Lung Cancer Flashcards
Small cell carcinoma
Small cell carcinoma of the lung is a malignancy commonly associated with smoking, often has metastasized at time of diagnosis to the liver, adrenals, and brain.
Extremely invasive, poor prognosis.
Small cell carcinoma, aka
oat cell carcinoma
Mostly arises in the lung, though it can arise in cervix, prostate, and gastrointestinal tract.
Shorter doubling time, higher growth rate, and earlier development of metastases than non-small cell carcinoma.
NSCLC
Non-small cell lung carcinoma (NSCLC) is any type of epithelial lung cancer other than small cell lung carcinoma.
Accounts for about 85% of all lung cancers.
Relatively insensitive to chemotherapy, as compared to small cell carcinoma.
Treatment: primarily surgical resection w/curative intent.
Lung cancer, definition, source, types, s/sx, risk factors
Lung cancer is a malignant lung tumor characterized by uncontrolled cell growth in tissues of the lung.
Lung cancer is the leading cause of cancer death in the US.
Most lung CA are carcinomas that derive from epithelial cells.
Main primary types are
- small-cell lung carcinoma (SCLC) and
- non-small-cell lung carcinoma (NSCLC).
Symptoms, common:
- coughing (including coughing up blood),
- weight loss,
- shortness of breath, and
- chest pains.
Risk factors include:
- smoking,
- radon,
- asbestos and
- family history.
Types of lung cancer, 2 main types and the subtypes, and association with smoking
Lung carcinomas may be divided into two large groups:
- small cell lung cancer (SCLC) and
- non-small cell lung cancer (NSCLC).
SCLC - minority of cases
NSCLC - majority of cases
Small cell lung CA - stronger association with smoking, relatively faster growing and faster to spread than NSCLC.
Non-small cell lung cancers are relatively slower growing and slower to spread than SCLC.
NSCLC subtypes include:
- adenocarcinoma,
- squamous cell carcinoma (SCC), and
- large cell carcinoma (LCC).
Correlated with smoking:
- SCLC and
- Squamous cell carcinoma subtype of NSCLC
Not associated with smoking:
- Adenocarcinoma (NSCLC) is the most common lung cancer in females and nonsmokers.
Lung CA arises from …
Epithelial cells of the lung
Types of epithelial cells in the lung
- Goblet cells - secrete mucin
- Ciliated cells - sweep debris, including pathogens, to the throat
- Club cells - protect the bronchiolar epithelium
- Neuroendocrine cells - secrete hormones into the blood in response to neuronal signals
- Basal cells - believed to be able to differentiate into any of the above.
Bronchial Tree
Trachea Right or Left Bronchus Lobar bronchi Segmental bronchi Subsegmental bronchi Conducting bronchioles Respiratory bronchioles Alveoli
Angiogenesis
the development of new blood vessels. Tumors engage in angiogenesis to provide energy to support their rapid growth.
Risk Factors for lung CA
- Smoking tobacco - SCLC and some types of NSCLC (squamous cell carcinoma subtype) - dose dependent
- Radon - colorless, ordorless gas, a product of uranium breakdown, happens in the soil
- Asbestos
- Air pollution
- Ionizing radiation (XR, CT)
- Genetics
Lung cancer metastasizes …. and common sites of secondary tumors include …
Lung CA, especially SCLC, metastasizes quickly. Sites of secondary tumors: 1. Mediastinum and hilar lymph nodes (b/c of proximity) 2. Lung pleura 3. Liver 4. Adrenals 5. Brain 6. Heart 7. Breasts 8. Bone
Small cell carcinoma, %, origination, staging, association, location, secretion,
Represents a small portion of lung cancers
Originates from small, immature neuroendocrine cells
- Small cell carcinoma is strongly associated with SMOKING!
- Often develops in the central part of the lung, near a main bronchus
- Grows faster and more rapidly metastasizes than NSCLC
- Can secrete hormones leading to paraneoplastic syndrome.
Staging:
- Limited - all CA sites contained within one lung
- Extensive - CA sites in both lungs
Non-small cell carcinoma, categories and description of the categories
Most lung cancers are NSCLC
There are four categories:
1. Adenocarcinoma - form glandular structures, can produce mucin - women, non-smokers
2. Squamous cell carcinoma - square shaped cells that can produce keratin*; associated with smoking
3. Bronchial carcinoid tumors - originate from mature neuroendocrine cells; not necessarily a true cancer, but can be
4. Large cell carcinoma - lacks both glandular and squamous differentiation.
Keratin is a fibrous protein forming the main structural component of hair, feathers, hoofs, claws, horns, etc. This of hair as brown, smoking causes brown mucus.
Paraneoplastic syndrome, types of hormones that can be released by lung cancers
- Adrenocorticotropic hormone (ACTH hormone) - the pituitary secretes ACTH. ACTH travels to the adrenal glands via the bloodstream. Cortisol from the adrenal then feeds back to the hypothalamus to shut down the cycle. Cortisol is a steroid hormone whose effects include controlling the body’s blood sugar levels thus regulating metabolism, acting as an anti-inflammatory, influencing memory formation, controlling salt and water balance, influencing blood pressure and helping development of the foetus. (SCLC)
- Antidiuretic hormone - Anti-diuretic hormone helps to control blood pressure by acting on the kidneys and the blood vessels. Its most important role is to conserve the fluid volume of your body by reducing the amount of water passed out in the urine. (SCLC)
- Auto-antibody production (SCLC)
- Parathyroid hornome - depletes caclium in the bone making them brittle and increases serum calcium levels. (Squamous cell carcinoma, NSCLC)
- Carcinoid syndrome - causes the secretion of hormones, particularly serotonin (Bronchial carcinoid, NSCLC)
SCLC, paraneoplastic syndrome, consequences of release of adrenocorticotropic hormone
Causes an increase of cortisol release from the adrenal gland, leading to the development of Cushing syndrome.
Symptoms:
- increased blood glucose
- hypertension
- Weight gain - around the midsection, fatty deposits on face and upper back, fat loss from arms and legs
- Thin skin and stretch marks
- Irritability
- Red, ruddy, round face face
- Fatigue
- Poor short-term memory
Cushing syndrome occurs when your body is exposed to high levels of the hormone cortisol for a long time. Cushing syndrome, sometimes called hypercortisolism, may be caused by the use of oral corticosteroid medication. The condition can also occur when your body makes too much cortisol on its own.
Too much cortisol can produce some of the hallmark signs of Cushing syndrome — a fatty hump between your shoulders, a rounded face, and pink or purple stretch marks on your skin. Cushing syndrome can also result in high blood pressure, bone loss and, on occasion, type 2 diabetes.
SCLC, paraneoplastic syndrome, consequences of release of antidiuretic hormone
Release of anti-diuretic hormone causes:
- water retention
- hypertension b/c of water retention
- edema
- concentrated urine
SCLC, paraneoplastic syndrome, consequences of release of auto-antibodies
Destroys neurons leading to Lambert-Eaton Myasthenic Syndrome, a Type II Hypersensitivity Reaction
NSCLC, squamous cell category, location, smoking
- Centrally located (in the lungs)
- Pancoast tumors can be formed
- Strong association with smoking
NSCLC, adenocarcinoma, location, smoking
- Peripheral location, in a bronchiole or aveolar wall
- Pancoast tumors can be formed
- Not linked with smoking
NSCLC, large cell, location, smoking
- Located throughout the lung
- Associated with smoking
NSCLC, bronchial carcinoid
- Located throughout the lung
- May not be considered a cancer?
Pancoast Tumors, location, type, complications
Masses in the pulmonary apex. It is a type of lung CA defined primarily by its location at the top of either the right or left lung. It typically spreads to nearby tissues such as the ribs and vertebrae. Most are NSCLC.
Typically, squamous or adenocarcinoma form pancoast turmors. Pancoast tumors can compress blood vessels and nerves located there. Pancoast tumors can cause Horner Syndrome (Horner syndrome results in miosis, partial ptosis, and anhidrosis on the affected side.)
Horner Syndrome, definition, characteristics, causes
Horner syndrome results from an interruption of the sympathetic nerve supply to the eye.
Characteristics, classic triad:
- miosis (i.e. constricted pupil),
- partial ptosis (dropping eyelid), and
- loss of hemifacial sweating (i.e. anhidrosis) on the side of the damage.
Causes include:
- Lesion of the primary neuron
- Brainstem stroke or tumor
- Trauma to the brachial plexus
- Tumors (e.g., Pancoast) or infection of the lung apex
- Lesion of postganglionic neuron
- Dissecting carotid aneurysm - can cause painful Horner Syndrome
- Carotid artery ischemia
- Migraine
- Middle crainial fossa neoplasm
NSCLC, classic paraneoplastic syndrome, squamous cell category
Release of parathyroid hormone which depletes calcium in bone increasing risk of fracture and increasing blood calcium levles.
NSCLC, classic paraneoplastic syndrome, bronchial carcinoid category
Carcinoid syndrome causes the secretion of hormones, particularly serotonin leading to:
- increased peristalsis and diarrhea
- bronchoconstriction and asthma
Staging NSCLC
TNM staging
- Tumor size and extent of local extension
- Nodes - spread to lymph nodes, especially the mediastinum and hilar lymph nodes
- Metastasis to secondary site(s)
Substages, within each of the above:
T0 - T4
N0 - N3
M0 - M1
Increasing number indicates increasing severity.
The three stages then determine the stage group, Stage Group 0 to Stage Group 4.
If the tumor has metastasized, it is Group 4 regardless of its T or N value.
Lung CA symptoms
Vary, depending upon the size and location of the cancer, if it has metastasized, and if it produces hormones.
- In response to the cancer, the body mounts an immune response leading to the release of chemokines like
– Tumor necrosis factor alpha
– Interleukin 1 beta
– Interleukin 6
These chemokines can cause weight loss, fever, and night sweats.
If the tumor obstructs the airway, it can cause a cough, SOB, and PNA in the lung distal to the obstruction.
Compression of nerves can cause pain.
Recurrent laryngeal nerve compression can cause voice changes.
Phrenic nerve compression can cause difficulty breathing.
Superior vena cava compression can cause a backup of blood leading to facial swelling and SOB.
Invasion of blood vessels can cause blood tinged mucus and coughing up of blood clots
Treatment
Varies by the category and stage, but commonly includes:
- Surgery - resection with clean margins + lymph nodes
- Chemotherapy
- Immunotherapy
- Radiation therapy
Small-cell carcinoma of the lung is rapidly progressive and is treated mostly with chemotherapy and radiation
NSCLC patients will undergo resection when possible.
Hypercalcemia, which type of lung CA, s/sx, pathology
Severe hypercalcemia, s/sx:
- abdominal pain,
- bone pain,
- renal stones, and
- cognitive dysfunction.
In the setting of malignancy, this electrolyte disturbance can occur from bony metastasis or a paraneoplastic release of parathyroid hormone-related protein (PTHrP), which mimics the effects of PTH.
This paraneoplastic syndrome is most commonly associated with squamous cell cancer, a non-small cell lung carcinoma.
