Lung Cancer
Disease Details
Family Health Simplified
- Description
- Lung cancer is a type of cancer that starts in the lungs and is characterized by uncontrolled cell growth in tissues of the lung.
- Type
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Lung cancer is primarily classified into two main types:
1. **Non-Small Cell Lung Cancer (NSCLC)**
2. **Small Cell Lung Cancer (SCLC)**
Regarding genetic transmission, lung cancer is generally not considered a hereditary disease. Most cases are caused by environmental factors, particularly smoking. However, certain genetic mutations that increase susceptibility can be inherited, and having a first-degree relative with lung cancer can slightly increase one's risk. Nonetheless, familial cases are relatively rare compared to those caused by environmental factors. - Signs And Symptoms
- Early lung cancer often has no symptoms. When symptoms do arise they are often nonspecific respiratory problems – coughing, shortness of breath, or chest pain – that can differ from person to person. Those who experience coughing tend to report either a new cough, or an increase in the frequency or strength of a pre-existing cough. Around one in four cough up blood, ranging from small streaks in the sputum to large amounts. Around half of those diagnosed with lung cancer experience shortness of breath, while 25–50% experience a dull, persistent chest pain that remains in the same location over time. In addition to respiratory symptoms, some experience systemic symptoms including loss of appetite, weight loss, general weakness, fever, and night sweats.Some less common symptoms suggest tumors in particular locations. Tumors in the thorax can cause breathing problems by obstructing the trachea or disrupting the nerve to the diaphragm; difficulty swallowing by compressing the esophagus; hoarseness by disrupting the nerves of the larynx; and Horner's syndrome by disrupting the sympathetic nervous system. Horner's syndrome is also common in tumors at the top of the lung, known as Pancoast tumors, which also cause shoulder pain that radiates down the little-finger side of the arm as well as destruction of the topmost ribs. Swollen lymph nodes above the collarbone can indicate a tumor that has spread within the chest. Tumors obstructing bloodflow to the heart can cause superior vena cava syndrome (swelling of the upper body and shortness of breath), while tumors infiltrating the area around the heart can cause fluid buildup around the heart, arrythmia (irregular heartbeat), and heart failure.About one in three people diagnosed with lung cancer have symptoms caused by metastases in sites other than the lungs. Lung cancer can metastasize anywhere in the body, with different symptoms depending on the location. Brain metastases can cause headache, nausea, vomiting, seizures, and neurological deficits. Bone metastases can cause pain, bone fractures, and compression of the spinal cord. Metastasis into the bone marrow can deplete blood cells and cause leukoerythroblastosis (immature cells in the blood). Liver metastases can cause liver enlargement, pain in the right upper quadrant of the abdomen, fever, and weight loss.Lung tumors often cause the release of body-altering hormones, which cause unusual symptoms, called paraneoplastic syndromes. Inappropriate hormone release can cause dramatic shifts in concentrations of blood minerals. Most common is hypercalcemia (high blood calcium) caused by over-production of parathyroid hormone-related protein or parathyroid hormone. Hypercalcemia can manifest as nausea, vomiting, abdominal pain, constipation, increased thirst, frequent urination, and altered mental status. Those with lung cancer also commonly experience hypokalemia (low potassium) due to inappropriate secretion of adrenocorticotropic hormone, as well as hyponatremia (low sodium) due to overproduction of antidiuretic hormone or atrial natriuretic peptide. About one of three people with lung cancer develop nail clubbing, while up to one in ten experience hypertrophic pulmonary osteoarthropathy (nail clubbing, joint soreness, and skin thickening). A variety of autoimmune disorders can arise as paraneoplastic syndromes in those with lung cancer, including Lambert–Eaton myasthenic syndrome (which causes muscle weakness), sensory neuropathies, muscle inflammation, brain swelling, and autoimmune deterioration of cerebellum, limbic system, or brainstem. Up to one in twelve people with lung cancer have paraneoplastic blood clotting, including migratory venous thrombophlebitis, clots in the heart, and disseminated intravascular coagulation (clots throughout the body). Paraneoplastic syndromes involving the skin and kidneys are rare, each occurring in up to 1% of those with lung cancer.
- Prognosis
- Around 19% of people diagnosed with lung cancer survive five years from diagnosis, though prognosis varies based on the stage of the disease at diagnosis and the type of lung cancer. Prognosis is better for people with lung cancer diagnosed at an earlier stage; those diagnosed at the earliest TNM stage, IA1 (small tumor, no spread), have a two-year survival of 97% and five-year survival of 92%. Those diagnosed at the most-advanced stage, IVB, have a two-year survival of 10% and a five-year survival of 0%. Five-year survival is higher in women (22%) than men (16%). Women tend to be diagnosed with less-advanced disease, and have better outcomes than men diagnosed at the same stage. Average five-year survival also varies across the world, with particularly high five-year survival in Japan (33%), and five-year survival above 20% in 12 other countries: Mauritius, Canada, the US, China, South Korea, Taiwan, Israel, Latvia, Iceland, Sweden, Austria, and Switzerland.SCLC is particularly aggressive. 10–15% of people survive five years after a SCLC diagnosis. As with other types of lung cancer, the extent of disease at diagnosis also influences prognosis. The average person diagnosed with limited-stage SCLC survives 12–20 months from diagnosis; with extensive-stage SCLC around 12 months. While SCLC often responds initially to treatment, most people eventually relapse with chemotherapy-resistant cancer, surviving an average 3–4 months from the time of relapse. Those with limited stage SCLC that go into complete remission after chemotherapy and radiotherapy have a 50% chance of brain metastases developing within the next two years – a chance reduced by prophylactic cranial irradiation.Several other personal and disease factors are associated with improved outcomes. Those diagnosed at a younger age tend to have better outcomes. Those who smoke or experience weight loss as a symptom tend to have worse outcomes. Tumor mutations in KRAS are associated with reduced survival.
- Onset
- Lung cancer typically presents with symptoms that may include a persistent cough, coughing up blood, shortness of breath, chest pain, unexplained weight loss, and fatigue. In some cases, there may be no early symptoms, and the disease is discovered incidentally during imaging for other reasons. The average age at diagnosis is around 70 years old.
- Prevalence
- The prevalence of lung cancer varies by region, age group, and smoking status. Generally, it is one of the most common cancers globally. In the United States, it is estimated that over 200,000 new cases are diagnosed each year. The prevalence is higher in individuals with a history of smoking, and it increases with age.
- Epidemiology
- Worldwide, lung cancer is the most diagnosed type of cancer, and the leading cause of cancer death. In 2020, 2.2 million new cases were diagnosed, and 1.8 million people died from lung cancer, representing 18% of all cancer deaths. Lung cancer deaths are expected to rise globally to nearly 3 million annual deaths by 2035, due to high rates of tobacco use and aging populations. Lung cancer is rare among those younger than 40; after that, cancer rates increase with age, stabilizing around age 80. The median age of a person diagnosed with lung cancer is 70; the median age of death is 72.Lung cancer incidence varies by geography and sex, with the highest rates in Micronesia, Polynesia, Europe, Asia, and North America; and lowest rates in Africa and Central America. Globally, around 8% of men and 6% of women develop lung cancer in their lifetimes. The ratio of lung cancer cases in men to women varies considerably by geography, from as high as nearly 12:1 in Belarus, to 1:1 in Brazil, likely due to differences in smoking patterns.Lung cancer risk is influenced by environmental exposure, namely cigarette smoking, as well as occupational risks in mining, shipbuilding, petroleum refining, and occupations that involve asbestos exposure. People who have smoked cigarettes account for 85–90% of lung cancer cases, and 15% of smokers develop lung cancer. Non-smokers' risk of developing lung cancer is also influenced by tobacco smoking; secondhand smoke (that is, being around tobacco smoke) increases risk of developing lung cancer around 30%, with risk correlated to duration of exposure.
- Intractability
- Lung cancer is generally considered challenging to treat, particularly in its advanced stages. While early-stage lung cancer may be more treatable and potentially curable with surgery, radiation, and chemotherapy, advanced lung cancer often requires more complex treatment strategies, including targeted therapies and immunotherapy. The disease's prognosis varies significantly based on the stage at diagnosis, the specific type of lung cancer, and the patient's overall health.
- Disease Severity
- Lung cancer severity varies depending on the stage at diagnosis and other factors such as tumor size, lymph node involvement, and metastasis. Early-stage lung cancer (Stages I and II) typically has a better prognosis and may be treated effectively with surgery, radiation, or chemotherapy. Advanced stages (Stages III and IV) often involve more extensive spread and may require complex treatment with a combination of therapies, and generally have a poorer prognosis. Nanotechnology is being explored for its potential in early detection, targeted drug delivery, and improved treatment outcomes, but it is still largely in the research and experimental phases.
- Healthcare Professionals
- Disease Ontology ID - DOID:1324
- Pathophysiology
- Pathophysiology of lung cancer involves the uncontrolled growth of abnormal cells in the lung tissues. It typically begins in the cells lining the bronchi, bronchioles, or alveoli. These abnormal cells proliferate and form tumors, which can disrupt normal lung function. The mutations in the DNA of these cells can be triggered by various carcinogens, such as tobacco smoke, asbestos, or radon gas. The cancer can invade nearby tissues and spread (metastasize) to other parts of the body through the bloodstream or lymphatic system. There are two main types of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), each with different behaviors, growth rates, and treatment responses.
- Carrier Status
- Lung cancer is not typically associated with a "carrier status," as it is not an inherited disease in the same manner as genetic disorders like cystic fibrosis or sickle cell anemia. Instead, lung cancer primarily results from environmental factors, such as smoking, exposure to radon gas, asbestos, or other carcinogens. Genetic mutations can play a role in lung cancer development, but these are usually acquired rather than inherited.
- Mechanism
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Lung cancer is primarily caused by genetic and environmental factors, with smoking being the leading risk factor. The mechanisms by which lung cancer develops are complex and involve multiple steps:
1. **Mechanism**:
- **Initiation**: Exposure to carcinogens (e.g., tobacco smoke, radon, asbestos) causes genetic mutations in lung cells.
- **Promotion**: These mutations can activate oncogenes or deactivate tumor suppressor genes, leading to uncontrolled cell growth.
- **Progression**: Further genetic and epigenetic changes contribute to tumor heterogeneity, invasiveness, and metastasis.
2. **Molecular Mechanisms**:
- **Oncogenes**: Genes like KRAS, EGFR, and ALK can become mutated or overexpressed, driving cellular proliferation and survival.
- **Tumor Suppressor Genes**: Genes such as TP53 and RB1 may be inactivated, removing normal growth controls and allowing for unchecked cell division.
- **Angiogenesis**: Tumors stimulate the formation of new blood vessels to supply the growing cancer cells with nutrients and oxygen.
- **Metastasis**: Cancer cells gain the ability to invade surrounding tissues and spread to distant organs via the bloodstream or lymphatic system.
- **Epigenetic Changes**: Alterations in DNA methylation and histone modification can affect gene expression without changing the DNA sequence, further promoting malignancy.
Understanding these mechanisms can help in developing targeted therapies aimed at specific molecular alterations in lung cancer. - Treatment
- Treatment for lung cancer depends on the cancer's specific cell type, how far it has spread, and the person's health. Common treatments for early stage cancer includes surgical removal of the tumor, chemotherapy, and radiation therapy. For later-stage cancer, chemotherapy and radiation therapy are combined with newer targeted molecular therapies and immune checkpoint inhibitors. All lung cancer treatment regimens are combined with lifestyle changes and palliative care to improve quality of life.
- Compassionate Use Treatment
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Compassionate use treatment for lung cancer involves providing experimental drugs or therapies to patients who have exhausted other options and cannot participate in clinical trials. These treatments are typically unapproved by regulatory bodies and are considered on a case-by-case basis.
Off-label or experimental treatments for lung cancer may include:
1. **Checkpoint Inhibitors**: Drugs like pembrolizumab or nivolumab, initially approved for other cancers, may be used off-label.
2. **Targeted Therapies**: Agents targeting specific mutations (e.g., EGFR, ALK) are sometimes used off-label for patients with corresponding genetic changes.
3. **Combination Therapies**: Combining existing drugs in novel ways, such as pairing chemotherapy with immunotherapy, may be experimental.
4. **Gene Therapy**: Introducing genetic material into a patient's cells to combat cancer is an ongoing experimental area.
5. **Personalized Vaccines**: Tailor-made vaccines designed to target specific tumor antigens are under investigation.
These treatments are managed by oncologists specialized in lung cancer and typically require careful monitoring for efficacy and side effects. - Lifestyle Recommendations
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Lifestyle recommendations for lung cancer include:
1. **Avoid Smoking**: If you smoke, quitting is the most important step you can take. Avoid secondhand smoke as well.
2. **Healthy Diet**: Eat a diet rich in fruits, vegetables, and whole grains. Limit intake of processed foods and red meats.
3. **Regular Exercise**: Engage in regular physical activity to improve overall health and lung function.
4. **Avoid Environmental Toxins**: Minimize exposure to environmental pollutants, such as radon gas and asbestos.
5. **Regular Medical Checkups**: Stay up-to-date with regular medical checkups and screenings, especially if you have a history of smoking.
6. **Manage Stress**: Practice stress reduction techniques such as meditation, yoga, or deep-breathing exercises.
7. **Limit Alcohol Consumption**: Reduce alcohol intake to lower the risk of additional health problems.
8. **Stay Informed**: Keep updated with the latest information on lung cancer research and treatments to make informed decisions about your health. - Medication
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Lung cancer treatment often involves a combination of therapies, including medication. Common medications for lung cancer include:
1. Chemotherapy drugs: Such as cisplatin, carboplatin, paclitaxel, and pemetrexed.
2. Targeted therapy: Drugs like erlotinib, gefitinib, and crizotinib target specific mutations in cancer cells.
3. Immunotherapy: Medications such as pembrolizumab, nivolumab, and atezolizumab help the immune system recognize and attack cancer cells.
It is essential to consult with a healthcare provider to determine the most appropriate treatment plan, as the choice of medication depends on the specific type and stage of lung cancer, as well as the patient's overall health. - Repurposable Drugs
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Several drugs originally approved for other conditions are being explored for their potential in treating lung cancer. Some repurposable drugs include:
1. **Metformin** (originally for diabetes) - has shown potential anti-cancer properties by inhibiting cancer cell growth.
2. **Aspirin** (anti-inflammatory) - may help reduce the risk of cancer metastasis.
3. **Itraconazole** (antifungal) - exhibits anti-angiogenic properties which can restrict tumor blood supply.
4. **Statins** (cholesterol-lowering drugs) - may induce apoptosis in cancer cells and inhibit tumor growth.
Further clinical research is ongoing to establish the efficacy and safety of these drugs in the context of lung cancer. - Metabolites
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Metabolites associated with lung cancer include various small molecules that are involved in different metabolic pathways altered in cancer cells. Some key metabolites linked with lung cancer include:
1. **Glucose** - Increased glucose uptake due to the Warburg effect, a phenomenon where cancer cells preferentially produce energy through glycolysis followed by lactic acid fermentation.
2. **Lactate** - Elevated levels due to anaerobic glycolysis.
3. **Amino acids** - Altered levels, including elevated glutamine, which is crucial for cancer cell proliferation.
4. **Lipids** - Changes in lipid metabolism, such as increased synthesis of phospholipids and cholesterol.
5. **Nucleotide derivatives** - Elevated due to increased nucleic acid synthesis required for rapid cell division.
6. **TCA cycle intermediates** - Variations in intermediates such as succinate, fumarate, and malate.
Metabolomics studies in lung cancer often aim to identify specific metabolites that can serve as biomarkers for early detection, prognosis, or therapeutic targets. - Nutraceuticals
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Nutraceuticals are products derived from food sources that provide both nutritional and medicinal benefits. For lung cancer, some nutraceuticals being researched include antioxidants like vitamins A, C, and E; polyphenols from green tea; and omega-3 fatty acids. These compounds may help reduce inflammation and oxidative stress, potentially aiding in the prevention and management of lung cancer. However, their efficacy and safety require further research.
Nanotechnology, or nanomedicine, involves using nanoparticles to deliver drugs more effectively to cancer cells while minimizing side effects on healthy tissue. In lung cancer, nanoparticles can be designed to carry chemotherapy drugs directly to tumor sites, enhancing treatment efficacy and reducing toxicity. Current research is focused on developing and optimizing these nanocarriers for clinical use to improve outcomes for lung cancer patients. - Peptides
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Lung cancer is a heterogeneous disease with various treatment approaches. Peptides, which are short chains of amino acids, have emerged as a potential avenue in cancer treatment. They can serve as therapeutic agents, vaccines, and drug delivery systems due to their specificity and lower toxicity. In lung cancer, peptide-based vaccines aim to elicit an immune response against tumor-associated antigens. Peptide inhibitors can also target specific oncogenic pathways involved in lung cancer progression.
Nanotechnology (nan) offers innovative solutions for lung cancer treatment and diagnosis. Nanoscale materials, such as nanoparticles, can enhance drug delivery, improve imaging, and provide targeted therapy with reduced side effects. Nanoparticles can encapsulate chemotherapy drugs, protecting them from degradation, and allowing for controlled release directly into the tumor, thereby minimizing damage to healthy tissues. Additionally, nanomaterials can be engineered to improve the detection of lung cancer at earlier stages through highly sensitive diagnostic tools.