Ovarian cancer is often diagnosed at a late stage because the symptoms are hard to recognize. According to the American Cancer Society, ovarian cancer is the fifth leading cause of cancer death in women in the U.S. The disease mostly impacts older women, with half of cases diagnosed after age 63.
There are several types of ovarian cancer, but the most common type is epithelial ovarian cancer, which begins in the surface cells. Drs. Anthony Costales and Claire Hoppenot, both assistant professors of gynecologic oncology at the Dan L Duncan Comprehensive Cancer Center at Baylor College of Medicine, answer common questions about risk factors, symptoms and screening.
Q: What risk factors influence the chances of developing ovarian cancer?
Hoppenot: Different types of ovarian cancer can be affected by different risks. Genetics can certainly play a strong role in the risk for ovarian cancer. We work closely with genetic counselors, and our patients with ovarian cancer have genetic testing. We are finding that 15-20% of patients will have a genetic component to their risk of ovarian cancer, and this allows us to both adjust their treatments and test their family members so that ovarian cancer can be prevented.
A first-degree relative with ovarian cancer can be enough to recommend genetic testing. Other potential risk factors have a much weaker effect. There does seem to be a slightly increased risk of ovarian cancer with obesity, irregular periods (due to factors like polycystic ovary syndrome), increasing age and more frequent menstrual cycles.
Q: Can birth control reduce the risk for ovarian cancer?
Costales: A few risk factors for ovarian cancer are similar in their proposed mechanism: having early onset of menstruation, late menopause or never being pregnant all increase the total number of ovulations in a patient’s lifetime. Repeat ovulation results in minor trauma to the ovary and may lead to a cancer transformation. This theory is plausible because birth control pills can reduce one’s risk of ovarian cancer by periodically suppressing ovulation.
The risk reduction with use of birth control pills depends somewhat on how long they are taken:
- Patients who ever used birth control have a 27% risk reduction
- Patients who used for more than 10 years have a greater than 50% risk reduction
- In patients with BRCA mutation (associated with breast and ovarian cancer genetic syndrome):
- Use of birth control led to a 50% risk reduction in ovarian cancer
- In one study, for every year of birth control use, the risk of ovarian cancer in BRCA patients is reduced by 5%
Breastfeeding and tying or removing the fallopian tubes after completing childbearing can also reduce the risk of ovarian cancer.
Q: What are the symptoms of ovarian cancer? What signs should women look for?
Costales: The most common symptoms are things we all may experience on a monthly, weekly or even daily basis: bloating, pelvic or abdominal pain, gastrointestinal issues, sour taste in the mouth, bad breath and getting full quicker. Because these symptoms are non-specific, most ovarian cancer patients are diagnosed at advanced stages of disease.
Q: Does an annual well woman exam check for ovarian cancer? Is there a screening or test?
Hoppenot: An annual well-woman exam checks for ovarian cancer during the internal digital exam and throughout the history-taking. The pap smear and speculum exam cannot look for ovarian cancer. There are some studies looking at vaginal tests that would help detect early ovarian cancer, but nothing reliable enough for approval at this time. In the history, your doctor should be asking about changes in bowel or bladder function, bloating, GI issues, changes in appetite and pelvic pain or discomfort that don’t have another explanation and have lasted longer than 10-14 days.
For high-risk patients such as BRCA carriers, we can screen with pelvic ultrasounds to look at the ovaries and a blood test called CA125. Even for these patients, it’s unclear whether there is a survival benefit of screening. For average-risk women, this screening has not been shown to improve survival or catch ovarian cancer earlier.
-By Molly Chiu