Man's own cells killing his skin cancer
As you probably know, melanoma is one of the deadliest forms of skin cancer, usually caused by too much exposure to the sun. Now U.S. researchers have developed a way to use a patient's own cloned T-cells against this skin cancer -- without chemotherapy or radiation. For example, 'a 52-year-old man whose Stage 4 melanoma had spread to a groin lymph node and to a lung,' is now tumor-free two years after being treated by 'immunotherapy.' Even if these results are encouraging, 'more studies are needed to confirm the effectiveness of the experimental T-cell therapy.' But read more...
This research project has been conducted by a team led by Cassian Yee, M.D., an associate member of the Clinical Research Division at Fred Hutchinson Cancer Research Center.
So what did the researchers achieve? "Yee and colleagues removed CD4+ T cells, a type of white blood cell, from a 52-year-old man whose Stage 4 melanoma had spread to a groin lymph node and to a lung. T cells specific to targeting the melanoma were then expanded vastly in the laboratory using modifications to existing methods. The lab-grown cells were then infused into the patient with no additional pre- or post-conditioning therapies, such as growth-factor or cytokine treatment. Two months later, PET and CT scans revealed no tumors. The patient remained disease free two years later, when he was last checked."
But can this result on one patient can be generalized? "Yee cautioned that these results represent only one patient with a specific type of immune system whose tumor cells expressed a specific antigen. More studies are needed to confirm the effectiveness of the experimental T-cell therapy. If proven successful in more patients, Yee predicted this therapy could be used for the 25 percent of all late-stage melanoma patients who have the same immune-system type and tumor antigen."
As you can guess, this result has been widely commented in the media. Here are two excerpts from a New Scientist article, "Cancer patient cured with his own immune system" (Ewen Callaway, June 19, 2008). "For a tumour to grow and spread, it must trick the immune system into thinking it is normal tissue. Immune cells that keep tumours in check remain oblivious to the malignancy or too low in number to make much of a difference. But researchers have slowly learned how to unleash this response. The most common strategy is to collect a patient’s white blood cells, grow the tumour-killing T-cells in a laboratory incubator and inject them back into the patient."
But it doesn't always work, even in labs. So Yee's team used a radical approach. "In hopes of developing a simple regimen, Yee’s team focused on a special kind of T-cell, called helper CD4 cells. The researchers isolated a handful of these cells from the patient, whose melanoma had spread to his lung and groin. All the cells recognised a protein called NY-ESO-1 – this existed in his tumour, but not most healthy cells. After the cells had been multiplying in the lab for two months, Yee’s team injected about five billion of them into the patient in one dose. The treatment annihilated the tumours within two months, and nearly two years later, there are no signs that the patient’s cancer has crept back, Yee says."
This research work has been published in the The New England Journal of Medicine under the title "Treatment of Metastatic Melanoma with Autologous CD4+ T Cells against NY-ESO-1" (Volume 358, Number 25, Pages 2698-2703, June 19, 2008). Here is a link to the abstract.
Sources: Fred Hutchinson Cancer Research Center news release, June 19, 2008; and various websites
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