For the past 25 years, scientists have tried to identify a screening test to detect ovarian cancer in its earliest stages, when the chance of cure is high. Unfortunately, multiple clinical trials with hundreds of thousands of participants have failed to identify an effective way to screen for ovarian cancer. In fact, the US Preventive Services Task Force gave ovarian cancer screening a grade of D in 2018, meaning it recommends against periodic screening because it doesn’t improve survival and can prove harmful to patients.
Because no effective screening test currently exists, 70% of people with ovarian cancer are diagnosed at advanced stages, when chances of cure are poor. Around 60% to 90% of people with stage I or II cancer that stays around the ovaries and pelvis are disease-free 5 years after diagnosis, compared with only 10% to 40% of those with stage III or IV cancer that has spread through the abdomen and beyond.
But even those with advanced disease have a higher chance of being cured if complete surgical removal is still possible. This makes early diagnosis all the more important for overall survival.
Without screening tests, many physicians wrongly assume that early diagnosis for ovarian cancer isn’t possible. As a gynecologic oncologist who treats hundreds of ovarian cancer patients each year, I was frustrated by these late diagnoses, and wondered if better recognition of its symptoms could help clinicians and patients identify ovarian cancer earlier.
Ovarian cancer has historically been called a “silent killer,” because clinicians thought its symptoms were undetectable. Patients were often diagnosed so late that doctors thought nothing could be done.
But there have been many studies over the past 20 years demonstrating that ovarian cancer does have early warning signs. My colleagues and I conducted one of the earliest studies in 2000. Our survey of 1700 people with ovarian cancer found that 95% of patients reported noticeable symptoms three to 12 months before diagnosis. The most common symptoms were pain in their pelvis and abdomen, increased frequency and urge to urinate, difficulty eating or feeling full quickly, and bloating or abdominal distension.
Importantly, people with both advanced- and early-stage disease reported similar types of symptoms. Subsequent studies from multiple researchers further confirm that patients with even early-stage ovarian cancer experience frequent symptoms.
We also found that providers often misdiagnosed ovarian cancer as another condition. When we asked patients what their doctors told them was the cause of their symptoms, 15% had their symptoms attributed to irritable bowel disease, 12% to stress, 9% to gastritis, 6% to constipation, 6% to depression and 4% to some other cause. Thirty percent were given treatment for a different condition. And 13% were told there was nothing wrong.
One major issue has been distinguishing ovarian cancer symptoms from those of common gastrointestinal and urinary conditions. In another study, my team and I found that patients with ovarian cancer have symptoms with a recent onset and occur more than 50% of the month.
To facilitate early detection of ovarian cancer, my team and I compared the symptoms ovarian cancer patients experienced with those of patients without ovarian cancer. We developed an index that identified 6 important symptoms of ovarian cancer: bloating, increased abdominal size, feeling full quickly, difficulty eating, pelvic pain and abdominal pain. Symptoms needed to occur more than 12 times a month but to have lasted for less than a year.
Based on these criteria, our index was able to detect ovarian cancer in 60% to 85% of the patients in our study, a range similar to that achieved through diagnostic blood tests for ovarian cancer.
Preventing ovarian cancer
While early detection is important, there are also prevention strategies that can help reduce the risk of developing ovarian cancer.
If you have a family history of ovarian cancer, inform your doctor, who may recommend genetic testing to fully determine your risk, or prophylactic surgery to prevent the development of cancer.
Oral contraceptives, tubal ligation (or surgery to close the fallopian tubes), pregnancy and breastfeeding all reduce the risk of ovarian cancer.
Finally, up to 70% of ovarian cancers may arise from the fallopian tubes. Removing the fallopian tubes at the time of another surgery may be another option to help reduce the risk of ovarian cancer. This should be done only if you do not plan on becoming pregnant in the future.
Barbara Goff, MD is a board-certified oncologist who specializes in treating patients with gynecologic malignancies and is the chair of the Department of Obstetrics and Gynecology at UW Medicine.
This article is republished from The Conversation under a Creative Commons license.