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Scientists tell us that they are making great advances in the treatment of cancer. This is not so. The total U.S. cancer death rate has barely budged in the past 60 years. Though deaths from some types of cancer have dropped, these drops have been offset by the rise in deaths caused by other cancers. Of the cancers that have dropped the most: stomach cancer and cancer of the uterine cervix, improved mortality is due to a drop in cancer incidence, not due to any progress in treating advanced cancers. The reduced incidence of stomach cancer is generally credited to refrigeration and improved methods of food preservation. With better preserved food, the incidence of stomach cancer dropped. The drop in cervical cancer has been due to effective Pap smear screening for precancerous lesions (small lesions that precede the development of invasive cancer). When uterine precancers are excised, the cancer never develops. Further reduction in deaths from uterine cancer will probably result from population-wide inoculations with the new HPV vaccine; an effective measure that bypasses the need to treat advanced cancers.
Beginning about 1991, the U.S. has seen a small, but continuous drop in the cancer death rate. This drop is due almost entirely to the reduced incidence of lung cancer among men (due to smoking cessation). Even with this small drop, the cancer death rate is still about the same as it was in the middle of the twentieth century (i.e., there is still a net increase in the long-term U.S. cancer death rate, even with the recent drop). With the exception of curing a few types of rare tumors, cancer research has yielded none of the dramatic medical advances we saw in the 1950s, against such diseases as polio and tuberculosis.
Cancer death rates that have increased since 1950 include: esophageal cancer, liver cancer, pancreatic cancer, lung cancer, melanoma, kidney cancer, brain cancer, non-Hodgkins lymphoma, and multiple myeloma. The list includes some of the most common types of cancer. If cancer research were effective, we would have prevented the rise in incidence of these common cancers.
If you speak to cancer researchers, they will tell you that we have made great advances in understanding cancer genetics; the mutations in DNA that contribute to the development of cancers. Yes; we've gotten a lot of news about cancer, but it's mostly bad news. We now know, thanks to billions of dollars of funding, that cancer cells are remarkably complex, often containing thousands of genetic alterations. No two genetically complex cancers can be characterized by the same set of mutations, and no two tissue samples of any one cancer will be genetically identical. The complexity of cancer far outstrips our ability to characterize the alterations in a cancer cell. Consequently, it is highly unlikely that any single drug will correct all of the genetic changes in the cells of advanced (i.e., invasive and metastatic) common cancers. Newly acquired knowledge of cancer genetics have taught us that we cannot cure advanced common cancers with currently available techniques.
There are a few exceptions. Not all cancers are complex. Some cancers (particularly rare inherited cancers and rare cancers occurring in children, and a few types of rare sporadic cancers) are characterized by simple genetic alterations. These genetically simple tumors turn out to be the tumors we can cure or the tumors for which we can most likely develop a cure in the near future. A simple genetic error can be targeted by a new generation of cancer drugs. Unfortunately, the commonly occurring cancers of adults are all genetically complex. It is unlikely that we will be able to cure these tumors anytime soon. The best chance of curing common cancers may come from studying how rare (genetically simple) tumors respond to new types of treatment.
In cancer research, as in so many other modern areas of scientific research, it seems that complexity is a major barrier to scientific progress.
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© 2010 Jules Berman
key words:informatics, complexity, jules j berman, medical history
Science is not a collection of facts. Science is what facts teach us; what we can learn about our universe, and ourselves, by deductive thinking. From observations of the night sky, made without the aid of telescopes, we can deduce that the universe is expanding, that the universe is not infinitely old, and why black holes exist. Without resorting to experimentation or mathematical analysis, we can deduce that gravity is a curvature in space-time, that the particles that compose light have no mass, that there is a theoretical limit to the number of different elements in the universe, and that the earth is billions of years old. Likewise, simple observations on animals tell us much about the migration of continents, the evolutionary relationships among classes of animals, why the nuclei of cells contain our genetic material, why certain animals are long-lived, why the gestation period of humans is 9 months, and why some diseases are rare and other diseases are common. In “Armchair Science”, the reader is confronted with 129 scientific mysteries, in cosmology, particle physics, chemistry, biology, and medicine. Beginning with simple observations, step-by-step analyses guide the reader toward solutions that are sometimes startling, and always entertaining. “Armchair Science” is written for general readers who are curious about science, and who want to sharpen their deductive skills.
