Chemoprevention of spontaneous ovarian cancer in the domestic hen

Ovulation induction drug and ovarian cancer: an updated systematic review and meta-analysis

OBJECTIVE

To explore the association between ovulation induction drugs and ovarian cancer.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Women without ovarian cancer who ever or never underwent ovarian induction.

INTERVENTION(S)

An extensive electronic search of the following databases was performed: PubMed, EMBASE, MEDLINE, Google Scholar, Cochrane Library and CNKI, from inception until January 2022. A total of 34 studies fulfilled our inclusion criteria and were included in the final meta-analysis. The odds ratio (OR) and random-effects model were used to estimate the pooled effects. The Newcastle-Ottawa Scale was used to assess the quality of included studies. Funnel plots and Egger tests were used to assess publication bias.

MAIN OUTCOMES

New diagnosed borderline ovarian tumor (BOT) and invasive ovarian cancer (IOC) between ovulation induction (OI) group and control (CT) group considering fertility outcome, OI cycles and specific OI drugs.

RESULTS

Primarily, there was no significant difference in the incidence of IOC and BOT between the OI and CT groups. Secondly, OI treatment did not increase the risk of IOC and BOT in the multiparous women, nor did it increase the risk of IOC in the nulliparous women. However, the risk of BOT appeared to be higher in nulliparous women treated with OI treatment. Thirdly, among women exposed to OI, the risk of IOC and BOT was higher in nulliparous women than in multiparous women. Fourthly, the risk of IOC did not increase with increasing OI cycles. Lastly, exposure to specific OI drugs also did not contribute to the risk of IOC and BOT.

CONCLUSION

Overall, OI treatment did not increase the risk of IOC and BOT in most women, regardless of OI drug type and OI cycle. However, nulliparous women treated with OI showed a higher risk of ovarian cancer, necessitating their rigorous monitoring and ongoing follow-up.

A Review of Principal Studies on the Development and Treatment of Epithelial Ovarian Cancer in the Laying Hen Gallus gallus

Often referred to as the silent killer, ovarian cancer is the most lethal gynecologic malignancy. This disease rarely shows any physical symptoms until late stages and no known biomarkers are available for early detection. Because ovarian cancer is rarely detected early, the physiology behind the initiation, progression, treatment, and prevention of this disease remains largely unclear. Over the past 2 decades, the laying hen has emerged as a model that naturally develops epithelial ovarian cancer that is both pathologically and histologically similar to that of the human form of the disease. Different molecular signatures found in human ovarian cancer have also been identified in chicken ovarian cancer including increased CA125 and elevated E-cadherin expression, among others. Chemoprevention studies conducted in this model have shown that decreased ovulation and inflammation are associated with decreased incidence of ovarian cancer development. The purpose of this article is to review the major studies performed in laying hen model of ovarian cancer and discuss how these studies shape our current understanding of the pathophysiology, prevention, and treatment of epithelial ovarian cancer.

Genistein Prevents Development of Spontaneous Ovarian Cancer and Inhibits Tumor Growth in Hen Model

Genistein, the major isoflavone in soybean, has been reported to exert anticancer effects on various types of cancer including ovarian cancer; however, its chemopreventive effects and mechanisms of action in ovarian cancer have not been fully elucidated in spontaneously developing ovarian cancer models. In this study, we demonstrated the preventive effects and mechanisms of genistein in the laying hen model that develops spontaneous ovarian cancer at high incidence rates. Laying hens were randomized to three groups: control (3.01 mg/hen, n = 100), low (52.48 mg/hen n = 100), and high genistein supplementation (106.26 mg/hen/day; per group). At the end of 78 weeks, hens were euthanized and ovarian tumors were collected and analyzed. We observed that genistein supplementation significantly reduced the ovarian tumor incidence (P = 0.002), as well as the number and size of the tumors (P = 0.0001). Molecular analysis of the ovarian tumors revealed that genistein downregulated serum malondialdehyde, a marker for oxidative stress and the expression of NFκB and Bcl-2, whereas it upregulated Nrf2, HO-1, and Bax expression at protein level in ovarian tissues. Moreover, genistein intake decreased the activity of mTOR pathway as evidenced by reduced phosphorylation of mTOR, p70S6K1, and 4E-BP1. Taken together, our findings strongly support the potential of genistein in the chemoprevention of ovarian cancer and highlight the effects of the genistein on the molecular pathways involved in ovarian tumorigenesis.