what is cancer? what causes cancer and how is it treated?
An explanation of cancer
Cancer is a condition when a few of the body’s cells grow out of control and spread to other bodily regions.
Of the millions of cells that make up the human body, cancer can develop practically anywhere. Human cells often divide (via a process known as cell growth and multiplication) to create new cells as the body requires them. New cells replace old ones when they die as a result of aging or damage.
Occasionally, this systematic process fails, causing damaged or aberrant cells to proliferate when they shouldn’t. Tumors, which are tissue masses, can develop from these cells. Tumors may or may not be malignant.
Cancerous tumors can move to distant parts of the body to produce new tumors, invade neighboring tissues, or both (a process called metastasis). Malignant tumors are another name for cancerous tumors. Cancers of the blood, including leukemias, seldom develop solid tumors although many other malignancies do.
Noncancerous tumors do not penetrate or spread to neighboring tissues. Benign tumors typically don’t come back after removal, however malignant tumors can. Yet, benign tumors can occasionally grow to be quite enormous. Some, like benign brain tumors, can have grave side effects or even be deadly.
Differences between Cancer Cells and Normal Cells
In many respects, cancer cells are different from healthy ones. Cancer cells, for instance:
develop despite without receiving commands to do so. Only when they get such signals do normal cells expand.
disregard signals that would typically instruct cells to cease dividing or die (a process known as programmed cell death, or apoptosis).
infiltrate adjacent regions before moving on to other body parts. Most normal cells do not travel across the body and cease growing when they come into contact with other cells.
instructing blood arteries to expand toward malignancies These blood veins transport waste from tumors and provide oxygen and nutrition to the tumors.
evade the immune system by hiding. Damaged or aberrant cells are typically eliminated by the immune system.
manipulate the immune system to fool the immune system into sustaining and promoting the growth of cancer cells. As an illustration, certain cancer cells persuade immune cells to defend the tumor rather than fight it.
acquire many chromosome alterations, including as chromosome component duplications and deletions. Some cancer cells contain twice as many chromosomes as healthy cells do.
depend on different nutrients than healthy cells do. Moreover, as opposed to most normal cells, certain cancer cells use a distinct process to produce energy from nutrients. This promotes the rapid growth of cancer cells. to
How Does Cancer Develop?
Cancer-causing genetic alterations can occur because:
of mistakes that happen when cells divide.
of DNA deterioration brought on by unfavorable environmental elements including the toxins in tobacco smoke and the sun’s UV radiation. (Further details can be found in our section on cancer causes and prevention.)
they were handed down to us by our parents.
Cells with damaged DNA are typically eliminated by the body before they develop into cancer. But as we become older, the body becomes less capable of doing so. This contributes to the increased chance of developing cancer later in life. The genetic mutations in every person’s cancer are different from one another. Further alterations will take place when the cancer spreads. Several cells in the same tumor may exhibit various genetic alterations.
Types of Genes that Cause Cancer
Proto-oncogenes, tumor suppressor genes, and DNA repair genes are the three primary gene groups that are typically impacted by the genetic alterations that cause cancer. These modifications are commonly referred to as cancer’s “drivers.”
Proto-oncogenes play a role in regular cell division and proliferation. However, these genes may develop into cancer-causing genes (or oncogenes), allowing cells to grow and survive when they shouldn’t by being changed in specific ways or being more active than usual.
Genes that decrease tumors are also involved in regulating cell division and proliferation. Some tumor suppressor gene mutations can cause cells to divide uncontrollably.
DNA damage must be repaired using DNA repair genes. These gene mutations frequently lead to other gene mutations and chromosomal alterations in affected cells.
When Cancer Spreads
Metastatic cancer is a type of cancer that has progressed from the site of its initial formation to another location in the body. Metastasis is the process through which cancer cells spread to other areas of the body.
The initial or original cancer’s name and cancer cell type also apply to metastatic cancer. For instance, breast cancer that spreads to the lung and develops a tumor is considered metastatic breast cancer rather than lung cancer.
Metastatic cancer cells typically resemble the original tumour’s cells when viewed under a microscope. Additionally, there are some biological similarities between metastatic cancer cells and the initial cancer cells, such as the presence of particular chromosome alterations.People with metastatic cancer may occasionally live longer with the aid of treatment. In other circumstances, preventing the spread of the cancer or reducing the symptoms it is causing are the main objectives of treatment for metastatic cancer. Most cancer patients die from metastatic disease, which can seriously impair how the body works.