Colon Cancer Current Topics in Colon Cancer

New Blood Test May Detect Cancer Early

A simple blood test may reveal cancer in its earliest stages, researchers report.

If proven accurate, this tool may make it easier and less expensive for doctors to screen for cancer and monitor treatment progress for those with cancer.

The blood test, developed by researchers at Purdue University, measures levels of a particular protein, called tNOX (tumor-associated NADH oxidase). In a healthy patient, this protein is only produced in low levels when cells are actively dividing, but since cancer cells divide more aggressively, blood levels of tNOX increase when cancer is present. The new blood test detects these higher than normal tNOX levels.

Dr. James Morre , one of the Purdue researchers, reports that there appear to be different forms of tNOX. And each form seems to be associated with a different form of cancer. Therefore, if a doctor could test for these specific types of tNOX. it may help doctors detect the presence of cancer. .

This cancer screening technique has already been put to the test in detecting prostate and lung cancers, and both studies were presented at a meeting of the American Association for Cancer Research.

The first study looked at 19 men with advanced metastatic prostate cancer undergoing treatment. Normally, prostate cancer is monitored using a PSA test which checks for a specific protein in the blood that is tied to the progression of the disease. However, PSA has recently fallen under some criticism for not always being the most accurate gauge of prostate cancer.

Among the men involved whose cancer seemed to have progressed based on rising PSA levels, Morre and colleagues found that their tNOX levels were 60 percent higher than in those who had falling PSA levels.

“It’s the first demonstration that we have that tNOX levels also reflect [the presence of tumors],” said Morre, “That is, the more prostate cancer present, the more tNOX protein that is present.”

Even better, tNOX may prove to be a better test for prostate cancer than PSA.

“It seems to be more uniform in terms of disease severity.” Said Moore.

In a separate test of tNOX, Morre’s team looked as 421 different volunteers, including some who had lung cancer, some who smoked but did not have lung cancer and healthy individuals.

Among those who had lung cancer, 103 out of 104 tested positive for tNOX, while none of the healthy individuals did, indicating that the protein is linked to the presence of lung cancer. Additionally, 12 percent of the smokers over 40 tested positive for this protein, possibly an early sign of lung cancer, said the researchers.

This screening tool may prove to be a useful screening test for lung cancer, say researchers. “We could screen a very large smoker population and eliminate perhaps 90 percent of them, while encouraging the other 10 percent to go on to the next stage of testing [for lung cancer],” said Morre.

The tNOX blood test may even determine what type of lung cancer is present, allowing doctors to determine the appropriate treatment early, a factor that may improve survival rates for this often lethal cancer.

The researchers have already begun to test the accuracy of tNOX measurement in other cancers, including colon, ovarian, prostate and breast cancer.

“This is a promising tool for detecting circulating cancer cells in patients,” said Morre .