Very big cancer news a few days ago, covered by everyone from the New York Times to Yahoo! News: Researchers have possibly found a way to make the body's own immune system turn on and destroy cancer cells. This could be a huge breakthrough in cancer treatment. (Please note the "could be," as I will explain below.)
The article that's causing all of the excitement appeared in The New England Journal of Medicine, and is called "Redirecting T Cells."
The story in Yahoo! News sums it up pretty decently. The study involved three patients (only three -- a very small sample) with chronic lymphocytic leukemia, a slower-growing type of leukemia. The three had T cells removed from their blood. (T cells are a type of white blood cell that destroys foreign bodies, like viruses, in the bloodstream.) The T cells were altered in the laboratory -- reprogrammed to find and destroy B cells (another type of white blood cell) that have the protein CD19 on them. These B cells include both leukemia cells and normal cells. The T cells were then reinjected back into their blood, where they did their thing, finding and destroying the cancer cells (as well as the normal cells). So far, so good: two of the three patients have been cancer-free for a year, and the third has had a partial response.
Researchers are hoping to eventually use this technique on other cancers as well, reprogramming the patient's immune system to destroy their tumors.
The response has been downright giddy, something that we rarely see from cancer specialists. And it does seem to be worth the excitement: up until now, no one has figured out how to get the body to recognize its own cells (cancer cells) as being invaders that need to be wiped out.
But here's the cold water:
First, it's an extremely small study. Three people is tiny. Larger studies are going to be needed to see just how effective this is for a wider population. That's going to take time, money, and volunteers.
Second, it's still very early. Cancer resarch is littered with treatments that were wildly successful for a short time, but then subverted by the cancer, which found a way around the treatment. A year is great, but we still need to see how it works over a longer time.
Third -- from what I've been reading, there's some concern about the T cells themselves, and the way they work. The T cells kill off normal cells as well as cancer cells, which is a problem becuase the cells being killed off are also part of the immune system, leaving some patients vulnerable to infection or other illness. Also, this type of T cell (the body has several) doesn't know how to turn off -- they keep multiplying, potentially killing off immune system cells forever, because they only look for CD19, whether it's on a normal or abnormal cell.
The reserachers acknowledge these problems, and seem realistic that this is only a first stage in this type of treatment. (As with any news about cancer treatment, you have to read carefully and make sure the news outlet doing the reporting isn't over-accentuating the positive.)
Still, I'm going to give this a cautious four golden nodes out of five, based on its potential. Because if it does get refined, and it is shown to work on a large population over time, it's going to be a very big deal.
Truly amazing. I was just talking about this story with a friend a few days ago. Science is the best.
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