Test could detect a range of cancers weeks before symptoms
U.K. researchers have found a way to test for a protein that could become a biomarker for many different types of cancer. The DNA damage-signaling protein, γH2AX (gamma-H2AX), signposts the points where both strands of the DNA double helix have broken, one of the first steps in development of cancer (known as tumorigenesis).
The team from Oxford University's Gray Institute for Radiation Oncology and Biology has built an imaging probe that targets this protein. The probe is in three parts--an anti-γH2AX antibody that targets the biomarker, a peptide (TAT) that penetrates the cell, and 111In, a radioactive marker used as an imaging agent.
To test out the concept, the researchers used the probe and SPECT imaging to find DNA damage in a type of genetically modified mice that tend to develop breast cancer lumps that can be felt after around 17 weeks. The test spotted potential cancers in mice up to 5 weeks before they developed these lumps. The same marker is also seen in lung, skin, kidney and bladder cancer.
Katherine Vallis of the institute told BBC News: "If larger studies confirm this, the protein could provide a new route to detect cancer at its very earliest stage--when it is easier to treat successfully."
As well as being a biomarker for many cancers, this finding could also lead to a way to deliver radiotherapy directly to the damaged cells and monitor its effects, treating established tumors or even heading off cancers almost before they start. As Vallis explained to BBC News, the system is "self-amplifying" because the radiotherapy will cause further damage to the cells, therefore attracting more antibodies that will deliver more radiation, eventually killing the cancer cells. However, the technology has only been studied in mice so far, and it is a long way off use in humans.