An increasing number of scientific articles are coming out showing a correlation between endometriosis and ovarian cancer. An increased risk of developing cancer is always a concern in general and the possibility of ovarian cancer in particular since it is so hard to detect early with vague, common symptoms and thus is usually in an advance stage when diagnosed with a resulting poor prognosis for survival. Common symptoms of ovarian cancer include bloating, fatigue, constipation, pelvic or abdominal pain, vaginal bleeding, back pain, pain with intercourse, difficulty eating or feeling full without eating much and urinary frequency. These symptoms describe in a large part those experienced by patients with endometriosis and thus are not very helpful in alerting us to the possibility of ovarian cancer. The PAP smear is a great screening tool for cervical cancer. Unfortunately we do not have anything like this for ovarian cancer.
Ovarian cancer is the sixth most common cancer for women in the U.S., second most common gynecological cancer and the most deadly gynecological cancer. Approximately 70% of women have advanced disease at the time of diagnosis and 65% die within the first 5 years. Approximate survival rates at 5 years based upon stage are; Stage I – 89%, Stage II – 66%, Stage III – 34% and Stage IV – 18%. A woman’s lifetime risk of developing ovarian cancer is about 1.4% or 1 in 70 women.
For those with a first-degree relative with ovarian cancer the risk increases to about 3.3% or a 1 in 30 chance. A family history of ovarian cancer is the most significant risk factor while not having children also increases the risk as well as early age of onset of menses, late menopause, infertility and use of talc in the genital area. Several factors seem to decrease the risk including use of birth control pills, pregnancy, breast-feeding, tubal ligation and hysterectomy.
Before I can talk about how endometriosis affects your chance of getting ovarian cancer, we need to gain a better understanding of ovarian cancer and how the information from scientific studies may or may not apply to individual patients. I will go over this in the next couple of blogs.