Study: New Blood Test Can Detect Wide Range of Cancers

A new blood test has detected more than 50 types of cancer as well as their location within the body, according to an international team of researchers led by the Dana-Farber Cancer Institute and the Mayo Clinic.

The results indicate that the test can play a key role in the early detection of cancer, since it is able to identify some particularly dangerous cancers that lack standard approaches to screening and help with a more successful treatment.

The test, developed by GRAIL, Inc, uses next-generation sequencing to analyze the arrangement of chemical units called methyl groups on the DNA of cancer cells, according to a press release.

Methyl groups help control whether genes are active or inactive by adhering to specific sections of DNA. In cancer cells, the placement of methyl groups, or methylation pattern, is often markedly different from that of normal cells, to the extent that abnormal methylation patterns are even more characteristic of cancer cells than genetic mutations are, according to the study authors. The DNA of tumor cells empties into the blood with methyl groups firmly attached when they die, where it can be analyzed in this kind of test.

Researchers used the test to analyze cell-free DNA, or DNA from normal and cancerous cells that had entered the bloodstream upon cell death, in 6689 blood samples. These samples included 2482 people diagnosed with cancer and 4207 people without cancer. The samples from patients with cancer represented more than 50 cancer types, including breast, colorectal, esophageal, gallbladder, bladder, gastric, ovarian, head and neck, lung, lymphoid leukemia, multiple myeloma, and pancreatic cancer.

Overall, the specificity of the test was 99.3%, meaning that only 0.7% of the results incorrectly indicated that cancer was present. The sensitivity of the assay for 12 cancers that account for nearly two-thirds of US cancer deaths was 67.3%, which means the test could find the cancer two-thirds of the time, but the test returned a negative result a third of the time, according to a press release.

Within the group, the sensitivity was 39% for patients with stage 1 cancer, 69% for those with stage 2, 83% for those with stage 3, and 92% for those with stage 4. Across all cancer types, stage 1-3 cancer sensitivity was 43.9%. When cancer was detected, the test correctly identified the organ or tissue where the cancer originated in more than 90% of cases, according to the study authors.

“Our results show that this approach to testing cell-free DNA in blood can detect a broad range of cancer types at virtually any stage of the disease, with specificity and sensitivity approaching the level needed for population-level screening,” said Dana-Farber’s Geoffrey Oxnard, MD, co-author of the study, in a press release. “The test can be an important part of clinical trials for early cancer detection.”

REFERENCE

New blood test can detect wide range of cancers, now available to at risk individuals in clinical study at Dana-Farber. Dana-Farber Cancer Institute. https://www.dana-farber.org/newsroom/news-releases/2020/new-blood-test-can-detect-wide-range-of-cancers--now-available-to-at-risk-individuals-in-clinical-study-at-dana-farber/. Published March 30, 2020. Accessed April 3, 2020.