Sooner or later every doctor is asked the same question, "will there ever be a cure for cancer?" And no doubt many of them, haunted by the memory of children with leukemia or young mothers with breast cancer, wonder the same. Of course, there has been no lack of effort. In the 1970s, President Nixon even declared war on the disease, and yet, over 40 years and $200 billion later, it remains a mass killer.
In his poem Miss Gee, the English poet W. H. Auden says of cancer:
Nobody knows what the cause is,
Though some pretend they do;
It's like some hidden assassin
Waiting to strike at you.
The American physicist Michio Kaku, referring to Nixon's declaration of war, agrees, "Back in 1971, before the revolution in genetic engineering, the causes of cancer were a total mystery." Things have changed. Now, as Kaku himself observes, we know that cancer is a disease of our genes. The body is built of cells, and within these cells there are genes, which dictate the cells' activities. Sometimes, these mutate and a cell "forgets how to die," to quote Kaku again. The cell then reproduces without limit and you have cancer.
First, it must be said that cancer isn't a single illness. In fact, there are over 100 different types, usually named for the tissues and organs in which they form. They are also named for the type of cell, such as a squamous cell. Carcinomas are the most common types of cancer, formed by the cells covering the inside and outside of the body. These are known as epithelial cells and can be subdivided, as can the cancers involved: Adenocarcinoma forms in the epithelial cells that produce mucus, while Basal cell carcinoma begins in the base or "basal" layer of the epidermis.
Then there are Sarcomas, which form in bone or soft tissue, including muscle, tendons, and ligaments. Leukemia begins in the blood-forming tissue of bone marrow, and can be subdivided into four further groups. Lymphoma begins in the white blood cells. Again, there are different types, with Hodgkin lymphoma and Non-Hodgkin lymphoma being the main ones. Multiple myeloma begins in a type of immune cell known as plasma cells. Melanoma begins in the cells that make melanin, or the pigment that gives skin its color.
As you can see even from this crude and incomplete summary, cancer is complex. It is therefore unlikely that there will ever be a simple cure, with some beaming, white-coated researcher announcing his discovery on the evening news. Cancer refers to a collection of diseases. All that unites them is the uncontrolled division of cells.
Of course, if cells did not grow and divide life would be impossible. Indeed, every human begins life as a single cell, which then divides. In most cases, the growth and division is orderly. When cells become damaged, or old, they die, and new cells take their place. Cancer means this process has broken down: damaged cells survive instead of dying, and new cells form when they are not required. If the new cells divide over and over again, a tumor appears. And if the tumor is malignant, it will spread into nearby tissue.
So what causes this disruption? Two obvious examples would be tobacco smoke and UV rays. But we know that genetics also plays a part. The American actress Angelina Jolie, for example, underwent a double mastectomy after learning that she had inherited a defective BRCA1 gene. This meant she had an 87% chance of developing breast cancer, and so she decided to take preventative measures.
Craig Venter, a key figure in the Human Genome Project, remarked that, "If the 20th century was the century of physics, the 21st will be the century of biology." Before getting carried away, however, it is worth noting just how poor we really are at healing the body and mind. Visit any random street, even in the richest and most sophisticated nation, and you will find individuals tormented by physical or mental illness, from Alzheimer’s and Parkinson's to OCD and depression. Yes, there are treatments, but few cures. And, if we are honest, the treatments themselves are often ineffective. Indeed, we cannot even cure trivial miseries like hay fever, hair loss, or the common cold.
Whether this will change in the 21st century is of course impossible to say. In his book Physics of the Future, Michio Kaku argues that medicine has moved through roughly three stages. Until very recently, it was dominated by witchcraft and superstition. Then, beginning in Europe in the 19th century, real medicine appeared. There was the germ theory and, later, antibiotics and vaccines. According to Kaku, we are now entering the third stage, that of molecular medicine. Breakthroughs in physics will enable us to treat the human body at the level of atoms, molecules, and genes. And that includes cancer.
So what does this mean for cancer, the "emperor of maladies," as Siddhartha Mukherjee calls it? We should remind ourselves at this point how little progress has actually been made. In spite of the billions spent, and in spite of the efforts of brilliant and determined researchers, the death rate from cancer dropped by just 5% between 1950 and 2005.
At present, there are three main ways of tackling cancer. First, there is surgery to remove tumors. Unfortunately, though sometimes highly effective, surgery isn't always suitable or possible. Next, there is chemotherapy, which kills cancer cells. The problem with chemotherapy is that it works indiscriminately, attacking not only cancerous but also healthy tissue. This in turn leaves the patient with unpleasant side effects. Finally, there is radiotherapy. This targets a particular region of the body, but like chemotherapy it has side effects.
In spite of new treatments now under development, a complete cure for all forms of cancer looks unlikely, at least in the near future. And yet we will learn to detect it earlier, stall its progress, and maybe even prevent it entirely. Kaku speculates that we will become so good at this that the word "tumor" could disappear from the English language, since cancer will rarely reach that stage. As Kaku puts it, there will be a "coexistence with cancer." In other words, we will not defeat it, but we will force it to the negotiating table. There will be a sort of pact, and cancer will be transformed from mass killer into nasty, chronic illness.
As for actual treatments, these will attack cancer at its root. Kaku lists some of the more promising, including gene therapy, drugs that target the cancer cells alone, antiangiogenesis (choking off the blood supply to a tumor), and nanoparticles (or microscopic smart bombs targeted at the cancer cells).
One of the most exciting new treatments is known as Immunotherapy. As the title suggests, Immunotherapy uses the body's immune system to destroy cancer cells. So excited have some oncologists become that Immunotherapy has been labelled the new, "fourth pillar" of cancer care.
Nanotech is another very exciting area of research. The science behind this is complex, but in essence nanoparticles could be used to carry a sequence of DNA into cancerous cells. Once there, they produce a toxic compound inside the cells, thus killing them. The surface of the nanoparticles are made of a structure that recognizes and binds to the cancer cells. The nanoparticles then disassemble and release the sequence of DNA. The cells produce an enzyme that converts into toxins, which break the cells down and kill them. This shrinks the tumor but, even more excitingly, leaves the healthy cells that surround it unharmed. Such nanoparticles have already been used to to destroy brain tumors in rats.
Of course, the reader might object at this point and say "well, that's all very interesting, but we have no idea when these treatments will appear. In the meantime, I'd rather not get cancer at all. What can I do to prevent it now?" The answer is a great deal. Obviously, you should stop smoking and avoid sunburn. But there is more you could do.
Let's take two of the most common forms of cancer: prostate and breast. The prostate is a gland, located between the bladder and penis. So common is prostate cancer that over half of men in their 80s have it, though many die of something else. In his book How Not to Die, Dr. Michael Greger devotes a whole chapter to the disease and makes several recommendations. First, he advises men to cut down on the amount of cow's milk they consume, since it contains growth hormones. Next, you should stop eating eggs. According to Greger, men who eat a single egg a day are twice as likely to see their prostate cancer spread. He also recommends a plant-based diet, and especially cruciferous vegetables, such as cauliflower, broccoli, kale, and cabbage.
Unsurprisingly, Greger also devotes a chapter to breast cancer. Again, he recommends a plant-based diet and plenty of exercise. But he also specifies the increased risk from excessive alcohol consumption and from high levels of cholesterol, and recommends cruciferous vegetables, apples (unpeeled), flaxseed (milled or ground), and green tea. Green tea is a particularly interesting item, since it may partly explain why Asian women are five times less likely to develop the disease.
Cancer is scary. Indeed, the dread of it hangs over almost everyone like a dark cloud. And people not only fear developing it themselves, they also fear watching it destroy someone they love. But, in spite of many false dawns, there are now grounds for serious optimism. As a health journalist recently remarked in the London Times, though cancer is not yet defeated, it is on the run.