Study of Cancer – Oncology
Definition of Cancer Or how it begins
- When in an abnormal cell suddenly division occur which is not in control, called Cancer.
- Cancer also defined as the proliferation of the cells.
- Cancer is one of the most fierce or dreadful diseases.
- All over the globe, it is also one of the main cause of death.
- Due to genetic changes or mutation it occurs.
- It’s neither a bacterial nor viral disease, e.g. AIDS.
Cancer cell’s characteristics
- Due to uncontrolled division, they form a large mass of tissue also called Tumour.
- These cells don’t require extracellular growth factors.
- They don’t have contact inhibition property.
- The abnormal cells form a tumour and then they pass out to new sites to form a secondary tumour.
- Metastasis – The invasion of cancerous cells by body fluid (blood), from one part of the body to another part.
- Tumours are of two types – Benign and Malignant.
- Benign is a non-cancerous tumour but Malignant is cancerous and also fatal.
- The main reason for cancer cause is the Mutation or also the chemical agents.
- Cellular oncogenes or proto-oncogenes are normal cells which have genes and they are present in an inactivated state but due to Mutation, which gets transformed into oncogenes which are cancer-causing genes.
- Carcinogens are the agents which cause cancer. Their types are –
- Physical Agents – Come in direct contact with Ionising radiations like X-rays and α, β, γ-rays, and also with non-ionising radiations like UV-rays. Others like Radion, Uranium.
- Biological Agents – (Oncogenic virus) Hepatitis virus B and C, HPV ( Human papillomavirus), Merkel cell polyomavirus, and also Some parasites.
- Chemical Agents – Benzopyrene, Aniline dyes, aflatoxin, (chemicals in cigarette smoke) N-nitrosodimethylamine, and also asbestos.
Some Carcinogens and their target organ list
Carcinogens Target organ
Mustard gas Lungs
Vinyl chloride Liver
Cadmium oxide Prostate gland
Nickel and chromium gas Lungs
The type depends on where it starts. They are 4 Types:
- Carcinoma – It is cancer of epithelial tissue and it covers the surface of internal organs and also glands. It’s a skin cancer. Melanoma is the cancer of melanocytes of the skin. So, it is also a type of skin cancer.
- Sarcoma – Cancer of mesodermal layer, which connects and also support the body. e.g. nerves, muscles, tendons, bone, lymph vessels, joints, fat, blood vessels, or also cartilage.
- Leukemia – Also known as blood cancer. In which mainly healthy blood cells get affect and they change and start growing (uncontrolled).
- Lymphoma – Affect the lymphatic system of the body. The lymphatic system is consist of blood vessels and glands, and they also fight against any kind of infection. Mainly responsible for the Immunity of the body but because of this immunity gets weaker.
- Blood and Bone-marrow test – In the case of blood cancer, the test of bone marrow and blood so they can count increase cell numbers.
- Monoclonal antibodies – Monoclonal antibodies increase in the body to fight against the foreign antigen. So, the Antibodies against cancer-specific antigens are also used to detect.
- Radiography – X-rays are used in this to detect cancer in the deep internal organ.
- Resonance imaging – It’s used to detect pathological and physiological changes in the living tissue. Diagnosis by MRI.
- Biopsy – Also called Histopathological study. In this, a part of suspected tissue cut into thin sections and then stain this and examine under the microscope to detect abnormalities.
- Computed tomography – In this, a three-dimensional image is formed of an internal organ of an object by the use of X-ray.
The treatment depends on the type of cancer and also the stage of cancer. There is some type of treatment:
- Radiant Therapy – By radiations. Radiations are passes throughout the body to destroy Cancerous cells or tumors by the lethal irradiation. In which it’s necessary not to harm normal cells which are near the Tumour.
- Surgery – This is the most common type of treatment. Removal of a tumour by surgery.
- Chemotherapy – By chemicals. In this, some chemotherapeutic drugs are provided to the body to kill the cancerous cells. There can be some side effects like anaemia, weight loss, and also hair fall. e.g. Vincristine and vinblastine
- Immunotherapy – To boost or activate the immune system, in this biological modifier α-interferons are used and it activates the immune system which helps to kill the tumours f the body.
Type of cancer and their Symptoms
Symptoms depend on the type of cancer and also on the stage.
- Breast cancer – There can change in size and shape of the breast, Discharge of some liquid from the nipples
- Lung cancer – Problems in the breath, pain in the chest, Vomit of blood
- Blood cancer – Red bumps on the skin, blood vomiting, hair fall
- Skin cancer – Red, Shiny pink, translucent, or pearly bump
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