What Causes Cancer?

Video Transcript

Every cell, including the ones that make up the human body, has the inherent ability to overcome obstacles and to grow and evolve.


But the human body possesses safeguards to prevent genetic alterations and ensure that cells continue to function properly. When those safeguards fail, cells can grow uncontrollably. This is what cancer is: cells growing independently of the host because of changes in their DNA sequence, known as mutations. These growths are called “tumors”. Tumor cells have acquired mutations which break down the cell’s defenses. Tumor cells continue to overcome significant pressures, including the immune system and chemotherapy to grow and spread to other parts of the body.


Mutations are the underlying cause of cancer. The genetic code gets mixed up, lost, or changed. This can be caused by environmental circumstances such as exposure to carcinogens, like cigarette smoke, or UV radiation. Mutations can also occur during normal cell division. Every time a cell divides it needs to copy every single bit of code so that both new cells get the same DNA sequence. This process is incredibly accurate, but it’s not 100% accurate and cancer-causing mutations can occur sporadically when a cell divides. Incredibly, cells have ways to fix these mistakes, but the system is not flawless. Mutations that escape repair are passed down to every subsequent cell it divides into. Therefore, new cells inherit the mutation. Not all mutations are the same.


Sometimes mutations can have absolutely no effect on the gene. Other mutations can alter the gene in a way that affects the function of the protein by changing the function, altering the function, or removing the function completely. “Loss of function” mutations result in a protein that is either not made or doesn’t have its original function at all. “Gain of function” mutations involve the protein gaining a new or altered function. A combination of these mutations, in certain types of genes, can allow cancer cells to grow uncontrollably. Caris Life Sciences can identify mutations in genes and determine the effect of that mutation on the tumor. Certain mutations can make tumors sensitive to certain drugs, and by recognizing what mutations are present in a tumor, we can assist physicians in finding the right therapies to use.

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Patient Education Videos

The Central Principles of Molecular Biology video series is meant to help explain molecular profiling and cancer, so that you can understand how Caris molecular profiling helps fight cancer through precision oncology.