Lung cancer
Updates to Article Attributes
Lung cancer, or frequently if somewhat incorrectly known as bronchogenic carcinoma is a broad term referring to the main histological subtypes of primary lung malignancies that are mainly linked with inhaled carcinogens, with cigarette smoke being a key culprit.
This article will broadly discuss all the histological subtypes as a group, focusing on their common aspects and for further details please refer to the specific articles on each subtype described below.
Epidemiology
Lung cancer is the most common cause of cancer in men and the 6th most frequent cancer in women worldwide. It is the leading cause of cancer mortality worldwide in both men and women and accounts for approximately 20% of all cancer deaths 1.
Clinical presentation
Patients with lung cancer may be asymptomatic in up to 50% of cases. Cough and dyspnoea are rather non-specific symptoms that are common amongst those with lung cancer.
Central tumours may result in haemoptysis and peripheral lesions with pleuritic chest pain.
Pneumonia, pleural effusion, wheeze, lymphadenopathy are not uncommon. Other symptoms may be secondary to metastases (brain(bone, contralateral lung, brain, adrenal glands, and liver, bonein frequency order for NSCLC 12) or paraneoplastic syndromes.
Pathology
The term bronchogenic carcinoma is somewhat loosely used to refer to primary malignancies of the lung that are associated with inhaled carcinogens 1 and includes four main histological subtypes. These are broadly divided into non-small cell carcinoma and small cell carcinoma as they differ clinically regarding presentation, treatment and prognosis:
-
non-small cell lung cancer (NSCLC) (80%)
-
adenocarcinoma (35%)
- most common cell type overall
- most common in women
- most common cell type in non-smokers but still most patients are smokers
- peripheral
-
squamous cell carcinoma (30%)
- strongly associated with smoking
- most common carcinoma to cavitate
- poor prognosis
-
large-cell carcinoma (15%)
- peripherally located
- very large, usually more than 4 cm
-
adenocarcinoma (35%)
-
small cell carcinoma (20%)
- almost always in smokers
- metastasises early
- most common primary lung malignancy to cause paraneoplastic syndromes and SVC obstruction
- worst prognosis
Other malignant pulmonary neoplasms include lymphoma and sarcoma (rare).
Each subtype has a different radiographic appearance, demographic, and prognosis:
- squamous-cell carcinoma of the lung
- adenocarcinoma of the lung
- large cell carcinoma of the lung
- small cell carcinoma of the lung
Risk factors
The major risk factor is cigarette smoking which is implicated in 90% of cases and increase the risk of lung cancer, which can be divided by histological subtype 10:
- squamous cell lung cancer: 11x (men), 15x (women)
- small cell lung cancer: 10x (men), 25x (women)
- large cell lung cancer: 7x (men), 8x (women)
- lung adenocarcinoma: 4x (men and women)
Other risk factors:
- asbestos: 5x increased risk
- occupational exposure: uranium, radon, arsenic, chromium
- diffuse lung fibrosis: 10x increased risk
- chronic obstructive pulmonary disease
Staging
Associations
Various paraneoplastic syndromes can arise in the setting of lung cancer:
- endocrine/metabolic
- SIADH causing hyponatraemia: small-cell subtype
- ACTH secretion (Cushing syndrome): carcinoid and small-cell subtypes
- carcinoid syndrome
- gynaecomastia
- adrenal insufficiency (Addison disease): from bilateral metastases 7
- hyperparathyroidism: NSCLC can produce parathyroid hormone (extremely rare) 8
- hypocalcaemia: occurs in the setting of skeletal metastases; especially associated with NSCLC 6
- PTHrp causing hypercalcaemia: squamous cell carcinoma
- neurological
- polyneuropathy
- myelopathy
- limbic encephalitis: particularly associated with SCLC 9
- cerebellar degeneration
- Lambert-Eaton myasthenia syndrome
- other
- finger clubbing
- hypertrophic pulmonary osteoarthropathy (HPOA): squamous cell carcinoma subtype
- nephrotic syndrome
- polymyositis 3
- dermatomyositis 3
- eosinophilia
- acanthosis nigricans
- thrombophlebitis: adenocarcinoma subtype
Treatment and prognosis
Treatment and prognosis vary not only with stage but also with cell type. In general, surgery, chemotherapy, and radiotherapy are offered according to the stage, resectability, operability, and functional status.
Non-small cell carcinoma
-
treatment
- operable disease (stage I to IIIA): surgery
- unresectable disease: neoadjuvant chemotherapy, radiotherapy
- advanced disease: palliative combined chemotherapy
-
prognosis (5-year survival rates):
- local (stage I): 55-67%
- locally advanced (stages II-IIIA): 23-40%
- advanced (stages IIIB and IV): 1-3%
Small-cell carcinoma
-
treatment
- limited disease: chemoradiotherapy
- extensive disease: palliative combined chemotherapy
-
prognosis: poor
- limited: 5-year survival rate 15-25%
- extensive: 2-year survival 20% (with palliative combined chemotherapy and supportive care)
See also
-<p><strong>Lung cancer</strong>, or frequently if somewhat incorrectly known as <strong>bronchogenic carcinoma</strong> is a broad term referring to the main histological subtypes of primary lung malignancies that are mainly linked with inhaled carcinogens, with cigarette smoke being a key culprit. </p><p>This article will broadly discuss all the histological subtypes as a group, focusing on their common aspects and for further details please refer to the specific articles on each subtype described below. </p><h4>Epidemiology</h4><p>Lung cancer is the most common cause of cancer in men and the 6<sup>th</sup> most frequent cancer in women worldwide. It is the leading cause of cancer mortality worldwide in both men and women and accounts for approximately 20% of all cancer deaths <sup>1</sup>.</p><h4>Clinical presentation</h4><p>Patients with lung cancer may be asymptomatic in up to 50% of cases. Cough and dyspnoea are rather non-specific symptoms that are common amongst those with lung cancer.</p><p>Central tumours may result in <a href="/articles/haemoptysis-1">haemoptysis</a> and peripheral lesions with pleuritic chest pain.</p><p>Pneumonia, pleural effusion, wheeze, lymphadenopathy are not uncommon. Other symptoms may be secondary to <a href="/articles/pulmonary-metastases">metastases</a> (brain, liver, bone) or paraneoplastic syndromes.</p><h4>Pathology</h4><p>The term bronchogenic carcinoma is somewhat loosely used to refer to primary malignancies of the lung that are associated with inhaled carcinogens <sup>1</sup> and includes four main histological subtypes. These are broadly divided into non-small cell carcinoma and small cell carcinoma as they differ clinically regarding presentation, treatment and prognosis:</p><ul>- +<p><strong>Lung cancer</strong>, or frequently if somewhat incorrectly known as <strong>bronchogenic carcinoma</strong> is a broad term referring to the main histological subtypes of primary lung malignancies that are mainly linked with inhaled carcinogens, with cigarette smoke being a key culprit. </p><p>This article will broadly discuss all the histological subtypes as a group, focusing on their common aspects and for further details please refer to the specific articles on each subtype described below. </p><h4>Epidemiology</h4><p>Lung cancer is the most common cause of cancer in men and the 6<sup>th</sup> most frequent cancer in women worldwide. It is the leading cause of cancer mortality worldwide in both men and women and accounts for approximately 20% of all cancer deaths <sup>1</sup>.</p><h4>Clinical presentation</h4><p>Patients with lung cancer may be asymptomatic in up to 50% of cases. Cough and dyspnoea are rather non-specific symptoms that are common amongst those with lung cancer.</p><p>Central tumours may result in <a href="/articles/haemoptysis-1">haemoptysis</a> and peripheral lesions with pleuritic chest pain.</p><p>Pneumonia, pleural effusion, wheeze, lymphadenopathy are not uncommon. Other symptoms may be secondary to <a href="/articles/pulmonary-metastases">metastases</a> (bone, contralateral lung, brain, adrenal glands, and liver, in frequency order for NSCLC <sup>12</sup>) or <a title="Paraneoplastic syndromes" href="/articles/paraneoplastic-syndromes">paraneoplastic syndromes</a>.</p><h4>Pathology</h4><p>The term bronchogenic carcinoma is somewhat loosely used to refer to primary malignancies of the lung that are associated with inhaled carcinogens <sup>1</sup> and includes four main histological subtypes. These are broadly divided into non-small cell carcinoma and small cell carcinoma as they differ clinically regarding presentation, treatment and prognosis:</p><ul>
References changed:
- 12. Tamura T, Kurishima K, Nakazawa K et al. Specific Organ Metastases and Survival in Metastatic Non-Small-Cell Lung Cancer. Mol Clin Oncol. 2015;3(1):217-21. <a href="https://doi.org/10.3892/mco.2014.410">doi:10.3892/mco.2014.410</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/25469298">Pubmed</a>
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