One of the most common questions cancer patients ask their doctors is: has the disease been contained or will it spread. A recent study by U.S. and Chinese researchers may help provide clues. The scientists examined genetic material from certain cancerous tumors and found that when high levels of a particular protein were present, there was a strong likelihood that these cancers would spread within two years.
The source of this discovery was among populations in Asia, where Hepatitis B and liver cancer are prevalent.
The World Health Organization estimates in Asia, liver cancer caused by Hepatitis B is one of three major causes of death in men and a major cause in women.
One fourth of the two billion people worldwide infected with the Hepatitis B virus eventually develop liver cancer and die.
Scientists in Hong Kong had been studying samples of liver tumor cells and found that some of the cells contained high levels of a variant of the protein Carboxypeptidase E or CPE.
At the same time, scientists at the National Institute of Child Health and Human Development just outside Washington, D.C. were also studying CPE and also identified the same variant, now called CPE-Delta N.
"We found that what's in cancer cells is in fact this variant form and so there we got together and [began] exploring this protein as this cancer protein," said Dr. Peng Loh, a neuro-endocrinologist at the National Institute.
The scientists in Washington injected tissue from the Hong Kong liver samples into mice and confirmed that when CPE-Delta N was present, there was a strong likelihood the cancer would metastacize, or spread, within two years.
CPE-Delta N has also been identified in cancers of the head and neck, colon, and breast. Preliminary tests indicate it may also be present in thyroid cancer.
In all, Dr. Loh says there could be as many as 14 types of cancer where CPE-Delta N is found.
"So we're very careful to say that each one has to be tested in its own right, but I think that it looks like it might cover quite a few," he said.
The researchers say the discovery could change treatment options for patients, especially those identified as having Stage I or II cancer and who carry CPE-Delta N.
"We feel that those are the ones that we can help the most, because they were the ones who were told most likely you won't get recurrence, so let's not treat," Dr. Loh said. "If we catch those, we have saved some people's lives."
The study was published in the Journal of Clinical Investigation.
