It is a common knowledge that cancer kills millions of people each year. In 2007, the American Cancer Society reported that 7.6 million people around the world died from cancer. While it is a known fact that cancer is a deadly disease, many of us do not really understand how this disease spreads inside the body leading to death.
Metastasis is a process by which cancer spreads. This involves the movement of cancer cells from the initial tumor to other parts of the body. This movement of cancer cells was initially thought to be a passive and random process. A recent study by researchers at Stanford University School of Medicine has shed some light on how cancer spreads.
Senior author Dr Amato Giaccia, professor of radiation oncology at Stanford, revealed: “Metastasis is not a passive process. Cells don’t just break off the primary tumour and lodge someplace else. Instead the cells actually secrete substances to precondition target tissue and make it more amenable to subsequent invasion.”
The report of Dr. Giccia and his colleagues is based on the series of experiments on mice to understand how cancer spreads. These researchers discovered that a protein called lysyl oxidase (LOX) which normally helps to strengthen connective tissues is involved in metastasis. It seems that the tumors are using LOX to help prepare other parts of the body to be invaded by cancer cells. They found that when LOX is absent in the body, bone-marrow derived cells that is involved in metastasis are prevented from moving to a site where cancer can spread. When LOX is present, however, specialized white blood cells accumulated in the lungs of the mice and a protein that breaks down collagen is produced so that cancer cells can invade the normal tissue. Therefore, if LOX production in mice is prevented, the spread of cancer is also reduced.
The researchers hope that if these series of events are blocked, it may be possible to stop cancer cells from migrating to other parts of the body and prevent metastatic cancer.
Dr Julie Sharp, Cancer Research UK’s science information manager, said: “A better understanding of how cancer spreads is crucial to improving the treatment of the disease. This research takes scientists a step closer to understanding this major problem – the next stage will be to find out if the LOX protein can be switched off to stop cancer spreading.”
According to a recent World Health Organization (WHO) report, cancer will soon overtake cardiovascular disease as the world’s top killer. While cancer rates are down in developing countries like the US, global death rate due to cancer is on the rise. This year, the number of cancer cases is expected to reach 12 million and 7 million of these will result in death. By 2010, it will be the world’s leading cause of death. By 2030, the number of cases may be almost triple.
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