Oncology (Cancer) is a branch in the healthcare sector that addresses the treatment, prevention, identification, and healing of cancer. An oncologist is a specialist who provides medical advice and treatment for a person diagnosed with cancer.
In the case of cancer, the body’s normal control mechanism stops working, and thus result in anomalous growth of cells in the body. Old cells do not die and instead grow out of control, forms new disease cells. These extra cells form a mass of tissue known as a tumor. The tumor can spread to other parts of the body and destroy the normal tissue. If not diagnosed early, these tumors can spread throughout your body through the lymph system and blood.
More than a hundred types of cancer exist and are usually named after the type of cell or organ from where they originate. The type of cancer can be categorized into 5 main groups.
This type of cancer originates in the human body tissues, mainly in the skin or the tissue of internal organs. It has four subtypes and are known as transitional carcinoma, basal cell carcinoma, adenocarcinoma, and squamous cell carcinoma.
It originates in the tissues that form blood or blood-forming tissue, and it also includes bone marrow.
The sarcoma mainly begins in supportive or connective tissue in cells outside the bone marrow. For example- fat, blood vessels, bone, muscle, and cartilage.
Myeloma and Lymphoma:
It originates from the cells of the immune system.
Central nervous system cancers: This type of cancer develops in the spinal cord and brain.
Cancer is caused by changes (mutation) to the DNA within cells. Genes are made up of DNA inside a cell and contain a set of instructions guiding the cell on how to grow and divide. Any disruption in the instructions affects the normal functioning of the cells and make them cancerous.
Gene mutations a person is born with: a genetic mutation that is inherited from the parents. Gene mutations that occur after birth: Most of the gene mutations occur after birth and are not inherited. There are many reasons other than gene mutations that cause cancer, such as smoking, cancer-causing chemicals (carcinogens), radiation, viruses, obesity, hormones, chronic inflammation, amongst others.
The gene mutations one is born with and those that are acquired throughout life, together cause cancer. If the inherited genetic mutation predisposes a person to cancer, it does not necessarily mean that the person will have cancer. One or more gene mutations combine to cause cancer.
The symptoms vary upon the type of cancer. Some of the common types of cancer and their symptoms are listed below:-
Skin cancer- scaly red patches, sores that bleed easily don't heal itself, flat areas of skin that look like scars, itchy, irritated, or painful skin.
Lung cancer- persistent cough, blood during coughing, bone pain, constant chest pain, regular lung infections.
Breast cancer- pain in breast, nipple discharge, a new lump in your breast, swelling in your breast.
Colon and rectal cancer- uneven weight loss, excessive weakness, change in bowel habits, blood in the stool, and bleeding in the rectum.
Prostate cancer- blood in urine, pain in the lower back, a problem in urinating, pain during urination.
Kidney cancer- uneven weight loss, blood in urine, a lump on one side of your lower back, continuous fever.
Thyroid cancer- persistent cough, trouble in swallowing, a lump in front of the neck
Different Stages of Cancer
There are four main stages of cancer -
This stage means cancer 'in situ' that means 'in place'. They are located at their place from where they have originated and are immobile. Stage 0 cancers do not spread to the other parts of the body. It can be completely cured by removing the tumor with the help of surgery.
It is also known as early stage, the cancer is small, and the tumor has not developed into the nearby tissues. They are immobile and hence do not spread to different parts of the body.
Stage II and III:
These stages usually represent the large size of the tumors. They have grown deep and starts affecting the surrounding tissues. Cancer in this stage has spread only to the lymph nodes, not to the different organs of the body.
Cancer has become massive and spreads to the different organs of the body. This stage is also known as the advanced cancer stage.
Many options are available for treating cancer. The treatment of cancer may vary on different aspects like the stage, type, location in the body, and size of cancer. Some of the standard therapy used in oncology for treating cancer are Radiation therapy, Surgery, Chemotherapy, Hormone therapy, Targeted therapy, Immunotherapy.
Radiation therapy, also known as radiotherapy, involves high doses of a radiation beam to kill or slow the growth of cancer cells by damaging the DNA. For the low treatment, mostly X-rays are used. This therapy involves an external machine that emits high-energy beams, which focuses on the precise area of the body that has cancer cells. It damages the cells by destroying the genetic material that controls the growth and division of cells. The patient typically receives external beam radiation five days a week over a certain period of time, with each treatment lasting for 10-30 minutes. In most cases, treatments are usually spread out over several weeks to let healthy cells to recover in between radiation therapy periods.
In the surgical procedure, the surgeon removes the tumor and its nearby tissues. The surgery is used to diagnose cancer, to find out if cancer has spread, to check whether the cancer is affecting other organs of the body, and to relieve side effects. There are many surgeries used in cancer treatment; some of the commonly used surgeries are Diagnostic surgery, Staging surgery, Curative surgery.
Chemotherapy uses special anti-cancer drug cells. These drugs help in destroying the cancer cells by stopping multiplication at a certain point in their life cycles. The drugs are given by direct injecting into the muscle, applied to the skin, or into the vein. This therapy is usually provided in cycles of alternating treatments and rest periods.
This therapy uses particular medicines to stop, block, or to reduce the number of hormones in the body to stop the growth of cancerous cells. The doctor can give you hormone therapy before or after other cancer treatments. It is also used as primary treatment before the surgery, to improve the success rate. Hormone therapy has opted in cases like breast cancer, ovarian cancer, and prostate cancer.
This treatment uses drugs to kill cancer cells. It is called targeted therapy because it targets cancer's specific genes, tissue, or proteins. Hormone therapy helps the immune system to suppress or to kill the cancer cells. Individual target therapies are used to make it easier for the immune system to find and kill the cancer cells, and many of them are used to boost the immune system to work against cancer.
It is also known as organic or biological therapy. Immunotherapy boosts the immune system of the body to fight against cancer cells. It enhances the body's natural immune responses. This therapy helps in stopping the cancer cells from growing, boosts the immune system to work better, and ending the cancer cells from spreading to other parts of the body.
Some common types of immunotherapies are-
Cancer vaccines, Non-specific Immunotherapies, Tumor-agnostic therapy, and Oncolytic virus therapy.