By ASCO Post Staff
Post date: 2023/10/3 14:36:00
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Two liquid biopsy tests designed to detect human papillomavirus (HPV) in the blood can be detected in the cervix after chemoradiation therapy, according to new research presented by Han et al. at the 2023 American Society of Radiation Oncology meeting. They announced that it may be possible to accurately identify patients at high risk of cancer recurrence. (ASTRO) Annual General Meeting (Summary 105).
background
Approximately 11,500 people are newly diagnosed with cervical cancer and 4,000 people die from cervical cancer each year in the United States. Approximately 30% to 40% of cervical cancer patients experience tumor recurrence after chemoradiotherapy, but currently residual disease is often detected too late to improve survival.
Tissue biopsy has long been the standard for identifying these tumors. However, this test requires an invasive procedure to sample enough tumor tissue to be visualized on images that provide only a snapshot of specific tumor areas. Liquid biopsies can detect minute components of tumors in body fluids such as blood and urine, providing a less invasive option for evaluating cervical cancer. Blood tests are the most widely used type of liquid biopsy and can identify circulating tumor DNA (ctDNA), circulating RNA, and other markers such as HPV that indicate the presence of cancer.
These tests can detect HPV fragments that remain in the blood after chemoradiotherapy and before the cancer comes back. Because HPV is the most common cause of cervical cancer, early detection allows early treatment of residual disease and may improve survival rates.
“[L]”Liquid biopsy provides insight before tissue biopsy is possible,” explained the study’s senior author. Dr. Cathy Han, a radiation oncologist at the University of Toronto Princess Margaret Cancer Centre. “Being able to predict who is at high risk of recurrence could signal to clinicians to follow these patients more closely,” she stressed.
In a previous study, Dr. Han and her colleagues collected blood samples from 20 cervical cancer patients before and after chemoradiotherapy. Using digital polymerase chain reaction testing, patients with detectable HPV ctDNA at the end of chemoradiotherapy were found to have worse outcomes than patients with undetectable HPV ctDNA.
Research methods and results
In the new study, researchers aimed to validate previous findings by recruiting 70 HPV-positive cervical cancer patients who had undergone chemoradiotherapy and using digital polymerase chain reaction testing to detect genetic material derived from HPV. Compared advanced sequencing tests.
The researchers took blood samples before treatment and conducted blood tests immediately after treatment, four to six weeks and 12 weeks after treatment.
After a median follow-up of 2.2 years, patients with HPV ctDNA detected in their blood at each of these three time points had significantly worse progression-free survival than patients without HPV detected in their blood.
Specifically, 53% of patients with detectable HPV ctDNA immediately after chemoradiotherapy experience 2-year progression-free survival, compared with 87% of patients without detectable HPV ctDNA immediately after treatment. This difference was even more pronounced at week 12, with a 2-year progression-free survival rate of 26% for patients with detected HPV ctDNA after chemoradiotherapy compared to 85% for patients without detectable HPV ctDNA. was.
The researchers also found that both tests were comparable in their ability to identify residual disease in patients’ blood.
conclusion
“We are pleased to be able to validate our first results. However, we were surprised that we did not see a significant difference compared to digital. [polymerase chain reaction] testing and HPV sequencing testing. Even though HPV sequencing was more sensitive than digital [polymerase chain reaction]Both approaches yielded similar results after treatment,” said Dr. Han.
Advances in technology are accelerating the use of liquid biopsies, which are believed to have great potential for non-invasive cancer screening in high-risk populations, but this test is not yet widely available.
One of the challenges in making HPV ctDNA testing more accessible to cervical cancer patients is the diversity of HPV strains that cause disease. The researchers detected 11 different HPV strains in their analysis. Nevertheless, HPV sequence testing was able to detect all 11 types with high accuracy, suggesting that it may be a generalizable approach for patients with HPV-positive cervical cancer.
Researchers say expanding access to liquid biopsies could be important for future studies that use liquid biopsies to identify patients at high risk of recurrence and randomly assign them to intensive care versus standard care. He emphasized that there is.
“These non-invasive tests can detect residual disease after chemoradiotherapy earlier than imaging or clinical tests,” Dr. Han emphasized. “By being able to detect tiny amounts of disease before it becomes large, we may be able to intervene earlier and improve treatment outcomes. [patients] It’s cervical cancer,” she concluded.
Disclosure: For full research author disclosure, please visit: redjournal.org.
The content of this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas or opinions of ASCO®.
