Cancer of the pancreas is a genetic disease which means that it is caused by changes (mutations) in DNA. These changes can be inherited (we are born with them) or they can be acquired (they develop after we are born). The inherited changes explain why cancer of the pancreas runs in some families, and the acquired changes can be the result of either bad luck during cell replication or by exposure to carcinogens (cancer causing chemicals) such as those found in cigarette smoke. There are several risk factors that have been associated with pancreatic cancer.
It may be hard to accept, but chance may play a big role in the development of pancreas cancer. In order to understand how this is possible, it is helpful to review the basics of genetics.
DNA (Deoxyribonucleic acid) carries all of the genetic information. DNA is a linear string (polymer) of four different units or base pairs labelled A, C, G and T. These can be thought of as the letters of the genetic code. These base pairs in turn spell the words (called the genes) of the genetic code.
A gene is the hereditary determinant of a characteristic (like eye color). The human genome (all of the information in a single human cell) is estimated to contain between 50,000 and 100,000 genes. Cells are normally dividing to copy themselves and replenish cells which have died. Each cell contains 3 billion base pairs (A, C, G and T).
So, every time a cell divides it must copy all 3 billion base pairs. Unfortunately, cells can make mistakes when copying this DNA. If one of these mistakes is made in a gene that prevents pancreas cancer, then that person will be at increased risk for developing pancreas cancer.
The image below shows a set of chromosomes from a pancreatic cancer cell. Each chromosome is "painted" a different color by a Spectral Karyotyping (TM) technique. The arrows mark multi-colored chromosomes which have exchanged parts of their genetic material (DNA). These changes, and other genetic abnormalities observed in pancreatic cancer are currently being investigated at Johns Hopkins.