Annual ovarian cancer screening fails to prevent deaths in US study
Annual screening for ovarian cancer with a blood test combined with an ultrasound scan did not reduce the risk of dying from the disease, but did increase the likelihood of invasive medical procedures, a US study has found. But these tests could yet be beneficial if they are used in an alternative way being assessed in a UK study.
Researchers at the University of Utah Health Sciences Centre examined data on ovarian cancer death rates from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial.
This trial measured the results of annual screening using ultrasound examinations, and a blood test to measure levels of a protein called CA-125, which is often increased in women with ovarian cancer.
Almost 80,000 women, aged 55 to 74 years, took part between November 1993 and July 2001. Half were screened annually and the other half received usual medical care with no interventions.
Those screened were offered a CA-125 test every year for six years, as well as an annual ultrasound exam every year for four years.
Participants were followed up for up to 13 years to see whether they developed ovarian cancer or died from the disease.
The researchers found that women who attended screening appointments were not significantly less likely to die from ovarian cancer than those who received standard care.
The research revealed that 212 women were diagnosed with ovarian cancer in the screening group, and 176 in the control group.
There were 118 deaths from ovarian cancer in the screening group and 100 in the control group - a difference that was not found to be statistically important.
The researchers also showed that women who attended screening were more likely to undergo invasive medical procedures and develop complications associated with surgery.
The results were presented at the annual meeting of the American Society of Clinical Oncology and will be published in the Journal of the American Medical Association.
Despite not finding any benefit from screening in this way, the study authors noted that CA-125 testing and ultrasound exams may still be beneficial if used in a different way - something that is currently being investigated in the UKCTOCS trial, which is being co-funded by Cancer Research UK, the Medical Research Council and the NHS.
Dr James Brenton, Cancer Research UK's ovarian cancer clinician, said: "This important research suggests that having a yearly ultrasound test along with a blood test which provides a snapshot of the levels of a protein associated with ovarian cancer - the serum CA125 test - is not going to cure more women of ovarian cancer. Ovarian cancer is very hard to detect at an early stage before it has spread.
"Ongoing research funded by Cancer Research UK is testing whether smaller rises in CA125 over time can be a better predictor of early ovarian cancer and is working with international groups to identify common genes that might slightly increase the risk of ovarian cancer. Combining genetic tests with ultrasound and serum markers will provide a more accurate way of detecting those women who have a greater chance of developing ovarian cancer, and curing them."