Ovarian cancer: Recognizing early symptoms can make a difference

With no reliable screening tests available, ob/gyns have tried to use their clinical judgment and the patient's medical history to detect the disease in its early stages. Recent studies have found, however, that a specific set of persistent signs and symptoms may signal emerging disease and warrant follow-up diagnostic testing.

No one has to remind an ob/gyn that ovarian cancer is the most deadly gynecologic malignancy. With over 15,000 deaths in the United States each year and over 70% of cases diagnosed in their advanced stages, it is one of the most frustrating diseases for clinicians to contend with.

Five-year survival rates for women with advanced stages are only 15% to 30% but if the disease is diagnosed in its early stages cure rates jump to 70% to 90%. Because survival is so much more likely when the disease is caught early on, extensive research has been done to find an effective screening strategy. But despite our best efforts, an effective screening test has yet to emerge.

Obstacles to a successful screening protocol

To successfully screen asymptomatic women for ovarian cancer, we have to overcome several obstacles.

• First, and foremost, an in situ phase of the disease must exist, but it's possible that, unlike in cervical carcinoma, a precancerous detectable ovarian lesion may not exist.
  
• Second, most ovarian cancers grow very quickly, and so the window of opportunity to make a diagnosis when the disease is still confined to the ovary may be very short.
  
• Third, the incidence in the general population is only 40 per 100,000 women. With so few women developing the disease annually, even a screening test with a specificity of 99.6% would yield a positive predictive value (PPV) of only 10%. (Put another way, 10 women would need to undergo surgery for one case of ovarian cancer to be detected).
  
• Fourth, false-positive screening results can cause some serious psychological and financial consequences.
  
• Finally, since the only way to confirm a diagnosis of ovarian cancer is with a major surgical procedure, the morbidity and mortality of screening may outweigh the benefit of early detection (Table 1).
  

TABLE 1: Pitfalls when 'screening' for ovarian cancer

No doubt these are some of the reasons the American College of Obstetricians and Gynecologists recommends against population-based screening for ovarian cancer and the United States Preventive Services Task Force (USPSTF) has assigned routine screening for ovarian cancer a "D" grade, a designation that indicates there is fair evidence to recommend its exclusion from a periodic health examination.