Pancreatic cancer still a mystery

There is perhaps more speculation about the health of Steve Jobs, the chief executive of Apple, than anyone else in the business world today.

Steve Jobs not only has excellent blood pressure but is in a minority of pancreatic cancer sufferers to survive five years after diagnosis.
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There is perhaps more speculation about the health of Steve Jobs, the chief executive of Apple, than anyone else in the business world today. Mr Jobs has been an incredible asset to his company. His vision for the imac and the iphone helped Apple beat the odds and to cement itself as a leader in a crowded industry. But on a personal level, Mr Jobs is also beating the odds, as he has survived far longer than most people who battle pancreatic cancer, an affliction he was diagnosed with in 2004.

His continued survival puts him in the tiny minority of patients who remain alive five years after the condition is identified. In developed countries survival rates are some of the worst for any type of cancer, with just two to three per cent living beyond five years. Pancreatic cancer proves so fatal because it is usually only identified at a late stage. The difficulty doctors have in detecting the cancer, and the even greater hurdles they face in curing patients, have led to it being dubbed the "silent killer".

The problem, according to Dr Julie Sharp of Cancer Research UK, is that the pancreas is buried deep within the abdomen and the cancers linked to it produce symptoms such as weight loss and abdominal pain associated with many other conditions. "These symptoms could be linked to many more minor illnesses and many patients never have symptoms while the cancer is progressing, so by the time most people are diagnosed the cancer is advanced and has often spread so it is difficult to treat," she says.

Raising awareness is difficult because there is no clear message to give the public on what to look out for. "With some cancers, such as breast cancer, it's easier for healthcare providers to say: 'These are the signs and symptoms, so if you spot them go for screening.' With pancreatic cancer the symptoms are unfortunately very vague," Dr Sharp says. The pancreas is a gland that produces insulin and substances that aid in digestion, and many different types of cancer can develop in it. The vast majority of pancreatic cancers are classed as adenocarcinomas, which are cancers of the gland itself. A minority of the cancers, and the ones that tend to be more treatable, are of the cells that produce insulin.

A range of treatments are used, including surgery, radiotherapy and chemotherapy, but the usual lateness of diagnosis means that often there is little that can be done to save patients. Perhaps as a result, says Dr Sharp, the condition has tended to attract less attention than some other forms of cancer. "The reason it's been neglected is that it's so difficult. Scientists are still at the first hurdle," she says.

Cancer Research UK, recognising that pancreatic cancer has not received enough attention in the past, has highlighted the disease in its five-year strategic plan as needing increased funding. The organisation is setting up research centres across the UK to work towards new methods of diagnosis and treatment. And there are reasons to hope that, in the least, survival rates for the condition may be increased.

One approach concerns earlier identification. For example, researchers are attempting to identify substances that could help to diagnose people with the disease. A blood test that looks for an increase or decrease in the level of certain proteins might be used as an indicator. "There isn't anything yet in clinical practice, but that's an aim. If they could find something early, that would be really, really helpful," Dr Sharp says.

Ultimately, if a very reliable early detection method could be developed, it could be incorporated into a screening programme. Trials are also taking place of a vaccine called TeloVac that, while unlikely to cure people, may in conjunction with chemotherapy improve the life expectancy and quality of life of sufferers. The vaccine might achieve this by stimulating the body's immune system to attack cancer cells.

Clinicians are additionally continuing to look at the order in which treatments are given and trying different drug combinations to improve survival rates. About 10 per cent of pancreatic cancers are the result of hereditary factors, while illnesses such as long-term inflammation of the pancreas also make people more likely to develop the condition. "Scientists are looking at how you can identify the first signs in people who are at greater risk, so they could be monitored," Dr Sharp says.

"For the majority of cases, they are not inherited, but they are still caused by genetic faults accumulated during a person's lifetime. "Scientists are starting to build up a picture, but the knowledge hasn't yet been translated into improved methods of diagnosis or treatment." In September, there was a major step forward when scientists from the Sidney Kimmel Comprehensive Cancer Centre at Johns Hopkins in Baltimore published the complete genetic blueprint for pancreatic cancer. At the same time, a map for brain cancer was also released.

The researchers found that a dozen regulatory gene pathways - each a series of genes that interact with one another - were altered in most tumours. Processes such as the control of damage to DNA and cell maturation were influenced by the pathways. As a result, scientists believe targetting the physiological effects of such pathways, rather than focusing on individual genes, will be the best approach for new drug treatments.

The task is formidable, since the same researchers discovered there were 83 mutated genes linked to pancreatic cancer. Speaking when the findings were published, Dr Kenneth Kinzler, a professor of oncology at Johns Hopkins University, said this showed human cancers were "clearly more complex" than was thought. "Fighting it is going to be more of a guerilla war than a conventional one, because there are dozens of mutated genes in each tumour," he said.

"Individually, these mutations don't seem formidable. But working together, they form an enemy that will require us to develop novel strategies to combat them, and the best long-term strategy may be early detection of tumours, when the number of guerilla warriors is still small and more easily handled." Because of the difficulties in treating pancreatic cancer, its no wonder that the Hollywood actor Patrick Swayze, diagnosed with pancreatic cancer a year ago, has sadly had to take a pessimistic view of his own chances of beating it.

While saying in a recent television interview he hoped he could have "a long and healthy life", Mr Swayze conceded it was "pretty wishful thinking" to think he would still be alive in five years' time. "Two years seems likely if you're going to believe statistics."