The most striking feature of cancer is that agents in the environment can produce cancer simply by us interacting with them. Does this mean that cancer comes from the environment only? Most people are largely aware of the fact that cigarette smoke is a carcinogen, a cancer causing agent which interacts with lung tissue to produce rather extreme forms of lung cancer. Pollutants from factories, household cleaning chemicals, and even pesticides from agricultural crop dustings may contain carcinogens that increase the likelihood of producing cancer.

Indeed, environmental agents and industrial chemicals cause cancer, but the fact of the matter is that cancer happens inside the body; being a result of slight chemical modifications to our DNA. Our genes dictate our resistance to carcinogenic agents, making cancer a result of our own inherited traits interacting with external environmental factors.

So what exactly is DNA, and how does it act as the basic molecule of life? DNA molecules are shaped liked a spiral staircase, with a backbone made of sugars and phosphates. The metaphorical stairs of the DNA molecule are the bases; the genetic alphabet made of A, T, C, and G. These bases are simple chemicals that act as the “morse code” for DNA, allowing cells to create proteins from sequences of A’s, T’s, G’s, and C’s. The cell requires proteins for a huge variety of tasks, including structural support and enzymatic activity.

Proteins are essentially the “skeleton” of cells and act as the functional unit and building block for all living things. Cancer causing agents act on the DNA molecule itself, altering the sequence of bases. Since the bases act as the genetic code, changing the code will ultimately change the protein that is produced. This is the basis of cancer; small changes in DNA that ultimately result in altered cellular functions.

When cells have enough of their DNA altered, they may be able to alter certain cellular growth pathways. Cell growth is kept in check and is governed by specific genes that control the timing of when cells should mature and divide. Each cell has a specific set of genes that it employs for its function. For example, a heart cell needs to beat and a nerve cell needs to transmit electricity. Cells become cancerous when a genetic susceptibility to cancer causing agents allows the cell to essentially free itself from the other cells around it. Cancer cells become self-sufficient; that is they stop responding to signals from other cells and grow out of control. Cancer cells can even recruit blood vessels to increase the amount of blood supply that they receive!

There is no reason to despair over cancer simply because you live in a densely populated city, even though you may have certain genetic susceptibilities. Prevention is the best weapon against cancer. If you wish to avoid cancer, then avoid cancer causing agents – meaning don’t smoke and try to switch to a more organic lifestyle. Freedom from carcinogens will not prevent cancer entirely, as some people are cancer prone in certain tissues due to accumulations of heritable genetic mutations. The best defense against cancer is to have a good doctor who can spot the cancer before it gets out of control. Your doctor can save your life, but only if you let them. Remember to always get checked and never reject a biopsy; it could save your life!