Surgeons noticing something than seemed like an anomaly, and then turned out to be almost predictable, that patients recovering from cancer surgery who suffered post-surgery infections like pneumonia, saw a speedy return of cancer, has motivated further research and a strange result. Researchers from McGill University in Montreal and the University of Calgary followed through on that common-enough occurrence to discover white cells used by the body's immune system to battle infection, in that process spin a web of sticky DNA. That web has a purpose; to trap and capture foreign invaders within the body.
In the case of cancer, that sticky substance traps and captures circulating cancer cells, but through some as-yet-undiscovered process the cancer cells are made stronger, more aggressive, more likely to re-invade the liver, lungs or other organs, rather than be killed as bacteria would be, by the body's immune system swinging into action.
"This changes the way we think about how cancer cellos spread. It's an entirely novel way of cancer spreading", explained Dr. Lorenzo Ferri, a thoracic surgeon, associate professor of surgery and oncology at McGill.
This realization spurred researcher to the use of drugs currently on the market, in a re-purposing manner, to block or tear down the cellular webs in patients who risk developing infection, as a post-surgery complication. A drug commonly utilized for the treatment of cystic fibrosis, and another used to prevent sepsis (blood poisoning) have been tested on cancerous mice. The treated animals appeared less likely to have their tumours grow or spread. And further laboratory tests gave similarly positive results for numerous types of cancers.
"Over the past five to seven years, there has been this increasing recognition that maybe something right after surgery may trigger a cancer's return", said Dr. Ferri in an interview. Surgeons around the world were taking note of cancer recurring more rapidly if patients developed infectious complications post-surgery. "We were seeing this with many different cancers -- head and neck cancer, colon cancer, stomach cancer, esophagus and lung cancer."
Dr. Ferri and his colleagues made the discovery that neutrophils, the most abundant white cells in blood recruited by the immune system to kill off invading organisms, can also, confoundingly, help cancer cells attach to organs such as the liver or lung. "We never even thought neutrophils were involved at all. We went one step further to find out, what exactly is causing this?
"This DA web comes out and it's decorated with certain proteins, which we are just now trying to understand. What we're finding is that these proteins are actually activating the cancer cells. If we understand this a little better, we can figure out the exact timing and dosage of drugs to use to break down the neutrophil web. It's a delicate balance, because if you give too much at the wrong time, you may make people more sick from the infection."
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