Examining the Evidence
Q. Which symptoms are most likely to arouse suspicion of ovarian cancer?
<huc>A.</huc> Gynecologic symptoms such as abdominal and pelvic swelling, abnormal bleeding, and genital organ pain were most likely to prompt evaluation for ovarian cancer in this review of Surveillance, Epidemiology, and End Results (SEER) and Medicare data for 3,250 women 65 years and older. Gastrointestinal (GI) symptoms such as nausea and vomiting, constipation, diarrhea, and other digestive disorders were associated with diagnosis at a later stage, whereas gynecologic symptoms were associated with earlier disease.
A substantial body of research over the past decade has demonstrated that, even in the earliest stages, ovarian cancer produces symptoms. This study by Ryerson and colleagues is a significant contribution to that body of evidence and underscores the importance of including ovarian cancer in the differential diagnosis when a patient reports gynecologic, GI, or abdominal symptoms.
Early recognition is critical
Because we lack an effective screening test for ovarian cancer, early recognition and prompt evaluation of symptoms may be critical to improve prognosis. The cure rate for early-stage disease is 70% to 90%, compared with 10% to 30% for advanced stages.
This study is consistent with other research demonstrating that more than 80% of women with early-stage ovarian cancer have symptoms months before they are given a diagnosis. Compared with women who have GI symptoms, those who have gynecologic symptoms underwent abdominal or pelvic imaging and surgical evaluation sooner after reporting symptoms.
Experts agree: Ovarian cancer is not silent
The so-called silent killer isn’t, apparently. That’s the word from the Gynecologic Cancer Foundation, American Cancer Society, and Society of Gynecologic Oncologists, which jointly issued an evidence-based consensus statement on ovarian cancer symptoms in June. Often referred to as the “silent killer” because of the common belief that there are no warning signs or symptoms, ovarian cancer is the deadliest reproductive cancer.
Barbara A. Goff, MD, who comments here on the study by Ryerson and colleagues, helped formulate the consensus statement, which cites the following symptoms that occur in women with ovarian cancer:
- Pelvic or abdominal pain
- Difficulty eating or feeling full quickly
- Urinary symptoms (urgency or frequency).
A woman who has symptoms almost daily for more than a few weeks should see her gynecologist, and the gynecologist should include ovarian cancer in the differential diagnosis. Ovarian cancer should be suspected if symptoms persist more than 2 to 3 weeks and occur 12 or more times a month.
“This agreement on common symptoms of ovarian cancer hopefully will lead to earlier diagnosis when a cure is more likely,” said Dr. Goff. “We know that when women are diagnosed in stage I of the disease, it is 90% curable.”
For more on the detection of ovarian cancer, see Dr. Barbieri’s editorial.
Large database and inclusion of ICD-9 data are strengths of this study
This study utilized population data from 13 geographic regions of the country. More important, it evaluated the ICD-9 diagnosis that prompted a visit to a physician or a procedure before ovarian cancer was diagnosed. Because women were unaware that they would subsequently be given a diagnosis of ovarian cancer, the design eliminates recall bias that has been at issue in earlier studies.
ICD-9 data are also a weakness
The fact that ICD-9 diagnostic data for billing purposes were used as a substitute for patient symptoms is a weakness of this study. Physicians frequently report only one ICD-9 diagnosis per encounter, so this study may significantly underreport the symptoms experienced by women with ovarian cancer.
The fact that this study included only women older than 65 years is another weakness, as is the fact that only 3,250 of 8,357 women were ultimately included in the final analysis—raising concern of selection bias.
Bottom line: Keep symptoms in mind
Both patients and physicians alike should be aware that gynecologic, GI, and urinary symptoms may be indicators of ovarian cancer and may warrant further diagnostic evaluation. Until there is a screening test for ovarian cancer, heightened awareness is best.