Asbestos is a mineral that comes in a fine needle-like fiber. The fiber is easily airborne, where it can be inhaled into the lungs or swallowed.
How Asbestos Causes Cancer
Asbestos is highly toxic and can cause various lung diseases, including asbestos-related cancer of the pleura (the lining of the lungs), the peritoneum (the lining of the gastrointestinal tract and abdomen), the pericardium (the lining around the heart), and the testes.
All of these cancers are the result of the fiber in the asbestos imbedding into the bodies’ tissues and irritating the tissues and traveling to various sites in the body. Asbestos causes cancerous changes in the above areas of the body.
When referring to asbestos-related cancer, one is usually referring to mesothelioma, which is almost exclusively caused by inhaling or ingesting asbestos. Mesothelioma is an aggressive and incurable cancer that preferentially causes cancer of the linings of various body areas, such as the lungs, heart and intestines.
Adenocarcinoma of the lung can also be associated with asbestos exposure, especially if the individual also smokes. Adenocarcinoma, like mesothelioma, is aggressive and has no cure. Both types of lung cancers are treated with surgery, radiation therapy and chemotherapy — all of which together usually only prolong the person’s life and don’t provide a cure.
There are weaker links to asbestos and other types of cancer. For example, it is associated with testicular cancer when it seems inconceivable that asbestos fibers could travel from the lungs or the abdomen all the way to the testes. Research is looking into the role asbestos plays in still other forms of cancer.
Currently, about 50 percent of all occupational cancers are related to an exposure to asbestos.
People who work directly in an industry that utilizes asbestos are at the highest risk of developing an asbestos-related cancer. In one study of more than 1,000 employees in the asbestos industry, the cause of death was secondary to cancer in more than 200 of these workers. Most of the cancer deaths were located in the respiratory tract, such as lung cancer, cancer of the trachea and bronchial cancer. More rarely the cancer deaths were from malignancies of the peritoneum or intestines.
Facts about Asbestos and Cancer
Asbestos causes various kinds of cancer because the fibers are easily ingested or inhaled and are not easily coughed out. The asbestos fibers are sharp and pointy, so they stick to lung tissue and the inner part of the digestive tract, where they travel and set up areas of inflammation and irritation to the affected tissues.
The fiber causes the genetic material (DNA) of the cells to mutate, which ultimately causes the cells to divide uncontrollably as a malignant tumor. Once the malignancy begins, it easily spreads to the lymph nodes and lymph system so the cancer can crop up anywhere in the body as a metastasis of the original tumor.
Asbestos is practically the only causation for mesothelioma, while both smoking and asbestos is required to have an increased risk for adenocarcinoma of the lungs. Asbestos and exposure to radon together can also lead to asbestos-related lung cancer.
Interestingly, being a smoker exposed to asbestos doesn’t increase one’s risk of getting mesothelioma; only adenocarcinoma of the lungs appears to have smoking as an additional risk factor for getting this type of cancer. It is also believed that things like poor nutrition, a sedentary lifestyle and stress also increase the risk of asbestos-related cancer of the lung.
Symptoms of Cancer
Anyone who has a history of exposure to asbestos need to know the various signs and symptoms of the types of cancer that asbestos causes.
About one fifth of all people who have been exposed to asbestos will come down with a disease related to their exposure.
The lungs are the area of the body most connected to asbestos-related cancer. Symptoms of lung cancer, laryngeal cancer, asbestosis and mesothelioma include shortness of breath, pain in the chest, problems breathing and a dry cough.
If asbestos exposure leads to peritoneal mesothelioma, colorectal cancer, GI cancer, ovarian cancer or renal cancer, the common symptoms are:
- Abdominal pain
- Fluid accumulation in the abdomen
- Changes in bowel function
- Problems with digestion
If a woman has asbestos-related ovarian cancer, symptoms include:
- Tiredness or exhaustion
- Menstrual abnormalities
- Back pain
- Pain during intercourse
Diagnosis and Treatment of Asbestos-related Cancer
It can be extremely difficult to diagnose asbestos-related cancer because, by the time there are symptoms, the disease may already be advanced. It often takes several trips to different doctors before someone discovers the mesothelioma or lung cancer. In particular, mesothelioma is difficult to diagnose because it has symptoms similar to much more common diseases.
Eventually, a doctor may order a chest X-ray, PET scan or CT scan of the chest or abdomen that shows the presence of cancer. When cancer is suspected using imaging testing, a biopsy is taken of the suspicious area or a sampling of fluid around the lungs is aspirated so that cancerous cells can be identified under the microscope.
Because mesothelioma isn’t the only cancer related to asbestos exposure, people generally require other screening tests for cancer, such as a colonoscopy, mammograms and Pap tests. Anyone who has been exposed to asbestos should remain vigilant about any unusual symptoms that arise that may be tied to various types of cancer.
Once cancer has been identified, it needs to be treated. With mesothelioma, a combination of surgery, radiation therapy and chemotherapy is performed to slow the progression of the cancer. Some cancers are also treated with immunotherapy, which is based on enhancing the immune system to fight off cancer. Lung cancer can be treated, in some cases, with photodynamic therapy. Certain endocrine cancers and breast cancer can be treated with hormone treatments.
Most of the time, the asbestos-related cancer is going to be mesothelioma. Nothing else increases the risk of mesothelioma besides asbestos. The exposure to asbestos usually happens over a period of time and the risk increases with the amount of asbestos inhaled or ingested. Usually the pleura of the lungs or the peritoneum of the abdomen become the primary sites of mesothelioma.
Lung Cancer and Asbestos
Asbestos contributes to adenocarcinoma of the lungs, particularly in workers who were exposed to asbestos and were also smokers. Smoking is felt to make it more difficult for the lungs to fight off cancer, so the lungs are more susceptible to become cancerous when exposed to asbestos.