Factors that increase risk

• Hormone factors. Things that shift the balance of hormones toward more estrogen increases a woman's risk for developing gynecologic cancers.
• Total number of menstrual cycles. Having more menstrual cycles during a woman's lifetime raises her risk of gynecologic cancers. Starting menstrual periods before age 12 and/or going through menopause later in life increases the risk.
• Obesity. Having more fat tissue can increase a woman's estrogen levels, which increases her gynecologic cancer risk. Gynecologic cancers are twice as common in overweight women, and more than three times as common in obese women.
• Tamoxifen. Tamoxifen, a drug that is used to prevent and treat breast cancer, acts as an anti-estrogen in breast tissue, but it acts like an estrogen in the uterus. In women who have gone through menopause, it can cause the uterine lining to grow, which increases the risk of endometrial cancer. But, the risk of developing gynecologic cancers from tamoxifen is very low, less than 1 percent per year.
• Ovarian tumors
• Polycystic ovarian syndrome
• Age. The risk of gynecologic cancers increases as a woman gets older.
• A high-fat diet
• Diabetes
• Prior breast or ovarian cancer diagnosis
• Prior endometrial hyperplasia diagnosis
• Prior pelvic radiation therapy

Factors that decrease risk

• Birth control pills. Using birth control pills (oral contraceptives) lowers the risk of endometrial cancer. The risk is lowest in women who take the pill for a long time, and this protection continues for at least 10 years after a woman stops taking this form of birth control.
• Multiple pregnancies
• Use of an intrauterine device (IUD). Women who used an intrauterine device (IUD) for birth control seem to have a lower risk of getting endometrial cancer, but information about this protective effect is limited to IUDs that do not contain hormones, and research on newer IUDs is limited.

Inherited gynecologic cancer clues

Hereditary nonpolyposis colon cancer (HNPCC), also called Lynch syndrome, is a genetic cancer syndrome that results in a high risk of gynecologic cancers.