A team at Johns Hopkins University has trialled a method that detects eight common forms of the disease.
Their vision is an annual test designed to catch cancer early and save lives. UK experts said it was "enormously exciting".
Tumours release tiny traces of their mutated DNA and proteins they make into the bloodstream.
The Cancer Seek test looks for mutations in 16 genes that regularly arise in cancer and eight proteins that are often released.
It was trialled on 1,005 patients with cancers in the ovary, liver, stomach, pancreas, oesophagus, colon, lung or breast that had not yet spread to other tissues.
Overall, the test found 70% of the cancers.
Dr Cristian Tomasetti, from Johns Hopkins University School of Medicine, told the BBC: "This field of early detection is critical, and the results are very exciting.
"I think this can have an enormous impact on cancer mortality."