What This Article Covers
This article explains the main reasons and risk factors for ovarian cancer, including how age, genetics, reproductive history, and lifestyle factors can influence risk. It clarifies what is known with confidence and where evidence is evolving. No single cause explains most cases, but patterns help clinicians and individuals understand likelihood and guide screening and prevention decisions.
Age and Cellular Changes
How Aging Affects Risk
Ovarian cancer is more common with increasing age, with the majority of cases occurring after menopause. The lifetime risk for a person assigned female at birth is about 1 in 78, and most diagnoses are in people over age 55. Aging leads to more cell divisions and accumulated DNA changes over time, which can contribute to the development of cancer. While younger people can develop ovarian cancer, the overall incidence rises steadily from the mid 40s onward.
Genetics and Family History
Inherited Mutations and Clustering
Certain inherited gene mutations substantially raise ovarian cancer risk. The most established are mutations in BRCA1 and BRCA2, which can also increase breast cancer risk. Lynch syndrome, which involves DNA mismatch repair genes, is another hereditary condition linked to higher risk. Family history of ovarian or breast cancer, even without a known mutation, can indicate a moderately elevated risk. Genetic counseling and testing are recommended when a family pattern suggests hereditary cancer.
Hormonal and Reproductive Factors
Menstrual and Pregnancy History
Reproductive events influence risk because they affect lifetime ovulation. More ovulations appear to increase risk, while protective factors reduce it. Examples and approximate relative risk include:
| Factor | Observed Risk Pattern | Context or Source Type |
|---|---|---|
| Early menarche (before age 12) | Slightly increased risk | Observational studies |
| Late menopause (after about age 52) | Slightly increased risk | Observational studies |
| Never giving birth | Higher risk versus having given birth | Observational data |
| Use of combined hormonal contraceptives | Reduced risk, especially with longer use | Large cohort studies and meta-analyses |
| Breastfeeding | Slightly reduced risk | Observational studies |
These factors are not deterministic but help reflect the balance between ovulation number and protective exposures.
Lifestyle and Environmental Influences
Smoking, Weight, and Talc
Smoking is linked to a higher risk of certain ovarian cancer types, such as mucinous tumors. Obesity in midlife has also been associated with increased risk, possibly through hormonal pathways. Perineal talc use has been investigated, with some studies suggesting a small elevated risk, though findings are inconsistent. Overall, avoiding tobacco, maintaining a healthy weight, and discussing personal product choices with a clinician can modestly influence risk.
Risk Reducers and Protective Factors
Medications and Procedures
Using combined oral contraceptives for several years can substantially lower lifetime ovarian cancer risk, with protection lasting many years after stopping. Tubal ligation and hysterectomy (with ovaries preserved) are also associated with reduced risk. For selected individuals with very high genetic risk, risk-reducing strategies such as prophylactic surgery or intensive surveillance may be considered under specialist guidance.
Summary and Practical Takeaways
Ovarian cancer arises from a mix of age related cellular changes, genetic vulnerabilities, reproductive history, and modifiable lifestyle factors. Because there is no single cause, focusing on known risk patterns is more useful than any one factor. If you are concerned about your personal risk due to family history, symptoms, or reproductive plans, discuss screening, prevention options, and timely testing with your healthcare provider.