What is cancer?

One of my patients once told me that a cancer cell is akin to a misbehaving child, which is an appropriate analogy. When a baby is born, it begins as a sperm fertilizing an egg, which combines to create a single cell. That cell is pluripotent, meaning that it is capable of eventually forming all of the different kinds of cells that will ultimately be needed to create the human body. That fertilized egg once implanted into the uterus, will divide billions of times and begin to differentiate into different types of cells which will eventually form the various tissues of the human body. By the time the child is born after 9 months of increasingly complex cellular division and differentiation, the baby has many different kinds of cells, each with very specialized functions, most of which have lost the ability to further divide or spread to other parts of the body. They are programmed to die in response to signals from other cells.

Each of these cells is akin to a little factory, performing specified functions. The tools that the cell uses to carry out these functions are called proteins. In order to make a protein, the cell starts with the DNA blueprint that is housed in a structure called the nucleus. The nucleus can be thought of as a little fortress-enclosed island containing stacks of blueprints instructing the cell how to replicate itself. The DNA is transcribed (copied) into a similar structure called RNA, which travels out of the nucleus into the cytoplasm (which could be thought of like the water in the lake). In the lake, the RNA attaches to a structure called the ribosome (think of it as a small, floating protein factory) where it is translated into a protein. These proteins are the worker bees of the human bodies and carry out nearly every important function required for life.

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