With that requirement in mind, researchers have refined ovarian cancer screening methods. One of these refinements is a risk-of-ovarian-cancer algorithm by which clinicians would be able to interpret serial CA-125 results.3,4
Interim results from a prevalence screen. The United Kingdom Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) evaluated these new screening methods in a multicenter, randomized, controlled trial in an effort that assessed not only mortality but also cost, acceptance by patients, and the physical and psychosocial morbidities associated with screening. At this point, investigators are reporting the results of a prevalence screen.
The team evaluated more than 200,000 low-risk women who were randomized to either 1) no screening, 2) multimodal screening (MMS), or 3) annual TVU screening, in, respectively, a 2:1:1 ratio. Multimodal screening comprised:
- annual CA-125 testing (interpreted using a risk-of-ovarian-cancer algorithm) and
- TVU as a second-line test.
Follow-up algorithms for women in both groups were determined a priori, based on a risk score (“normal,” “intermediate,” and “high”) from initial screening results. An initial, basic level-1 sonogram was performed on all women; a subsequent, more focused level-2 sonogram was performed only if indicated.
Among women assigned to screening, the following was noted:
- fewer women in the MMS group (0.3%) required clinical evaluation than in the TVU group (3.9%)
- fewer women in the MMS group (0.2%) required surgery than in the TVU group (1.8%)
- a similar number of cancers was detected in the two groups (MMS, 42; TVU, 45)
- more borderline tumors were detected in the TVU group than in the MMS group.
MMS had higher specificity and positive predictive value than TVU (respectively: 99.8% and 98.2%; 43.3% and 5.35%). Almost 50% of cancers detected on the initial screen were Stage I or II.
WHAT THIS EVIDENCE MEANS FOR PRACTICE
Again, do not screen for ovarian cancer with combined annual CA-125 testing and TVU. This study suggests, however, that large-scale screening strategies are feasible, and that they may provide useful guidance. We await the results of the researchers’ ongoing screening trial to determine what effects such screening might have on mortality from ovarian cancer.
Symptoms are not predictive of the risk of ovarian cancer
Rossing MA, Wicklund KG, Cushing-Haugen KL, Weiss NS. Predictive value of symptoms for early detection of ovarian cancer. J Natl Cancer Inst. 2010;102(4):222–229.
Evaluation of symptoms has been suggested as a way of identifying women who may be at risk of ovarian cancer. In a 2007 consensus statement on the topic, contributors note that certain symptoms—bloating, pelvic or abdominal pain, difficulty eating, early satiety—are more common in women who have ovarian cancer than they are in the general population.5 They recommend that women who have these symptoms consult their physician for prompt evaluation.
But concerns have been raised about the true utility of these symptoms as a tool for detecting ovarian cancer at an earlier stage and, therefore, improving survival.
Linking symptom onset to time of diagnosis. Using a population-based registry that is part of the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute, the investigators conducted a large, population-based study to examine the occurrence and timing of symptoms in 1) women who have ovarian cancer and 2) controls. They identified women in a 13-county area of western Washington State, ranging from 35 to 74 years old, who were given a diagnosis of epithelial ovarian cancer or had a borderline epithelial ovarian tumor over a 3-year period.
Of 1,058 eligible women who had ovarian cancer, the team interviewed 812. An additional 1,313 controls (providing a 69% response rate) were interviewed.
Results showed that most case patients who had symptoms often associated with ovarian cancer experienced those symptoms only within 5 months before their initial diagnosis. Symptoms were also less likely to occur in early-stage ovarian cancer than in late-stage disease.
The positive predictive value for the symptom index was extremely low (<0.5% in early-stage disease and 0.6%–1.1% in late-stage disease).
WHAT THIS EVIDENCE MEANS FOR PRACTICE
Proceed cautiously with use of any symptom index to trigger referral to a subspecialist, because it will detect ovarian cancer in only 1 of every 100 women in the general population whose presentation includes such symptoms. Data suggest that it will have limited utility for detecting early-stage cancer. Symptoms should not be completely ignored, however, because they do manifest more often in women who have ovarian cancer than in the general population.
Ultrasonography in combination with serum CA-125 can facilitate early referral to a subspecialist
McDonald JM, Doran S, DeSimone CP, et al. Predicting risk of malignancy in adnexal masses. Obstet Gynecol. 2010;115(4):687–694.