Cancer is a growth of abnormal cell in the body. It develops anywhere in the body part. These abnormal growth is also known as cancer cells, malignant cells or tumour cells.
In cancer the body’s cells begin to be divided without stopping and it spread into surrounding tissues. Cancer can be started anywhere in the human body, that is made up of trillion of cells.
Normal process in human cells, it grow and divide to form new cells as body need. When cells grow, become old and damaged and at last it is die and new cells take their place. In cancer, this normal process breaks down. Cells grow, old and become abnormal and damaged cells survive. New cells form when they are not needed. Like this extra cells can be divided without stopping.
Cancer is a group of more than 100 different cells. Cancer could be starts any part of the body. Cancer is a genetic disease which is caused by changes in genes. Cancer can be inherited from our parents to us through genetic changes. Changes occur with cell divided or damage of DNA by certain environmental exposures. Environmental exposure includes substances such as, the chemicals present in tobacco smoke, radiation, and ultraviolet rays of the sun.
Each person’s cancer has a unique combination of genetic changes. Cancer cells have more genetic changes, such as mutation in DNA, than normal cells.
“Drivers” of Cancer
The genetic changes affected three main types of genes
Proto-oncogenes are involves in normal cell growth and its division. When these genes are altered or more active than normal, they became cancer causing genes or oncogenes, it allowing cells to grow and survive when they should not.
Tumour Suppressor Genes
Tumour suppressor genes also function in controlling growth of cells and its division. With certain alterations, tumour suppressor genes starts to divide in an uncontrolled manner.
DNA Repair Genes
DNA repair genes are also function in fixing damaged DNA. In these genes cells with mutations tends to develop additional mutations in other genes. Together, these mutation causes the cells to become cancerous.
Changes occurs in these three types is sometimes called “Drivers” of cancer.
Tissue Changes that Are Not Cancer
Every tissue changes in the body are not a cancer. Some kind of tissue changes may be developed into cancer if they are not treated in time.
In hyperplasia, cells changes within a tissue, which divide faster than normal and extra cells build up or proliferate. However, the cells and the tissue are organized in such a way, under the microscope it looks normal. Hyperplasia can be caused due to chronic irritation.
In dysplasia, there are extra cells growth. The tissues organized in such a way, we can identify the abnormal cells. In general, the tissues and cells looks more abnormal, there would be a greater chances of cancer will form. Dysplasia is an abnormal mole, it called a dysplastic nevus. It is form on the skin of human. This dysplasia nevus can be turned into melanoma.
Carcinoma in Situ
This condition sometimes called cancer. This is a more serious condition. Carcinoma in situ is the abnormal cells which do not spread beyond the original tissue. They do not invade tissues nearby abnormal mole. But there would be chances of some carcinoma in situ become cancer,
How Cancer Spread
A cancer has spread from one cell, tissue to another cells and tissues or another place in the body is called metastatic cancer. In metastasis, cancer cells are break down from where they formed first is called primary cancer, it is travel through the blood or lymph system and forms new tumour in the other part of the body, which is called metastasis tumour.