Defining cancer can be difficult because there are a broad group of diseases that involve unregulated cell growth. With cancer, these cells divide and grow with no control, which can cause tumors that are malignant. These tumors can then invade other parts of the body. When things get really bad, cancer can spread through the body in the bloodstream, or in the lymphatic system.
To define how cancer is caused is not easy. The causes are highly diverse and complex and we only partially understand them. There are several risks to cancer though, including smoking, eating poorly, infections, certain radiation, obesity and a lack of exercise. Environmental pollutants can also lead to cancer.
Due to these factors damaging genes, they can lead to cancer mutations. Only about five to 10 per cent of cancers can actually be traced to genetic defects. In fact, most cancers can be prevented by refraining from smoking, eating vegetables and fruits, less carbs and maintaining a healthy weight through exercise.
Today, cancer causes about 13 per cent of all deaths worldwide each year, amounting to roughly eight million people. Due to the rising lifespans of humans, as well as the obesity epidemic, cancer rates are higher than ever before. When people live longer, there is a greater chance for genetic problems, which can lead to cancer growth. Cancer can be detected in a number of ways, including looking for symptoms and signs, doing screening tests and medical imaging.
It is believed that cancer has existed for all of human history. The earliest writing of cancer actually dates back to 1600 BC, when an Egyptian papyrus described cancer of the breast. Hippocrates also described several kinds of cancer, describing them as karkinos, the word for crab. This is why cancer, the astrological sign, is a crab as well. Celsus, who lived from 25 BC to 50 AD, recommended surgery to remove cancer tumors but Galen, a doctor of the time, recommended purgatives (purging from the system with bowel movements).
Galen’s recommendation was widely accepted for over 1,000 years. By the 15th to 17th centuries, it became acceptable for doctors to dissect bodies after death and through this more was learned about cancer. As early as 1761, John Hill described the use of tobacco snuff as being the cause of nose cancer. In 1775, Percivall Pott found that cancer of the scrotum was common in chimney sweeps. With the creation of the microscope, a greater understanding of cancer began to emerge.
Since cancer is a class of diseases, there will probably never be a cure for cancer, but there are various treatments that can be used to prevent cancer or manage it, depending on the cancer. With improved understanding in areas such as molecular biology and cellular biology, a number of treatments are beginning to emerge to deal with cancer.
Cancer research is heavily funded and since 1971, $200 billion has gone into cancer research in the United States. This has shown to have a strong impact as there has been a five per cent decrease in the cancer death rate from 1950 to 2005.
It is estimated that the overall costs of cancer in the United States, including treatments and mortality expenses, amounts to $226.8 billion per year.
Things are changing though, and they are changing for the better.
In 2008, 12.7 million cancers were diagnosed and 7.98 million people died from cancer in 2010. The most common cause of death from cancer is lung cancer, followed by stomach and liver cancer. In 1990, deaths from cancer were 5.8 million but the population has increased heavily since then, while the number of cancer deaths has slowed considerably. Old age is a significant cause of cancer and it is believed that if we live long enough, sooner or later, we all get cancer.
Cancer can also hit children, with leukemia, brain tumors and lymphomas being the three leading cancers among children. In the United States, one out of 285 children will have cancer and while the rates of childhood cancer have increased by .6 per cent per year from 1975 to 2002, the number of deaths from childhood cancer have fallen by 50 per cent during that same period.
Cancer is a horrible disease but through gene therapy and other cutting edge treatments, more and more people are surviving from cancer. A good example is Terry Fox, the Canadian who helped create the biggest one-day cancer fundraiser in the world. When he died in 1981 it was because the cancer that took his leg had eventually spread to his lungs. Today, thanks to research, that cancer would be highly treatable and he never would have lost his leg.