All about cancer
All about cancer
Cancer causes cells to divide uncontrollably. This can lead to tumors, damage to the immune system, and other disorders that can be fatal.
In the United States, there were about 15.5 million people living with a history of cancer as of January 1, 2016, according to a 2018 report by the American Cancer Society.
In this article, we examine the types of cancer, how the disease develops, and many treatments that help improve the quality of life and survival rate.
What is canser?
Cancer is a broad term. This term describes a disease that occurs when cellular changes cause cells to grow and divide out of control.
Some types of cancer cause cells to grow rapidly, while others cause cells to grow and divide at a slower rate.
Certain forms of cancer lead to visible growths called tumors, while others, such as leukemia, do not.
Most of the cells in the body have specific functions and a fixed life span. While it may seem like a bad thing, cell death is part of a natural and beneficial phenomenon called apoptosis.
A cell receives instructions to die so the body can replace it with a newer cell that functions better. Cancer cells lack components that tell them to stop dividing and die.
As a result, they build up in the body using the oxygen and nutrients that would normally feed other cells. Cancer cells can form tumors, disrupt the body’s immune system, and cause other changes that prevent the body from functioning properly.
Cancer cells may appear in one area, then spread through the lymph nodes. These are clusters of immune cells located throughout the body.
Causes of cancer
There are many causes of cancer, some of which are preventable
For example, according to data reported in 2014, more than 480,000 people die each year in the United States due to smoking.
In addition to smoking, cancer risk factors include:
- Excessive alcohol consumption
- lack of movement
- Improper and poor nutrition
Other causes of cancer are not preventable. Currently, the most important unpredictable risk factor is age. According to the American Cancer Society, doctors in the United States diagnose 87% of cancer cases in people 50 years of age or older.
Is cancer genetic?
Genetic factors can contribute to the development of cancer
A person’s genetic code tells their cells when to divide and expire. Changes in genes can lead to faulty instructions, and cancer can result.
Genes also affect the production of proteins in cells, and proteins carry many instructions for cell growth and division.
Some genes change proteins that normally repair damaged cells. This can lead to cancer. If a parent has these genes, they may pass the altered instructions on to their children.
Some genetic changes occur after birth, and factors such as smoking and sun exposure can increase the risk.
Other changes that can lead to cancer occur in chemical signals that determine how the body settles, or “express” certain genes. Finally, a person can inherit a predisposition to some type of cancer. A doctor may refer to this as having veterinary cancer syndrome. Inherited genetic mutations significantly contribute to the development of 5-10% of cancer cases.
Innovative research has fueled the development of new drugs and therapeutic technologies.
Doctors usually prescribe treatments based on the type of cancer, its stage at diagnosis, and a person’s overall health.
Below are some examples of cancer treatment approaches:
- Chemotherapy aims to kill cancer cells with drugs that target rapidly dividing cells. Medications can also help shrink tumors, but side effects can be severe.
- Hormone therapy involves taking drugs that change the way certain hormones work or interfere with the body’s ability to produce them. This is a common approach when hormones play a significant role, such as in prostate and breast cancers.
- Immunotherapy uses drugs and other treatments to boost the body’s immune system and encourage it to fight cancer cells. Two examples of these treatments are checkpoint inhibitors and host cell transport.
- Precision medicine, or personalized medicine, is a newer and developing approach. This involves using genetic testing to determine the best treatment for a person’s specific presentation of cancer. Researchers have not yet shown that it can effectively treat any type of cancer, however.
- Radiation therapy uses high-dose radiation to kill cancer cells. The doctor may also recommend the use of radiation to shrink the tumor before surgery or to reduce symptoms related to the tumor.
- Stem cell transplants can be especially helpful for people with blood-related cancers, such as leukemia or lymphoma. It involves destroying cells, such as red or white blood cells, that have been destroyed by chemotherapy or radiation. Then laboratory technicians strengthen the cells and give them back to the body.
- Surgery is often part of a treatment plan when a person has a cancerous tumor. A surgeon may also remove lymph nodes to slow or prevent the spread of the disease.
- Targeted therapies work inside cancer cells to prevent them from multiplying. They can also strengthen the immune system. Two examples of these therapies are small molecule drugs and monoclonal antibodies.
Doctors will often use more than one type of treatment to maximize effectiveness.
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