Full Information About Cancer
- What is Cancer?
- Why Does Cancer Occur?
- What Causes DNA Damage?
- What Causes Cancer?
- What Does Cancer Do?
- How Does Cancer Spread?
- Are There Cancer Types?
- Are All Tumors Malignant?
- Cancer Symptoms
- Is Cancer Preventable?
Cancer is a cumulative term for a wide group of oncologic diseases characterized by an uncontrollable growth and spread of body cells. Without treatment such diseases become fatal. Even ancient Egyptians knew that cancer is a fatal disease. Hippocrates of Cos gave the name to this disease after noticing that the tumor shape often has a lot in common with that of a crab.
What is Cancer?
Normal body cells grow, divide, and die in a certain order. Child’s cells divide and grow intensely. When a human grows up, the process of cell division of growth slows down. Usually, cells replicate only to replace damaged, exhausted or old cells.
Every type of cancer starts when body cells start growing uncontrollably. Instead of dying, cancer cells continue to grow and replicate. Cancer cells, unlike normal cells, can invade other tissues slowly expanding the tumor.
Why Does Cancer Occur?
Normal cells become cancerous due to DNA damage. DNA carries our genetic information. Usually, when DNA is damaged, a cell can fix it. Otherwise, a cell dies.
However, cancer cells keep their DNA damaged. Simultaneously, a cancerous cell continues to live and becomes immortal. On top of that, this cell actively replicates itself producing new immortal cells with the same damaged DNA. Such cells are of no use for our organism, since they are no longer capable of fulfilling their initial purpose.
What Causes DNA Damage?
Damaged DNA in some tissues can be inherited from parents. Some genetic dysfunctions can be caused by external factors such as smoking. Oftentimes, the cause of damage cannot be determined.
What Causes Cancer?
- Carcinogens. Substances and radiations capable of damaging DNA cells causing cancer. An incomplete list of typical carcinogens include tobacco, arsenic, asbestos, x-ray radiation, and various substances in exhaust gases. Smoking causes about 30% of fatal cancer cases.
- Genetic heredity. Some people are born with errors in their genes. Such errors significantly increase cancer risks.
- Age. Aging is usually accompanied by an increasing amount of mutations. Some mutations can cause cancer.
- Viruses. Certain viruses can cause cancer. For example, HPV (Human Papillomavirus) increases risks of cervical cancer. Hepatitis C and B often cause liver cancer. HIV drastically weakens the immune system and increases the risk of cancer.
What Does Cancer Do?
Tumor cells expand, pressuring and damaging surrounding tissues. This causes serious malfunction of an organ where cancer started. Besides that, a cancer tumor produces toxins poisoning the organism, exhausting its resources, and disrupting the immune system.
How Does Cancer Spread?
Growing cancer cells infiltrate blood and lymphatic vessels using them as transportation. This is how cancer cells invade other parts of the body and form new tumors. This process is called metastasis. New tumors are called metastases.
Leukemia, for example, is a perfect example. Cancer cells appear initially in blood and parts of haematopoietic system. Such cells then invade the whole organism through blood vessels.
Are There Cancer Types?
Depending on where cancer started, its cells may function differently. For example, breast cancer and lung cancer are two completely different diseases. Tumor cells grow with different speed and each type of cancer cells requires specific treatment.
Are All Tumors Malignant?
Those tumors that are not called cancerous we usually call benign. These tumors do not produce metastases or invade other tissues. This is why they are rarely dangerous.
However, an active growth of a benign tumor may pressure and affect healthy tissues and body parts, while a tumor itself may turn into a malignant one.
Symptoms vary from case to case and depend on where cancer resides, the size of a tumor, and how it spreads. Some tumors are easily palpable underneath skin or even seen on skin. Examples are breast cancer and skin cancer.
Other types of cancer, especially during early stages, are less apparent. Brain cancer affects its functions, liver cancer provokes jaundice symptoms, colorectal cancer may cause constipations, and prostate cancer may affect urinating.
Cancer cells exploit the resources of the body. This is why some symptoms are weakness, intense sweating, and unexplainable weight loss. At the same time, these symptoms may indicate a wide array of other diseases.
Nevertheless, if you discover such symptoms, you should immediately go to the hospital for a thorough medical examination.
Is Cancer Preventable?
Research has shown that smoking, unbalanced diets, and the lack of physical activity are the most common factors increasing cancer risk. Amongst people living a healthy life, oncologic diseases are less common.
The Most Important!
A cancer tumor consists of cells with damaged DNA information. Such tumor not only grows rapidly, but also expands to other tissues and organs disrupting their functionality. The only way to lower the risk of getting cancer is healthy lifestyle!