Lung Cancer Flashcards
What is the most common cancer death?
Lung cancer.
what are the main causes of lung cancer?
smoking
asbestos
occupational exposure - chromates, hydrocarbon, nickel
air pollution and urban environment
other radiation
pulmonary fibrosis
what figures are associated with lung cancer and smoking?
>85% of cancers seen attribute to tobacco
10% of smokers get lung cancer
risk of cancer increases 22x in males and 12x in females
however, females are more susceptible
RISK is related to consumption and “pack years” (packs per day per year
no safe smoking threshold
Are passive smokers still at risk of lung cancer?
yes
50-100% increased risk
- causes at least 25% of so-called non smoking lung cancers
what happens when you stop smoking in relation to lung cancer?
risk does not immediately disappear
- takes a long time for risk to return to a “non-smoker” (still risk for non-smokers, just less than smoker)
reason slow is genomic damage takes a long time to be cleared out of epithelial cell population
what are the two main carcinogens in tobacco
polycyclic aromatic hydrocarbon
n-nitrosamines
what area do polycyclic aromatic hydrocarbons tend to enhance cancer development?
what tends to arise?
the central part of the lung - in the bronchi
tumours called squamous cell carcinoma or small cell carcinoma arise
where do N-nitrosamines tend to cause lung cancer and what tends to arise?
n-nitrosamines more prone to causing adenocarcinoma (ant more in female than male)
Adenocarcinoma is a type of cancer that starts in mucus-producing glandular cells of your body.
Lung adenocarcinoma is a subtype of non-small cell lung cancer (NSCLC).
starts in glandular cells tends to develop in smaller airways, such as alveoli.
some chemicals in tobacco smoke are pro-carcinogens. What does this mean?
metabolised into carcinogens by our defence mechanisms in our body (primarily enzymes in the liver) which are meant to metabolise foreign chemicals and get rid. but metabolise these chemicals into carcinogenic elements.
what are the two main pathways of carcinogenesis in the lungs?
in the lung periphery - bronchioalveolar epithelial stem cell transformation
adenocarcinoma (n-nitroamines)
in the central lung airway - bronchial epithelial stem cells transform
squamous cell carcinoma (polycyclic aromatic hydrocarbon)
two main pathways of carcinogenesis in the lungs? process to invasive
adenocarcinoma- atypical adenomatous hyperplasia > adenocarcinoma in situ > invasive adenocarcinoma
squamous cell carcinoma - bronchial basal cell hyperplasia > squamous dysplasia and carcinoma in situ > invasive squamous cell carcinoma
what are benign tumours in the lung
where pneumonia rather than resolving turns in to fibrous lump (mimics cancer)
what other tumours that dont class as lung cancer are there?
other tumours, neoplasms (may be invasive) and cause death but are not traditionally as primary lung cancer : e.g. carcinoid tumour (arisen bronchial gland) and other malignancies which are not epithelial in origin like carcinoma
tumours of bronchial glands (rare) adenoid cyctic carcinoma - mucoepidermoid carcinoma - benign adenoma
- lymphoma - sarcoma - metastases to lung (from elsewhere) are common
Carcinoma of the lungs : cell type
four main types
- squamous cell
adenocarcinoma
small cell carcinoma
large cell carcinoma
** bronchioalveolar cell carcinome (alveolar cell Ca) was a subtybe of adenocarcinome. now called adenocarcinoma insitu **
is adenocarcinoma more common in males or females?
females
types of lung cancer histology
Squamous from identifying evidence of squamous differentiation of characterization
- *adenocarcinoma** - seeing glandular differentiation in tumour
- *small cell carcinoma** morphologically undifferentiated differentiation at molecular level towards newer endocrine type cells
Large cell carcinoma morphologically undifferentiated
primary lung cancer what is this?
grows “clinically silent for many years”
presents late in natural history
may have few (if any) signs/symptoms until disease advanced
maybe found incidentally, during investigation for something unrelated
- generally speaking, symptomatic lung cancer is fatal
primary lung cancer - imaging
not spread beyond thorax confined to lung 50% patients are cured if found and not invasive
what is important to note about central tumours - what are they likely to do?
likely to bleed. important red flag symptom caused by lung cancer is bleeding so blood in the sputum
if pt coughing blood - investigate for lung ca.
local effects of lung cancer
bronchial obstruction: collapse of lung - endogenoud lipid pneumonia -infection/abcess
- bronchiectasis
-pleural - direct invation - lymph metastases
squamous cell carcinoma lung
Squamous cell carcinoma of the lungs, also called epidermoid carcinoma, is a type of non-small cell lung cancer that typically develops in one of the air passages, or bronchi, of the lungs.
collapse lobes, area, retain secretions - consolidations macrophages risk infection = endogenous lipoid pneumonia
also bronchiectasis
Secondary illnesses to lung cancer
endogenous lipoid pneumonia
bronchiectasis
growth into pleural space - fibrosis in pleura - pleural effusion, pleural irritation, pleural inflammation
Invasion of nerves lung cancer
Phrenic = diaphragm paralysis - dramatic increase in breathlessness
left recurrent laryngeal nerve (begins in neck down to chest, loops main bronchus, goes back up the neck to supply motor function to left vocal cord)- hoarse, bovine cough
brachial plexus - Pancoast t1 damage
cervical sympathetic - horners syndrome
where in lung cancer if it spereads is almost impossible to operate?
if spread to superiorly to neck
or medially to the mediastinum
due to other structures being involved.
whee is the left recurrent laryngeal nerve
left recurrent laryngeal nerve (begins in neck down to chest, loops main bronchus, goes back up the neck to supply motor function to left vocal cord)-
what is a bovine cough? explain physiology
Bovine comes from the Latin word for “cow”,
cough that sounds like a cow -
if you cannot increase intrathoracic pressure to suddenly release air (making a cough)
that is a bovine cough
what is horners syndrome (signs) why can this happen in lung cancer?
Horner syndrome is a relatively rare disorder characterized by a constricted pupil (miosis), drooping of the upper eyelid (ptosis), absence of sweating of the face (anhidrosis), and sinking of the eyeball into the bony cavity that protects the eye (enophthalmos).
if invasion spreads the cervical sympathetic nerve - lead to loss of cervical sympathetic innervation of the face.
What are signs the lung cancer has spread to superior vena cava?
Plethoric infused face
engorged upper limbs even when raised above heart height
facial plethora - is typically the redness of the face brought about by an increase in the level of blood or increase in blood flow.
what distant effects of lung cancer can you find in: skeletal
finger clubbing
Hypertrophic pulmonary osteoarthropathy (HPOA) is a syndrome characterized by the triad of periostitis, digital clubbing and painful arthropathy of the large joints, especially involving the lower limbs.
types of non-small cell carcinoma
Squamous cell carcinoma (25% of lung cancers). Adenocarcinoma (40% of lung cancers). Large cell carcinoma (10% of lung cancers).
cannonball metastasis - lung cancer
multiple lung nodules which is generally metastatic disease from a primary ca elsewhere
can also be present as a cavity
after x-raying a patient and you see this picture (below) what further investigation will you do?
further CT to clarify findings, stage cancer and scan lower chest and abdomen to try find primary tumour location
also tissue diagnosis
treatment options of lung cancer: surgery
18% of patients - mainly stage 1 and some stage 2
- wedge resection surgical procedure that is done to remove a wedge-shaped section of lung tissue
- lobectomy removal of a section of the lung (lobe)
- pneumonectomy remove one of your lungs
