Oncology - General Flashcards
Neo-adjuvant Chemo - Indications
Pre-operative
Make tumour smaller to decrease extent of surgery
Minimise occult metastasis
Primary Chemo
Initial treatment if unoperable tumour
Adjuvant
Following surgery
Treat occult mets
Adjuvant - Used for what cancers?
Breast
Colorectal
Palliative
Alleviation of symptoms, no intention of cure
Curative - What cancers?
Germ cell
Hodgkins
Non-hodgkins
Prophylactic Example
Tamoxifen for in situ breast cancer
Three Principles of Chemo Combo Therapy
- Different classes have different actions: synergism
- less chance of drug resistance
- Dose maintained due to differing toxicities in different drugs
Chemo - Cycles
Every 3-4 weeks
Allows recovery of normal cells e.g. stem cells and GI tract
Chemo - Treatment length
Max effectiveness = 6 months
Then resistance and increased toxicity
Conventional Dose - Involves?
Outpatient setting, tolerable side effects
Use drug known to be toxic against specific Ca
High Dose - Involves?
May need support e.g. bone marrow rescue
Justified if high chance of cure
High Dose - Curative?
Hodgkin’s Disease
Ewing’s sarcoma
Maintenance Chemo?
Only if good evidence
e.g. childhood leukaemia - for 18 months following remission
Chemo - Oral Route
No hospital
Reduced toxicity
Only certain drugs
Chemo - Oral Drugs
Cyclophosphamide
Tamoxifen
Chemo - IV route
Majority
By infusion bolus
Lines - Central, tunnelled (PICC)
Chemo - Regional examples
Intravesical - bladder Ca
Intraperitoneal - transcolaemic e.g. ovarian
Intra-arterial e.g. hepatic artery for liver mets
Chemo - Dose calculation
Dubois and Dubois Surface area calculation
Carboplatin from renal function!
Radiotherapy - Dose
Unit Gray (Gy) Increased dose if radical treatment
Radiotherapy - Factors affecting success
- Treatment dose/total volume/overall treatment time
- Comorbitities (diabetes IBD)
- Radiosensitivity of tumour (Seminoma and hodgekins = very sensative)
Delivery - GTV
Gross tumour volume
- Directly attacked
Delivery - CTV
Clinical target volume
allows margin for microspread of tumour
Delivery - PTV
Planned target volume
allows margin for patient movement
RT - Total target area
Gross + Clinical + Planned target volume
RT - Side Effects (Acute)
After 5-10 treatments, peaks following completion
Reversible but require management
E.g.
- Oral mucositosis
- Diarrhoea
- Local skin reaction (can be v. severe)
RT - Side Effects (Chronic)
More than 3 months after course ends, maybe years
- irreversible and progressive
E.g.
- Lung fibrosis
- Skin atrophy
- Infertility
RT - Malignancy Risk
Increased risk if good prognosis Ca, as higher dose given
Breast cancer = 4 in 10000 Ca after RT
RT - In pregnancy?
Teratogenic, avoid!
Bracytherapy
- Intracavity
- Uterus/cervix - Interstitial
- Prostate, into tumour directly
Radioisotopes
Radioactive iodine, thyroid Ca
- Selective to thyroid
- Must stay in lead room for protection of others
Markers - CEA
Colorectal
Increased in
- Smokers, IBD, Hepatitis, Pancreatitis, Gastritis
Markers - Ca-125
Ovarian Ca (82% will have high)
Raised in pancreatic, lung, colorectal and breast Ca.
Markers - AFP
High in teratoma, hepatocellular Ca
- usually undetectable after age of 12 months
Markers - bHCG
Non-seminomatous Ca
Markers - PSA
Prostate Ca and BPH,
may rise in DRE, UTI etc.
Can be used to monitor response to treatment
RECIST - Treatment response on imaging
CR - Complete response (no tumour seen)
PR - Partial (shrunk by >30%)
SR - Stable (increase <20, Decrease less than 30%)
PD - Progressive >20% increase or new lesions
