lung cancer

Question 1

main types of lung cancer

Answer 1

beningn, malignant, non-small cell, small cell

Question 2

2 features of benign lung tumours

Answer 2

do not metastasise, cause local complications (e.g. Chondroma)

Question 3

2 features of malignant lung tumours

Answer 3

potential to metastasise, variable clinical behaviour

Question 4

3 types of non-small cell tumours

Answer 4

squamous cell carcinoma, adenocarcinoma, large cell carcinoma

Question 5

what % of tumours are small cell, and 2 characteristics of their growth

Answer 5

20%, grow faster and more aggressively

Question 6

what cells are affected by squamous cell carcinoma

Answer 6

tough epithelium lining skin

Question 7

describe the pathway from normal columnar epithelium to squamous cell carcinoma

Answer 7

normal columnar epithelium becomes irritated by smoke, undergoes hyperplasia, undergoes metaplasia, all columnar become squamous, dysplasia, carcinoma in situ, invasive carcinoma

Question 8

effect of squamous cell carcinoma

Answer 8

more resistant to damage but no cilia to move mucous

Question 9

what occurs in formation of squamous cell carcinomas as mutations accumulate, and what does it become

Answer 9

dysplasia and disordered growth, become a carcinoma in situ

Question 10

what % of pulmonary carcinomas are squamous cell

Answer 10

25-40%

Question 11

what risk factor are pulmonary squamous cells closely associated with

Answer 11

smoking (most associated)

Question 12

what is the traditional location of squamous cell carcinomas

Answer 12

central, arising from bronchial epithelium

Question 13

what is another location and feature of spread of squamous cell carcinomas

Answer 13

peripheral, with a local spread and then metastasise late

Question 14

what are adenocarcinomas

Answer 14

40%, glandular epithelium tumours e.g. columnar goblet cells

Question 15

where do adenocarcinomas develop

Answer 15

interstitium, peripheral airways

Question 16

pathway for adenocarcinoma formation from precursor

Answer 16

proliferation of atypical cells along alveola wall, increasing in size (hyperplasia) and becoming invasive - not related to smoking

Question 17

how to treat early adenocarcinomas and why

Answer 17

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

Question 18

what are large cell carcinomas

Answer 18

5%, poorly differentiated tumours composed of large cells

Question 19

what may an electron microscope show evidence of for large cell carcinomas that isn’t possible in histology

Answer 19

glandular, squamous or neuroendocrine differentiation

Question 20

what % of pulmonary tumours are small cell carcinomas

Answer 20

20-25%

Question 21

what is a major risk factor for small cell carcinomas

Answer 21

smoking, men

Question 22

why are small cell carcinomas treated with chemoradiotherapy

Answer 22

very chemosensitive as turn over rapidly

Question 23

what are small cell carcinomas present with and how does this affect prognosis

Answer 23

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

Question 24

prognosis of small cell carcinomas (untreated, treated)

Answer 24

untreated: 2-4 months; treated: 10-12 months

Question 25

prognosis of non-small cell (stage 1 to stage 4) for 5 year survival

Answer 25

stage 1: 60%; stage 4: 5%

Question 26

describe 5 treatments for lung cancers

Answer 26

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)

Question 27

2 mutually exclusive mutations for adenocarcinoma formation (smoker vs non-smoker)

Answer 27

smoker: kRAS mutation; non-smoker: EGFR mutation

Question 28

“clinical coathanger”: In A Surgeons Gown Physicians May Make Some More Progress

Answer 28

Incidence, Age, Sex, Geography, Pathogenesis, Macro path, Micro path, Symptoms and signs, Management, Prognosis