Definition of cancer.
Cancer is not one disease. It is a group of almost 100 disease. Normally there are two major characteristics of cancer. 1st one is “uncontrolled growth of the cells and 2nd is the ability of these infected cells to travel from the original place and spread to distant sites. In short this uncontrolled growth of cell in human body is called cancer.
Cancer is a disease of genes. A gene is a small part of DNA. A majority of cancers are caused by changes in the cell’s DNA. It is because of damage due to the environment.
There are two types of cancer. Benign and malignant. Normally a benign tumor is not considered cancer. Benign tumor grows slowly and it does not spread surrounding tissue. In many cases benign tumor once removed, it does not appear again in the human body. On the other hand, A malignant tumor is a series cancer. It spreads to the other parts of the human body. Even after the malignant tumor is removed, there are still chances to reappear.
There are many different types of the cancer.
1. CARCINOMAS.
This kind of cancer often appears in the epithelium. 90% of cancer fall in to this type of category. It can also be subdivided into two types. One of them is Adenocarcinomas and second one is squamous cell carcinomas. Adenocarcinomas cancer develop in a gland or in an organ. Squamous cell carcinomas originate in the skin.
2. Melanomas.
It also originate in the skin. Usually it appears in the pigment cells.
3. Sarcomas.
It is a cancer of the supporting tissues of human body. For example muscle, bone etc.
4. Leukemias/Lymphomas.
Normally leukemias is called blood cancer and lymphomas is the cancer of lymph glands.
5. Gliomas.
Cancer of the Nerve tissue is called gliomas.
Causes of Cancer.
There are many causes of cancer but major factors for cancer are as below.
Tobacco
Alcohol
Diet
Infectious agents
Sexual behavior
Occupation
Family history
Environment and pollution.
Etc.
According to critical survey of ACS (American Cancer Society), 40% of cancer deaths in 1997 were due to tobacco and alcohol use. One third of the deaths were related to diet and nutrition. In 1998, approximately one million skin cancers diagnosed were due to over exposure to ultraviolet light from the sun rays. 80 to 90% lungs cancer cases occurs in tobacco user or smokers. Tobacco can cause cancer of upper respiratory tract, esophagus, larynx, bladder, pancreas, liver, stomach and kidney as well.
Alcohol increases the chance of liver cancer. 35% of all cancers are due to dietary causes. Diet is a main reason of the cancer of breast, colon, prostate, gall bladder, uterus etc.
Having too many sex partners increases cancer chances. Similarly becoming sexually active early has been shown to increase this disease. Women who do not have kids or have children late in their life have more risk for cancer of ovarian and breast.
15% of the worlds cancer death can be traced to different viruses or parasites.
Cancer is a progressive disease. It goes through different stages. When a tumor grows, it puts pressure on the nearby organs and blood vessels. This pressure can cause pain. There are seven important symptoms, known as warning signals of cancer.
A sore that does not heal
Continues cough, sore throat
Changes in the size, color of a wart.
A lump in the breast
Bleeding/discharging
Change in bladder habits.
However cancer is dangerous but in early stages it is curable.