Approximately 240,000 Americans are diagnosed with lung cancer annually. Nearly all are caused by environmental factors. While smoking is the leading cause, occupational asbestos exposure remains one of the top causes of this disease. Moreover, asbestos exposure, combined with smoking, dramatically increases the risk for developing lung cancer.
Asbestos is a known human carcinogen and a recognized cause of lung cancer. The scientific literature is replete with studies over the years establishing asbestos as a cause of lung cancer.
Starting in the 1930s and 1940s, doctors in England, Germany and the United States began treating cancer patients who were asbestos workers. Some of these cases were reported in the medical literature as case studies – reports of single instances of patients with certain asbestos exposures.
Dots continued to be connected by the scientific community. By the 1950s, scientific studies continued to mount – culminating in the landmark study of Sir Richard Doll, a British epidemiologist who, in 1955, was the first to show a significant excess of lung cancer in asbestos workers. Doll’s study involved a cohort of 113 men who worked for more than 20 years in an asbestos textile plant. Doll showed a ten-fold excess risk of lung cancer.
Early studies of lung cancer in asbestos workers reflected that the workers also had asbestosis, a scarring of the lungs from asbestos. Asbestosis is a separate disease process from lung cancer. Asbestosis, while not a prerequisite, can be viewed as a marker or fingerprint establishing a history of occupational asbestos exposure. Scientific consensus long ago established that lung cancer is caused by asbestos exposure even without underlying asbestosis.
By the early 1960s, a separate type of cancer called malignant mesothelioma had also been identified and definitively linked to asbestos exposure.
Countless scientific studies have cataloged asbestos related diseases in a wide range of occupations from textile workers, shipyard workers, petrochemical plant workers, insulators, construction workers, power plant workers and lineman, to name a few.
What about smoking?
Smoking, of course, is the leading cause of lung cancer. But, occupational asbestos exposure remains one of the top environmental causes other than smoking. In turn, the combination of smoking and occupational asbestos exposure can be particularly lethal.
Numerous scientific studies establish a synergistic, or multiplying effect, of asbestos exposure and tobacco use. Synergism between asbestos and tobacco for causing lung cancer was demonstrated in several studies to involve increased risk, by several order of magnitude, for lung cancer in asbestos exposed workers who smoked.
Smoking, combined with asbestos exposure, increases the risk for the development much more dramatically than for smokers who were never exposed to asbestos.
What is Lung Cancer?
Lung cancer develops in the interior of the lung – most often beginning in the cells that line the air passages. It occurs when these cells start to grow and multiply uncontrollably because of environmental factors like smoking, asbestos or other factors. Lung cancer is distinct from malignant mesothelioma – a cancer that most commonly develops along the lining of the lung, but can also appear in the lining of the heart and/or abdominal cavity.
A long period of time, known as the latency period, usually passes from the time of a toxic exposure until the development of cancer. Upon exposure to a toxin such as asbestos, changes begin to occur at a subclinical level – damage happening at a cellular level which is too early to be detected. It typically takes decades, in the case of asbestos, for that structural damage to the body to keep developing to the point that an individual begins to experience symptoms and the disease manifests itself. As the disease grows, it starts to impact surrounding tissue and interferes with the lungs’ normal function.
A diagnosis based on the type of cell where the cancer started helps doctors understand the patient’s condition and develop a treatment strategy. There are two main types of lung cancer:
Non-small cell lung cancer (NSCLC)
The vast majority of lung cancers are non-small cell lung cancers. This arises from the epithelial lining of the lung – a type of cell that covers the surface of major organs. Several subtypes of NSCLC include: adenocarcinoma, large cell carcinoma, and squamous cell carcinoma, sarcomatoid carcinoma and adenosquamous carcinoma.
Adenocarcinoma is the most common NSCLC. It is usually found in the outer parts of the lung and often is found before it has spread. Nonsmokers who develop lung cancer most often get adenocarcinoma.
Small-cell lung cancer (SCLC)
Small-cell lung cancer typically develops more in the center of the lung and can develop more rapidly and aggressively than non-small cell lung cancer. Small-cell lung cancer can typically spread through the body’s lymph node system.
Cancers that start in other organs such as the kidney or pancreas can also metastasize to the lung, but since the disease did not originate in the lung, these are not lung cancers. Lung cancer is also distinct from another cancer, mesothelioma, in that lung cancer develops in the interior or meat of the lung whereas mesothelioma grows along the pleural lining along the outside of the lung.
Before the industrial revolution, lung cancer was a rare disease. Increasing use of tobacco, however, combined with the industrialization of the modern world brought its dubious position in the 20th Century as the most common but yet preventable form of cancer.
Lung cancer is caused by environmental factors, including:
Another risk factor is age. The risk of developing the disease increases with age because of the length of time from when environmental exposures begin until lung cancer develops. More than half of all newly diagnosed occur in people over the age of 60. Additionally, men develop lung cancer slightly more than women. This may be because men have typically worked in occupations with a higher likelihood of toxic or environmental exposures.
Prior to diagnosis, individuals often present to their doctor with complaints of one or more of the following: increasing shortness of breath, wheezing, a lingering cough, pain in the chest or back, coughing up blood, feeling tired all of the time, and unexplained weight loss.
Of course, many of these symptoms are common with other illnesses. Only through medical examination, chest radiology and eventually a biopsy can a diagnosis be rendered.
To obtain a sample of the suspect tumor for testing, doctors perform a biopsy in a number of ways including: a needle biopsy and thoracoscopic biopsy.
A needle biopsy occurs when a doctor uses a needle that is guided through the chest wall into the area of the suspected tumor. This is most often guided through a CT or CAT scan or through fluoroscopy.
A larger diameter tube, called an endoscope, is inserted through the chest wall into the chest cavity. Numerous kinds of biopsy tools can be inserted through the endoscope in order to obtain the biopsy sample. Often, this procedure is video assisted (video-assisted thoracic surgery (VATS).
After a successful biopsy is obtained, the sample is sent to be cut and mounted to microscope slides. A special type of staining, called immunohistochemical (IHC) staining is then performed. IHC involves the process of identifying antigens (proteins) in cells by using antibodies to bind to the antigens. IHC markers are then used in to render a diagnosis.
Some IHC markers for lung cancer include: thyroid transcription factor-1 (TTF-1), p63, cytokeratins (CK) 5/6 and CK7.
Following a diagnosis, staging is the next step in the diagnosis and treatment process. Staging includes finding out where the tumor is located, the size of the tumor and whether the tumor has spread.
Three factors are used to classify a lung cancer stage. The stage is determined by all 3:
T – tumor size and location
N – regional lymph node involvement. It is important to know whether the tumor has spread through they lymph node system
M – metastasis refers to which organs the cancer has spread.
Non-small cell lung cancers are staged from one to four. The lower the number, the less the cancer has spread and the better the prognosis.
Stage 0 – early stage that is still in the top of the lung or bronchus and had not spread.
Stage I – Stage IA or IB depending on size of the tumor. A Stage 1 has not spread to the lymph nodes.
Stage II – larger than Stage I and while the tumor may have spread to lymph nodes, it has not spread to distant organs.
Stage III – classified as Stage III because it is larger than Stage II and based on how far the tumor has spread
Stage IV – the most advanced stage of lung cancer. In this stage, the cancer has metastasized to in the lung or other areas of the body.
Great strides in lung cancer treatment, combined with more early detection, have resulted in a 5% decrease in new cases since 2015.
After a confirmed diagnosis is reached, doctors are increasingly using biomarker testing to guide treatment plan options. Biomarker testing gives doctors ways to find out more about specific genetic mutations in cancer cells. Depending on a gene mutation, a person may have targeted treatment options.
Treatment options can include:
If detected at an early stage, some lung cancers can be removed surgically
Using special medicines to shrink or kill the cancer. Drugs can be taken by pill or through the veins. Cisplatin is the most common chemotherapy used for lung cancer.
Using high energy rays (similar to X-rays) to kill the cancer.
Drugs used to block the growth and spread of cancer cells. The drugs can be in pill form or medicines given intravenously. Biomarker tests are used to determine what may be the right targeted therapy for a patient.
Vaccines, as a treatment, are still mostly in the experimental stage. One such vaccine has been developed in Cuba with parallel research occurring at Roswell Park cancer center in Buffalo, New York.
New treatment options are researched through clinical trials to see if they are safe and effective. You can find current clinical trials for lung cancer through the National Cancer Institute
Early detection is critical to the treatment and long-term survival rate following a lung cancer diagnosis. The U.S. Preventive Services Task Force (USPSTF), comprised of 16 physicians and scientists, has recommended screening for individuals over the age of 50.
Testing by annual low-dose computed tomography (LDCT) scan is the recommended method of screening. People with cancer have a much better chance of survival when diagnosed early. This type of screening identifies small possible cancers and has shown a substantially reduced risk of dying from lung cancer.
However, it does have limitations. Detection of false positives is possible.
Anyone over the age of 50 who currently smokes or quit smoking within the past 15 years should have annual early screening per the USPSTF recommendations. Since this is a recommendation of the USPSTF, the Affordable Care Act requires insurers to provide it free of charge. So, early screenings are covered by insurance.
Additionally, anyone with a known occupational exposure to asbestos (or a family member with known occupational asbestos exposure) should inform their doctor who can then perform annual screenings for asbestos disease.
In the not too distant future, there may also be a blood test available for early detection of lung cancer similar to one currently being tested in China.
Lung Cancer Lawyers
The Lung Cancer Lawyers of DuBose Law Firm has over 25 years of experience helping mesothelioma and asbestos lung cancer victims obtain justice for the environmental exposures that contributed to their disease.
DuBose Law Firm has represented asbestos lung cancer victims with varying trades including, but not limited to: US Navy veterans, carpenters, insulators, pipefitters, welders, millwrights, boilermakers, sheetrock workers, oilfield workers, refinery workers, chemical plant workers, power plant workers, brake mechanics, shipyard workers, steel mill workers and many more.
We have also represented victims with a parent or spouse that was occupationally exposed to asbestos and unknowingly brought the dust home on their work clothes.
Depending on an individual’s asbestos exposure history, claims may be brought in the court system against solvent defendants as well as through claims against various asbestos bankruptcy trusts. Claims can be brought even for smokers with occupational asbestos exposures.
If you or a loved one have been diagnosed with lung cancer, contact our office today for a free evaluation. We’re here to help.