News

Ovarian cancer screening may increase survival

Richard Woodman , London

New data suggest that screening for ovarian cancer may increase survival in women found to have the disease, but it will be at least another six years before larger studies can confirm the extent of the survival advantage.

The findings are based on a pilot feasibility study of ovarian cancer screening in postmenopausal women aged 45 years or older. The women were randomised into two groups-10997 were offered screening and 10958 were not. Those in the screening group were offered annual screens for three years that entailed measurement of the cancer antigen, Ca125, and ovarian ultrasonography.

The results showed that screening identified 29 women with possible ovarian cancers. Only six cancers were confirmed, however, and the remaining 23 cases were false positives. During the seven year follow up after the screening phase, 10 more cases of ovarian cancer were found in the screened group and 20 in the control group. The median survival time of women with the cancer was 73 months in the screened group and 42 months in the control group (P=0.01). There were nine deaths from cancer in the screened group compared with 18 in the control group, but this was not statistically significant (95%confidence interval 0.78 to 5.13) (Lancet 1999;353:1207-10).

The investigators suggested that the results showed that screening for ovarian cancer was feasible, had a satisfactory positive predictive value of 21%and showed preliminary evidence of survival benefit. They said, however, that a larger randomised trial was needed to confirm this and to establish all the implications of screening before a national programme was considered.

One of the researchers, Ian Jacobs, consultant gynaecological oncologist at St Bartholomew's Hospital, London, said: "The results are exciting, because for the first time we have evidence that there may be a survival benefit as a result of screening." But he warned that it would be "unscrupulous" of the private sector to publicise provision of screening for ovarian cancer. He said: "There may be a temptation in the private sector to try to offer ovarian cancer screening. I would say that this is totally wrong, unless the women are properly counselled about the possible limitations and disadvantages, such as the false positive rate. We don't yet know if screening makes any difference in terms of mortality." A bigger trial that is being coordinated at St Bartholomew's Hospital and includes 120000 women should eventually provide definitive answers.