Early trials of a potential cancer treatment in which white blood cells are modified to target certain types of the disease have been an "extraordinary" success, scientists said Monday. 

In one study, 94 percent of participants suffering from acute lymphoblastic leukemia (ALL) said their symptoms vanished completely after they were treated with the modified blood cells, known as T-cells. 

In another study, 80 percent of patients with non-Hodgkin's lymphoma responded positively to the treatment, while more than half ended up symptom-free. 

"This is extraordinary," said lead researcher Professor Stanley Riddell from the Fred Hutchinson Cancer Research Center in Seattle. "This is unprecedented in medicine to be honest, to get response rates in this range in these very advanced patients."

The treatment involves removing the T-cells from patients, tagging them with "receptor" molecules that target cancer, and putting them back into the body in an infusion.The targeting molecules, known as chimeric antigen receptors or Cars, came from specially bred genetically engineered mice.

Once attached to the T-cells, they reduce the ability of the cancer to shield itself from the body's natural immune system.

Such reprogramming of the immune system is often considered a last-ditch option due to its dangerous side effects. The researchers noted that seven of the ALL patients required intensive care after suffering an immune reaction called cytokine release syndrome (sCRS). Two of those patients died.

Riddell himself said that much more work was still required, and it was not clear how long the symptom-free patients will remain in remission.

Great Reddit comment:

I currently work in an Immuno-Oncology lab and wanted to address a few comments I read on this thread:

1. The jaded disillusionment with so called “miracle cures” we now feel with these headlines is due partially to the media saturation in today’s society. Every little breakthrough is reported while it takes years of research from various research groups and labs across the world to first investigate a possible novel therapy and report their findings in scientific journals. If that early data looks good, then clinical trials are initiated to see if these findings will translate to patients in a clinical setting which also takes years. 
2. Additionally, we will never discover a catchall cure for cancer such as the polio vaccine. Cancer exists in too many forms and varies among each individual patient. So this is again sensationalized reporting intending for the general public to click and read that article. 
3. Major improvements have been made in cancer research. As many people of this thread have mentioned, leukemia was a death sentence in the early 20th century and now has an almost 90% survival rate. All the major advances have occurred within the past 30 years and many cancers have a decent survival rate.
4. I will probably be crucified for saying this but FDA clinical testing is extremely important. Yes, everyone wants the best treatment for their family member with cancer but it needs to be thoroughly investigated before for multiple reasons. a. A proper dosage range needs to be determined. Immunotherapy like chemotherapy can have toxic side effects. At the beginning of chemotherapy, doctors were literally killing patients with the chemo drugs in an attempt to treat them since cancer was a death sentence anyway. They eventually found the proper dosing where they could be as aggressive as possible while balancing the toxic side effects. The same must be done with all future therapies. b. The Emperor of All Maladies has a great section on the balance between the desire to push forward with an experimental approach and the need for concrete statistical evidence. If were we to make these experimental immunotherapies available to everyone in an uncontrolled fashion, we would not know their actual effectiveness compares to current treatments. If these immunotherapies are to become the next standard of care, they must be proven more effective in stringently controlled scientific studies and not by anecdotal evidence. There have been so many false leads in 50 years of cancer research, that making a therapy open to the public too early can be a disaster. Yes, this may mean a loved one will die waiting for these “miracle cures” to get FDA approval, but if the treatment is given a go ahead without evidence, how many patients may die receiving this treatment when it could be substandard to current treatment options. 
5. Currently CART therapy is astronomically expensive as it is incredibly personalized where a patient’s T cells are extracted from their blood, modified according to their specific cancer with its own unique genetic mutations, expanded in cell cultures in a lab, and infused back into the patient. However, if the clinical trials prove it is effective, the cost will greatly be reduced thanks to large pharmaceutical companies (again I know reddit will hate me for saying this). One pharmaceutical companies see this treatment is proven effective and may become the standard of care, they will begin to create large divisions within their company dedicated to these treatments which will greatly reduce the cost compared to a lab handling the same job for 20 patient in a clinical trial. When the costs decrease, the therapy could become standard care for certain cancers and will be covered by a patient’s insurance. 
6. Lastly, people are currently investigating the effectiveness of using these CART and other immunotherapies in combination with radiation and chemotherapy. Yes, chemotherapy damages the immune system but since CART is an outside infusion of T cells it should still work. However, immune checkpoint inhibitor therapies may not be as effective in combination with chemo as they rely on the innate T cells within the body to attack the cancer. Additionally, radiation causes inflammation in treated areas, which should bolster the immune system response in those areas which can be combined with immune checkpoint inhibitors.

300+ Reddit comments:

https://reddit.com/r/Futurology/comments/461k7v/scientists_claim_extraordinary_success_94/

Also, running helps mice slow cancer growth.

http://pandawhale.com/post/70668/running-helps-mice-slow-cancer-growth

CRISPR scientists have also experimented with T cell treatments:

http://pandawhale.com/post/66417/in-crispr-advancement-scientists-successfully-edited-human-t-cells-to-resist-hiv-and-to-fight-cancer-t-cell-ftw