMC9800649 DOI: 10.1097/cej.0000000000000763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Strategies for breast cancer prevention in women with germline BRCA1/2 mutations are limited. We previously showed that recombinant human chorionic gonadotropin (r-hCG) induces mammary gland differentiation and inhibits mammary tumorigenesis in rats. The present study investigated hCG-induced signaling pathways in the breast of young nulliparous women carrying germline BRCA1/2 mutations. METHODS We performed RNA-sequencing on breast tissues from 25 BRCA1/2 mutation carriers who received r-hCG treatment for 3 months in a phase II clinical trial, we analyzed the biological processes, reactome pathways, canonical pathways, and upstream regulators associated with genes differentially expressed after r-hCG treatment, and validated genes of interest. RESULTS We observed that r-hCG induces remarkable transcriptomic changes in the breast of BRCA1/2 carriers, especially in genes related to cell development, cell differentiation, cell cycle, apoptosis, DNA repair, chromatin remodeling, and G protein-coupled receptor signaling. We revealed that r-hCG inhibits Wnt/β-catenin signaling, MYC, HMGA1 , and HOTAIR , whereas activates TGFB/TGFBR-SMAD2/3/4, BRCA1, TP53, and upregulates BRCA1 protein. CONCLUSION Our data suggest that the use of r-hCG at young age may reduce the risk of breast cancer in BRCA1/2 carriers by inhibiting pathways associated with stem/progenitor cell maintenance and neoplastic transformation, whereas activating genes crucial for breast epithelial differentiation and lineage commitment, and DNA repair.
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Affiliation(s)
- Yanrong Su
- The Irma H Russo, MD, Breast Cancer Research Laboratory at the Fox Chase Cancer Center-Temple Health, 333 Cottman Avenue, Philadelphia, PA 19111, USA
- These authors contributed equally: Yanrong Su, Nhi M. Dang, and Herman Depypere
| | - Nhi M. Dang
- The Irma H Russo, MD, Breast Cancer Research Laboratory at the Fox Chase Cancer Center-Temple Health, 333 Cottman Avenue, Philadelphia, PA 19111, USA
- These authors contributed equally: Yanrong Su, Nhi M. Dang, and Herman Depypere
| | - Herman Depypere
- Department of Gynecology, Breast and Menopause clinic, University Hospital of Ghent, Corneel Heymanslaan 10, 9000 Ghent, Belgium
- These authors contributed equally: Yanrong Su, Nhi M. Dang, and Herman Depypere
| | - Julia Santucci-Pereira
- The Irma H Russo, MD, Breast Cancer Research Laboratory at the Fox Chase Cancer Center-Temple Health, 333 Cottman Avenue, Philadelphia, PA 19111, USA
| | | | - Joice Kanefsky
- The Irma H Russo, MD, Breast Cancer Research Laboratory at the Fox Chase Cancer Center-Temple Health, 333 Cottman Avenue, Philadelphia, PA 19111, USA
| | - Jaak Ph. Janssens
- European Cancer Prevention Organization, University of Hasselt, Klein Hilststraat 5, 3500 Hasselt, Belgium
| | - Jose Russo
- The Irma H Russo, MD, Breast Cancer Research Laboratory at the Fox Chase Cancer Center-Temple Health, 333 Cottman Avenue, Philadelphia, PA 19111, USA
- Dr. Russo conceived the study and supervised the work. Dr. Russo passed away on September 24, 2021
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Murrow LM, Weber RJ, Caruso JA, McGinnis CS, Phong K, Gascard P, Rabadam G, Borowsky AD, Desai TA, Thomson M, Tlsty T, Gartner ZJ. Mapping hormone-regulated cell-cell interaction networks in the human breast at single-cell resolution. Cell Syst 2022; 13:644-664.e8. [PMID: 35863345 PMCID: PMC9590200 DOI: 10.1016/j.cels.2022.06.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/02/2022] [Accepted: 06/22/2022] [Indexed: 01/26/2023]
Abstract
The rise and fall of estrogen and progesterone across menstrual cycles and during pregnancy regulates breast development and modifies cancer risk. How these hormones impact each cell type in the breast remains poorly understood because they act indirectly through paracrine networks. Using single-cell analysis of premenopausal breast tissue, we reveal a network of coordinated transcriptional programs representing the tissue-level response to changing hormone levels. Our computational approach, DECIPHER-seq, leverages person-to-person variability in breast composition and cell state to uncover programs that co-vary across individuals. We use differences in cell-type proportions to infer a subset of programs that arise from direct cell-cell interactions regulated by hormones. Further, we demonstrate that prior pregnancy and obesity modify hormone responsiveness through distinct mechanisms: obesity reduces the proportion of hormone-responsive cells, whereas pregnancy dampens the direct response of these cells to hormones. Together, these results provide a comprehensive map of the cycling human breast.
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Affiliation(s)
- Lyndsay M Murrow
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - Robert J Weber
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA; Medical Scientist Training Program (MSTP), University of California, San Francisco, San Francisco, CA 94518, USA; Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Joseph A Caruso
- Department of Pathology and Helen Diller Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Christopher S McGinnis
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Kiet Phong
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Philippe Gascard
- Department of Pathology and Helen Diller Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Gabrielle Rabadam
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Alexander D Borowsky
- Center for Immunology and Infectious Diseases, Department of Pathology and Laboratory Medicine, University of California, Davis, Davis, CA 95696, USA
| | - Tejal A Desai
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | | | - Thea Tlsty
- Department of Pathology and Helen Diller Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Zev J Gartner
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
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3
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Kumar R, Abreu C, Toi M, Saini S, Casimiro S, Arora A, Paul AM, Velaga R, Rameshwar P, Lipton A, Gupta S, Costa L. Oncobiology and treatment of breast cancer in young women. Cancer Metastasis Rev 2022; 41:749-770. [PMID: 35488982 DOI: 10.1007/s10555-022-10034-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 04/14/2022] [Indexed: 12/20/2022]
Abstract
Female breast cancer emerged as the leading cancer type in terms of incidence globally in 2020. Although mortality due to breast cancer has improved during the past three decades in many countries, this trend has reversed in women less than 40 years since the past decade. From the biological standpoint, there is consensus among experts regarding the clinically relevant definition of breast cancer in young women (BCYW), with an age cut-off of 40 years. The idea that breast cancer is an aging disease has apparently broken in the case of BCYW due to the young onset and an overall poor outcome of BCYW patients. In general, younger patients exhibit a worse prognosis than older pre- and postmenopausal patients due to the aggressive nature of cancer subtypes, a high percentage of cases with advanced stages at diagnosis, and a high risk of relapse and death in younger patients. Because of clinically and biologically unique features of BCYW, it is suspected to represent a distinct biologic entity. It is unclear why BCYW is more aggressive and has an inferior prognosis with factors that contribute to increased incidence. However, unique developmental features, adiposity and immune components of the mammary gland, hormonal interplay and crosstalk with growth factors, and a host of intrinsic and extrinsic risk factors and cellular regulatory interactions are considered to be the major contributing factors. In the present article, we discuss the status of BCYW oncobiology, therapeutic interventions and considerations, current limitations in fully understanding the basis and underlying cause(s) of BCYW, understudied areas of BCYW research, and postulated advances in the coming years for the field.
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Affiliation(s)
- Rakesh Kumar
- Cancer Research Institute, Himalayan Institute of Medical Sciences, Swami Rama Himalayan University, Dehradun, India. .,Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Trivandrum, India. .,Department of Medicine, Division of Hematology and Oncology, Rutgers New Jersey Medical School, Newark, NJ, USA. .,Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, VA, USA.
| | - Catarina Abreu
- Department of Medical Oncology, Hospital de Santa Maria- Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - Masakazu Toi
- Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Sunil Saini
- Cancer Research Institute, Himalayan Institute of Medical Sciences, Swami Rama Himalayan University, Dehradun, India
| | - Sandra Casimiro
- Instituto de Medicina Molecular-João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisbon, Portugal
| | - Anshika Arora
- Cancer Research Institute, Himalayan Institute of Medical Sciences, Swami Rama Himalayan University, Dehradun, India
| | - Aswathy Mary Paul
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Trivandrum, India
| | - Ravi Velaga
- Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Pranela Rameshwar
- Department of Medicine, Division of Hematology and Oncology, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Allan Lipton
- Hematology-Oncology, Department of Medicine, Penn State University School of Medicine, Hershey, PA, USA
| | - Sudeep Gupta
- Department of Medical Oncology, Tata Memorial Centre and Homi Bhabha National Institute, Mumbai, India
| | - Luis Costa
- Department of Medical Oncology, Hospital de Santa Maria- Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal.,Instituto de Medicina Molecular-João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisbon, Portugal
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Pitzer LM, Moroney MR, Nokoff NJ, Sikora MJ. WNT4 Balances Development vs Disease in Gynecologic Tissues and Women's Health. Endocrinology 2021; 162:6272210. [PMID: 33963381 PMCID: PMC8197283 DOI: 10.1210/endocr/bqab093] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Indexed: 12/15/2022]
Abstract
The WNT family of proteins is crucial in numerous developmental pathways and tissue homeostasis. WNT4, in particular, is uniquely implicated in the development of the female phenotype in the fetus, and in the maintenance of müllerian and reproductive tissues. WNT4 dysfunction or dysregulation can drive sex-reversal syndromes, highlighting the key role of WNT4 in sex determination. WNT4 is also critical in gynecologic pathologies later in life, including several cancers, uterine fibroids, endometriosis, and infertility. The role of WNT4 in normal decidualization, implantation, and gestation is being increasingly appreciated, while aberrant activation of WNT4 signaling is being linked both to gynecologic and breast cancers. Notably, single-nucleotide polymorphisms (SNPs) at the WNT4 gene locus are strongly associated with these pathologies and may functionally link estrogen and estrogen receptor signaling to upregulation and activation of WNT4 signaling. Importantly, in each of these developmental and disease states, WNT4 gene expression and downstream WNT4 signaling are regulated and executed by myriad tissue-specific pathways. Here, we review the roles of WNT4 in women's health with a focus on sex development, and gynecologic and breast pathologies, and our understanding of how WNT4 signaling is controlled in these contexts. Defining WNT4 functions provides a unique opportunity to link sex-specific signaling pathways to women's health and disease.
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Affiliation(s)
- Lauren M Pitzer
- Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Marisa R Moroney
- Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Natalie J Nokoff
- Department of Pediatrics, Section of Endocrinology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Matthew J Sikora
- Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- Correspondence: Matthew J. Sikora, PhD; Department of Pathology, University of Colorado Anschutz Medical Campus, Mail Stop 8104, Research Complex 1 South, Rm 5117, 12801 E 17th Ave, Aurora, CO 80045, USA. . Twitter: @mjsikora
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Boonyaratanakornkit V, McGowan EM, Márquez-Garbán DC, Burton LP, Hamilton N, Pateetin P, Pietras RJ. Progesterone Receptor Signaling in the Breast Tumor Microenvironment. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1329:443-474. [PMID: 34664251 DOI: 10.1007/978-3-030-73119-9_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The tumor microenvironment (TME) is a complex infrastructure composed of stromal, epithelial, and immune cells embedded in a vasculature ECM. The microenvironment surrounding mammary epithelium plays a critical role during the development and differentiation of the mammary gland, enabling the coordination of the complex multihormones and growth factor signaling processes. Progesterone/progesterone receptor paracrine signaling interactions in the microenvironment play vital roles in stem/progenitor cell function during normal breast development. In breast cancer, the female sex hormones, estrogen and progesterone, and growth factor signals are altered in the TME. Progesterone signaling modulates not only breast tumors but also the breast TME, leading to the activation of a series of cross-communications that are implicated in the genesis of breast cancers. This chapter reviews the evidence that progesterone and PR signaling modulates not only breast epitheliums but also the breast TME. Furthermore, crosstalk between estrogen and progesterone signaling affecting different cell types within the TME is discussed. A better understanding of how PR and progesterone affect the TME of breast cancer may lead to novel drugs or a therapeutic approach for the treatment of breast cancer shortly.
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Affiliation(s)
- Viroj Boonyaratanakornkit
- Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand.
- Age-Related Inflammation and Degeneration Research Unit, Chulalongkorn University, Bangkok, Thailand.
- Graduate Program in Clinical Biochemistry and Molecular Medicine, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand.
| | - Eileen M McGowan
- School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
- Central Laboratory, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, China
| | - Diana C Márquez-Garbán
- UCLA Jonsson Comprehensive Cancer Center and Department of Medicine, Division of Hematology-Oncology, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
| | - L P Burton
- UCLA Jonsson Comprehensive Cancer Center and Department of Medicine, Division of Hematology-Oncology, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
| | - Nalo Hamilton
- UCLA Jonsson Comprehensive Cancer Center and Department of Medicine, Division of Hematology-Oncology, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
| | - Prangwan Pateetin
- Graduate Program in Clinical Biochemistry and Molecular Medicine, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Richard J Pietras
- UCLA Jonsson Comprehensive Cancer Center and Department of Medicine, Division of Hematology-Oncology, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
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6
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Slepicka PF, Cyrill SL, Dos Santos CO. Pregnancy and Breast Cancer: Pathways to Understand Risk and Prevention. Trends Mol Med 2019; 25:866-881. [PMID: 31383623 DOI: 10.1016/j.molmed.2019.06.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 06/10/2019] [Accepted: 06/17/2019] [Indexed: 12/14/2022]
Abstract
Several studies have made strong efforts to understand how age and parity modulate the risk of breast cancer. A holistic understanding of the dynamic regulation of the morphological, cellular, and molecular milieu of the mammary gland offers insights into the drivers of breast cancer development as well as into potential prophylactic interventions, the latter being a longstanding ambition of the research and clinical community aspiring to eradicate the disease. In this review we discuss mechanisms that react to pregnancy signals, and we delineate the nuances of pregnancy-associated dynamism that contribute towards either breast cancer development or prevention. Further definition of the molecular basis of parity and breast cancer risk may allow the elaboration of tools to predict and survey those who are at risk of breast cancer development.
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Affiliation(s)
- Priscila F Slepicka
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA
| | - Samantha L Cyrill
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA
| | - Camila O Dos Santos
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.
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7
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Dall GV, Hawthorne S, Seyed-Razavi Y, Vieusseux J, Wu W, Gustafsson JA, Byrne D, Murphy L, Risbridger GP, Britt KL. Estrogen receptor subtypes dictate the proliferative nature of the mammary gland. J Endocrinol 2018; 237:323-336. [PMID: 29636363 DOI: 10.1530/joe-17-0582] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 04/10/2018] [Indexed: 12/20/2022]
Abstract
Estrogen induces proliferation of breast epithelial cells and is responsible for breast development at puberty. This tightly regulated control is lost in estrogen-receptor-positive (ER+) breast cancers, which comprise over 70% of all breast cancers. Currently, breast cancer diagnosis and treatment considers only the α isoform of ER; however, there is a second ER, ERβ. Whilst ERα mediates estrogen-driven proliferation of the normal breast in puberty and breast cancers, ERβ has been shown to exert an anti-proliferative effect on the normal breast. It is not known how the expression of each ER (alone or in combination) correlates with the ability of estrogen to induce proliferation in the breast. We assessed the levels of each ER in normal mouse mammary glands subdivided into proliferative and non-proliferative regions. ERα was most abundant in the proliferative regions of younger mice, with ERβ expressed most abundantly in old mice. We correlated this expression profile with function by showing that the ability of estrogen to induce proliferation was reduced in older mice. To show that the ER profile associated with breast cancer risk, we assessed ER expression in parous mice which are known to have a reduced risk of developing ERα breast cancer. ERα expression was significantly decreased yet co-localization analysis revealed ERβ expression increased with parity. Parous mice had less unopposed nuclear ERα expression and increased levels of ERβ. These changes suggest that the nuclear expression of ERs dictates the proliferative nature of the breast and may explain the decreased breast cancer risk with parity.
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Affiliation(s)
| | - Samuel Hawthorne
- Department of Anatomy and Developmental BiologyMonash University, Melbourne, Australia
| | - Yashar Seyed-Razavi
- Department of Anatomy and Developmental BiologyMonash University, Melbourne, Australia
| | | | - Wanfu Wu
- Department of Biology and BiochemistryUniversity of Houston, Houston, Texas, USA
| | - Jan-Ake Gustafsson
- Department of Biology and BiochemistryUniversity of Houston, Houston, Texas, USA
| | - David Byrne
- Department of PathologyPeter MacCallum Cancer Centre, Melbourne, Australia
| | | | - Gail P Risbridger
- Peter MacCallum Cancer CentreMelbourne, Australia
- Department of Anatomy and Developmental BiologyMonash University, Melbourne, Australia
| | - Kara L Britt
- Peter MacCallum Cancer CentreMelbourne, Australia
- The Sir Peter MacCallumDepartment of Oncology, University of Melbourne, Melbourne, Australia
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8
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Cohn BA, Cirillo PM, Hopper BR, Siiteri PK. Third Trimester Estrogens and Maternal Breast Cancer: Prospective Evidence. J Clin Endocrinol Metab 2017; 102:3739-3748. [PMID: 28973345 PMCID: PMC5630249 DOI: 10.1210/jc.2016-3476] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 07/25/2017] [Indexed: 01/07/2023]
Abstract
Context Full-term pregnancy is associated with a transient increase and life-time decrease in maternal breast cancer risk. Estrone (E1), estradiol (E2), and estriol (E3) are in high concentration during the third trimester. E1 and E2 metabolism produces carcinogenic intermediaries, and E3 metabolism does not. Objective We tested the hypothesis that higher E3 in pregnancy is protective while higher E1 plus E2 increases risk. Design Prospective case-cohort study (n = 620; 204 cases) nested in a 38-year follow-up of 15,528 pregnant women in the Child Health and Development Studies. We measured E1, E2, and E3 in archived third trimester serum and estimated associations with breast cancer. Setting Northern California Kaiser members receiving obstetric care from 1959 to 1967. Main Outcome Measure Breast cancer diagnosed through 1997. Results Doubling of E1+E2 was associated with greater risk [hazard ratio (HR), 1.7; 95% confidence interval (CI), 1.2 to 2.4]. In contrast, doubling of E3 or the E3/E1+E2 ratio was associated with protection (HR, 0.7; 95% CI, 0.5 to 1.0; HR, 0.6; 95% CI, 0.4 to 0.8, respectively). Associations were stronger for diagnoses within 15 years after delivery compared with 16 to 38 years (Pinteraction = 0.0002) for gravidas >27 years at delivery vs ≤27 (Pinteraction = 0.01) and for primiparas vs multiparas (Pinteraction = 0.02). Conclusions Relatively high third trimester E3 levels might protect parous women from breast cancer and E1 and E2 might enhance the risk. If findings are confirmed, third trimester pregnancy estrogens could help explain how parity affects breast cancer.
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Affiliation(s)
- Barbara A. Cohn
- Child Health and Development Studies, Public Health Institute, Berkeley, California 94709
| | - Piera M. Cirillo
- Child Health and Development Studies, Public Health Institute, Berkeley, California 94709
| | - Bill R. Hopper
- Child Health and Development Studies, Public Health Institute, Berkeley, California 94709
| | - Pentti K. Siiteri
- Child Health and Development Studies, Public Health Institute, Berkeley, California 94709
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