Around 90% of deaths from ovarian cancer are due to high-grade serous cancer (HGSC), which is frequently diagnosed at an advanced stage. Several cancer organisations made a joint recommendation that all women with specified symptoms of ovarian cancer should be tested with the aim of making an early diagnosis. In the Diagnosing Ovarian Cancer Early (DOvE) study we investigated whether open-access assessment would increase the rate of early-stage diagnosis.

Between May 1, 2008, and April 30, 2011, we enrolled women who were aged 50 years or older and who had symptoms of ovarian cancer. They were offered diagnostic testing with cancer antigen (CA-125) blood test and transvaginal ultrasonography (TVUS) at a central and a satellite open-access centre in Montreal, QC, Canada. We compared demographic characteristics of DOvE patients with those of women in the same age-group in the general population of the area, and compared indicators of disease burden with those in patients with ovarian cancer referred through the usual route to our gynaecological oncology clinic (clinic patients).

Among 1455 women assessed, 402 (27·6%) were in the highest-risk age group (≥65 years). 239 (16·4%) of 1455 required additional investigations. 22 gynaecological cancers were diagnosed, 11 (50%) of which were invasive ovarian cancers, including nine HGSC. The prevalence of invasive ovarian cancer, therefore, was one per 132 women (0·76%), which is ten times higher than that reported in screening studies. DOvE patients were significantly younger, more educated, and more frequently English speakers than were women in the general population. They also presented with less tumour burden than did the 75 clinic patients (median CA-125 concentration 72 U/mL, 95% CI 12–1190 vs 888 U/mL, 440–1936; p=0·010); Eight (73%) tumours were completely resectable in DOvE patients, compared with 33 (44%) in clinic patients (p=0·075). Seven (78%) of the HGSC in the DOvE group originated outside the ovaries and five were associated with only slightly raised CA-125 concentrations and minimal or no ovarian abnormalities on TVUS.

The proportion of HGSC that originated outside the ovaries in this study suggests that early diagnosis programmes should aim to identify low-volume disease rather than early-stage disease, and that diagnostic approaches should be modified accordingly. Although testing symptomatic women may result in earlier diagnosis of invasive ovarian cancer, large-scale implementation of this approach is premature.

Canadian Institutes of Health Research, Montreal General Hospital Foundation, Royal Victoria Hospital Foundation, Cedar’s Cancer Institute, and La Fondation du Cancer Monique Malenfant-Pinizzotto.