Infertility as a Cancer Risk Factor – A Review

Abstract

Ovarian, endometrial and breast cancers are associated with several risk factors, such as low parity, infertility, early age at menarche, and late age at menopause. Frequently most of these risk factors coexist in infertile patients and some studies suggested that the different infertility causes can be involved in cancer risk development. In particular case-control and cohort studies investigated the possible role of ovulatory disorders, endometriosis and unexplained infertility in increasing the risk of this disease. Most studies have shown no overall increased risk in invasive ovarian cancer in subfertile patients, although nulliparity has been consistently associated with increased rates of ovarian tumor, in particular with borderline and endometrioid cancers in patients with a history of endometriosis. Different studies reported that infertile women are not at risk for breast cancer. However, women affected by infertility may be more at risk for endometrial cancer, particularly if affected by ovulatory disorders. Moreover, infertility is now often treated with medical devices that could by themselves modify the hormonal environment and be cofactors in the cellular changes towards cancer development. However, although early studies suggested that infertility medications were associated to increased risk in ovarian cancer, subsequent studies have been mainly reassuring, although suggesting that type and duration of medical treatment can increase the malignancy risk. An increased risk of endometrial cancer in patients undergoing infertility treatment has been reported, as expected by the similar structure shared by clomiphene and tamoxiphene. Since breast cancer is widely recognized as having a hormonal etiology, a possible role of fertility medications to promote cancer has been hypothesized. However, many large studies were not able to find an associated risk of breast cancer. In conclusion, nowadays, firm answers about the precise effects of infertility and its treatment on cancer risk are not available but findings are generally reassuring. Further studies about fertility drug treatments on larger populations may offer in the future longer follow-up and more precise data with better adjustments for confounding factors.

Assessment of Thyroid Functions Test among Hyperprolactinemic Sudanese Infertile Females

“…Extremes of weight can influence fertility by affecting ovulatory function [43]. Studies from western countries suggest that intricate and complex hormonal balance of the hypothalamo-pituitary-gonadal axis is affected by an individual's BMI [44].…”

Brain tumors and hormonal factors: review of the epidemiological literature

“…Cumulative exposure scores by type of hormone might be calculated from the combination of dosage and duration of use and used to search for a dose-effect relationship. Other hormonal treatments like those for infertility [78] or for other reasons (gynaecologic or not) should be analyzed. The role of menopause should be examined by taking into account HRT use.…”

Association of Obesity with Hormonal Imbalance in Infertility: A Cross-Sectional Study in North Indian Women

“…Extremes of weight can influence fertility by affecting ovulatory function [3]. Studies from western countries suggest that intricate and complex hormonal balance of the hypothalamo-pituitarygonadal axis is affected by an individual's BMI [4].…”