One of the deadliest diseases responsible for about 9.5 million lakh deaths in 2018, according to WHO, is cancer. Cancer is a term used to describe a large group of diseases that are characterized by cellular malfunction. Cancer is the deregulation of cell growth. In medical terms, cancer is known as malignant neoplasm; a broad group of diseases involving unregulated cell growth, and the unregulated cell growth forms a “tumour.” Cancer can start anywhere in the human body which is made up of a trillion cells.
When cells become old or damaged they die and new cells take their place. But when cancer develops, this orderly process breaks down. Old and damaged cells survive when they should die and new cells form when they are not needed. These extra cells can divide without stopping and may form tumours.
How Does Cancer Develop?
Cancer is known to be a very dangerous genetic disease because it is caused by mutations in genes that control how our cells work, particularly how they divide and grow. So, errors that occur while cells divide can generate genetic alterations that cause cancer.
Chemicals and hazardous compounds in the environment, like chemicals in cigarette smoke and ultraviolet raysfrom the sun cause DNA damage that results in cancer. It can also be passed down to us from our parents as a genetic disease. Before the cells that have damaged DNA become malignant, they are eliminated by the body. But with growing age. the ability of the body to do so decreases. This is the reason why cancer is developed later in our life.
A unique set of genetic alterations are there in each person’s cancer. As the malignancy progresses, additional alterations occur. Even within the same tumour, distinct cells may have diverse characteristics. Certain changes to genes cause cancer, the basic physical measure of inheritance.
Causes of Cancer
Carcinogens like chemicals, tobacco, alcohol, and radiations such as ultraviolet rays coming from the sun are considered the lead causes of cancer.
Types of Cancer
There are more than a hundred types of cancer. They are usually named for the organs or tissue where the cancer forms. Here are some categories of cancer.
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Carcinoma
It is formed by epithelial cells, cells that cover the inside and outside surface of the body. Carcinoma in different epithelial cells has different names.
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Sarcoma
These are the types of cancer that form in the bone and soft tissues including muscles, fat, lymph, cells, and fibrous tissue.
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Melanoma
Melanoma cancer begins in the cell that begins with melanocytes. It is considered the most serious type of skin cancer. Melanoma occurs when the pigment cells, which give coloured skin become cancerous.
Diagnosis of Cancer
The earlier stage of diagnosis in cancer provides the best chance for cure. Doctors may use one or more following approaches to diagnose cancer.
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Biopsy
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Radiography technique
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Computed tomography
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Magnetic resonance imaging
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Molecular biology techniques
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Laboratory test
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Physical exam
Treatment of Cancer
The type of treatment depends on the type of cancer and how advanced it is. Depending on cancer, a patient can have a combination of treatments such as:
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Surgery
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Chemotherapy
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Radiation therapy
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Immunotherapy
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Targeted therapy
Many drugs have side effects in cancer patients like hair loss. So, interferons are injected into cancer patients to develop immunity against these side effects.
Types of Tumour
Based on their ability to undergo metastasis, tumours can either be cancerous or non-cancerous and are classified into three types:
Benign Tumour
This type of tumour is localized to a particular location in the body so it doesn’t spread to the other body parts, and due to this reason, it is not that harmful. This tumour occurs in regions like the brain, and sometimes they turn fatal also. Surgery is one of the most common treatments to remove benign tumours.
Malignant Tumour
Malignant tumours are known to be cancerous, which shows that they tend to grow quickly to other tissues of the body. This tumour has high metastasis properties, and it grows frequently into the bloodstream, and from there it can form secondary tumours across different sites in the body part.
Premalignant Tumors
This tumour is a kind of benign tumour but it shows features of malignant tumours. This tumour has an increased risk of becoming cancer. Benign tumours become premalignant and eventually, malignant.