Terminal Cancer May Not Be So Terminal, Researchers Find

One reason cancer is among the most dreaded diseases is its progression. Once it reaches an advanced stage, there seems to be no stopping it.

But what if you could?

It's a question researchers at California Pacific Medical Center Research Institute in San Francisco are asking, and they now think they have an answer.

For the first time, they say, they have developed a therapy that can effectively treat the now invariably lethal, terminal stages of cancer in animals. The study appears in the latest issue of the Proceedings of the National Academy of Sciences.

"Our research shows that a novel monoclonal antibody can help block the now terminal stage of cancer," said Robert Debs, MD, researcher/scientist with the Institute and one of the lead authors of the study. "So far it has shown effectiveness in mice against colon and breast cancers and melanoma."

Currently untreatable

Currently, the end stages of metastatic cancer - the highly advanced cancers that have already spread to other parts of the body from its original location - are untreatable. This advanced stage of cancer destroys organs and attacks other systems of the body. The patient gets weaker and weaker, and then dies.

Part of the problem with finding a treatment was the lack of understanding of the molecular mechanisms governing the lethal growth of these already large and destructive cancers. There's also the fact that terminal stages of cancer have been considered just that. Treatment ends and the patient begins putting their affairs in order. Because of this hopelessness, Debs says, this stage hasn't gotten much study.

Debs believes the present study shows that the moratorium on studying terminal cancers, as well as developing treatments effective against them should now end. He and his colleagues say they have isolated the molecule that drives cancer growth. By focusing on that molecule, they say, they have an effective way to treat what has, until now, been the terminal stages of cancer.

Shown to be effective

"The anti-PECAM-1 antibody is very exciting because it shows effectiveness against a number of terminal cancers, and also concurrently slows the debilitating wasting syndrome that can develop as cancerous tumors become large, disseminated and destructive," Debs said.

The anti-PECAM-1 antibody produces its anti-tumor effects by binding to a protein on the surface of cells that line normal blood vessels, instead of binding to tumor cells. The protein to which the antibody binds appears to control the secretion of critical growth factors, which regulate the growth of advanced tumor metastases.

"Identifying these growth-promoting factors represents an important advance," said Dr. Michael Rowbotham, the Institute's director. "It would provide us with additional anti-cancer targets which may significantly increase our ability to stop the fatal growth of terminal cancers."

While this current round of research was done in mice, the researchers say they hope to be able to begin testing this approach in people within 24 months.