A method has been developed to diagnose recurrent ovarian cancer through blood biopsy. The results of this study were published in the international academic journal “Cancer Research” (IF 12.701).
The research team, including Professor Seungtae Lee from the Department of Laboratory Medicine at Yonsei University College of Medicine, Professor Jeongyoon Lee and Professor Yuna Kim from the Gynecological Cancer Center at Yonsei Cancer Hospital, and Jinho Heo, Department of Medicine laboratory at the national health insurance Ilsan Hospital, has developed and validated a liquid biopsy method capable of diagnosing the recurrence of ovarian cancer. On the 23rd it was announced that it had been confirmed.
Ovarian cancer recurs more frequently when it reaches a later stage. The recurrence rate of advanced stage ovarian cancer is 80% compared to the early stage (25%). Prediction of recurrence is important in the treatment of ovarian cancer. This is because when relapses occur, resistance develops and treatment becomes more difficult.
Currently, to detect the recurrence of ovarian cancer, CA-125 protein levels are examined through blood tests. CA-125 is a biomarker often found in ovarian cancer patients, but its level increases due to pregnancy and uterine inflammation, hence its specificity, which refers to the likelihood of a negative test in a person without cancer, she is low.
The research team developed a next-generation sequencing (NGS) panel that allows liquid biopsy with a small amount of blood and analyzed its effectiveness in real patients. Liquid biopsy is a method of cancer diagnosis that is a step up from tissue biopsy, which involves removing organ tissue and diagnosing cancer under a microscope.
The biopsy material used by the research team is a genetic fragment of the cancer (ctDNA, circulating tumor nucleic acid) floating in the patient’s blood. We created a panel capable of detecting genetic mutations such as TP53, BRCA1, BRCA2 and ARID1A, which are frequently found in ovarian cancer. It has the advantage of reducing testing costs by modifying the target gene.
↑The liquid biopsy used by the research team allows genetic analysis of the primary tumor by analyzing the genes of the cancer fragment in the blood.
Subsequently, the efficacy of the developed panel was confirmed through next-generation sequencing (NGS) on real patients. 201 patients with ovarian cancer and 95 patients with benign tumors participated. Periodic examinations were performed every 3 months starting from diagnosis or surgery.
Genetic mutations were observed in 70% of ovarian cancer patients using the panel used in the study. In contrast, no pathogenic mutations were detected in patients with benign tumors, boasting a test specificity of 100%.
Even if a tumor mutation was detected in the initial test, if the mutation was not detected in the test six months after treatment, the rate of stopping cancer progression was as high as 70%. On the other hand, if a mutation was detected even after 6 months of treatment, the percentage of ovarian cancer patients who progressed to a recurrence was 90%.
The research team’s testing method was able to detect ovarian cancer recurrence approximately three months earlier than the existing CA-125 test. Since CA-125 is a protein also present in healthy people, relapse is diagnosed when it exceeds a certain level. The panel used in this study targets genetic mutations that cause ovarian cancer. Compared to existing tests, minimal residual disease can be diagnosed not only more quickly but also more sensitively.
Professor Seungtae Lee said: “The advantage of this study is that we confirmed the effectiveness of liquid biopsy by securing a large number of research subjects, about 300 patients, including ovarian cancer patients and benign tumors,” and added “We will continue to look to scale up the research so that it can be used in real-world clinical trials,” he said.
