Lung cancer

Question 1

What is the leading cause of cancer deaths in the UK?

Answer 1

Lung cancer (most frequent in both men and women)

Question 2

What % of lung cancers are attributed to smoking? Name 2 other risk factors

Answer 2

80%; asbestos, previous chest radiotherapy, radon gas

Question 3

Compare SCLC and NSCLC in terms of aggressiveness and % of cases

Answer 3

SCLC: 15-20%, highly aggressive, neuroendocrine origin.

NSCLC: 80-85% (adenocarcinoma 40%, squamous 30%, large cell 10-15%).

Question 4

Where do adenocarcinomas vs. squamous cell carcinomas typically arise?

Answer 4

Adenocarcinoma: Peripheral lung.

Squamous: Proximal segmental bronchi

Question 5

What genetic alterations are hallmark in SCLC?

Answer 5

Loss of TP53 and RB; MYC amplification.

Question 6

Name 2 targetable mutations in NSCLC adenocarcinomas

Answer 6

EGFR, ALK, ROS, MET, RET, or KRAS mutations

Question 7

Why is CXR not used for lung cancer screening?

Answer 7

No mortality benefit; low-dose CT is now standard for high-risk patients (age 55-74, smokers/ex-smokers).

Question 8

Name 4 “red flag” symptoms of lung cancer.

Answer 8

Persistent cough, haemoptysis, hoarse voice (vocal cord palsy), SVC obstruction

Question 9

What paraneoplastic syndrome is classic for SCLC?

Answer 9

SIADH (Syndrome of inappropriate antidiuretic hormone secretion)

(or Lambert-Eaton myasthenic syndrome)

Question 10

What is first-line therapy for limited-stage SCLC?

Answer 10

Etoposide + platinum chemotherapy + concomitant radiotherapy ± prophylactic cranial irradiation

N.b. Etoposide inhibits DNA synthesis by forming a complex with topoisomerase II and DNA. This complex induces breaks in double stranded DNA and prevents repair by topoisomerase II binding. Accumulated breaks in DNA prevent entry into the mitotic phase of cell division, and lead to cell death.

Question 11

What targeted therapy is used for EGFR-mutant adenocarcinoma?

Answer 11

EGFR TKIs (e.g., erlotinib, gefitinib)

Front-line epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) therapy is the standard of care for lung cancer patients with sensitising EGFR mutations (exon 19 deletion or L858R mutation).

Question 12

How is SCLC staged differently from NSCLC?

Answer 12

SCLC uses “limited” (confined to one hemithorax) vs. “extensive” (metastatic); NSCLC uses TNM (Tumour, Node, Metastasis).