Oncology basics Flashcards
What are cancer cells?
Cells which undergo uncontrolled and unregulated cell proliferation with the ability to metastasise to other places in the body
What are some characteristics of cancer cells that underline their behaviour?
Sustaining proliferative signalling
Evading growth suppressors
Activating invasion and metastasis
Enabling replicative immortality
Inducing angiogenesis
Resisting cell death
Reprogram cellular metabolism to most actively support neoplastic proliferation
Evade immunological destruction by B and T lymphocytes, macrophages
Describe the cell cycle.
G0: resting phase
G1: pre-DNA synthesis phase
- cellular contents excl. chromosomes are duplicated
S: DNA synthesis
- chromosome duplication
G2: post-DNA synthesis
- double checks duplicated chromosomes and repairs any mistakes
Mitosis: Interphase Prophase Metaphase Anaphase Telophase
Cytokinesis (cell division)
Describe the stages of mitosis?
Interphase: DNA is in chromatin form
Prophase: nuclear envelope disappears, chromatin condenses to form chromatids
Metaphase: sister chromatids line up along the centre
Anaphase: pulled apart by telomeres
Telophase: chromatids at different poles, two nuclear envelopes form
What is meant by quiescence?
When a cell is permanently in G0 phase, resting phase
It can’t enter the cell cycle again
Pharmacokinetics vs pharmacodynamics?
Dynamics: how drug affects body
Kinetics: how body affects the drug
What are 3 features of a good chemotherapy drug?
What’s the main idea behind how chemotherapy works?
- reach the cancer cells
- cancer cells must be sensitive to the drug
- must have a minimal toxic effect on normal cells
Cancer cells are rapidly replicating, they go through cell cycle more, so if we can get a drug to inhibit part of the cell cycle, this will reduce cells ability to replicate and reduce tumour growth
List a few criteria of Wilson’s criteria?
Condition must be important
Natural history should be understood
Recognisable latent or early symptomatic stage
Test that’s easy to perform and accurate, reliable etc
Treatment more effective if started earlier
What’s the difference between sensitivity and specificity?
Sensitivity: ability of test to correctly identify patients with the disease
Specificity: ability of test to correctly rule out patients who don’t have the disease
What are positive predictive value and negative predictive value?
PPV: likelihood of a patient having the disease if they test positive
NPV: likelihood of a patient not having the disease if they test negative
Who is screened and how often:
- breast
- cervical
- bowel?
Breast: women 50-70, every 3 yrs
Cervical: women 25-49 every 3 yrs, 50-64 every 5 yrs
Bowel: age 60-74 every 2 yrs
How are tumours graded?
TNM
T - primary tumour
- T0: can’t be found
- T1-4: size and extent, growth into nearby tissues
N: regional lymph nodes
- N0: no cancer in nearby lymph nodes
- N1-3: number of affected lymph nodes
M: distant metastasis
- M0: no spread to rest of body
- M1: spread to rest of body
What treatments are available for cancer?
Surgery Radiotherapy Chemotherapy Immunotherapy Hormone treatments
What’s the difference between neoadjuvant and adjuvant chemotherapy?
What’s the purpose of each?
Neoadjuvant: given before surgery
- eradicates micrometastatic disease
- downstage tumour
- improves survival
Adjuvant: after surgery
- eradicates micromets
- ensures margins are cancer free
- improves survival
How does radiotherapy work?
Administering ionizing radiation with the intent on killing cancer cells or preventing replication.
When cells are ionized, free radicals and reactive oxygen species cause injury to the cell, inducing apoptosis AND damage the cell DNA rendering it unable to replicate
