An article, by David Robson, in BBC Future looks at the mysterious cases of people diagnosed with cancer who undergo what doctors call spontaneous remission, where the body cures itself without outside treatment such as chemo or drugs. This is a rare occurrence, happening to only one in 100,000 cancer patients.
Some might call these rare cases miracles, but what scientists do know is that in these cases the body's immune system kicked into high gear as a result of fevers or infections, where macrophages and T-Cells swallowed up mutant cancer cells This knowledge is helping medical researchers to look at novel approaches to battle cancer that centre on immunotherapy, or helping the body’s robust immune system defeat cancer.
Robson writes in “Cancer: The mysterious miracle cases inspiring doctors (March 6, 2015)”:
Could infection be the key to stimulating spontaneous remission more generally? Analyses of the recent evidence certainly make a compelling case for exploring the idea. Rashidi and Fisher’s study found that 90% of the patients recovering from leukaemia had suffered another illness such as pneumonia shortly before the cancer disappeared. Other papers have noted tumours vanishing after diphtheria, gonorrhoea, hepatitis, influenza, malaria, measles, smallpox and syphilis. What doesn’t kill you really can make you stronger in these strange circumstances.Whether or not medical researchers ever fully understand the mechanisms of spontaneous remission is not as important as learning and benefiting from its results. It seems that cancer treatment in the form of immunotherapy is on the right track to help defeat cancer, and that our bodies will be doing most of the work, and without the need for treatments that have unwelcome and unpleasant side effects, is even better news. Over-all, the day when this becomes the normal and preferred mode of treatment can’t come too soon.
It’s not the microbes, per se, that bring about the healing; rather, the infection is thought to trigger an immune response that is inhospitable to the tumour. The heat of the fever, for instance, may itself render the tumour cells more vulnerable, and trigger cell suicide. Or perhaps it’s significant that when we are fighting bacteria or viruses, our blood is awash with inflammatory molecules that are a call to arms for the body’s macrophages, turning these immune cells into warriors that kill and engulf microbes – and potentially the cancer too. “I think the infection changes the innate immune cells from helping the tumours to killing them,” says Henrik Schmidt at Aarhus University Hospital in Denmark. That, in turn, may also stimulate other parts of the immune system – such as our dendritic cells and T-cells – to learn to recognise the tumorous cells, so that they can attack the cancer again should it return.
Schmidt thinks that understanding the process of spontaneous remission is vital, since it could help refine the emerging class of “immunotherapies” that hijack our natural defences to combat cancer. In one treatment, for instance, doctors inject some cancer patients with inflammatory “cytokines” in order to kick the immune system into action. The side effects – such as high fever and flu-like symptoms – are typically treated with drugs like paracetamol, to improve the patient’s comfort.
But given that the fever itself may trigger remission, Schmidt suspected that the paracetamol might sap the treatment’s potency. Sure enough, he has found that more than twice as many patients – 25% versus 10% – survive past the two-year follow-up, if they were instead left to weather the fever.
There could be many other simple but powerful steps to improve cancer treatment inspired by these insights. One man experienced spontaneous remission after a tetanus and diphtheria vaccination, for instance – perhaps because vaccines also act as a call to arms for the immune system. Along these lines, Rashidi points out that a receiving standard vaccine booster – such as the BCG jab against tuberculosis – seems to reduce the chance of melanoma relapse after chemotherapy.
For more, go to [BBC Future]