Bright-Sided by Barbara Ehrenreich Read Free Book Online Page A

microbes, cancer cells are not “foreign”; they are ordinary tissue cells that have mutated and are not necessarily recognizable as enemy cells. As a recent editorial in the Journal of Clinical Oncology put it: “What we must first remember is that the immune system is designed to detect foreign invaders, and avoid our own cells. With few exceptions, the immune system does not appear to recognize cancers within an individual as foreign, because they are actually part of the self.” 16

    More to the point, there is no consistent evidence that the immunesystem fights cancers, with the exception of those cancers caused by viruses, which may be more truly “foreign.” People whose immune systems have been depleted by HIV or animals rendered immunodeficient are not especially susceptible to cancer, as the “immune surveillance” theory would predict. Nor would it make much sense to treat cancer with chemotherapy, which suppresses the immune system, if the latter were truly crucial to fighting the disease. Furthermore, no one has found a way to cure cancer by boosting the immune system with chemical or biological agents. Yes, immune cells such as macrophages can often be found clustering at tumor sites, but not always to do anything useful.

    To my intense shock and dismay as a former cellular immunologist, recent research shows that macrophages may even go over to the other side . Instead of killing the cancer cells, they start releasing growth factors and performing other tasks that actually encourage tumor growth. Mice can be bred to be highly susceptible to breast cancer, but their incipient tumors do not become malignant without the assistance of macrophages arriving at the site. 17 A 2007 article in Scientific American concluded that at best “the immune system functions as a double-edged sword. . . . Sometimes it promotes cancer; other times it hinders disease.” 18 Two years later, researchers discovered that another type of immune cell, lymphocytes, also promote the spread of breast cancer. 19 All those visualizations of courageous immune cells battling cancer cells missed the real drama—the seductions, the whispered deals, the betrayals.

    Continuing in an anthropomorphic vein, there’s an interesting parallel between macrophages and cancer cells: compared with the body’s other cells, both are fiercely autonomous. Ordinary, “good” cells slavishly subject themselves to the demands of thedictatorship of the body: cardiac cells ceaselessly contract to keep the heart beating; intestinal lining cells selflessly pass on nutrients that they might have enjoyed eating themselves. But the cancer cells rip up their orders and start reproducing like independent organisms, while the macrophages are by nature free-ranging adventurers, perhaps the body’s equivalent of mercenaries. If nothing else, the existence of both is a reminder that the body is in some ways more like a loose, unstable federation of cells than the disciplined, well-integrated unit of our imaginings.

    And, from an evolutionary perspective, why should the body possess a means of combating cancer, such as a form of “natural healing” that would kick in if only we get past our fears and negative thoughts? Cancer tends to strike older people who have passed the age of reproduction and hence are of little or no evolutionary significance. Our immune system evolved to fight bacteria and viruses and does a reasonably good job of saving the young from diseases like measles, whooping cough, and the flu. If you live long enough to get cancer, chances are you will have already accomplished your biological mission and produced a few children of your own.

    It could be argued that positive thinking can’t hurt, that it might even be a blessing to the sorely afflicted. Who would begrudge the optimism of a dying person who clings to the hope of a last-minute remission? Or of a bald and nauseated chemotherapy patient who imagines that the cancer experience