The Common Cold: Key to Cancer Cure?

The common cold has been the scourge of humanity for aeons, causing misery and making us more susceptible to worse diseases. Worse, it's almost impossible to eradicate because the germs that cause cold are so varied, numbering in the dozens or even in the hundreds. But what if you could exploit the traits of the cold -- its variation, the ease with which it infects humans, and the relative mildness of the disease -- to deliver a cancer cure directly to sick cells?

Stanford researchers found out by making people sick to make them better.

A Preliminary Study: Colds Curing Cancer

The researchers started with an ordinary live cold virus, genetically modifying it in some standard ways so that it was not as infectious as an ordinary cold virus. The 35 participants were taken from a group who had secondary liver tumors that had spread from colon cancer, and who had a projected survival period of only six months. The modified cold virus was injected directly into a vein leading to the liver; this way, it reached all the cancerous cells in the organ, which a more general injection would not have done.

The virus was modified to take advantage of a common defect in cancer cells -- the fact that in as many as two-thirds of cancers, the p53 protein is defective and shuts down production entirely. This kills normal cells; in cancer cells, however, the lack of this protein allows for unchecked reproduction, causing a tumor. There's a flip side to the p53, though; it protects cells against infection.

The weakened cold virus, unable to attack healthy cells, infects only the cancer cells that have no defense. The patient's immune system, detecting an infection, kicks in and attacks the cancer cells, killing them to get at the virus. Researchers documented swelling and inflammation at the tumors, indicating serious immune system reactions. And though not all the tumor cells die, the tumor starts to shrink.

Outcomes of the Study

Side effects included flu-type symptoms for a week -- just like any cold. This, the participants agreed, was a big improvement over the much more severe side effects of chemotherapy.

The effects on the tumors, and the patients, were dramatic. In the group who received the viral dose, they were expected to live an average of six months; instead, they averaged a year's survival. In addition, the tumors started shrinking and ceased producing cancerous proteins that are a hallmark of cancer.

This was only a small trial study, but has been repeated with varying success over the last few years. The main proof in the study was that the treatment was safe. No one caught cold from the participants, and the participants weren't harmed by the modified virus.

While this study was limited only to liver cancers, researchers have been investigating the use of the same therapy in head, neck, ovarian, and pancreatic cancers.