{"id":94,"date":"2013-04-08T14:40:35","date_gmt":"2013-04-08T14:40:35","guid":{"rendered":"http:\/\/joshmitteldorf.peachpuff-wolverine-566518.hostingersite.com\/?p=94"},"modified":"2013-04-08T14:40:35","modified_gmt":"2013-04-08T14:40:35","slug":"the-immune-system-protects-us-against-cancer","status":"publish","type":"post","link":"https:\/\/scienceblog.com\/joshmitteldorf\/2013\/04\/08\/the-immune-system-protects-us-against-cancer\/","title":{"rendered":"The immune system protects us against cancer"},"content":{"rendered":"

For decades, we have been treating cancer by hammering away at cancer cells with radiation and chemical poisons. \u00a0Fearful that even one surviving cell can seed a recurrence, we routinely apply the maximum tolerable dose, with side-effects ranging from nausea and hair loss to permanent impairment of the immune system. \u00a0Is there a better approach?<\/em><\/p>\n

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Cancer is an aging-related disease. There are very different views on how aging\u00a0impacts on cancer development in humans. A dominant view believes that somatic\u00a0cells accumulate mutations during aging until the point where mutations cause cells\u00a0to be changed into cancer cells that then clonally expand into populations of cancer\u00a0cells. The premise of this theory is that cancer begins when the \ufb01rst cancer cell is\u00a0formed and undergoes uncontrolled clonal expansion.<\/p>\n

Another view believes that having cancer cells in the body is not necessarily a problem. This theory holds that cancer cells are formed continuously in our bodies on a daily basis but that their presence in our body can reach a dynamic balance with our body\u2019s pre-existing ability to remove them, after they formed. Such a hypothetical natural ability to remove cancer cells was termed a cancer \u201csurveillance system\u201d about 100 years ago by Paul Ehrlich (1909). As long as this balance is maintained, the presence of cancer cells would not pose any health problem. Clinically signi\ufb01cant malignancies can form only when such a dynamic balance is tilted in the direction of having more cancer cells, less surveillance against them, or both.<\/p>\n

– Zheng Cui<\/a><\/p>\n<\/blockquote>\n

In the early part of the last century, we learned to kill invading pathogens with antibiotics. \u00a0A generation later, we sought to apply the same approach to cancer cells. \u00a0The classic approach to curing cancer has been to kill the cancer cells, but it turns out that is difficult to do without collateral damage to healthy body tissues*. \u00a0So research has focused on selectivity. \u00a0We are seeking approaches that kill malignant cells more reliably while sparing normal cells more completely.<\/p>\n

Too often, we find that such treatments drive cancer into remission, but cancer recurs in a few years or sometimes months. \u00a0According to the standard thinking, the treatment killed all but an undetectable handful of cells, but as long as even one malignant cell remains, it will multiply unchecked, eventually recreating the full pathology. \u00a0Hence standard treatments are pushed to the limit, where side-effects are fatal for some patients.<\/p>\n

But all around the edges of the cancer literature, there are alternative pictures that may better describe the broad clinical phenomena of cancer. \u00a0There is an enormous and varied literature of alternative approaches to cancer. \u00a0I can\u2019t begin to survey them, but this brief article offers my personal impressions of one vein in the literature that I find compelling. \u00a0This is the view that cancer is a systemic disease, a failure of the body\u2019s central controls, especially the immune system, that continually detects cells that are cancerous or pre-cancerous and eliminates them, or induces them to eliminate themselves via cell suicide (apoptosis). \u00a0Perhaps mutations produce potential malignancies through our lives on a daily basis, but these are efficiently eliminated by the immune system before they can do any damage, just as invading microbes are kept in check. \u00a0In this picture, the reason that cancer so often recurs after treatment is not that the treatment has missed a few cells, but that the original systemic weakness that permitted the cancer to escape the body\u2019s defenses in the first place has not been addressed.<\/p>\n

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\u00a0Reasons to believe that rogue cells are not the essence of the problem<\/strong><\/p>\n

Here are three pieces of evidence in favor of this picture:\u00a0<\/b><\/b><\/p>\n