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Cancers can be successfully fought or eradicated, if caught early enough. The deadliest varieties of tumor, like that of the pancreas, are the ones that go undetected until late stages.

A new Johns Hopkins study outlines a potentially game-changing screening methodology to catch some of the most common cancers at their earliest stages.

The screening for tumor-wrought DNA changes, outlined in Science Translational Medicine, could save lives of the future, report the scientists.

“These analyses provide a broadly applicable approach for noninvasive detection of early-stage tumors that may be useful for screening and management of patients with cancer,” they conclude.

The approach is called “targeted error correction sequencing” – what they have dubbed “TEC-Seq.” The custom method captures multiple regions of the genome and does deep sequencing of the fragments within those swaths.

In looking at four cancers – colorectal, breast, long and ovarian – they isolated 58 culprit genes. But those genes amounted to a staggering 80,000 captured base pairings.

The team assessed the blood of 200 patients with various cancers, and 44 with no cancer at all, they write.

The team detected 62 percent of the stage I and II cancers. The detection rate increased into the 90s for the later stages of tumors, based on the tumor type, the results show.

 Isolating the cancer’s genetic signature from normal DNA changes and mutations was the difficulty, the researchers report. To minimize “false positives” is the major hurdle, they add.

The targeted cancer mutations were not detected among blood samples of the 44 cancer-free subjects, they report.

“The challenge was to develop a blood test that could predict the probably presence of cancer without knowing the genetic mutations preset in a person’s tumor,” said Victor Velculescu, the corresponding author of the work, who is a professor of oncology at Johns Hopkins’ Sidney Kimmel Comprehensive Cancer Center.

“We’re trying to find the needle in the haystack, so when we do find a DNA alteration, we want to make sure it is what we think it is,” he added.

The deep sequencing method would be costly currently – but since the technology is becoming cheaper, and the number of genes could potentially be reduced, the screening could become available in the near future.

Of particular clinical use would be for high-risk populations, including smokers, and women with hereditary cancer risks, such as BRCA1 and BRCA2 genes.

“This study shows that identifying cancer earlier using DNA changes in the blood is feasible and that our high accuracy sequencing method is a promising approach to achieve this goal,” said Velculescu.

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