Answering Questions About Ovarian Cancer
I’ve had some questions recently about cancer of the ovaries so I’ll try and tackle this complex subject. Ovarian cancer is frightening because it is often very advanced before a woman receives a diagnosis. Most women present with stage III disease meaning the cancer has spread outside the ovary into the abdominal cavity and/or lymph nodes. This results in less than half of women surviving five years after diagnosis.
Ovarian cancer cases in the U.S. in 2021 numbered about 21,000 and approximately 14,000 died from the disease. It accounts for less than three percent of all female cancers. It is the fifth leading cause of cancer deaths in women following breast, lung, colorectal, and uterine cancers.
The chance of developing ovarian cancer increases with age and peaks in the late 70s with an average age of 63. Fortunately, the prevalence of ovarian cancer is relatively low with about a 1.3 percent lifetime risk of developing it. Also, the incidence has been trending downward since the late 1980s.
Women have an increased risk of ovarian cancer with increasing age, infertility, endometriosis, polycystic ovarian syndrome, cigarette smoking, estrogen use, obesity, or a family history of breast or ovarian cancer (especially those who test positive for one or both of the BRCA1 or BRCA2 genes).
Women with one first-degree relative (mother or sister) with ovarian cancer have an increased risk of about 4 to 5 percent while those with two first-degree relatives have about a 7 percent risk. Women have a decreased risk if they have had a previous pregnancy, have breastfed, taken oral contraceptives, used an intrauterine device, or had a tubal ligation.
Signs and symptoms of ovarian cancer may be quite subtle or absent entirely. The most common symptoms, described by about half of women, are bloating or enlargement of the abdomen and abdominal or pelvic pain. Decreased appetite, a feeling of getting full quickly, urinary urgency and/or frequency, and a change in bowel habits, particularly constipation, may also be present.
Like most cancers, diagnosing ovarian cancer at earlier stages leads to improved survival. However, there is no evidence that supports a benefit of routine screening of average risk, asymptomatic women. All screening strategies in this group are associated with a high rate of false-positive tests that can cause psychological stress and, more importantly, carry a risk of harm from invasive testing and surgery.
The disease is occasionally detected on routine pelvic exam, often when it is in an advanced stage. Women who are at increased risk for ovarian cancer or who have persistent, unexplained pelvic or abdominal symptoms, may benefit from a combination of pelvic examination, pelvic ultrasound and a blood test called CA-125.
The CA-125 blood test has been touted in social media posts as a screening tool for ovarian cancer. Some readers may have even received an e-mail describing the benefits of having a yearly CA-125 blood test to screen for ovarian cancer. Various versions of this e-mail have been circulating since 1998. The message states that if you don’t have the test done regularly, you may be putting your life in danger. It also accuses the medical community and insurance companies of intentionally withholding the test from women.
While the CA-125 test is useful for following women with diagnosed ovarian cancer in order to gauge their response to treatment, ongoing studies looking at the utility of the test as a screening tool continue to confirm its poor performance. Screening with CA-125 has never been shown to improve survival from ovarian cancer.
The test is not very sensitive since it’s only elevated in about half of women with ovarian cancer and it frequently doesn’t become elevated until the cancer has already spread. In other words, a negative test does not mean a woman doesn’t have ovarian cancer.
The test is also very non-specific. It can be elevated for a number of reasons including normal menses, endometriosis, pregnancy and benign tumors of the uterus. It can also be elevated with pancreatitis, appendicitis and other cancers such as breast, lung and colon.
So, when should a woman be concerned? If she has any of the symptoms mentioned above for more than a few weeks, she should consult her care provider to provide her medical history and undergo a pelvic examination. Her provider may then recommend additional testing based on her overall risk and physical findings.
Dr. John Roberts is a retired member of the Franciscan Physician Network specializing in Family Medicine.