Welcome to my first part of research where i would like to introduce my inquiry question.
The Definition of Cancer
Cancer is a disease in which some of the body’s cells grow uncontrollably and spread to other parts of the body.
Cancer can start almost anywhere in the human body, which is made up of trillions of cells. Normally, human cells grow and multiply (through a process called cell division) to form new cells as the body needs them. When cells grow old or become damaged, they die, and new cells take their place.
Sometimes this orderly process breaks down, and abnormal or damaged cells grow and multiply when they shouldn’t. These cells may form tumors, which are lumps of tissue. Tumors can be cancerous or not cancerous.
Cancerous tumors spread into, or invade, nearby tissues and can travel to distant places in the body to form new tumors by a process called metastasis. Cancerous tumors may also be called malignant tumors. Many cancers form solid tumors, but cancers of the blood, such as leukemias, generally do not.
Benign tumors do not spread into, or invade, nearby tissues. When removed, benign tumors usually don’t grow back, whereas cancerous tumors sometimes do. Benign tumors can sometimes be quite large, however. Some can cause serious symptoms or be life threatening, such as benign tumors in the brain.
How Cancer Cells Arise
Cancer typically originates from genetic mutations, which are changes in the DNA sequence, accumulating over time within a cell. These mutations can alter the function of specific genes that regulate cell growth and division. Oncogenes are mutated versions of proto-oncogenes; normally promoting cell growth, they become hyperactive when mutated, constantly signaling the cell to divide.
Conversely, tumor suppressor genes normally act to regulate cell growth and division, often by initiating programmed cell death or repairing DNA damage. When these genes become mutated, they lose their protective function, allowing uncontrolled cell proliferation. Beyond genetic mutations, epigenetic changes can also contribute to cancer development. These changes affect gene expression without altering the underlying DNA sequence, influencing how genes are turned on or off.
External factors also play a significant role in inducing these cellular changes. Exposure to carcinogens, such as chemicals found in tobacco smoke, can directly damage DNA. Radiation, like excessive exposure to ultraviolet light or medical radiation, can also cause DNA mutations.
Cancer cells invade nearby tissues through several key processes:
- Escape from the primary tumor; cancer cell must break from the original tumor into the nearby tumor.
- They can enter lymphatic system travelling to distant parts of the body.
- survival and growth in new environments; once in the blood stream, cancer cell can survive and establish new tumor in distant organs.
- metastasis; this process involves the formation of secondary tumor known as metastases, in other parts of the body. These mechanisms enable cancer cells to spread and grow uncontrollably, leading to the development of metastatic tumors.
Hi Zamzam, your post clearly explains how cancer may arise. I totally agree that the genetic mutation sequence may change. I look forward from learning from you.
Hello Zamzam your research has opened the mind of many people. I am astonished that the cancer can Cancer can start almost anywhere in the human body. According to me I thought that the cancer cell originates in specific parts. Really, I cannot wait to learn other new things from your posts.
HI Zamzam your post is reaally nice as it tries to explain one of the questions that i have been asking myself in life time that what is this we do call cancer. Now that you have this topic i hope that by the end of it i will clearlly underastand all.