Week 3 - Lecture 3a - Clinical Models Pt.1 Flashcards
Lung cancer pathophysiology
leading cause of cancer deaths world wide
lung cancer patho # 2
tumour growth is initiated by mutations that can
- activate oncogenes
- subdue tumour suppressor genes
- cause deletion in chromosome 3
lung cancer is the end stage of multiple mutations and cellular transformation
- tumour enlarges
- penetrates epithelial layer
- moves into lung tissue, pleural cavity, chest wall (Seeding)
- metastatic spread : lymph channels, blood vessels
lung cancer metastases are tropic to bone, liver, brain
lung cancer patho #3
tumours originate most frequently in the epithelial lining of the - bronchi -bronchioles -alveoli four subtypes 1. adenocarcinoma (35%) - C 2. squamous cell carcinoma (30%) - A 3. small cell carcinoma (20%) - B 4. Large cell carcinoma (15%) - D
adenocarcinoma (lung cancer)
develop in peripheral bronchiolar and alveolar lung tissue
leads to pleural fibrosis and adhesions
further subdivisions
squamous cell carcinoma (lung cancer patho)
cell injury of bronchiolar columnar epithelium (smoking) triggers metaplasia – dysplasia – carcinoma in situ – invasive carcinoma
tumour cells can be detected in sputum (coughed up from respiratory tract)
small cell carcinoma
highly malignant
grows and develops metastases rapidly
tumour cells cause hemorhharge and necrosis
strongly linked to smoking
large cell carcinoma
tumour cells are large
high levels of anaplasia
metastasise readily
diagnosis is based on exclusion of others
subtypes prevalence vary by gender
adenocarcinoma : most common in women and non smokers
small cell carcinoma : higher rate in males
squamous cell carcinoma : higher rate in males, linked to smoking
clinical manifestations of lung cancer
common clinical manifestations relates to location - persistent cough -hemoptysis -chest pain -shortness of breath often ignored as 'smoker's cough'
common general manifestations are present
paraneoplastic manifestations are present
Lung cancer diagnostic criteria
history taking, physical examination, imaging
- bronchoscopy
- chest x ray
- MRI/CT/ultrasound
- carcinoembryonic antigen (CEA) may be present
prognosis for lung cancer is dependant on
CEA level
ability to surgically remove the tumour
lymph node involvement
presence of metastasis
Lung cancer treatment
based on tumour type
- small cell carcinoma
- chemotherapy
- - more likely to respond
- - more likely to be widely disseminated at diagnosis- patients develop distant metastases
- surgical resection and radiation : limited contribution to long term survival
non small cell carcinoma : treatment depends on the ability to resect (surgery) (adenocarcinoma, squamous cell carcinoma, and large cell)
-resectable : may be cured by surgery alone or with chemotherapy combination.
- non resectable : local control of tumour growth with radiation, cure is unlikely
lung cancer treatment part 2
least favourable prognosis
- small cell carcinoma
- large cell carcinoma
many lung carcinoma are not detected until tumour is well advanced early symptoms (chronic cough ) often ignored
overall 5 year survival rate 15%
colorectal cancer patho
exact cause is often not clear primary risk factor : age 90% of cases in adults diagnosed over >50 multiple lifestyle risk factors protection - selenium, ACE vitamins, veggies
colorectal cancer
tumours are most often of epithelial origin
- adenoma (benign)
- adenocarcinoma (malignant)
three groups of colorectal cancer
- non - neoplastic polyps (not generally considered a cancer precursor)
- neoplastic polyps (adenomatous polyps, adenomas, increased carcinoma development, considered a cancer precursor)
- cancers (most often adenocarcinoma)