Cancer causes: numerous and varied...
and largely avoidable.

Cancer causes are all linked to carcinogens; those physical, chemical and biologic agents that cause cancer.

One might be tempted to think that getting to the root cause of a cancer would be a pretty simple thing, such as, if we smoke cigarettes we get lung cancer.  

Sounds good but not true in most cases.  People who never
smoked a cigarette in their life get lung cancer and people who smoked two or three packs a day may never get lung cancer.

A couple of things that complicate the picture are time and exposure.  The time between exposures to a carcinogen and development of a detectable tumor can range from seven years to several decades.  

In addition the amount and duration of exposure to the carcinogen is often hard to determine.  On top of that, there are geographic and
racial factors that contribute to cancer causes.

The basic question in seeking cancer causes is, "what has the ability to damage DNA?"  

Photo below: Damaged DNA showing multiple broken chromosomes

DNA damage resulting in multiple broken chromosomes such as might be caused by UV or radiation

Getting to the answer is critical in that the implication is that if we know the cause, we can avoid the cause.  We know that cancer, with some exceptions, does not spring from a bacteria or virus. 

We can't catch cancer in the sense that we could catch a cold.  Something has to enter our body or impact on our body and cause a cellular mutation of the DNA.

It is believed that about 80% of all cancers are self-inflicted.  Let's see why.

Physical Cancer Causes

Natures Sunshine

Start with sunshine.  We need some amount of sun to create vitamin D but we know that too much exposure to the sun’s ultraviolet rays do damage skin cells. 

There are vastly more cases of skin cancer in Florida, Australia, and sunny tropical regions than in areas of less intense sunlight.  A carcinoma is defined as a cancer formed on
epithelial tissue such as skin. 

Slide of melanoma from NIH

Unfortunately, epithelial cancer has the fastest rate of replication of any cancers which is why we still have so many deaths from melanoma, accounting for about 75% of all deaths from skin cancer.  This translate to about a million cases of skin cancer each year in the U.S. 

It should be a very avoidable type of cancer simply by limiting exposure to the sun, covering exposed skin when in the sun for long periods of time and checking out changes in shape and coloring of moles.

The photo above shows a typical melanoma skin cancer.


One of the most costly cancer causes, at least to industry, is asbestos; that white fibrous mineral substance that makes great insulation but will kill you in about 40 years once you inhale it.  Ever seen those mesothelioma commercials that law firms put on TV trolling for new clients? 

Mesothelioma is a malignancy that develops in the mesothelium, the protective lining that covers most of the body's internal organs.

It's most common site is the outer lining of the lungs (pleura) and internal chest wall), but it may also occur in the lining of the abdominal cavity (peritoneum), the heart's pericardium (a sac that surrounds the heart).    

Anyone that has worked around asbestos fibers is susceptible as is anyone living in the same household as an asbestos exposed worker.  Asbestos miners, construction workers, boilermakers, electricians, and shipyard personnel are among the many people who have contracted mesothelioma.

Photo:  Micrograph of asbestos fibers; breathe in these and expect to die from mesothelioma in about 40 years.

Asbestos fibers from Scanning Electron Micrograph, from USGS file

If the fibers are carried into the home on the workers clothes and someone in the home handles those clothes, for example to wash them, they are also at risk. 

It is a deadly disease with no cure and subsequent litigation has bankrupted numerous companies involved in asbestos production or use.

Asbestos exposures are a thing of the past but industry is cranking out new carcinogens as fast as they can.

Want to learn more about Mesothelioma? Follow the link to below for information on the book, 100 Questions & Answers About Mesothelioma, an in-depth study into this terrible affliction.

Nuclear Radiation and
Electrical Power

When it comes to cancer causes from the nuclear power industry or emissions from high voltage power lines, the record is exceptionally clean. 

Accidents happen such as Chernobyl and Three Mile Island but barring human error, it is a very safe industry.  There is no evidence that electrical fields from power lines cause cancer.

Nuclear weapons are another story.  Volumes of data have been collected on the radiation effects of the Hiroshima and Nagasaki atomic bombs and the long term effects of nuclear radiation are deadly.  Let's not be playing around with nuclear weapons.

Cancer Causes from Chemical Exposure

Devil Weed and Demon Rum

It was said earlier that not every smoker gets cancer, in fact most of them don't.  Nevertheless, tobacco use causes 30% of all cancers and is the largest of the avoidable chemical carcinogens followed closely by alcohol.

If everyone suddenly quit smoking or chewing tobacco, deaths from these cancer causes would drop from about 200,000 per year to about 2,000 per year. 

Cigarette smoke by Tomasz Sienicki, 2005

If we dropped dead immediately after smoking a cigarette, there would be no one would smoke.  The problem is that, on average, it takes about 20 years for cancer to manifest itself in a smoker.

Cigarette smoke is a heated gas containing a witch’s brew of chemicals, most of which have the ability to damage delicate DNA.  Second hand smoke is no safer. 

Lung cancer is a lifestyle choice that is almost 100% avoidable.  To quote Yul Brynner, the actor who died of lung cancer in 1985, "Now that I'm gone, I tell you, don't smoke".

Regarding alcohol, a report from the American Institute for Cancer Research, there is evidence that heavy alcohol use increases the risk of cancer of the mouth, pharynx, larynx and esophagus.

Photo:  Endoscopic image of esophageal carcinoma at gastro-esophageal junction.

Endoscopic image of patient with esophageal adenocarcinoma at the gastro-esophageal junction, author: Samir, 2 June 2006

Alcohol also increases the risk of liver cancer and possibly the risk for colon, rectal and breast cancer.
If drinkers also smoke, the risk for upper respiratory tract cancers (mouth, tracheal, and esophagus) cancer is 35 times greater than for people who neither smoke nor drink. 

The implied carcinogenic interaction between alcohol and tobacco-related carcinogens is very strong.

Martini ingredients

Here's another lifestyle choice.  Evidence shows that a little alcohol each day has health benefits. 

Photo:  Gin plus a touch of Vermouth equals the perfect martini.  Go easy on these things or end up with one of those beauties in the photo above.
That means no more than two drinks a day for men and one for women and done without smoking.  Also that drink a day is a normal sized drink, not a bucket full of martinis.

What other cancer causes are there?

Other common chemical carcinogens are:
  • Food flavoring and saccharine can cause bladder cancer
  • Barbeque grilling, if eaten frequently and charred
  • herbicides used in the home garden or lawn
  • pesticides used in the home or around the house
  • urban air pollution
  • chemicals and pharmaceuticals in the water supply
  • medicines account for about 1% of cancer causes: chemo, immunosuppressants, hormone therapy, and steroids

At least we can protect ourselves from the carcinogens coming into our homes through the water pipes.  Take a look at Aquasana's whole house water filtration system.

whole house water filtration system

Biologic Cancer causes

There is a host of biologic cancer causes of which many are due to viruses, including:

  • Hepatitis B and C
  • Human Papilloma virus, a uterine cancer related to unprotected sex and numbers of sex partners
  • Human T-cell leukemia and lymphoma
  • HIV and its related cancers: Kaposi's sarcoma and Hodgkin’s lymphoma
  • Epstein-Barr virus more commonly known as mononucleosis
  • Helicobacter pylori, if untreated can cause gastric cancer

There are several genetically transmitted cancers.  If there is a family history of cancer, a person is possibly 2 or 3 times more likely to be at risk.  Retinoblastoma, which develops in the cells of the retina, is a good example. 

If both parents have the gene, there is a 10,000 times increase in risk. Xeroderma pigmentosum, a recessive gene that impairs the ability of DNA to repair sun damaged skin, is an example of a cancer caused by
both parents. 

A couple of genes labeled, BRCA1 and BRCA2, account for 5% of breast cancers.  Li-Fraumeni syndrome is a repair gene that, if damaged, causes all kinds of cancers. 

Only 5% of all cancer patients have a genetic link and most with a family history never get cancer.  Most doctors will take the position that history doesn't matter in determining treatment.

Chronic inflammation leads to more cancer due to constant turnover of cells.  If you irritate something enough, cancer is likely to develop.

What's the Next Stop?

If you want to continue the thread on Cancer, the next stop is a page on the statistics and cost of cancer in the U.S.  Just click on "Cancer Statistics" below or any of the other Cancer links shown.  It's not necessary to take them in order.

However, if anyone wants to see what the National Cancer Institute lists as cancer causes, feel free to browse their site.

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