ADVANCES IN MEDICAL SCIENCE
The first decade of the 21st Century brought a number of discoveries, mistakes, and medical advances that have influenced medicine from the patient’s bedside to the medicine cabinet. In some cases these advances changed deep-seated beliefs in medicine; in others, they opened up possibilities beyond what doctors thought was possible years ago.
In 2000, scientists in with the International Human Genome Project released a rough draft of the human genome to the public. For the first time the world could read the complete set of human genetic information and begin to discover what our roughly 23,000 genes do. Mapping the human genome had become a race of time and money in the 1990s, with two competitors at the forefront: the government-funded Human Genome Project, which completed its task in 15 years with more than $3 billion in taxpayer money, and a private company, Celera Genomics, which was financed with $100 million and took less than a decade.
Both groups announced a rough draft at joint press conference on June 26, 2000. In 2003 a “final” draft was released by researchers, and in 2007 more updates to the genome were published by Craig Venter, PhD, chief scientist behind Celera Genomics. “It’s the precursor for lots of medical advances,” said Venter, now chairman and president of the nonprofit J. Craig Venter Institute. “That was absolutely the hope for it, that it will begin to change things,” said Venter, who was awarded the National Medal of Science by President Obama for his work on the human genome. Venter sees more medical potential than medical achievements in genomic research. But when those advances do come, Venter predicts it will help preventative medicine and cut our rapidly accelerating medical costs from increasingly expensive treatments. “I think the biggest area of the future will be preventive medicine,” said Venter. “By understanding the genetic causes and links to disease we can spend more and more attention on preventing disease.”
Doctors have developed a genetic test for a gene associated with prostate cancer, “and there’s a drug available that greatly lowers the risk for prostate cancer in the future.” Patients may not even think of it as they sign in with a pad and pen, then sit in the waiting room while the nurse pulls their file. But doctors say the Internet and information technology has actually changed the way they practice medicine for the better. Even doctors need to look things up from time to time.
Information technology has also, to some degree, made life safer for the patient. Once admitted to a hospital, they get a bar code which matches their blood samples and their IVs. “The ways in which computer systems are improving hospital care& are pervasive and radical,” explained Margaret Humphreys, MD, PhD, editor of the Journal of the History of Medicine. But many physicians have been reluctant to go digital because there is a significant upfront investment, which is why several of the healthcare reform measures now before Congress include provisions to underwrite some of this cost. With or without reform, the Obama administration has an ambitious program aimed at converting paper records to electronic health records and has earmarked $20 billion to pay for the switch-over and named medical IT wonk David Blumenthal, MD, to serve as National Coordinator for Health Information Technology.
There is no national smoking ban in the U.S., but 27 states and the District of Columbia have enacted smoking bans, including seven states that ban smoking in bars and casinos in recent years. In a report issued last October, the Institute of Medicine said those public smoking bans have cut exposure to secondhand smoke, which, in turn, has contributed to a reduction in heart attacks and death from heart disease.
“Anti-smoking campaigns (at least in the U.S.), including banning of smoking in workplaces and public places, [have] enormous impact across socioeconomic classes on many diseases,” said Humphreys, who added that smoking increases the risk for strokes and many cancers. In terms of the greatest good for the greatest number, there can be no doubt that the decline in smoking (through various means) has had the greatest impact.” “Virginia and North Carolina are just getting around to banning cigarettes in all restaurants now, so the public bans do track over the last 10 years.” While public smoking bans protect people from second hand smoke doctors say they also motivate people to quit. “It’s probably the most important ‘doable’ public health measure for decreasing morbidity and mortality,” said Richard Kahn, MD, of Tenants Harbor, Maine. “There is good data that as it becomes more difficult for people to smoke, more will quit.”
Those looking for dramatic improvements in public health need look no further than the world of heart disease. A mere 25 years ago, when a patient came to a hospital with a heart attack, the best that could be done was to put the patient in a darkened room, give him or her morphine for pain and lidocaine, which doctors believed would prevent dangerous irregular heartbeats, and hope for the best. Heart attacks, called infarcts, were “big” and the damage to the heart muscle was often catastrophic, leading eventually to heart failure and death. By contrast, today treating a heart attack is all about speed: speed the patient to the hospital so that a clot that blocks the life-saving flow of blood can be “busted” with drugs like the genetically engineered tissue plasminogen activator or tPA. If the problem is a vessel narrowed by buildup of plaque, a tiny flexible tube called a stent can be guided from an artery in the groin or the forearm up into the heart, where it is used to prop open the vessel to allow blood to flow normally. Still other patients are sent to surgery, where surgeons have learned sophisticated techniques to sew new vessels into the heart to bypass diseased arteries. Moreover, drugs that didn’t exist 25 years ago — chiefly statins like simvastatin, Lipitor, mevacor, and Crestor — are now routinely used to slow the progression of atherosclerosis, the medical term that describes the build-up of the hard, waxy substance called plaque that narrows arteries. Cardiologists say these efforts really began to bear fruit after 2000.
Probably no area of research has so fired the public imagination and so ignited the fires of public controversy as that of stem cell research. In reality, this area has generated more political action than reproducible clinical advances – the much-publicized ban on Federal funding of embryonic stem cell research was recently rescinded. But the clinical advances with embryonic or adult stem cells — even when they have come from pilot studies — have been tantalizing. For example, European researchers genetically manipulated bone marrow cells taken from two 7-year-old boys and then transplanted the altered cells back into the boys and apparently arrested the progress of a fatal brain disease called adrenoleukodystropy or ALD, which was the disease that affected the child in the movie “Lorenzo’s Oil.”
Cases like those fuel the promise of stem cell research, be it embryonic or adult stem cells. As the population ages, the opportunity for ‘replacement parts’ becomes more and more inviting, and I’m counting on stem cell research to give me, at least, new cartilage for my knees,” joked Humphreys. “This seems likely to be the future of regenerative medicine.” Stem cell researcher George Daley, MD, PhD, of Children’s Hospital in Boston, called progress in both adult and embryonic stem cell research this decade “breathtaking.” “Now we can make embryonic-like stem cells directly from skin cells, which makes it possible to model a multitude of human diseases in the petri dish. New drugs based on stem cells are being developed, and the first human clinical trial based on products of human embryonic stem cells is expected. “The science of the past decade has been spectacular, and we’re hopeful that in the next decade, we’ll start to realize the promise of new stem cell therapies.”
Two blockbuster-targeted therapies burst on the cancer scene in late 1990s, and arguably changed forever the concept of cancer treatment, converting what was often a fatal disease into a chronic illness. The first, Herceptin, is a drug that targets a type of breast cancer that is characterized by a specific cancer gene — an oncogene — called HER-2. Women whose cancers express HER-2, which is estimated to be about 25 percent of women with breast cancer, will respond to Herceptin even when other powerful chemotherapy drugs have failed.
“The introduction/approval of trastuzumab (Herceptin) and lapatinib (TyKerb) in breast cancer will prevent many women’s breast cancers from recurring and have significantly improved survival for many women faced with breast cancer. More important, these drugs represent highly effective agents that target the cancer, not the patient. The other drug, a cancer pill called Gleevec, targets genetic mutation called bcr-abl (b.c.r. able) that causes cancer cells to grow and multiply in patients with a variety of cancers, including chronic myeloid leukemia or with a stomach cancer called GIST. These two breakthrough agents opened the door to a number of cancer drugs that target specific molecules that control not only cell growth, but also the blood supply that feeds tumors.
Since the introduction of highly active antiretroviral therapy, or HAART, as this combination therapy approach is called, HIV/AISA has evolved into a serious, but chronic disease with survival stretching into decades. Moreover, this “cocktail” approach to treatment where drugs are combined in different ways or different sequences has become a model for treating other diseases ranging from lung cancer to heart disease.
“In 1996 a 20-year-old person in the U.S. with AIDS expected to live about three to five years and now expects to live to be 69 years. That is amazing,” said John Bartlett, MD, past president of the Infectious Diseases Society of America. “Think of it — in 1996 everyone in our HIV clinic was prepared to die. Now they all live. And most of them look great. They just need to take the meds.” In more than a decade since the emergence of HAART, researchers have constantly refined the regimens to improve results, with evidence now emerging that some combinations may be more effecting patients with more extensive disease.
Doctors have also used robotic surgery to improve the accuracy of procedures, especially in cancer cases. “Robotic surgery increased the ability of cancer surgeons to get clean margins as well due to the magnification of the structures,” said Douglas Bacon, MD, of the Mayo Clinic in Rochester, Minn. Richard Caselli, MD, of the Mayo Clinic in Scottsdale, Ariz., pointed out that robotic surgery “offers the potential for surgeons to operate on patients remotely.” But critics, say the cost of the robotic hardware may outweigh the benefit. Moreover, critics say that the robot revolution is racing ahead of the evidence.
Until July 2002 most doctors treating middle-age women believed that giving their patients hormones — either estrogen alone or estrogen combined with progestin — would protect their hearts from the ravages of age that seemed to attack women after menopause. Hormone replace therapy, or HRT, was also thought to be good for the bones, the brain, the skin, the figure, and the libido, and was considered the best treatment to control the annoying and sometimes disabling symptoms of menopause such as hot flashes, depression, and sleep disturbances. And then the world changed, the National Heart Lung and Blood Institute, which was sponsoring a placebo-controlled trial of hormone replacement therapy in more than 161,000 healthy women, announced that it was shutting down the study because HRT increased the risk of heart attack, stroke, blood clots, and breast cancer. Larry Norton, MD, of the Memorial Sloan-Kettering Cancer Center in New York City, believes the two biggest advances in breast cancer this decade was the targeted-breast cancer treatment with Herceptin and “the finding that postmenopausal hormone replacement is associated with a huge increase in the risk of breast cancer.”
Mind-reading has moved from carnival attraction to the halls of medicine with what is known as a functional MRI. The medical mind-readers are not trying to identify a card randomly selected from a deck — they are using sophisticated imaging techniques to map the way the mind works. The process, often called fMRI, traces the working of neurons — brain cells — by tracking changes in the oxygen levels and blood flow to the brain. The more brain activity in one area, the more oxygen will be used and the more blood will flow to that area. The patient lies awake inside an MRI scanner. He or she is asked to perform a simple task, like identifying a color or solving a math problem. As the patient answers the question, the fMRI tracks the areas of the brain that are activated by tracing the speed at which the cells metabolize the sugar, or glucose. First developed in the early 1990s, fMRI began to shape research at the beginning of the decade. “It has certainly taken off in the past 10 years as a means for studying the living human brain in action,” said Caselli. “It has given us innumerable insights into cognition, social interactions, reward systems, decision-making, and so on.”
Using this technique, researchers are learning valuable information about disease such as depression, brain cancer, autism, memory disorders, and even conditions such as the skin disorder psoriasis.