Oncology Mistakes

Basal cell carcinoma commonly occurs on the nose because it is associated with what major risk factor?

Chronic UV/sun exposure affecting sun-exposed facial areas

What is the role of p53 in the cell cycle?

Detects DNA damage, stops the cell cycle, activates DNA repair or apoptosis

Why is p53 called the “guardian of the genome”?

It prevents damaged DNA from being passed on during cell division

What is the function of cyclins?

Promote cell cycle progression by activating CDKs

What is the function of CDKs?

Drive the cell cycle forward and promote mitosis

What is the main function of Rb protein?

Blocks G1→S phase transition in the cell cycle

Which tumour suppressor is most associated with DNA damage response?

p53

What is the earliest mutation in the adenoma-carcinoma sequence of colorectal cancer?

APC mutation

What is the classic colorectal cancer mutation sequence?

APC → KRAS → p53

What is the role of KRAS mutation in colorectal cancer?

Promotes adenoma growth and progression

What is the role of p53 mutation in colorectal cancer?

Associated with progression to carcinoma

What syndrome is associated with MLH1 mutation?

Lynch syndrome (HNPCC) with mismatch repair defects

What is PD-1?

An inhibitory immune checkpoint receptor on T-cells

What is PD-L1?

An inhibitory ligand expressed on tumour cells that suppresses T-cells

What happens when PD-L1 binds PD-1?

T-cell activity is inhibited, allowing tumour immune escape

What is the goal of PD-1/PD-L1 immunotherapy?

Reactivate T-cells against tumour cells

Which immune checkpoint molecule is commonly targeted in cancer immunotherapy?

PD-L1 or PD-1

What is EGFR?

A growth factor receptor involved in tumour proliferation

What is ALK?

An oncogene mutation associated with some lung cancers

What is RAF?

A signalling protein in the MAP kinase pathway

What promotes tumour invasion and metastasis?

Loss of cell adhesion molecules such as E-cadherin

What is the role of E-cadherin?

Helps cells adhere to one another

How does loss of E-cadherin contribute to metastasis?

Allows tumour cells to detach and spread

What is angiogenesis?

Formation of new blood vessels

Why do tumours require angiogenesis?

To obtain oxygen and nutrients for growth

Which factor stimulates tumour angiogenesis?

VEGF

Do tumours require increased or reduced angiogenesis?

Increased angiogenesis

What are monoclonal antibodies in cancer therapy?

Targeted therapies against tumour antigens or immune checkpoints

What does pembrolizumab target?

PD-1 immune checkpoint receptor

What does trastuzumab target?

HER2 receptor in breast cancer

Do monoclonal antibodies broadly stop all cell division?

No, they specifically target tumour pathways or checkpoints

Do checkpoint inhibitors suppress or enhance immunity?

Enhance anti-tumour immunity

What is pelareorep?

An oncolytic virus used in cancer therapy

What is an oncolytic virus?

A virus that selectively infects and destroys tumour cells

How do oncolytic viruses stimulate immunity?

Release tumour antigens that activate adaptive T-cell responses

What is the main role of pelareorep?

Prime adaptive T-cell immune responses against tumours

What is a major mechanism of tumour immune escape?

Expression of inhibitory checkpoint proteins such as PD-L1

Does increased antigen presentation promote immune escape?

No, it enhances anti-tumour immunity

Does activation of cytotoxic T-cells promote immune escape?

No, it strengthens tumour killing

What is a paraneoplastic syndrome?

Symptoms caused by tumour products rather than direct tumour spread

Which lung cancer commonly causes ectopic ACTH production?

Small cell carcinoma of the lung

Which lung cancer commonly causes PTHrP-mediated hypercalcaemia?

Squamous cell carcinoma of the lung

What causes paraneoplastic hypercalcaemia in squamous cell carcinoma?

Parathyroid hormone-related peptide (PTHrP)