So, what is a cancer cluster? And how does it affect your health?

A cancer cluster is the repeated occurrence of a particular type of cancer in a specific community or neighborhood. Because of its health hazards, a cancer cluster requires medical intervention and investigation to determine the causes of the outbreaks of cancer.

Cancer occurrence may be due to the pollution of the air, the underground water, the toxic waste dumps, and the power lines, among others.

If repeated outbreaks have occurred in a specific neighborhood or at workplace, then there should be concern from the authorities about the formation of a cancer cluster.

For example, in shipyards, due to the greater exposure to asbestos, shipbuilders are more prone to lung cancer; or in factories where there is greater exposure to vinyl chloride, workers have higher risk of liver cancer. These work environments are grounds for cancer clusters.

Although there have been many cancer cluster investigations, very few of them have produced tangible results, that is, a definitive connection of a cancer outbreak with a certain chemical or toxic material. In addition, given that cancer may take many years to develop in an individual, proving the cause and effect of cancer due to an external factor is extremely difficult, if not impossible.

To illustrate, breast cancer has increased significantly in recent years. This drastic increase may be attributed to several factors. Nowadays, many women tend to bear children later in life because of their career, and this trend may affect their hormone balance. Having children earlier may decrease breast cancer risk, while delaying childbirth may increase the risk. Other factors, such as obesity, diet and lifestyle, also play a critical role in the incidence of breast cancer. Therefore, to pin down the cause of breast cancer to a specific agent is almost impossible. For this reason, common cancers, such as breast cancer, do not fall into a cancer cluster.

Indeed, given that each type of cancer has its unique causes and risk factors, only the frequent causes of the same type of cancer, which does not occur frequently elsewhere, can be counted towards a cluster and compared against background rates.

There are approximately over one million cases of cancer diagnosed each year in the United States. So, to prove or to investigate into the possibility of a cancer cluster, there must be many cases of similar type of cancer outbreak in a specific geographic area. In addition, this type of cancer must be uncommon, or at least apparently less frequent elsewhere. Furthermore, there must be an evident source of environmental pollution as the cancer agent.

That said, it is still difficult to prove the formation of a cancer cluster, simply because of the power of the establishment to stop it, as portrayed in the movie "Erin Brochovich."

The moral of the story is this: Be vigilant of the environment - the place you live in, the place your work at, and the chemicals or toxic substances you may be directly or indirectly exposed to. Prevention is better than cure. Beware of the health hazards, whether it is a cancer cluster or not is irrelevant.

Copyright (c) 2008 Stephen Lau