Cancer is a common name given to a set of related diseases. In all sorts of cancer, a number of the body’s cells begin to divide in an uncontrollable way and spread into surrounding tissues. Cancer can start almost anywhere within the physical body, which is formed from trillions of cells. “Usually, our somatic cells grow and divide to make new cells to fulfill the requirement of the human body. As the cells get older or they become damaged, usually they die, and new cells will take their place. When cancer develops, however, this orderly process is impacted. Old cells somehow survives when unwanted new cells are developed uncontrollably. These extra cells can divide uncontrollably and can form growths called tumors.” Says Dr. Sandeep Nayak who is one of the best oncologist in India.
Many cancers form solid tumors, which are actually masses of tissue resulted from abnormal growth. However, cancers like leukemias, generally don’t form any sort of solid tumors. Cancerous tumors are mostly malignant in nature, which means that they will spread into, or invade, nearby tissues & organs. As these tumors grow, some cancer cells can break off and visit foreign places within the body through the blood or the lymph system and form new tumors faraway from the first tumor.
Unlike malignant tumors, benign tumors don’t spread into, or invade, nearby tissues. Benign tumors can sometimes be quite large. When removed, they typically don’t grow back, whereas malignant tumors sometimes do. Unlike the other benign tumors which develops elsewhere within the body, benign brain tumors are often life threatening & needs serious attention..
Differences between Cancer Cells and Normal Cells
Cancer cells differ from normal cells in some ways that allow them to grow without stopping and become invasive. According to the cancer specialists, one important difference is that cancer cells are less specialized than normal cells. That is, whereas normal cells mature into very specific cell types with their specific functions, cancer cells don’t develop in such a specific way. This is often one reason that, unlike normal cells, cancer cells still divideuncontrollably.
In addition, cancer cells are ready to ignore signals that normally tell cells to prevent dividing or that begin a process referred to as programmed necrobiosis, or apoptosis, which the body uses to urge obviate unneeded cells.
Cancer cells could also be ready to influence the normal cells, molecules, and blood vessels that surround and feed a tumor—an area referred to as the microenvironment. As an example, cancer cells can induce nearby normal cells to make blood vessels that provide tumors with oxygen and nutrients, which they need to grow. These blood vessels also remove waste materials produced in tumors.
Cancer cells also are often ready to evade the human immune system, a network of organs, tissues, and specialized cells that protects the body from infections and other conditions. Although the system normally removes abnormal or damaged cells from the body, some cancer cells are somehow able to hide from thissystem.
Tumors also can use the human immune system to remain alive and grow. For instance, cancer cells can actually prevent the system from killing cancer cells with the assistance of certain immune system cells that normally prevent a runaway immune reaction,.
How Cancer Arises
Cancer may be a genetic disease—that is, it’s caused by changes to genes that control the way our cells function, especially how they grow and divide. Genetic changes that cause cancer are often inherited from our parents. There are several reasons behind cancer which includes damage to DNA, unwanted & uncontrollable cell division. Cancer-causing environmental exposures include toxic substances, like the chemicals in tobacco smoke, and radiation, like ultraviolet rays from the sun.
Each person’s cancer features a unique combination of genetic changes. As the cancer continues to grow, there are additional changes that will occur. Even within a single tumor, different cells may have different genetic changes.
In general, cancer cells have more genetic changes, like mutations in DNA, compared to normal cells. A number of these changes may don’t have anything to do with the cancer; they’ll be the results of the cancer, instead of itscause.
“Drivers” of Cancer
The genetic changes that usually results in cancer mostly affect three main sorts of genes— tumor suppressor genes, proto-oncogenes, and DNA repair genes. These changes are sometimes called “drivers” ofcancer.
Proto-oncogenes are involved in natural cell growth and division that are completely normal. However, when these genes are altered in certain ways or are more active than normal, they’ll become cancer-causing genes (or oncogenes), allowing cells to grow and survive once they shouldn’t.
Tumor suppressor genes also are involved in controlling cell growth and division. Cells with certain alterations in tumor suppressor genes may divide uncontrollably without stopping.
DNA repair genes fix damaged DNA. Cells with mutations in these DNA repair genes tend to develop additional mutations in other genes. Together, these mutations may cause the cells to form tumor & become cancerous.
As scientists have learned more about the molecular changes that cause cancer, they have noticed that certain mutations commonly occur in many sorts of cancer. Because of this, cancers are sometimes identified by the kinds of genetic alterations that are believed to be driving them, not just by where they develop within the body and the appearance of the cancer cell.