lung cancer Flashcards
histopathology of lung cancer: explain the common types of lung cancer, their biological behavior, prognosis and treatment
main types of lung cancer
beningn, malignant, non-small cell, small cell
2 features of benign lung tumours
do not metastasise, cause local complications (e.g. Chondroma)
2 features of malignant lung tumours
potential to metastasise, variable clinical behaviour
3 types of non-small cell tumours
squamous cell carcinoma, adenocarcinoma, large cell carcinoma
what % of tumours are small cell, and 2 characteristics of their growth
20%, grow faster and more aggressively
what cells are affected by squamous cell carcinoma
tough epithelium lining skin
describe the pathway from normal columnar epithelium to squamous cell carcinoma
normal columnar epithelium becomes irritated by smoke, undergoes hyperplasia, undergoes metaplasia, all columnar become squamous, dysplasia, carcinoma in situ, invasive carcinoma
effect of squamous cell carcinoma
more resistant to damage but no cilia to move mucous
what occurs in formation of squamous cell carcinomas as mutations accumulate, and what does it become
dysplasia and disordered growth, become a carcinoma in situ
what % of pulmonary carcinomas are squamous cell
25-40%
what risk factor are pulmonary squamous cells closely associated with
smoking (most associated)
what is the traditional location of squamous cell carcinomas
central, arising from bronchial epithelium
what is another location and feature of spread of squamous cell carcinomas
peripheral, with a local spread and then metastasise late
what are adenocarcinomas
40%, glandular epithelium tumours e.g. columnar goblet cells
where do adenocarcinomas develop
interstitium, peripheral airways
pathway for adenocarcinoma formation from precursor
proliferation of atypical cells along alveola wall, increasing in size (hyperplasia) and becoming invasive - not related to smoking
how to treat early adenocarcinomas and why
excise early lesions as in situ must acquire invasive phenotype before invading local tissue and stroma (peripheral and early metasasis); mucin made so can do cytology test
what are large cell carcinomas
5%, poorly differentiated tumours composed of large cells
what may an electron microscope show evidence of for large cell carcinomas that isn’t possible in histology
glandular, squamous or neuroendocrine differentiation
what % of pulmonary tumours are small cell carcinomas
20-25%
what is a major risk factor for small cell carcinomas
smoking, men
why are small cell carcinomas treated with chemoradiotherapy
very chemosensitive as turn over rapidly
what are small cell carcinomas present with and how does this affect prognosis
paraneoplastic syndrome, present with advanced disease; affect central area near bronchi, often metastasising to brain, liver or bones, so have poor prognosis and death within 18 months
prognosis of small cell carcinomas (untreated, treated)
untreated: 2-4 months; treated: 10-12 months
prognosis of non-small cell (stage 1 to stage 4) for 5 year survival
stage 1: 60%; stage 4: 5%
describe 5 treatments for lung cancers
surgical excision (adenocarcinomas); chemoradiotherapy (small cell carcinomas); immunemodulatory therapy for non-small cell carcinomas (PDL1 inhibitors prevent cancerous cells with new antigens blocking cytotoxic T-cell action, so are destroyed); EGFR/ALK target for small cell carcinomas (tyrosine kinase inhibitors, as stop downstream process, increasing survival time), cisplatin for small cell carcinomas (kRAS target)
2 mutually exclusive mutations for adenocarcinoma formation (smoker vs non-smoker)
smoker: kRAS mutation; non-smoker: EGFR mutation
“clinical coathanger”: In A Surgeons Gown Physicians May Make Some More Progress
Incidence, Age, Sex, Geography, Pathogenesis, Macro path, Micro path, Symptoms and signs, Management, Prognosis
