Lung cancer is one of the most pervasive cancers in the United States and causes 25 percent of cancer deaths. Cigarette smoking is the most common cause of lung cancer, but toxic chemicals and substances like radon gas and asbestos may also cause the disease or increase the risk of developing it. Depending on the size, location and spread of the tumor, doctors can develop specific treatment plans for patients — including surgery, chemotherapy and radiation therapy.
Each year, thousands of Americans receive a diagnosis of lung cancer. This disease is one of the most frequently occurring cancers, second only to skin cancer, and is responsible for one in four of all cancer deaths. The American Cancer Society estimates upwards of 200,000 new diagnoses in 2016 alone.
Medical experts and researchers have been studying lung cancer for years and have identified tobacco use as the biggest risk factor for developing lung cancer. Some studies estimate tobacco use causes 80% of lung cancer deaths. People exposed to toxic natural compounds like asbestos are also at a high risk for developing lung cancer.
Along with the most common causes of this cancer, scientists are also learning strategies for prevention, early detection and treatment.
What is Lung Cancer?
Lung cancer is cancer that begins in the lungs. If the tumor started elsewhere in the body and spread to the lungs, it is not lung cancer. This disease is the second-most common occurring cancer in men and women and the leading cause of cancer death in America. Experts estimate 224,390 new cases of lung cancer will be diagnosed in 2016, and 158,080 people will die from lung cancer the same year.
According to the American Cancer Society, there are three types of lung cancer — non-small cell lung cancer, small cell lung cancer and lung carcinoid tumors, and about 85 to 90 percent are non-small-cell lung cancers. There are also several sub-types of lung cancer, including squamous cell carcinoma and adenocarcinoma. Most people who develop lung cancer are seniors. The average age at diagnosis is 70 years old.
Causes of Lung Cancer
Scientists have identified many risk factors for developing lung cancer. Certain risk factors are more common than others. Smoking tobacco is the leading risk factor for developing lung cancer, and is the leading preventable cause of death in the U.S. Researchers first identified smoking as a major cause of lung cancer in the 1960s.
Traditionally, most smokers have developed squamous cell carcinomas, a small-cell lung cancer, but recent research has shown now many smokers are contracting adenocarcinomas, a non-small cell lung cancer. Many scientists believe changing cigarette formulas caused tumors types to change. In addition to smoking, several other factors may contribute to developing lung cancer.
These risk factors include:
- Smoking. This is the number one cause of lung cancer. Data estimates secondhand smoke exposure causes more than 7,000 lung cancer deaths each year.
- Asbestos exposure. Smokers exposed to asbestos have an amplified risk — they are 50 to 90 times more likely to develop lung cancer than those exposed to the mineral who don’t smoke. Studies prove inhaling asbestos fibers — used in a variety of goods before the 1960s, including building materials and safety clothing — leads to the development of lung cancer, pulmonary disease and other types of cancers.
- Radon gas.The U.S. Environmental Protection Agency says breathing in radon is the second-highest cause of lung cancer in the country. Because people cannot see, smell or taste the gas, it is difficult to detect.
- Family history. Some people may have a higher risk of developing lung cancer if members of their immediate family have developed the cancer.
- Air pollution. Some researchers believe 5 percent of lung cancer deaths worldwide are due to air pollution. Exposure to other natural pollutants, like breathing in radioactive radon gas and air polluted with gas and diesel fumes or drinking water tainted with arsenic, can also lead to lung cancer.
Some people are more likely to develop lung cancer than others. A person’s profession and where they live may also put them at risk.
These populations include:
- Those regularly exposed to secondhand tobacco smoke, including family members of smokers
- People who live or work in buildings with high indoor radon levels
- People who worked in industries with heavy asbestos exposure, including construction workers, miners, factory workers, firefighters and shipyard workers
- City dwellers who live near highly trafficked roads
Symptoms of Lung Cancer
The signs and symptoms of lung cancer often don’t appear until the disease is in its advanced stages. For this reason, it’s important people see their doctor immediately if they notice any of these symptoms. The earlier lung cancer is detected, the more effective treatment may be.
Common symptoms of lung cancer include:
- Coughs that do not go away or increasingly worsen
- Coughing up blood
- Chest pain during deep breathing, coughing or laughing
- Shortness of breath
- Persistent infections like bronchitis and pneumonia
Lung cancer starts in the lung, but can spread to other organs. When it does, the cancer may show additional symptoms. Some symptoms of lung cancer that’s spread to other organs are:
- Bone pain
- Lumps in the neck
- Changes to the nervous system like headache, weakness, dizziness and seizures
Less commonly, lung cancer can also cause syndromes in certain people. These syndromes cause very specific, less common symptoms. If a person develops any of these symptoms, they should visit a doctor immediately to test for lung cancer.
These syndromes and their symptoms include:
- Horner syndrome – one drooping eyelid, a smaller pupil in the same eye, lack of sweat on the same side of the face, severe shoulder pain
- Superior vena cava syndrome — swelling in the face, neck, arms and upper chest, blue or red skin in those areas, headaches, dizziness
- Paraneoplastic syndromes — nausea and vomiting, confusion, easy bruising, trouble rising from a sitting position, loss of balance, trouble speaking, thirst and frequent urination, blood clots, painful fingertips, breast growth in men
Diagnosing Lung Cancer
Doctors can diagnose lung cancer after looking at a lung cell sample under a microscope. The diagnosis process often begins when a patient experiences symptoms, but regular screenings can also detect the disease. After lung cancer is detected, the doctor will determine the stage of the cancer before developing a treatment plan.
Lung Cancer Tests
Testing for lung cancer begins with more common tests to look for signs of the cancer, such as a mass in the lung of a family history of the disease. If these tests indicate the patient has lung cancer, the doctor may do more extensive tests to harvest lung cells. The first round of lung cancer tests often includes:
- Family medical history and physical exam
- Chest x-ray
- CT scan (computed tomography)
- MRI scan (magnetic resonance imaging)
- PET scan (positron emission tomography)
- Bone scan
- Radionuclide scans
If these tests indicate a patient may have lung cancer, doctors may run a diagnostic test for lung cancer. To make the diagnosis, doctors must examine lung cells under a microscope. Doctors use several diagnostic procedures to obtain lung cells for testing, including:
- Sputum cytology, when doctors examine phlegm a patient coughed up
- Thoracentesis, when doctors use a needle to drain excess fluid from around the lungs and examine it
- Biopsy, when doctors use a needle or surgery to remove cells directly from the lung and examine it
- Bronchoscopy, when doctors place a lighted scope through a patient’s nose or mouth to examine the inside of the lungs and take cell samples
- Blood and urine tests, when doctors can identify a tumor through excess amounts of hormones it may secrete
In advanced stages, lung cancer can spread to other parts of the body. To test if the lung cancer has spread, doctors use tests like:
- Endobronchial ultrasound
- Endoscopic esophageal ultrasound
- Mediastinoscopy or mediastinotomy
Stages of Lung Cancer
If the doctor confirms a patient has lung cancer, they will then determine what stage the cancer is in before developing a treatment plan. Doctors often stage small cell lung cancer and non-small cell lung cancers differently, but lung carcinoid tumors are only staged using the TNM system. Depending on the size, location and spread of the tumor, doctors develop a plan for treatment. Oncologists will first use diagnostic tests such as blood tests, biopsies and imaging tests to begin staging. After, the doctor can determine more details about the tumor from surgery.
Doctors doctors use the TNM Staging System — a mainstream system most hospitals and medical centers use to identify all types of cancer — to classify the lung cancer. This system provides a tumor classification based on size, location and spread. While most doctors use this system, it can be difficult for patient to understand. Patients should ask their doctors to explain each stage in detail.
|Component and definition||T — size and extent of the primary tumor||N — the number of nearby lymph nodes with cancer||M — how the tumor has metastasized, or spread|
|Subtypes||TX — cannot be measured||NX — cannot be measured||MX — cannot be measured|
|T0 — cannot be found||N0 — no cancer in the nearby lymph nodes||M0 — cancer has not spread|
|T1, T2, T3, T4 — size and extent of the main tumor||N1, N2, N3 — number and location of the lymph nodes with cancer||M1 — cancer has spread|
After the TNM staging is complete, doctors then use the information to provide a numerical stage of 0, I, II, III or IV. This system is less complex and easier for patients to understand. Patients in the lower stages of cancer will have more treatment options and a better prognosis.
|Stage||Limited Stage||Extensive Stage|
|Location of cancer||A limited portion of one lung; in the lymph nodes on the side of the chest affected||Throughout the origin lung; in the second lung; in the lymph nodes on the opposite side of the chest affected; in other parts of the body; in the fluid around the lung|
|Treatment options||Radiation therapy in a single field||Treatment varies||Commonality upon diagnosis||1 in 3 small cell lung cancer patients||2 in 3 small cell lung cancer patients|
|Stage||Stage I||Stage II||Stage III||Stage IV|
|Location of cancer||Only in the lungs||In one lung and surrounding lymph nodes||In one lung and the lymph nodes between the lungs||In both lungs and fluid around the lungs or other parts of the body|
|Subtypes||IIIA — In the lymph nodes on the same side of the chest
IIIB — In the lymph nodes on the opposite side of the chest
Treatment for Lung Cancer
A person’s lung cancer treatment plan varies based on the severity, or stage, of the cancer. The earlier the cancer is detected, the more likely it is the patient will have a positive outcome. In general, the three lung cancer treatments doctors use are surgery, chemotherapy and radiation therapy.
Surgery is often the first step in cancer treatment if the cancer is located in one place and has not spread. In this case, surgeons will remove the cancerous tumor and any affected lymph nodes. In some cases, surgery to remove the tumor is the bulk of the treatment plan. In other cases, it’s supplemented with chemotherapy or radiation therapy.
Chemotherapy is the use of pharmaceuticals to treat or cure cancer. There are hundreds of different chemo medicines, such as Taxotere, that kill quickly growing cancer cells, which can slow down or stop the disease from spreading. Other non-cancerous cells that grow quickly may also die during chemotherapy, which is why many chemo patients lose their hair. Most chemotherapy is distributed intravenously, but the drugs can also be taken in pill form.
Radiation therapy exposes certain parts of the body to targeted high doses of radiation, which kill the cancerous cells. Unlike chemotherapy, radiation only treats a specific tumor. If the cancer has spread throughout the body, chemotherapy may be a better course of action for some patients. Similar to chemotherapy, radiation can kill normal cells surrounding cancer cells, sometimes causing symptoms like hair loss. For some patients, radiation therapy is used to shrink a tumor before curative surgery.
Some doctors are specially trained to treat cancer and work with cancer patients. These doctors include:
- Medical oncologists, who treat cancer using medicines and procedures such as chemotherapy
- Pulmonologists, who treat diseases of the lungs
- Radiation oncologists, who treat cancer with radiation therapy
- Thoracic surgeons, who specialize in surgery on the lungs and chest
In addition to pursuing a traditional treatment plan, some patients may want to participate in a clinical trial. Clinical trials are research studies that use humans as the test subjects to determine if a new drug or treatment is effective. Clinical trials must pass many levels of testing before reaching human test subjects, and must show likelihood that the trial drug or procedure is more effective than the standard method.
Patients must first meet the specific trial criteria before electing to participate in a clinical trial. All clinical trial participation is voluntary. People choose to participate in clinical trials for different reasons — for example, in some cases the trial may be free, and in other cases the patient may have limited traditional treatment options.
Lung cancer is an especially deadly cancer because its symptoms often don’t manifest until late stages of the disease, causing late diagnosis and low survival rates. According to the American Lung Association, only 15 percent of lung cancer cases are diagnosed during an early stage, and overall its survival rates are much lower than other cancers (17.8 percent for lung cancer compared to 65.4 percent for colon cancer and 90.5 for breast cancer).
For people with lung cancer that’s limited to the lungs, the five-year survival rate is 54 percent. If the lung cancer has spread, the five-year survival rate is 4 percent. Early detection and an effective treatment plan are both crucial to a high survival rate.
Doctors often measure survival rate in five-year increments. The five-year survival rate indicates the percentage of cancer patients who will be living five years after their diagnosis. Many live beyond the five years.
Lung Cancer Lawsuits
Lung cancer is a costly condition — to a patient’s health, quality of life and finances. In some cases, people develop lung cancer after unknowingly taking part in activities that conditioned them to get the disease. Lung cancer patients or their loved ones have often used the legal system to get justice after being exposed to a lung cancer risk factor, experiencing a misdiagnosis or falling victim or medical malpractice.
Some of the most significant lung cancer lawsuits are due to unknown exposure to risk factors such as asbestos or smoking. Settlements vary, extending from thousands to millions of dollars. In one 2014 lung cancer lawsuit, a Florida widow was awarded $23.6 billion after suing tobacco giant R.J. Reynolds for the death of her husband, who died of lung cancer at age 36 after smoking since he was 13 years old. Similarly, a jury awarded a Shell Oil refinery worker who contracted asbestos lung cancer $34.1 million in 2000.