Ovarian surface epithelium as a source of ovarian cancers: unwarranted speculation or evidence-based hypothesis?

Our plain-English summary of Ovarian surface epithelium as a source of ovarian cancers: unwarranted speculation or evidence-based hypothesis?, by N. Auersperg (Gynecologic Oncology, 2013).

The study

• Author: N. Auersperg
• Journal: Gynecologic Oncology
• Published: 2013;130(1):246-51
• Type of article: Review
• Cited by: 95 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objectives: There has been increasing evidence that high grade serous ovarian carcinomas (HGSOCs), the most common and most lethal of all ovarian cancers, originate in oviductal fimbriae and metastasize to the ovary. The alternate hypothesis, that ovarian carcinomas may originate within the ovarian stroma in inclusion cysts lined by ovarian surface epithelium (OSE), has been criticized and often dismissed on the basis of the OSE's embryonic origin, mesothelial phenotype, tissue-specific markers, questionable ability to undergo metaplasia, and the lack of identifiable precursor lesions. This review analyzes these criticisms and summarizes evidence indicating that OSE as a source of ovarian cancers cannot be ruled out.

Methods: The literature was reviewed and representative reports were chosen to evaluate the current criticisms of, and evidence in favor of, the OSE hypothesis.

Results: The close developmental relationship between the oviduct and OSE, both of which originate in the mesothelial coelomic epithelium, accounts for their capacity to produce similar tumors. Histopathologic and experimental data show that OSE does undergo serous metaplasia, and that transformation of pure OSE cultures produces aggressive neoplasms resembling high- and low-grade serous carcinomas, but never mesotheliomas. There is evidence of premalignant changes (e.g. p53 inactivation) in morphologically normal OSE and of rare but definitive dysplastic and early preinvasive lesions in OSE-lined inclusion cysts. Conclusions based on tissue-specific markers to identify origins of inclusion cysts usually disregard the changes in differentiation occurring when OSE is displaced to the stroma. Lastly, an explanation is offered for the rare detection of precursor lesions in OSE-lined cysts, based on the likelihood that the duration from initiation of malignant transformation to invasive growth is minimal and thus difficult to detect.

Conclusion: The likelihood that HGSOCs originate both in fimbriae and in OSE should be considered in clinical decisions involving choices between prophylactic salpingo-oophorectomies and salpingectomies.

Copyright © 2013 Elsevier Inc. All rights reserved.

In plain English

This article was a review by a single author, published in 2013, about where high grade serous ovarian carcinomas, the most common type of ovarian cancer, begin. It did not study asbestos or any other exposure, and it reported no new patient data. The author reviewed selected published reports. Other researchers had proposed that these cancers start in the fimbriae at the end of the fallopian tube and spread to the ovary. The author argued that the ovarian surface epithelium, the mesothelial lining that covers the ovary and lines small cysts inside it, could also be a source. The review pointed to the shared embryonic origin of the two tissues and to published evidence that this lining can change into tube-like cells. It also cited experiments in which pure ovarian surface epithelium was transformed into tumors resembling serous carcinomas, but never into mesotheliomas. The author acknowledged that very early tumors arising in the ovary have been seen only very rarely, and offered an explanation for this. The author concluded that this possible origin should be kept in mind in decisions about preventive surgery for women at high risk of ovarian cancer.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Narrative review of the literature by a single author
• Who was studied: No study population. The author reviewed selected published reports, including human tissue studies, mouse and hen models, and cultures of human ovarian surface epithelium.
• Main results:
  • The review cited published experiments in which pure ovarian surface epithelium was transformed into serous carcinomas.
  • In the experimental studies the review cited, transformation of ovarian surface epithelium produced carcinomas but never mesotheliomas.
  • The author argued that cysts showing gradual transitions from flat surface cells to tube-like cells rule out the idea that the tube-like cells are implants from the fimbriae.
  • The author argued that the markers calretinin and PAX8 do not reliably show whether a cyst came from the ovarian surface epithelium or from the fimbriae.
• The authors' conclusion: The author concluded that the evidence for a fallopian tube origin does not rule out ovarian surface epithelium as an additional, and likely significant, source of these cancers. The author said this should be kept in mind in decisions about prophylactic surgery for women at high risk.
• Limitations the authors state:
  • The author acknowledged that very early stage high grade serous carcinomas arising in the ovary have been observed only very rarely, and called this perhaps the most convincing argument against the hypothesis.
  • The author stated that only some examples of the reported precursor changes were cited.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Ovarian cancer.

Medical terms in this study, explained in our Lexicon: Epithelium, Ovarian Cancer, Carcinoma, Metastasis, Neoplasm, Mesothelioma, Malignant Transformation.

Related studies

• Pre-diagnostic serum levels of inflammation markers and risk of ovarian cancer in the prostate, lung, colorectal and ovarian cancer (PLCO) screening trial — B. Trabert, L. Pinto, et al. (2014)
• p16/CDKN2A FISH in Differentiation of Diffuse Malignant Peritoneal Mesothelioma From Mesothelial Hyperplasia and Epithelial Ovarian Cancer — T. Ito, M. Hamasaki, et al. (2015)
• WT1 expression in the female genital tract — C. Bárcena, E. Oliva (2011)
• Peritonectomy and hyperthermic intraperitoneal chemotherapy: cost analysis and sustainability — P.F. Bagnoli, F.C. Cananzi, et al. (2015)
• Asbestos and ovarian cancer: examining the historical evidence — B. Slomovitz, C. de Haydu, et al. (2021)
• Novel mesothelin antibody-drug conjugates: current evidence and future role in the treatment of ovarian cancer — D. Mauricio, J. Harold, et al. (2021)

Browse more research in Gynecologic Oncology, or return to medical research.