The 20th century saw a string of world-changing technological breakthroughs - mass-produced automobiles, television, space travel, computers and the internet - that would have been met with incredulity just a few decades before. But the astonishing speed at which 21st-century medicine is advancing looks set to outstrip even those giant leaps for mankind. It is possible that over the course of our lifetime, vaccines will help prevent or cure many of our most lethal cancers; we will be able to grow an unlimited supply of hearts, kidneys and other organs in the lab for transplantation (rendering irrelevant the current drastic shortage of donors); stem-cell technology will cure some forms of blindness and help paralysed, spine-damaged patients regain mobility; and nanotechnology will allow us to develop drug-dispensing devices no bigger than a molecule.
It may sound like science fiction, but these technologies - and many others, too numerous to list here - are either available now, or at least will be in the next decade or two. For example, within 10 years, all surgery could be scarless. How? By using the body's natural orifices and the navel, it will be possible to insert robots into the body which can perform any surgical procedure. And prototypes already exist that can crawl and swim inside us, taking pictures of hard-to-access bodily nooks and crannies.
One such system, Ares, has been developed by the Scuola Superiore Sant'Anna, in Italy. This ultra hi-tech robot will self-assemble in the body after the patient has swallowed up to 15 separate parts, then aid the surgeon in carrying out procedures. And surgeons are already using robot assistants for operations such as tumour removals, gastro and neurological procedures. The advantage of this mechanised support is that, by avoiding external incisions, surgeons will minimise the discomfort and lengthy recovery time currently associated with major surgery.
Allied to developments in nanotechnology, genetics, stem-cell technology and tissue regeneration, these techno-surgeons will revolutionise the way we conceptualise and treat illness. "I see the body as nothing more than a very clever, very complicated machine," says Robin Manning, a futurologist with British Telecom. "As time goes on we'll discover more and more about how that machine works and, with technologies like stem cells and organ regeneration, we can start to engineer it. Some of these developments are closer to being ready than you might imagine - certainly not many decades away and some within the decade."
As well as predicting the next generation of computer wizardry, Manning is an expert in nanotechnology: the hard-to-comprehend branch of medical technology which produces unimaginably small devices (the word "nano" refers to objects with dimensions of less than 100 thousand millionths of a metre) and uses fiendishly complicated chemistry to put molecules together, like a very, very small Lego set. This two-pronged approach is then used in the diagnosis, prevention and treatment of disease.
The possibilities are endless. "One use of nanotechnology could be a biodegradable pill you buy from the chemist which, once swallowed, will pass through your system performing a battery of tests on your blood, internal organs and arteries," says Manning. "That data could be transmitted wirelessly to your mobile phone to give you instant results. It sounds far-fetched, but this technology could be available within five years."
That kind of data - easily and cheaply obtained whenever necessary - could lead to a drastic reduction in deaths from diseases such as bowel cancer, which has a 90 per cent survival rate if detected early and a 90 per cent mortality rate if found late. According to Ruth Duncan, a professor of cell biology and drug delivery at Cardiff University, nano-sized tools fall into three main categories: diagnostic, imaging and treatment. "The first refers to tools we might use outside the patient, like biosensors in an operating theatre that analyse blood samples," she says. "The imaging technology we have now allows us to see much smaller tumours, for example, and so treat them earlier. Or we could inject nano-scale objects into a patient to see how they're responding to a particular therapy."
But it is the third category, treatment, that most excites researchers such as Duncan. "We're looking at better drug targeting for diseases like cancer. Most people who die of cancer have metastatic disease, which means it has spread around the body," he explains. "If we can localise a drug specifically to the tumours we can overcome some of the side effects and increase its therapeutic benefit." This involves nanomedicines called "magic bullets", tiny particles carrying a drug payload and coated in a polymer to evade the body's immune system. "These would be imprinted with a targeting group, like an address label, which would seek out the metastasised tumours and deliver their drug payload."
This kind of technical sophistication - unimaginable to physicians just 20 or 30 years ago - is radically altering every sphere of medicine. In the US last year, surgeons performed the first near-total face transplant. Doctors at the Cleveland Clinic, Ohio, carried out the successful operation on a woman by taking skin, blood vessels and nerves from a donor in one sheet, called a "skin envelope". They then painstakingly connected it to the recipient once her own facial scar tissue had been removed in a gruelling 10-hour operation.
This followed the first-ever face transplant in 2005, when a French woman named Isabelle Dinoire had her lips, cheek, part of her chin and nose replaced with donor tissue. The 38-year-old has made a remarkable recovery, with natural movement and normal sensation returning to her face. And, in another world's first last year, British doctors announced that they had transplanted an organ grown from stem cells - a major medical breakthrough. Surgeons replaced the damaged windpipe of Claudio Castillo, 30, with one created from stem cells grown in a laboratory at Bristol University. Because the new windpipe was made from cells taken from the mother-of-two's body, using a process known as tissue engineering, her body accepted it even without powerful anti-rejection drugs.
Christopher Scott Thomas, the director of the Stanford Program on Stem Cells in Society, at California's Stanford University, explains why stem cells hold such promise for clinicians. "Stem cells are the only cells in the body that renew and repair damaged tissue, or cells that die," he says. "The fact that they have the ability to repair organs naturally means they are a very exciting tool for medicine, if we can harness that ability and use it in the lab and clinical setting."
Thomas, the author of Stem Cell Now: A Brief Introduction to the Coming Medical Revolution, explains that the major current application of stem-cell technology is in cancers of the blood, like leukaemia. "We've actually been using them for these conditions for 20 years or so, but we really didn't know until recently which cell was doing the trick," he says. "We've now isolated the cells that can repair a faulty or cancerous blood system, so the future for blood cancers and anaemias is very bright.'
There has also been a great deal of publicity for the work done with stem cells to repair spinal cord injuries, by regrowing damaged sections of the cord. And millions of blind and partially sighted people could be given their sight back after a major advance by scientists at Australia's University of New South Wales School of Medical Sciences. Researchers used patients' own stem cells, grown on a contact lens which was placed into the sufferer's eye - within days new cells had attached themselves to the damaged area to rehabilitate the damaged cornea.
These parts of the body are especially receptive to stem-cell treatment, explains Thomas. "We call the eye, brain and spinal cord privileged sites because they're places where stem cells hang out. So you can put foreign cells in there from another genetic source and not worry about them being rejected by the body, or have to give immune-suppressant drugs to keep the cells working after being transplanted."
Another approach currently causing widespread excitement is the use of cancer vaccines, both to stave off and treat our most dreaded disease. Last year, it was disclosed that a cancer patient in the US became the first person to make a full recovery after being injected with billions of his own immune cells by a team from the Fred Hutchinson Cancer Research Centre, Seattle. The 52-year-old man, who was suffering from advanced skin cancer, made such a miraculous recovery that he was free from tumours within eight weeks of undergoing the procedure. Last June, two years after the treatment, he was still cancer-free.
Professor Angus Dalgleish, who heads a team at the UK's Cancer Vaccine Institute, explains the importance of these vaccines: "We have developed prophylactic vaccines to protect women against cervical cancer and for hepatitis B, which causes hepatoma, or liver cancer. And we have recently made great strides with therapeutic vaccines, which we give to people once the cancer has started, to induce an immune response to eliminate the disease."
Let's put this into perspective: hepatoma accounts for one in three deaths in Asia, while cervical cancer is the world's biggest killer of women. And researchers hope therapeutic vaccines will prove highly effective with prostate cancer, the second leading cause of death in North America. So will experts like professor Dalgleish ever find a cure for cancer? "I don't think so," he says cautiously. "But we will be able to achieve a marked reduction in the number of people who die from it."
And this is the key message - it's unlikely we will ever see the end of illness per se. But the incredible medical advances that will benefit us and our children should eradicate many of our nastier diseases, helping us lead longer, healthier, happier lives.