American study on ovarian cancer boosts hopes of early detection
Technique used in trial is similar to that used in much larger study in the UK which is due to report in 2015
An important new element is the rise in the level of a protein, CA125, in a woman’s blood compared with that shown in her last test. Photograph:Getty Images
Hopes of a screening programme for ovarian cancer, which is often lethal because detected at a late stage, rose this week with the publication of the results of a trial in the United States.
Ovarian cancer is the fifth most common cancer among women, with 7,000 new diagnoses in Britain alone each year. It causes great anxiety and concern because there are few symptoms and they are not very distinctive in the early stages – they include a bloated stomach and abdominal pain. Many women arrive at the GP with a cancer that proves fatal.
The trial, of 4,051 women at the University of Texas MD Anderson cancer centre, in Houston, showed it is possible to identify ovarian tumours correctly through a blood test and internal ultrasound examination with a low rate of errors, which means that few women should be wrongly suspected of having cancer.
In ovarian cancer, this is crucial, because the next step is abdominal surgery, which carries serious risks.
The Houston study was very small – because ovarian cancer is relatively rare, only 10 women were identified as cause for concern and operated on, and four of those were found to have invasive ovarian cancer.
However, it will raise hopes because the technique used is similar to that used in a far bigger study in the UK, involving 300,000 women, which is due to report in 2015.
The results of the Houston trial are being published early online in Cancer, the journal of the American Cancer Society, and will raise hopes that were dashed by an earlier and bigger US study that looked at screening for four cancers – prostate, lung, colorectal and ovarian cancer.
The ovarian cancer arm of that study used the same blood test – which measures raised levels of a protein called CA125 – followed by transvaginal ultrasound in suspicious cases.
Unfortunately, the level of CA125 can be raised by a number of other factors besides ovarian cancer, including liver cirrhosis, appendicitis and heart problems.
Many unnecessary operations have been done. More than 3,000 women were wrongly thought to have ovarian cancer and more than 1,000 of those had surgery, 163 of whom suffered serious complications.
The new trial shows it is possible to use the same tests and get a far better result by assessing each individual’s risk of a high reading given their age and state of health.
An important new element is the rise in the CA125 level in a woman’s blood compared with that shown in her last test.