Lung Cancer Flashcards
operative mortality of different lung surgeries
- Pneumonectomy (5-10%)
- lobectomy (2%) - lowest mortality rate but also highest rate of recurrence
- wedge resection (<1%)
- open/close thoracotomy (5%)
what is the purpose of minimally invasive lung surgery?
avoid opening the chest like in open surgery. This prevents the intercostal muscles and nerves from being stretched and damaged.
side effects of chemotherapy
* side effect and duration depends on the course of chemo
- marrow suppressed and increased risk of fatal infection
- nausea, vomiting, GI upset, mucositis (breakdown of mucous membrane taht my extend to affect the GI tract)
- fatigue and lethargy
- hair loss, nail changes
- stroke
side effects of radiotherapy
- lethargy
- pneumonitis, dysphagia (difficulty swallowing) - these are acute symptoms
- long term fibrosis, stricture, increased MI risk, secondary malignancies
side effects of immunotherapy
- colitis
- pneumonitis
- dermatitis
- endocrinopathies
what are the 3 major causes of lung cancer?
- SMOKING - the biggest (10% of smokers have lung cancer)
- second hand smoking (increases your chance of lung cancer by 50-100%)
- asbestos, radon, chemical exposure
*tobacco + asbestos have MULTIPLICATIVE effect
lung cancer stats
- causes more deaths than prostate + breast cancer combined
- 10% of smokers have lung cancer but >85% of lung cancer is linked to smoking
- average 2-3 years survival
- second hand smoking causes 25% of nonsmoking cancer
- women are more susceptible to carcinogenic factors, and they take deeper puffs
other causes of lung cancer
- addictive oncogene drivers
- inherited predisposition to nicotine addiction (the liver easily mets procarcinogens in tobacco into carcinogens)
carcinogens in tobacco and what they do
- nitrosamines: adenocarcinomas at the side of the lungs
- polycyclic aromatic hydrocarbons (PAH): squamous SCLC at the center of the lungs
describe the multihit theory of carcinogens
for lung cancer to happen, there must be numerous mutations happening in the right order in the same cell, and there must be no other mutation that will cause the cell to die before becoming cancerous. This will require accumulation and multiple hits.
Although it seems like it is impossible to get lung cancer, there would be billions of cells affected while smoking and so the chances are not that low
histological progression of lung cancer
squamous dysplasia (half of the required mutations, treatment still possible) β> carcinoma in situ (CIS) β> invasive adenocarcinoma (malignant stage, usually the symptoms show at this stage where it is already too late for treatment)
describe addictive oncogene drivers
- susceptibility from birth to have mutations that will stimulate mutations in the oncogenes for lung cancer compared to how normally you would need accumulation of mutations
- common cause of lung cancer in nonsmokers
- common in Asians
- if we can identify the oncogene, we can pharmacologically interfere with it
tobacco induced and non-tobacco induced key driver mutations
Tobacco induced:
- EGFR (15%, the most common - can cause lung cancer all by itself)
- BRAF/HER2 (1-2% each)
- ALK (2%)
- ROS1 (1%)
non-tobacco indued:
- KRAS (35%)
list the 4 main types of carcinomas of the lungs
- Small cell carcinoma (SCLC) (15%)
Non small cell carcinoma (NSCLC):
- squamous cell (40%)
- adenocarcinoma (41%)
- large cell carcinoma (4%)
what kind of tumor is likely to be caused by smoking?
squamous cell carcinomas, there are very few suitable addictive oncogenes for this and are mostly caused by smoking
SCLC vs NSCLC
SCLC: very invasive and aggressive, surgery not a suitable treatment
NSCLC: (70-80%) not as invasive and surgery is preferred at initial stages
early symptoms of lung cancer
- can be clinically silent until malignant stage
- overlaps with COPD
- CXR lumps
- haemoptysis
local effect of lung cancer
- bronchial obstruction (collapsed lung, bronchiectasis, abscess, pneumonia)
- pleural effect (inflammation, effusion, malignant spread)
- direct invasion into chest wall
- nerves
- mediastinum (affects pericardium abd SVS)
- lymph nodes (local effects, including mets, lymphagitis, carcinomatosa)
- vascular invasion (like into the vena cava)
nervous effects of lung cancer
- phrenic nerve: diaphragmatic paralysis (uneven diaphragm)
- left recurrent laryngeal nerve (hoarse voice, yell-like coughs from paralysed vocal cords)
- brachial plexus, pancostal T1 damage (tingly fingers)
- cervical sympathetic (Hornerβs syndrome affecting nerves in the face and eyes)
distant effects of lung cancer
- mets (to liver, adrenal glands, bones, brain, skin)
- skeletal (finger clubbing, hypertopic osteoarthropathy HPOA in small hand joints)
- endocrine (happens in SCLC) (1. excess ACTH/SIADH resulting in excess hormone symptoms, 2. excess PTH resulting in hypercalcemia)
- neurological
- cutaneous
- harmotologic - affecting the blood
- CVS (thrombus, inflammation)
- nephrotic syndrome
when to switch to palliative care?
when distant organs are affected by metastasis
things that prognosis of lung cancer depends on
- stage of disease
- histological classification (type of cancer - treatment will also differ)
- markers, oncogenes, gene expression profiles
- cell proliferation
- DNA aneuploidy
- immune cell infiltration
prognosis for lung cancer?
prognosis is usually bad <10% survive after 5 years (and only 10-15% gets surgery) - stage I operable >60% - stage II operable 35% 5 years survival by histology type: - NSCLC 10-25% - SCLC 4%, 9 months
target predictive biomarkers for each type of cancer
adenocarcinoma: EGFR, ALK, ROS1 (also KRAS, HER2, BRAF)
squamous cell carcinoma: no effective molecular targeted therapy, caused by accumulation of mutation from smoking
effectiveness of immunotherapy on cancer
- immunotherapy effective lung cancer that is caused by accumulation of mutations because this leads to production of abnormal proteins in which the immune system can recognize as nonself cells and attack
- nonsmoker lung cancer caused by oncogene drivers do no have enough mutation to produce enough abnormal proteins for immunotherapy to be effective.
- PD1/PDL1 and CTLA4 is another important immune checkpoints and therapeutic target. the drugs used to work against these are called immune checkpoint inhibitors
name the mutated oncogene and the chemotherapy drug used for each mutation
first line treatment
- EGFR (erlotinib, gefitinib, afatinib)
- ALK (crizotinib, ceritinib)
- BRAF (vemuratenib, dabrafenib)
- ROS1 (crozotinib)
- these drugs are kinase inhibitors
- make sure to rebiopsy after treatment because the nature of the tumor is always changing and the chemo plans would need to change as well
second line chemo treatment drugs
- docetaxel +/- nintedanib
- pemetrexed
- erlotinib