Endometrial Cancer: Overview and Risk Factors

The inner lining of the uterus is known as the endometrium. Cancer of the endometrium makes up about 90 percent of uterine cancers. It is the most common gynecologic cancer in the United States, accounting for approximately 40,000 cases annually.

The most common symptom is abnormal vaginal bleeding. In fact, vaginal bleeding in any postmenopausal woman should be considered to be due to endometrial cancer until proven otherwise. Other symptoms include abdominal pain, pain during urination, and pain during intercourse.

Although there is no known cause for this disease, many cases are associated with excess levels of estrogen.

The five–year survival rate for endometrial cancer is high, particularly with early detection and treatment.

Risk Factors

Although endometrial cancer is more common in Caucasians, African–Americans often have worse outcomes with the disease.

The following factors are also associated with risk: 

• Obesity: The majority of people diagnosed with endometrial cancer at a young age are obese, and some studies have found that being overweight and having low levels of physical activity were strong risk factors for endometrial cancer. The relationship between obesity and cancer may be explained by increased estrogen levels in obese persons.
  
• Age: Endometrial cancer risk increases with age. It most commonly affects women over 50 years old.
  
• Estrogen Replacement Therapy: Estrogen therapy in menopausal women increases the risk for endometrial cancer. However, the combined use of estrogen and progestin is not associated with an increased risk.
  
• Diabetes
  
• Hypertension
  
• Polycystic ovary syndrome
  
• Prolonged exposure to estrogen: Early onset of menstrual periods, late onset of menopause, and an absence of pregnancies all result in increased estrogen exposure over the course of adult life. This may increase the risk for endometrial cancer.
  
• Estrogen–secreting tumors or history of an estrogen–responsive cancer (e.g., breast cancer) increase the risk.
  

Use of birth control pills, multiparity (multiple pregnancies), and exercise are considered protective.