Nature-Cancer: Individualized blood tests can quickly predict the effectiveness of immunotherapy.

In a recent study published in Nature's Nature Cancer, scientists tailored an individual test to a patient's tumor condition, using a simple, fast, non-invasive method to assess each patient's response to a specific immunotherapy drug.
team from the Princess Margaret Cancer Centre in Canada found that individuals could be predicted to benefit from immunotherapy within six to seven weeks, based on changes in the level of DNA fragments that fall off the tumor and enter the bloodstream.
, the researchers note that using a variety of scanning techniques could take months to detect whether the tumor is shrinking.
new technology to detect genomes, the same changes can be detected in blood-circulating DNA fragments, known as circulating tumor DNA (ctDNA). Professor Scott Bratman, a radiation oncologist and lead author of the
paper, said:
The next generation of sequencing technology can accurately and sensitively detect and measure ctDNA, allowing us to pinpoint whether a cancer is active or not quite quickly."
the prospective study, researchers analyzed changes in ctDNA in 74 patients with different types of advanced cancer who were being treated with the immunotherapy drug pembrolizumab.
researchers examined all genes in a patient's tumor biopsy tissue, paying particular attention to mutations that occur in cancer.
, the number of cancer mutations in each tissue sample ranged from tens to tens of thousands, depending on the type of cancer.
researchers selected 16 gene mutation development and customized individual tests for each patient's condition, testing their ctDNA changes with simple blood pumping.
. Trevor Pugh, co-author of the study, said, "What's new is that instead of taking a one-size-fits-all approach, we designed individual blood tests based on each person's list of cancer mutations."
" researchers found that in the sixth to 7th weeks after treatment, 33 patients had a decrease in ctDNA levels from their original baseline levels.
these patients have better treatment responses and longer lifetimes.
even more striking was the fact that 12 patients had ctDNA reduced to untested levels during treatment, and all survived the 25-month follow-up period.
, the rise in ctDNA levels was mostly associated with rapid progress and low survival rates in patients.
Professor Lillian Siu, a senior medical oncologist and co-author of the study, said the study was the first to span multiple tumors, suggesting that measuring ctDNA levels could serve as an indicator of whether patients are responding well to immunotherapy, "and observing ctDNA removal during treatment and its link to long-term survival is novel and exciting, suggesting that this biomarker can have a wide range of clinical effects."
" References: (1) Scott Bratman et al., (2020) 2020) Posteded lying tumall DNA analysiss as a predictive biomarker in solid tumor patients treated with pembrolizumab. Nature Cancer. DOI: a blood test can predict who benefits from the immunotherapy. Retrieved 2020-08-04, from.