Ovarian Cancer risk factors:
Several epidemiologic studies have suggested that exposure to endogenous and exogenous hormones play an important role in ovarian cancer etiology.
Some risk factors are reportedly associated with specific histotypes of ovarian cancer. It is also well established that endometriosis is risk factor for clear cell and endometrioid ovarian cancer, but not for high-grade serous or mucinous histotypes.
Menopausal hormone therapy (particularly estrogen only therapy) appears to be more associated increased risks of serous and endometrioid ovarian cancers compared to other subtypes. Several studies have indicated an approximate 20% increases of ovarian cancer risk per 5 years of postmenopausal estrogen use.
Tubal ligation is another well-established risk factor which is inversely associated with ovarian cancer risk.
Younger age at menarche, breastfeeding and hysterectomy are associated with a reduction in ovarian cancer risk
Oral contraceptive use is associated with reduced risk for the serous and endometrioid subtypes, but is only weakly associate with reduced risks of mucinous and clear cell ovarian cancers. Oral contraceptives decrease risk with increase duration of use.
Breastfeeding both at a younger age and over multiple offspring has been found to reduce the risk of ovarian cancer
Pregnancy and Parity are both protective, with decreased risk associated with increased parity.
OTHER DECREASED RISK FACTORS
Young age of menarche and hystorectomy
Obesity may be weakly associated with an increased risk of low-grade serous invasive tumors but not invasive high-grade serous disease; and high body mass index may be associated with increased risk of borderline serous, invasive endometrioid, and invasive mucinous ovarian cancers. A BMI greater than 30 not only increases risk, but also negatively affects survival outcome.
As one ages, the risk increases of developing ovarian cancer. Women who are post-menopausal are most at risk, with half of all cases of the cancer occurring after the age of 60. Hormone therapies during this time are also associated with increase risk as compared to women who have never had hormone replacement therapy.
There is an association between smoking and mucinous ovarian cancer, an inverse association for risks of endometrioid and clear cell ovarian cancers, and no association with high-grade and borderline serous histotypes.
BRCA1 and BRCA2 gene mutations are responsible for most inherited ovarian cancers, with a cancer risk between 35% and 70% in BRCA1 patients and between 10% and 30% in BRCA2. In comparison, the general population OC risk without these mutations is less than 2%. Other genes associated with hereditary OC include BRIP1, RAD51C, PALB2, and ATM.
Family history of disease must also be considered when assessing risk. Ovarian cancer risk increases the more relatives you have diagnosed with the disease. Colorectal and breast cancer in close family members can also be associated with increased risk.
OTHER INCREASED RISK FACTORS
Endometreosis& Hormone Therapy