Cancer therapeutic options + Flashcards
Prevention
- environment / behaviour change
- diet
- Screening
- genetics
- medication / vaccination
Treatment
- surgery
- radiotherapy
- systemic therapy
- immunotherapy
Diet
• evidence from cohort studies
- CRC : probably a link with red meat consumption
- breast cancer : probably a link with saturated fat intake
- physical activity decreases risk
• current advice:
- eat 5 or more portions of fruits and vegetables / day
- avoid obesity
- take regular exercise (30 minutes / day)
NoteL also of benefit for reducing cardiovascular risk
Screening
• high quality research evidence available
- Cervical cancer: smear tests
- Colorectal Cancer : Faecal Occult Blood the most commonly used test
- breast cancer : mammography
Note: FOB refers to blood in the faeces that is not visibly apparent.
• more controversial
- prostate cancer : PSA blood test
- lung cancer : MR / CT scanning
- breath test
Note: PSA test is a blood test that measures the amount of prostate specific antigen (PSA) in your blood. PSA is a protein produced by normal cells in the prostate and also by prostate cancer cells. It’s normal to have a small amount of PSA in your blood, and the amount rises as you get older and your prostate gets bigger.
Genetics
high quality research evidence available
CRC & familial adenomatous polyposis coli (FAP)
- autosomal dominant
- screen families for APC mutations
- regular colonoscopy
- offer panprotocolectomy when adenomas found
breast cancer & BRCA1 & BRCA2
Chemo-prevention
• more controversial
primary: oesophageal cancer
- high rates in parts of China
- supplement diet with anti-oxidants
primary: breast cancer
- known at risk women
- prophylactic tamoxifen
secondary: previous H&N or lung cancers
- give anti-oxidant supplements
- no benefit
Treatnent
local or regional treatment
- surgery
- radiotherapy
- ablation (freezing, radio-frequency, etc)
- isolated limb perfusion
systemic treatment
- hormonal therapy
- chemotherapy
- immunotherapy
- whole body irradiation (for BMT)
Staging
• Location of cancer?
- examination
- use of radiology / imaging
- CT , MRI, USS, PET etc
• Type?
- pathology / cytology
- classification, risk factors etc
- genomics now plays a role & will increase
- immune / stromal environment will also have a role
Surgery & radiotherapy
- both are ‘local’ therapies
- surgery needs anatomical clearance
- of cancers cured about 50% by surgery
Radiotherapy
- needs anatomical coverage
- can treat inoperable lesions
- can make surgery become possible
- of cancers cured ~40% by radiotherapy
- can be combined with chemotherapy
- important role in palliation (symptom relief)
5 R’s of radiobiology
- radiosensitivity-of cells
- repair-pathways
- re-population-of malignant cells
- re- oxygenation-of malignant cells
- re-assortment
Medical treatment
• systemic treatment
- beneficial for widespread disease
- can result in widespread toxicity
- of cancers cured ~ 3% by chemotherapy
- palliation in about 50% of cancers
- potential to be very specific!
- hormone therapy :
- targeted a tumour mutation :
Indications for use of cytotoxic drugs
- ‘curative’
- palliative - no cure, but enhanced quality of life
- adjuvant-risk of cancer coming back
- ‘neoadjuvant’ - given before surgery to shirnk cancer
Immune therapy
- ‘non specific’ / ‘innate’
- ‘specific’
- monoclonal antibodies
- programmed cell death pathway - uses immune system to attack ‘foreign’ cancer cells
- chimeric antigen receptor (CAR) T-cells- artificial T-cell receptors, using retroviral vectors to give a specific cell killing function directed against cancer cells
