Cancer is a nightmare for everybody and represents one of the chronic diseases affecting millions of people world over. Let us look little bit deep into the disease from the scientific insight.
Cancer is a disease originating in the body cells and affects the individual. Our body is made up of different types of cells and hence cancers also are of different types depending on the type of body cells from where they originate. But all types of cancers have something in common. All cancer cells multiply out of control and show abnormal features and behaviour. Some cancers are more serious, while others are less, some of them can be treated more easily than the others, subject to early stage diagnosis, some of them can be monitored before and during treatment. Unlike, other diseases, cancer is not uniform and show stereotype symptoms in all patients. This demands, thorough diagnosis to assess the type of cancer, what extent it has developed, how large it has grown, did it spread in different parts of the body, and how it responds to the treatment.
What happens to cells during onset of a cancer ?
Cells are the structural and functional units of our body and body consists of millions of cells. Thousands of similar cells performing identical functions form functional groups called tissues such as muscles, skin, bones, blood, nerves, etc. Several such tissues get organized into definite structural patterns to form different organs like brain, heart, eyes, ears, hands, legs etc. Different parts of the body such as organs, All cells of the human body except the red blood cells have a centre called nucleus which controls all the activities of the concerned cell. The nucleus contains thousands of tiny particles called genes, which control all the activities and functions of the cell.
Most of the cell types in the body keep dividing and multiplying from time to time. Old and damaged cells get replaced by new cells. But the frequency of multiplication varies among different cell types. Normally body makes and maintains only the required number of cells of each type.
Sometimes one of the cells suddenly become abnormal and undergoes uncontrolled multiplication. This happens when one or more gene(s) regulating cell division malfunction or do not function. The abnormal cell keeps dividing exponentially. They form lumps initially and later start migrating to other parts of the body at a later stage, if not intervened. Large clumps of abnormal cells are called tumors.
Tumours are classified into two types: benign and malignant.
Benign tumors can be formed in various parts of the body. These tumours grow slowly and do not invade other tissues or spread to different parts of the body. They are usually harmless . However, some of them can cause other problems like local pressure symptoms, unsightly appearance or over production of hormones enzymes or other cellular products leading to different complications.
Unlike the benign tumours, malignant tumours grow fast due to the higher rate of cell division and often invade other tissues and organs, through a process called metastases. During metastases, part of the tumour breaks off and the tumour cells enter the blood stream and carried to distant parts of the body, get settled in some other organ and form new tumours. The original tumour in the original site is called as ‘primary tumour and the new tumours developed in other parts of the body are called as ‘secondary tumours’. The secondary tumours may also invade and damage neighbouring tissues, and spread again. All cancers may not form solid tumours. For example, in blood cancer, abnormal cells are produced in the bone marrow and released into circulating blood.
Source : http://patient.info/health/cancer-a-general-overview.