Chemotherapy

Question 1

How many chemotherapy drugs are there?

Answer 1

More than 90 drugs available

Question 2

Describe the cell cycle

Answer 2

• M: mitosis - cell divison
• daughter cells
• G0: resting, no proliferation
• G1: cellular contents other than chromosomes duplicated
• S: chromosomes duplicated
• G2: duplicated chromosomes are double-checked for errors
• M: mitosis - cell divison -> daughter cells

Question 3

How do chemotherapy drugs work?

Answer 3

• acts on cell cycle within which cell repro occurs
• drugs divided into:
  
  • cell-cycle phase specific (CCPS)
  • cell-cycle phase non-specific (CCPNS)
• ​combining CCPS + CCPNS drugs -> help achieve max cell kill
• cytotoxic drugs interfere with synthesis of DNA, RNA + proteins
• CCPNS are effective in all phases, direct effect on DNA + more toxic
• cells in rest phase are unaffected

Question 4

What is the cell kill hypothesis?

Answer 4

• Constant proportion of cells killed rather than absolute number
• eg. if drug kills 90% of tumour cells containing 100,000 cells then 10,000 left, next dose 1000 left, next 100, next 10, next 1 = 5 doses
• treatment given in cycles

Question 5

Is chemotherapy used alone?

Answer 5

• Chemo can be used alone
• in combo with other therapies too
• as neo-adjuvant or adjuvant treatment (eg before or after surgery)
• combos of chemo may be synergistic, reduce toxicities + allow normal cell recovery
• not all cancers are chemosensitive

Question 6

How is chemotherapy administered?

Answer 6

• intravenous (bolus or infusion)
• oral
• sub-cutaneous
• intramuscular
• intrathecal
• intracavitary

Question 7

What is extravasation and what can it cause?

Answer 7

Extravasation is the leakage of intravenously (IV) infused potentially damaging medications into the extravascular tissue around the site of infusion

Vesicant drugs can cause tissue death + necrosis

ADRs may occur, safe handling principles for staff.

Question 8

What are side-effects of chemo?

Answer 8

• haematological - myelosuppression
• GI - nausea, mucositis, diarrhoea/constipation
• hair loss
• fatigue
• organ toxicity (cardio, lung fibrosis, liver, kidney, neuro)
• gonadal toxicities - infertility + sexual dysfunction
• secondary malignancies

Question 9

Who is involved in chemotherapy/patient care (MDT)?

Answer 9

• medical team (medical + clinical oncologists, pathologists, radiologist)
• clinical nurse specialist (usually key worker)
• chemotherapy-trained nurses
• pharmacist
• dietician
• counsellor
• physio, OT
• complementary therapy team