Screening can detect aggressive ovarian cancer earlier

01 Sep 2023

A new exploratory analysis of the UKCTOCS trial results provides robust evidence for the first time that aggressive high-grade serous ovarian cancer can be detected earlier through screening. These findings published this week in The Lancet Oncology journal provide hope that newer early detection approaches may be able to impact disease mortality. 

Ovarian cancer is the most lethal gynaecological cancer for women in high-income countries. Most women are diagnosed with advanced disease when the cancer has already spread beyond the ovaries, and more than half die within 5 years.  

Previous results from the UKCTOCS, the largest ovarian cancer screening trial in the world, showed that screening using an annual multimodal approach can detect ovarian cancer earlier when compared to no screening. However, earlier detection did not translate into a reduction in deaths from ovarian cancer. The multimodal approach used a statistical algorithm to monitor changes over time in the blood levels of the protein CA-125, a marker that is raised in women with ovarian cancer. A transvaginal ultrasound was used as a second-line test if CA-125 levels were abnormal. 

The pre-specified outcome of UKCTOCS included women with all types of ovarian and tubal cancers, some more aggressive than others. To understand better why early detection using multimodal screening did not reduce deaths, the team has analysed stage, treatment, and survival in women with high-grade serous cancer which accounts for the majority of deaths.

The new analysis has revealed that multimodal screening picked up high-grade serous cancer cases earlier, compared with no screening. As a result, women with high-grade serous cancer in the multimodal screening group had better treatment outcomes and a small improvement in survival.  The fact that there was no overall reduction in disease deaths is likely due to a combination of factors – just over 1 in 10 women with advanced-stage disease were picked up earlier and the innate aggressiveness of high-grade serous ovarian cancer.

To save lives, we need to identify biomarkers and develop approaches that can detect more women with high-grade serous cancer earlier in the course of the disease. During UKCTOCS, over half a million samples were donated by the participants. This bioresource is currently being used by many collaborators worldwide to develop new tests and improve approaches to detect ovarian and other cancers earlier.  

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