Arab Board Oncology Part 1 flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Oncogene

A mutated or overexpressed gene that drives cell growth; gain-of-function; one altered allele can contribute; examples include RAS, MYC, and HER2.

Tumour suppressor gene

A gene whose loss permits uncontrolled growth; usually requires inactivation of both alleles; examples are TP53, RB1, APC, and BRCA1/2.

Knudson two-hit hypothesis

Retinoblastoma requires inactivation of both RB1 alleles; hereditary cases inherit one hit, so fewer somatic events are needed and tumours appear earlier and bilaterally.

Driver mutation

A somatic or germline alteration that confers a growth advantage and contributes to cancer development; passenger mutations lack this selective advantage and accumulate by chance.

Immune checkpoint blockade

Monoclonal antibodies targeting CTLA-4 or PD-1/PD-L1 remove inhibitory signals, permitting T cells to attack tumour cells; immune-related adverse events can affect skin, gut, liver, and endocrine organs.

CAR T-cell therapy

Autologous T cells engineered to express a chimeric antigen receptor recognizing a tumour antigen; used in B-cell malignancies; toxicities include cytokine release syndrome and neurotoxicity.

Cell-cycle-specific chemotherapy

Drugs killing cells only during a particular cell-cycle phase, such as antimetabolites in S phase or taxanes in M phase; schedule and infusion duration affect efficacy.

Leucovorin rescue

Folinic acid given after high-dose methotrexate to bypass dihydrofolate reductase blockade and protect normal tissues, especially bone marrow and gastrointestinal mucosa, from toxicity.

Linear quadratic model

A radiobiological model of cell survival after dose D, expressed as S = exp(−αD − βD²); the α/β ratio reflects repair capacity and guides fractionation.

Oxygen enhancement ratio

The ratio of radiation dose needed to produce a given effect in hypoxic versus well-oxygenated cells; typical value is about 2.5–3 for sparsely ionizing radiation.

R0 resection

Microscopically margin-negative resection with no residual tumour at the surgical margins; associated with lower local recurrence and better prognosis than R1 or R2 resection.

Tumour grade

A pathological description of tumour cell differentiation and mitotic activity; higher grade generally indicates more aggressive biology and poorer prognosis, independent of stage.

Liquid biopsy

Analysis of circulating tumour DNA or cells in blood; can detect actionable mutations, monitor response, and identify resistance, but sensitivity is limited in low tumour burden.

Tumour marker limitation

Markers such as CEA and CA-125 can rise in benign conditions and may be normal in cancer; they are not diagnostic alone and are mainly used for monitoring known disease.

FDG PET-CT

Combines positron emission tomography using fluorodeoxyglucose with CT; highlights glucose-avid tumours and metastases, useful for staging, detecting recurrence, and assessing treatment response.

RECIST target lesions

Measurable lesions chosen at baseline, up to five total and two per organ; response is defined by changes in the sum of their longest diameters.

TNM staging

Describes anatomical extent: T for primary tumour size or invasion, N for regional lymph node involvement, and M for distant metastasis; combined into stage groups.

Partial response RECIST

At least a 30% decrease in the sum of target lesion diameters from baseline, with no new lesions and no unequivocal progression of non-target lesions.

Number needed to treat

The reciprocal of the absolute risk reduction; it estimates how many patients must receive an intervention for one additional beneficial outcome.

Type II error

Failure to reject a false null hypothesis, often due to insufficient power or sample size; its probability is beta, and power equals 1 minus beta.

Intention-to-treat analysis

Analyzes participants according to randomization regardless of adherence; preserves prognostic balance from randomization but may dilute estimated treatment effect.

Selection bias

Systematic difference between groups arising from how participants are selected or allocated; randomization and allocation concealment are key methods to prevent it.

Incidence versus prevalence

Incidence is the number of new cases in a period; prevalence is the proportion with disease at a point or period, reflecting both incidence and survival.

Age-standardized rate

A cancer rate adjusted to a standard population age structure, allowing fair comparison between populations with different age distributions; it is not the crude rate.

HPV vaccination

Prophylactic vaccines against high-risk human papillomavirus types prevent cervical and other HPV-related cancers; they do not treat existing infection or lesions.

Faecal immunochemical test

A colorectal cancer screening test detecting human haemoglobin in stool; positive results require colonoscopy; sensitivity for cancer is good but interval screening is needed.

Febrile neutropenia

Fever with severe neutropenia after chemotherapy; requires urgent cultures and empirical broad-spectrum antibiotics because infection can progress rapidly to sepsis.

Tumour lysis syndrome

Metabolic emergency from rapid cancer cell breakdown causing hyperkalaemia, hyperphosphataemia, hyperuricaemia, and hypocalcaemia; prevention with hydration and allopurinol or rasburicase is key.

Spinal cord compression

Oncologic emergency from tumour pressing the spinal cord; presents with back pain, weakness, sensory loss, or bladder dysfunction; urgent steroids and imaging are needed.

Superior vena cava syndrome

Obstruction of the superior vena cava by tumour or thrombus causing facial swelling, distended neck veins, and dyspnoea; urgent imaging and supportive treatment are required.

Informed consent

A voluntary decision after receiving information about diagnosis, proposed treatment, alternatives, risks, and benefits; the patient must have capacity and be free from coercion.

Breaking bad news

Communicating serious information using a structured approach such as SPIKES: setting, perception, invitation, knowledge, emotions, and strategy; it should be patient-centred and documented.