Possible role of ovarian epithelial inflammation in ovarian cancer

Our plain-English summary of Possible role of ovarian epithelial inflammation in ovarian cancer, by R.B. Ness, C. Cottreau (Journal of the National Cancer Institute, 1999).

The study

• Authors: R.B. Ness, C. Cottreau
• Journal: Journal of the National Cancer Institute
• Published: 1999;91(17):1459-67
• Type of article: Review
• Cited by: 440 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Ovarian cancer is a commonly fatal disease for which prevention strategies have been limited, in part because of a lack of understanding of the underlying biology. This paper reviews the epidemiologic literature in the English language on risk factors and protective factors for ovarian cancer and proposes a novel hypothesis that a common mechanism underlying this disease is inflammation. Previous hypotheses about the causes of ovarian cancer have attributed risk to an excess number of lifetime ovulations or to elevations in steroid hormones. Inflammation may underlie ovulatory events because an inflammatory reaction is induced during the process of ovulation. Additional risk factors for ovarian cancer, including asbestos and talc exposure, endometriosis (i.e., ectopic implantation of uterine lining tissue), and pelvic inflammatory disease, cannot be directly linked to ovulation or to hormones but do cause local pelvic inflammation. On the other hand, tubal ligation and hysterectomy act as protective factors, perhaps by diminishing the likelihood that the ovarian epithelium will be exposed to environmental initiators of inflammation. Inflammation entails cell damage, oxidative stress, and elevations of cytokines and prostaglandins, all of which may be mutagenic. The possibility that inflammation is a pathophysiologic contributor to the development of ovarian cancer suggests a directed approach to future research

In plain English

This article was a review, not a new study. The authors searched English-language literature through MEDLINE and article bibliographies on risk and protective factors for epithelial ovarian cancer. They proposed that inflammation may be a common underlying mechanism, working alongside ovulation and hormones. On asbestos, they reported that female asbestos workers were recognized in the early 1960s as having an increased risk of ovarian cancer. Later retrospective cohort studies of women in industries with heavy asbestos exposure found about a twofold excess of ovarian cancers, with a dose-response relationship suggested. They cited a study that found asbestos in ovarian tissue twice as often in women with household exposure as in women without it. Results in animals were mixed. For talc dusted on the perineum, eight of at least 12 studies reported elevated risk (odds ratios 1.3 to 3.9). The authors noted that talc was commonly contaminated with asbestos before 1976. Other studies they reviewed linked endometriosis and pelvic inflammatory disease to higher risk, and tubal ligation and hysterectomy to lower risk. The authors concluded that further observational and experimental data were needed to confirm the hypothesis.

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: Review of published epidemiologic literature, proposing a hypothesis (inflammation as a mechanism for ovarian cancer); no new data collected
• Who was studied: Published English-language studies on epithelial ovarian cancer, found through MEDLINE and the bibliographies of the articles retrieved; only epithelial ovarian cancers were discussed
• Exposure: Factors reviewed included parity, oral contraceptives, breast-feeding, hormone replacement therapy, infertility, asbestos and talc exposure, endometriosis, pelvic inflammatory disease, hysterectomy, tubal ligation and anti-inflammatory medications; no asbestos fiber types were specified in the text
• Main results:
  • Reviewed literature: female asbestos workers were recognized in the early 1960s as having an increased risk of ovarian cancer and other intra-abdominal neoplasms
  • Reviewed literature: retrospective cohort studies of women employed in industries with possible heavy asbestos exposure found about a twofold excess of ovarian cancers over what was expected, with a dose-response relationship suggested
  • Reviewed literature (Heller et al.): asbestos was found in ovarian tissue twice as often in women with household exposure (fathers or husbands in high-asbestos occupations) as in women without such exposure
  • Reviewed animal studies: after intraperitoneal injection of asbestos into guinea pigs and rabbits, changes in the ovarian epithelium similar to early ovarian cancer were found in 20% of exposed and 0% of unexposed animals; asbestos had no effect on the ovaries of mice and hamsters in vivo
  • Reviewed literature on talc: of at least 12 studies, eight reported elevated ovarian cancer risk among women who dusted powder on the perineum, with odds ratios from 1.3 to 3.9; one study found no association
  • Reviewed literature (Brinton et al., Sweden): among women hospitalized with endometriosis, ovarian cancer risk was elevated 2.5-fold for those followed 10 or more years
  • Reviewed literature (Risch and Howe, Toronto, 450 cases and 565 controls): women who had had an episode of pelvic inflammatory disease had increased ovarian cancer risk (OR 1.5; 95% CI 1.1 to 2.1)
  • Reviewed literature: odds ratios ranged from 0.03 to 0.8 for hysterectomy without oophorectomy and from 0.2 to 0.9 for tubal ligation
• The authors' conclusion: The authors proposed that inflammation may work together with, and in addition to, ovulation and steroid hormones in ovarian cancer risk. They concluded that further observational and experimental data will be needed to confirm the hypothesis.
• Limitations the authors state:
  • Differences between histologic types of ovarian tumors were not addressed
  • Early studies relating talc to ovarian cancer may have been confounded by asbestos contamination of talc
  • The talc link is limited by a lack of supporting animal data and inconsistent detection of talc in the ovarian tissue of heavy users
  • Animal evidence for asbestos was inconsistent: no effect on the ovaries of mice and hamsters in vivo

Topics

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

Medical terms in this study, explained in our Lexicon: Inflammation, Ovarian Cancer, Talc, Epithelium, Oxidative Stress, Cytokine.

Related studies

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• Perineal talc exposure and epithelial ovarian cancer risk in the Central Valley of California — P.K. Mills, D.G. Riordan, et al. (2004)
• Association of malignant mesothelioma and asbestos related conditions with ovarian cancer: shared biomarkers and a possible etiological link? — A.J. Rai, R.M. Flores (2011)
• Airway epithelial NF-kappaB activation modulates asbestos-induced inflammation and mucin production in vivo — A. Haegens, T.F. Barrett, et al. (2007)
• Epidemiology, etiology, and fertility drugs in ovarian epithelial carcinoma: where are we today? — Z. Shoham (1994)
• Human ovarian tumors of epithelial origin express PDGF in vitro and in vivo — M.A. Versnel, M. Haarbrink, et al. (1994)

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