Asbestos and Cancer
Asbestos is a group of minerals which is available naturally. Because of its useful properties of strength, insulation and chemical resistance, it was used widely in many products across the globe. According to some estimates more than 3,600 products around us have asbestos in it. But later it was realised that asbestos fibres (which can be 1000 times lighter than human hair) are cause of fatal diseases, asbestos has been banned in many countries and its usage limited in many others.
Asbestos Fatalities - Great Concern
While people associate asbestos exposure to only mesothelioma, it is known to be cause of many other disease such as lung cancer, gastrointestinal, colorectal cancer and asbestosis. According to a study by Environmental Working Group, close to 10,000 Americans die due to asbestos exposure yearly. Asbestos exposure has taken more than 200,000 lives between 1979 and 2001 in America alone.
Maximum deaths are reported due to lung cancer (4,800) followed by mesothelioma (2,590), Asbestosis (1,398) and gastrointestinal cancer (1,200). The deaths caused by asbestos exposure are more than cause by skin cancer and marginally lower than cause due to alcohol consumption.
How asbestos harms our body
What makes this mineral so deadly. The answer lies in those very fine asbestos fibres. Asbestos fibres can remain airborne for hours and days when released in air. These fibres when inhaled or swallowed get into our body and stick there as our body does not have any mechanism to purge them. These fibres cause cell damage leading to various kinds of fatal diseases in human body.
Asbestos and Cancer
There are many types of cancer associated with asbestos exposure -
- Lung cancer
- Gastrointestinal Cancer
- Colorectal Cancer
- Breast Cancer
- Prostate Cancer
- Hodgkin's Lymphoma
- Non-Hodgkin's Lymphoma
The above cancers can be directly attributed to asbestos exposure while there are many more cancers who's chances increase due to asbestos exposure such as kidney, throat etc.
Asbestos and cancer : Mesothelioma
While lung cancer has many more causes such as smoking etc. mesothelioma primarily is caused due to asbestos exposure. As asbestos fibres enter the body they cause genetic changes in healthy mesothelial cells. These cells are nothing but lining of the lungs, abdomen, and heart. This malignancy destroys health cells and tumours grow in their place.
Mesothelioma is generally classified into five types based on where it occurs:
- Pleural mesothelioma : This is the most common type of mesothelioma affecting the lining if lungs (the lining is known as pleura). when asbestos fibres enter lungs, gradually they make their way to pleura. In course of a long period extending to a decade or more, these cause changes in the pleura cells developing tumors. The common symptoms of this type of mesothelioma include fatigue, weight loss, continuous pain in chest, shortness in breath, dysphagia, coughing blood, etc.
- Peritoneal mesothelioma : This cancer occurs in the lining of abdominal cavity known as peritoneum. This is second most common type ff mesothelioma and impacts 10-20% of overall mesothelioma patients. This occurs when asbestos fibres reach peritoneal membrane travelling through digestive organs. Another way can be when asbestos fibres reach this membrane via lymphatic system. It takes decades before these fibres cause damage to the membrane leading to tumors. Symptoms of this kind include abdominal pain, fatigue, nigh sweat, weight loss, anemia etc.
- Pericardial mesothelioma : This cancer occurs in the lining of the heart, pericardium. This is a rare cancer occurring to 1-6% of mesothelioma patients. Symptoms of this type include irregular heartbeats, chest pains, cough, fatigue, dyspnea, Orthopnea, murmurs, etc.
- Testicular Mesothelioma : It can also occur on the sac surrounding the testis (tunica vaginalis). This is one of the rarest type of mesothelioma type. It is also considered to be most treatable type of mesothelioma.
- Omental Mesothelioma: It is the rarest form of mesothelioma. This cancer occurs in omentum, a sheet of fatty tissue in the abdomen. Omentum hangs in front of intestines. Most common reason of this mesothelioma is spreading of Peritoneal mesothelioma to omentum. Symptoms include fatigue, weight loss, back pain, etc.
Survival rates of mesothelioma patients
The survival rates of mesothelioma patients is not very encouraging, primarily because its detected at a very late stage. Some of the key factors which determine the life expectancy of mesothelioma patients are:
- Overall health : If a person has been healthy overall in past then the chances are high for a longer life expectancy. Non smokers are believed to have higher chances that smokers.
- Type of mesothelioma: Of all the mesothelioma, pleural mesothelioma is believed to have higher survival rates, More than 10% can survive for more than 5 years.
- Stage of mesothelioma: Stage 1 patients are expected to have better prognosis and longer life expectancy as compared to Stage 3 and Stage 4.
- Tumor location and spread : If the tumor has spread to other parts, it is tougher to treat and thus have poorer prognosis.
- Age and gender : patients below 55 have better prognosis. Females have better prognosis as compared to males.
Asbestos and Cancer : Lung Cancer
Lung cancer is the second most common cancer in America. Approximately 200,000 Americans are diagnosed with it annually. Asbestos exposure is the not the major cause of lung cancer but it is one of the causes. Lung cancer are of two types - small cell and non-small cell lung cancer. Asbestos exposure can cause either of these types of cancer. It is believed that people with smoking habit and asbestos exposure have higher chances of lung cancer.
One big challenge in treatment of asbestos related lung cancer is latency period which can extend upto 22 years! This is the primary reason that many senior citizens are diagnosed with lung cancer in America.
Some of the common symptoms of lung cancer include, chest pain, fatigue, weight loss, bone pain, shortness in breath etc. But it should be noted that many of them are also symptoms of many other disease and thus proper tests have to be performed before arriving at the result.
Survival rates for lung cancer
Based on various studies, average prognosis for asbestos-related lung cancer was 16.2 months. 25% of patients with asbestos exposure have life expectancy of more than 5 years. Factors which impact the prognosis are:
- Stage of lung cancer: A stage 1 cancer patient has lot better chances of 5+ years survival than higher stages ones
- Age: The prognosis becomes poor with increase in patients' age
- Cancer type : Small cell lung cancer has better prognosis as compared to non-small cell lung cancer
- Gender: Females have better prognosis as compared to males.
- Smokers: people who quit smoking after diagnosis have longer life expectancy than ones who do not
Asbestos has been cause of many fatal types of cancer - mesothelioma and lung cancer are the most common ones. If you have any of the symptoms and you believe you were exposed to asbestos in past, it is best to get a check up done as soon as possible. An early diagnosis can really make a difference.