Lung Cancer

Lung cancer is the leading cause of cancer death globally, causing 3 million deaths a year. In the United States, about 234,030 new cases of lung cancer will be diagnosed in the U.S. this year and is expected to kill more than 154,000 people in 2018. In the U.S., lung cancer is by far the leading cause of cancer-related death among both men and women; more deaths are caused by lung cancer every year than by breast, prostate, and colon cancer combined.

It is undeniable that Cigarette smoking remains the most significant risk factor for the disease, accounting for approximately 80% of all lung cancers.

Lung cancer is the uncontrolled growth of abnormal, Abnormal cells which form cancer of the lungs normally arises from cells lining the air passages.  As these cells begin to multiply, without any control. The expanding begin to interfere with the normal functions of the lung.

Cancer cells may is spread through the lymph system.  Lymph is a clear and transparent fluid where the cells that help fight infections and cancer flow through all your body, always vigilant and ready to mount an immune response when tissue is irritated, damage in the presence of foreign invaders, and when abnormal cells are detected.  Lymph nodes are small being shape structures linking lymph vessels and serve as immune response stations were cells are trained to fight and mature into the protective professional cells known as T and B lymphocytes.  B lymphocytes developed into memory cells or antibody-producing cells known as plasma cells.

What Are The Lung Cancer Types?

 The two major forms of lung cancer are non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), so named because of how the tumor cells look under a microscope. NSCLC comprises approximately 85% of all lung cancers. Of these, the great majority are the non-squamous type of NSCLC, while a smaller fraction is the squamous type.

 Lung cancer is classified according to the size of the cell.  If the cells are small the cancer is known as small cell lung cancer (NCLC).  When the cancer cells are not small, the cancer is known as none–small cell lung cancer (NSCLC).

Small cell lung cancer makes approximately 10 to 20% of all lung cancers and invariably is caused by tobacco smoking.  He often begins in the bronchi, spreading to another part of the body, including the lymph nodes. They develop more quickly than NSCLC and show a positive response to chemotherapy.

Non-small cell lung cancer is the most common types of lung cancer.  Different subtypes of these cancers are found- adenocarcinoma, squamous cell carcinoma, and large cell carcinoma.

Adenocarcinomas arise in the sac like structures of the lungs nominated Alveoli–alveoli is where the oxygen-carbon dioxide exchange occurred and where mucus is produced. Nearly 40% of lung cancers are adenocarcinoma. Adenocarcinoma is found in both smokers and non-smokers population and more common in females than males. The subtype of adenocarcinoma is known as bronchioloalveolar carcinoma, which is commonly observed in women who do not smoke.

Squamous cell carcinomas begin in the flat cells in the lungs.  Highly associated with tobacco smoking.  It is also called epidermoid carcinoma. It constitutes approximately 30% of lung cancers.

Large Cell Carcinoma- They constitute about 9% of lung cancers. They are named as large cell carcinoma because the cancer cells are large, with large nuclei, more cytoplasm, and clearly visible nucleoli.

Other Types of Lung Cancer

Less common types of lung cancer include:

• Carcinoid tumors
• Salivary gland carcinoma
• Some sarcomas
• Cancer of unknown primary

Cancer of the lung due to lung metastases.

Cancer found in the lungs is sometimes a result of another type of cancer that started somewhere else in the body and a spread or metastasized, to the lungs.  They are referred to as lung metastasis and are totally different from primary lung cancer.

What Are The Lung Cancer Risk Factors?

Smoking is the main risk factor for lung cancer.  But anything that makes contact with the lungs and increases the chance of getting lung cancer is a risk factor.

• Smoking tobacco in cigarettes, cigars or pipes is responsible for 87% of lung cancer cases in the United States.
• The more years you smoke and the greater amount you smoke, the higher your risk of lung cancer.
• If you stop smoking, your risk of lung cancer becomes lower as time goes by.
• If you smoke and have other risk factors, your chance of getting lung cancer is higher.
• Read more about MD Anderson’s smoking cessation clinical trials

Other risk factors for lung cancer include:

• Family history of lung cancer
• Previous lung cancer
• Exposure to certain materials including radiation, arsenic, radon, chromium, nickel, soot, tar or asbestos
• Radiation therapy to the breast or chest
• Air pollution
• Secondhand smoke
• Lung diseases such as tuberculosis (TB)
• Rubber production and crystalline silica dust
• Products of combustion (burning coal, incomplete combustion, coal gasification, soot, diesel engine exhaust)
• Toxic gases such as methyl ether, sulfur mustard
• Exposure to certain chemical substances such as asbestos, beryllium, nickel, arsenic, and silica
• Exposure to radon gas
• Ionizing radiations

Not everyone with risk factors develops lung cancer. However, if you have risk factors, it’s a good idea to discuss them with your doctor or oncologist.

What Are Symptoms Of Lung Cancer ?

In most instances, lung cancers do not have any symptoms.  Lung cancer symptoms vary from person to person.  Symptoms may not be evident until the lung disease is in its severe stage.  Symptoms may include:

• Breathlessness
• Fever
• Loss of appetite
• Weakness
• Difficulty with swallowing
• Coughing up blood
• Voice change or being hoarse
• Sputum color change
• Clubbing of fingernails (unusual rounded appearance)
• Pain in the chest, back, and shoulders, not related to coughing
• Repeated lung diseases such as pneumonia or bronchitis
• Persistent and intense coughing

If lung cancer spreads to other parts of the body, it may cause:

• Bone pain
• Arm or leg weakness or numbness
• Headache, dizziness or seizure
• Jaundice (yellow coloring) of skin and eyes
• Swollen lymph nodes in the neck or shoulder

How Is Lung Cancer Diagnosed?

If you have symptoms that may signal lung cancer, your doctor will examine you and ask you questions about your health; your lifestyle, including smoking habits; your family history; and whether you have been around certain chemicals or substances. To diagnose lung cancer, initially, a chest X-ray is done if the person complains of lung cancer-related symptoms.

One or more of the following tests may be used to find out if you have lung cancer and if it has spread. These tests also may be used to find out if treatment is working.

If lung cancer is present, then further investigations will be conducted to know more about the nature and extent of the lung disease. These tests include-

• Computerized Tomography (CT Scan) – This test is usually done after a chest X-ray and it can help identify the cancerous area.
• Bronchoscopy –This diagnostic procedure helps the doctor to look inside the airways. Your doctor will place a thin tube, bronchoscope into your nose or mouth and then down the trachea. During this procedure, the doctor may take lung tissues samples for biopsy.
• Fine-needle Aspiration Biopsy (FNAB) –It is a diagnostic procedure largely done if the tumor is in the peripheral parts of the lungs. A very small needle is placed into the tumor. Suction is used to remove a small amount of tissue, which is then looked at under a microscope.
• Sputum Cytology –It is an evaluation of phlegm or mucus from the lungs (sputum). Microscopic examination of sputum is done to find out the presence of any unusual cells.
• Mediastinoscopy –In this procedure contents, examination of the mediastinum is done, mainly for biopsy. This test is recommended for the staging of lymph nodes in lung cancer.
• Thoracoscopy –This method involves an internal examination, biopsy or removal of the lung tumor. Thoracoscopy is done under general anesthesia.
• Thoracentesis: Fluid from around the lungs is drawn out with a needle and looked at under a microscope.
• Endobronchial Ultrasound (EBUS): Guided biopsy to check for lung cancer and find out if cancer has spread to nearby lymph nodes.
• Video-Assisted thoracoscopic surgery (VATS) 
• Imaging tests, which may include:

1. CT or CAT (computed axial tomography)
2. MRI (magnetic resonance imaging) scans
3. PET (positron emission tomography) scans

• PET-CT Scan – It is called positron emission tomography-computerized tomography. It is performed when the CT scan results show that your cancer is in its early stage. PET-CT Scan helps in detecting active cancer cells, which can help in the treatment of lung cancer.

What Are The Stages of Lung Cancer?

Staging is an essential part of your treatment and it is a way to classify the cancer by how far into which part of the body it has a spread.

Stage 0: Abnormal cells are found only in the innermost lining of the lung. The tumor has not grown through this lining. A stage 0 tumor is also called carcinoma in situ. The tumor is not invasive cancer.

Stage 1A: The lung tumor is invasive cancer. It has grown through the innermost lining of the lung into deeper lung tissue. The tumor is no more than 3 centimeters across. It is surrounded by normal tissue and does not invade the bronchus. Lung cancer cells are not found in nearby lymph nodes.

Stage 1B: The tumor is larger or has grown deeper, but lung cancer cells are not found in nearby lymph nodes. The lung tumor is one of the following:

• More than 3 centimeters across
• Grown into the main bronchus
• Grown through the lung into the pleura

Stage 2A: The lung tumor is no more than 3 centimeters across. Lung cancer cells are found in nearby lymph nodes.

Stage 2B: The lung cancer is one of the following:

• Not found in nearby lymph nodes but has invaded the chest wall, diaphragm, pleura, main bronchus or tissue that surrounds the heart
• Cancer cells are found in nearby lymph nodes and the tumor in the lung is one of the following:
• More than 3 centimeters across
• Grown into the main bronchus
• Grown through the lung into the pleura

Stage 3A: The tumor may be any size. Lung cancer cells are found in the lymph nodes near the lungs and bronchi and in the lymph nodes between the lungs on the same side of the chest as the lung tumor.

Stage 3B: The tumor may be any size. Lung cancer cells are found on the opposite side of the chest from the lung tumor or in the neck. The tumor may have invaded nearby organs, such as the heart, esophagus or trachea. More than one malignant growth may be found within the same lobe of the lung. Cancer cells may be found in the pleural fluid.

Stage 4: Tumors may be found in more than one lobe of the same lung or in the other lung. Lung cancer cells may be found in other parts of the body, such as the brain, adrenal gland, liver or bone.

How Is Lung Cancer Treated?

Lung cancer is treated with a multidisciplinary approach, depending on the type of cancer and how far it has spread in the body–stage. The treatments followed for lung cancer include-

• Surgery People suffering from early-stage cancer will usually undergo surgery to remove the tumor. There are three important types of lung cancer surgeries:
  • Lobectomy: An affected lobe of the lung is removed
  • Pneumonectomy: Here, a lung is removed
  • Wedge Resection: A segment of the affected lung is removed
• Targeted Drug Therapy interferes with the ways cancer cells function, for example, they may affect specific metabolic pathways of cancer cells. The advantage is that normal cells are not affected, unlike conventional chemotherapy.
• Radiotherapy can be given as sole therapy or in combination with surgery or chemotherapy.  During the initial stage of lung cancer, it is used to eliminate cancer cells completely. In advanced stages, it aims to slow down the progress of cancer and lessen its symptoms.
• Chemotherapy is the method, where drugs are used to kill or retard the growth of cancerous cells. It aims to eliminate cancer cells and protect the healthy cells. These drugs can be given orally or intravenously, or sometimes both.
• Ablation– This treatment is preferred if you cannot undergo surgery or radiotherapy. In ablation, the treatment is given directly into the tumor, destroying only the cancerous cells without affecting the nearby healthy tissues. It includes radiofrequency ablation and microwave ablation.
• Palliative care– Its objective is to improve the quality of life by reducing lung cancer symptoms without aiming to treat the lung disease. It controls symptoms like nausea and pain and assists to slow the progression of lung cancer to other parts of the body.
• Immunotherapy. The majority of lung cancer patients are diagnosed with advanced disease (stage IIIb/IV). For these patients, conventional treatment options including surgery, chemotherapy, and radiation are unlikely to result in complete cures, although they may significantly improve survival and provide symptom relief.  Odds of survival can greatly improve for people with the most common type of lung cancer if they are given a new drug that activates the immune system along with chemotherapy. Immunotherapy has been making steady gains against a number of cancers. Four such drugs, called checkpoint inhibitors, which unleash the patient’s own immune system to kill malignant cells, have been approved so far.

The majority of lung cancer patients are diagnosed with advanced disease (stage IIIb/IV). For these patients, conventional treatment options including surgery, chemotherapy, and radiation are unlikely to result in complete cures, although they may significantly improve survival and provide symptom relief.

Odds of survival can greatly improve for people with the most common type of lung cancer if they are given a new drug that activates the immune system along with chemotherapy.

Immunotherapy has been making steady gains against a number of cancers. Four such drugs, called checkpoint inhibitors, which unleash the patient’s own immune system to kill malignant cells, have been approved so far.

What Is A Prognosis and Survival Lung Rate Cancer?

Prognosis and survival depend on the type and the stage of cancer when it was diagnosed. This means how big it is and whether it has spread.  The overall 5-year survival rate is only 5-15%. The five-year survival rate for lung cancer is 55 percent for cases detected when the disease is still localized (within the lungs). However, only 16 percent of lung cancer cases are diagnosed at an early stage. For distant tumors (spread to other organs) the five-year survival rate is only 4 percent. The terms 1-year survival and 5-year survival don’t mean that you will only live for 1 or 5 years. They relate to the number of people who are still alive 1 year or 5 years after their diagnosis of cancer. Some people live much longer than 5 years. Statistics are averages based on large numbers of patients.

1-year survival by stage for lung cancer

Stage 1

More than 80 out of 100 people (more than 80%) will survive their cancer for a year or more after diagnosis.

Stage 2

More than 60 out of 100 people (more than 60%) will survive their cancer for a year or more after diagnosis.

Stage 3

More than 40 out of 100 people (more than 40%) will survive their cancer for a year or more after diagnosis.

Stage 4

Less than 20 out of 100 people (less than 20%) will survive their cancer for a year of more after they are diagnosed.

Unknown Stage

It is not possible to find the stage of the cancer for some people. This is sometimes because they are too ill to have tested.

In this situation, more than 20 out of 100 people (more than 20%) will survive their cancer for a year or more after they are diagnosed.

5-year survival by stage for lung cancer

Stage 1

Around 35 out of 100 people (around 35%) will survive their cancer for 5 years or more after diagnosis.

Stage 2

More than 20 out of 100 people (more than 20%) will survive their cancer for 5 years or more after diagnosis.

Stage 3

Around 6 out of 100 people (around 6%) will survive their cancer for 5 years or more after diagnosis.

Stage 4

There are no statistics for stage 4 cancer because sadly many people don’t live for more than 2 years after diagnosis.

Unknown stage

Around 6 out of 100 people (around 6%) will survive their cancer for 5 years or more after diagnosis.

Lung Cancer Prevention

• Stay away from smoking
• Keep away from passive smoking, i.e. stay away from others who smoke. Exposure to smoke is a risk factor for cancer by itself.
• Check your home for radon if you happen to reside at a place where radon is a problem
• Protect yourself from inhaling toxic gases
• Avoid harmful chemical substances
• Eat a healthy balanced diet
• Exercise regularly

 

The information in this document does not replace a medical consultation. It is for personal guidance use only. We recommend that patients ask their doctors about what tests or types of treatments are needed for their type and stage of the disease.

Sources:

• American Cancer Society
• The National Cancer Institute
• National Comprehensive Cancer Network
• American Academy of Gastroenterology
• National Institute of Health
• MD Anderson Cancer Center
• Memorial Sloan Kettering Cancer Center