Cancer

Cancer is a class of diseases or disorders. It is when the body has no control over cells that begin to split. In cancer, body cells copy their contents. They then make new cells with these copies. These cells are able to go into other tissues. They go into other tissues by growing into them. They can also go into other tissues by putting themselves into far away places by metastasis. Metastasis is the process in which cancer cells move through the bloodstream or lymphatic system. Cancer can affect anybody at any age. People are more likely to get it as they get older. This is because DNA damage becomes more apparent in older DNA. An exception is testicular cancer. It is more common in young men. Cancer is one of the biggest and most researched causes of death in developed countries.

Causes

Cancer is a leading cause of death. It causes about 12.5% of all deaths worldwide. This is according to the World Health Organization. There are some things that can be causes or triggers of different types of cancer. They include tobacco (smoked or smokeless),, lots of sunlight, radiation (including X-rays in large or many doses and exposure to radiation in a nuclear power plant), chemicals used in building and manufacturing (for example, asbestos and benzene), high-fat or low-fiber diets, air and water pollution, people who eat very little fruits and vegetables, obesity, not enough physical activity, drinking too much alcohol, and household use of some chemicals. Some cancers can also be caused by viruses.

Kinds

There are lots of different kinds of cancers. Some of the most common include breast cancer, brain cancer, leukemia, testicular cancer, mesothelioma, and lung cancer. Breast cancer begins in the breast. It can be found in anybody at anytime. It can even be found in men. Brain cancer starts in the brain (cancer of the brain is called a brain tumour). Testicular cancer starts in the testicles. It is most common in young men. Mesothelioma and lung cancer start in the lungs. Mesothelioma is usually caused by exposure to asbestos.

Treatment

There is no sure cure for cancer. It can only be cured if all of the bad cells are cut out or killed in place. So the earlier cancers are treated the better. Cancer can sometimes be treated using radiotherapy (also called radiation therapy), chemotherapy, or immunotherapy (also called biological therapy). In some cases it is possible to use surgery to remove at least a part of the tumor. But this is not the end of treatment. After surgery patients may need radio- or chemotherapy to prevent the tumor from growing once again.

One hard problem in treating cancer is that most things that kill cancer also kill normal cells. Cancerous cells are often quite weak. Since the cancer is actually a part of the body, the body will not attack it, even though the cancer often could easily kill the body. Another hard problem in treating cancer is that there are many different types of cancer. Each have their own symptoms and causes. Some people can handle cancer better than others. However, it is harmful to everybody. It can be fatal.

There is always progress in finding treatment. Many cancers are treated successfully. For example, a study showed that if someone with lymphedema (a swelling of the arm linked to breast cancer) lifts weights, they be able to fight cancer better than somebody who does not.

History

The Greek term carcinoma is a medical term. It is used for a malignant tumour from epithelial cells. Celsus translated the Greek word carcinos into the Latin cancer. Cancer also means crab. Galen used "oncos" to describe all tumours. This is the origin for the current word, oncology.

Hippocrates named many kinds of cancer. He called benign tumours oncos. In Greek, oncos means swelling. He called malignant tumours carcinos. This means crab or crayfish in Greek. The veins of the cut surface of solid malignant tumor looks like a crab: "the veins stretched on all sides as the animal the crab has its feet, whence it derives (gets) its name". He later added -oma after the word. It is Greek for swelling. This has given the name carcinoma. Hippocrates only described and made drawings of tumors he saw from outside. This is because the Greeks did not open up the body. He drew tumors that were on the skin, nose, and breasts. People were treated based on the humor theory. The humor theory describes four bodily fluids (black, yellow bile, blood, and phlegm). The patient's treatment was made up of diet, blood-letting, and/or laxatives. The treatment was according to the patient's humor. Through the centuries it was discovered that cancer could occur anywhere in the body. The humor theory treatment was popular until the 19th century with the discovery of cells.

The oldest known description and surgical treatment of cancer was discovered in Egypt. It dates back to approximately 1600 B.C. The Papyrus describes eight cases of ulcers of the breast. They were treated by cauterization. They used a tool called "the fire drill." The writing says about the disease, "There is no treatment."

Another very early surgical treatment for cancer was described in the 1020s. It was described by Avicenna (Ibn Sina) in The Canon of Medicine. He stated that the removal should be radical and that all diseased tissue should be removed. This included the use of amputation or the removal of veins running in the direction of the tumor. He also recommended the use of cauterization for the area treated if necessary.

In the 16th and 17th centuries, it became more acceptable for doctors to dissect bodies to discover the cause of death. The German professor Wilhelm Fabry believed that breast cancer was caused by a milk clot in a mammary duct. The Dutch professor Francois de la Boe Sylvius believed that all disease was the outcome of chemical processes. He believed that acidic lymph fluid was the cause of cancer. Nicolaes Tulp believed that cancer was a poison that slowly spreads. He said that it was contagious. He lived at the same time as Sylvius.

British surgeon Percivall Pott was the first to find a cause for cancer. In 1775, he discovered that cancer of the scrotum was a common disease among chimney sweeps. The work of other physicians led to different views. Physicians then started working together. They reached better conclusions.

The microscope began to be widely used in the 18th century. With the microscope, it was discovered that the 'cancer poison' spread from the one tumor through the lymph nodes to other sites ("metastasis"). This view of the disease was first made clear by the English surgeon Campbell De Morgan. He made it known between 1871 and 1874. The use of surgery to treat cancer had bad results. This was because of problems with hygiene. The well known Scottish surgeon Alexander Monro saw only 2 breast tumor patients out of 60 surviving surgery for two years. In the 19th century, asepsis made surgical hygiene better. As the survival statistics went up, surgical removal of the tumor became the primary treatment for cancer. Cancer treatment became dependent on the individual art of the surgeon at removing a tumor, except for William Coley. In the late 1800s, Coley felt that the rate of cure after surgery had been higher before asepsis. He had injected bacteria into tumors with mixed results. During the same period, the idea was that the body was made up of many kinds of tissues. They in turn were made up of millions of cells. This laid rest the humor-theories about chemical imbalances in the body. The age of cellular pathology was born.

At the end of the 19th century, Marie Curie and Pierre Curie discovered radiation. They had found the first non-surgical cancer treatment. With radiation also came the first signs of multi-disciplinary approaches to cancer treatment. The surgeon was no longer operating in isolation. The surgeon worked together with hospital radiologists to help patients. This made things difficult in communication. It also made it necessary for the patient's treatment to be done in a hospital rather than at home. This made a process of putting all of the patient data into hospital files. This led to the first statistical patient studies.

Janet Lane-Claypon wrote a paper on cancer epidemiology. It was a founding paper. She published a comparative study in 1926. It was about 500 breast cancer cases and 500 control patients. They both had the same background and lifestyle. It was published for the British Ministry of Health. Her work on cancer epidemiology was carried on by Richard Doll and Austin Bradford Hill. They published "Lung Cancer and Other Causes of Death In Relation to Smoking. A Second Report on the Mortality of British Doctors" followed in 1956 (otherwise known as the British doctors study). Richard Doll left the London Medical Research Center (MRC). He left to start the Oxford unit for Cancer epidemiology in 1968. With the use of computers, the unit was the first to bring together large amounts of cancer data. Modern epidemiological methods are closely related to current ideas of disease and public health policy. Over the past 50 years, great efforts have been made on collecting data across medical practice, hospital, provincial, state, and even country boundaries. This data is used to study the sharing dependence of environmental and cultural causes on cancer incidence.

Cancer patient treatment and studies were only allowed to individual physicians' practices. This changed during World War II. This is when medical research centers found that there were large international differences in disease incidence. This idea made national public health bodies to make it possible to bring together health data across practices and hospitals. Many countries use this process today. The Japanese medical community found that the bone marrow of victims of the atomic bombings of Hiroshima and Nagasaki was completely destroyed. They said that diseased bone marrow could also be destroyed with radiation. This led to the discovery of bone marrow transplants for leukemia. Since World War II, improvements in cancer treatment are getting much better. There are some things that still need to get better. They need to be better on a micro-level with existing treatment methods. They need to be standardized. They need to be globalized to find cures through epidemiology and international partnerships.

Other websites

New Global Cancer Facts