Carcinoma of lung

Question 1

Epidemiology

Answer 1

MCC cancer deaths worldwide
MCC in men (breast CA in women)
Age: 60-70 y.o.
Male predominance, Female smoking increasing now
150K die each year

Question 2

Etiology: Smoking/Nonsmoking

Answer 2

85% from smoking–Polycyclic Hydrocarbons
Smoking association with: Squamous cell & Small cell carcinoma
Nonsmoker: Adenocarcinoma

Question 3

Classifications

Answer 3

Small cell vs Non-small cell
Small-cell: responsive to chemotherapy
Need pathologist to make this distinction

Question 4

Etiology: Genetics

Answer 4

1. Activate carcinogenic on DNA
2. Activate oncogenes
3. Mutation/Inhibition of tumor suppressor genes

Smoke: Procarcinogens inhaled and turned into carcinogens via cytoplasmic enzymes in bronchial cells

Question 5

Mutated oncogenes

Answer 5

1. K-ras
   Assoc with cigarette smoking
2. Myc

Question 6

Mutated Tumor suppressors

Answer 6

1. p53

2. Rb (Retinoblastoma)

Question 7

Chromosome abnormalities

Answer 7

Deletion of short arm chromosome 3p

In all types

Question 8

Cellular adaptations before lung CA

Answer 8

Preneoplastic lesions:
1. Metaplasia of bronchial epithelium (reversible)
  Pseudostratified ciliated columnar ---
  Stratified squamous epithelium
2. Dysplasia (in-situ)
3. Anaplasia

Question 9

Reversible?

Answer 9

D/C smoking, lesion disappear & normal structure

BUT cilia do not come back