Oncology Flashcards
Give 5 examples of inherited conditions that can cause cancer?
- neurofibromatosis (6+ cafe au lait spots)
- adenomatous polyposis coli
- Von Hippel Lindau syndrome
- Li Fraumeni syndrome (mutation in p53)
- BRCA 1 and 2
How can chemicals cause cancer?
damage cellular DNA and produce mutations in oncogenes and tumour suppressor genes
which type of cancer can vinyl chloride cause?
angiosarcomas
which type of cancer does benzene cause?
leukaemia
Which type of cancer do aromatic amines cause?
bladder
which type of cancer does wood dust cause?
nasal adenocarcinoma
How does radiation cause cancer?
increases DNA damage leading to the accumulation of mutations in tumour suppressor and oncogenes
How does HPV cause cancer?
produces E6 which inctivates p53
which types of cancer does HPV cause?
- cervical
- anal
- oropharyngeal
Which two strains of HPV are the cancerous ones?
- 16 and 18
which type of cancer can EBV cause?
non-hodgkins lymphoma
Which type of cancer is hCG (as a tumour marker) raised in?
Testicular
non-seminomatous testicular cancer
seminoma
Which benign conditions can lead to a raise in PSA?
- BPH
- rectal exam
- prostatitis
- UTI
what is the common clinical use of carcinoemryonic antigen (CEA) tumour marker?
i.e. which cancer?
colorectal cancer
Which conditions is CA125 raised in?
- ovarian cancer
- pregnancy
- pancreatic ca
- lung cancer
- colorectal cancer
- breast cancer
- endometriosis
- PID
which cancer is AFP raised in?
Hepatocellular carcinoma
For staging cancer which 2 areas do you use CT for and which 4 areas do you use MRI for?
CT:
- chest
- abdomen
MRI
- bone
- soft tissue
- pelvis
- posterior cranial fossa
Using imaging- what is the definition of a partial response to treatment?
all lesions shrunk by >= 30%
disease is still present
Using imaging- what is the definition of stable disease?
<20% increase in size OR
<30% decrease in size
Using imaging- what is the definition of progressive disease?
new lesions
lesions increased in size by >20%
what is CT/ what images does it take?
- rotating x-ray tube
- axial cross-sectional images
What is the principle concern with CT?
the dose of radiation
MRI is the golf standard for which 4 types of tumours (locations)?
- neurospinal tumours
- rectal tumours
- prostate tumours
- MSK tumours
What is the principle concern with MRI?
- magnetic field
- therefore check pacemakers, metal in body, equipment in the area
What is ultrasound/ how does it work?
high frequency sound waves
give 4 uses of ultrasound in cancer care?
- detecting mets in solid visceral abdo organs
- doppler–> assess tumour blood flow
- soft tissue
- guidance of biopsies and procedures
What is the principle behind bone scintography and what is it most commonly used for?
- radioisotope labelled drugs given IV
- main investigation for skeletal mets
What type of images do PET scans produce and what tracer is commonly used?
- produces functional images
- tracer used in FDG-18 ( fluorine 18 deoxyglucose)
- PET has potential to differentiate between malignant and benign pathologies
- PET usually combined with CT to map functional images to detailed anatomy
4 advantages to screening programmes?
- reduction of mortality
- less radical treatment ( decreases morbidity)
- saving health resources by increased cure rates
- reassurance given by a negative test
6 disadvantages to screening programmes?
- increased anxiety if no effective intervention possible
- over investigation of false positive cases
- over treatment of borderline cases
- false reassurance from a false negative
- possible harmful side effects of the screening test
- cost of screening a large population
for which 3 cancers are there screening programmes in place?
- cervical
- breast
- colorectal
What is the current cervical cancer screening programme?
- cervical smears for all women between 25-64
- every 3 years for women 25-49
- every 5 years for women 50-64
What is the current breast cancer screening programme?
- mammogram every 3 years for women aged 50-70
- screen younger patients if high risk e.g. FHx
What is the current colorectal cancer screening programme?
- foecal occult blood (FOB) every 2 years 60-69
- 69-74 can request screening kit
- high risk patients reviewed regularly e.g. UC
is there a screening programme for prostate cancer?
- no
- but informed choice programme with PSA
4 different types of biopsy that can be done to diagnose cancer?
- fine needle aspiration cytology
- tru-cut needle biopsy (under local)
- incisional biopsy
- excisional biopsy
what is cytoreductive surgery?
reducing the bulk of the disease
What is radiation? when is it used?
- use of ionising radiation in the management of cancer
- has curative potential in the absence of mets
- can be used in a neo-adjuvant, adjuvant or palliative setting
how is radiotherapy delivered most commonly in UK?
- external beam radiotherapy
- using photons/ x-rays
- 3D conformal radiotherapy ( individual tumour mapping to target the tumour)
What are the units of radiotherapy?
- gray units (Gy)
- given in small fractions rather than a large single dose
What is the mechanism of action of radiotherapy? (4 steps)
- high energy short wavelength X-rays by a linear accelerator
- X-rays penetrate deep into body tissue (sparing overlying skin)
- X-rays produce secondary electrons and free radicals (cause DNA damage)
- cancer cells defective at repair–> mitotic or apoptotic cell death
What 3 things does the success vs toxicity of radiotherapy depend on?
- treatment issues ( total dose, total volume, overall treatment time)
- co-morbidities (diabetes, IBD, smoking)
- radio-sensitivity of the cancer
What three measurements are taken during a planning CT for tumour mapping before radiotherapy?
- Gross tumour volume (GTV)
- Clinical target volume (CTV)
- Planning target volume (PTV)
What is the gross tumour volume?
- The tumour is delineated on each CT slice it appears on
- so the tumour on each CT slice
What is clinical target volume?
- added margins to allow for microscopic disease spread
What is the planning target volume?
- a further margin is added to allow for daily variations in patient and tumour position
Is radiotherapy safe in pregnancy?
NO
it is teratogenic
When do the acute side effects of radiotherapy usually develop?
- during treatment
- usually after the first 5-10 fractions
Why do you get the acute side effects of radiotherapy?
- due to damage of normal tissue and the ability of normal cells to repair damage
- therefore usually completely resolve once treatment has finished
3 examples of acute side effects of radiotherapy?
- localised skin reaction
- oral mucositis
- diarrhoea
When do the late side effects of radiotherapy usually develop and are they reversible?
- usually develop at least 3 months after radiotherapy (can be longer)
- often irreversible and may get worse over time
Why do the late side effects of radiotherapy occur?
- some of the damage to normal cells cannot be repaired
- partly due to development of fibrosis and blood vessel damage within the irradiated tissue
what are 4 examples of late side effects of radiotherapy?
- lung fibrosis
- skin atrophy
- infertility
- risk of second malignany
- radiotherapy itself is carcinogenic
- risk is significantly greater in younger patients
What is brachytherapy?
- radiation sources placed within or close to tumour
- localised high dose (intercavity or interstitial)
- prostate, gynae, oesophageal, head and neck
- patient is radioactive (risk to others)
What is chemotherapy?
- systemic treatment of cancer using cytotoxic agents
What is the MOA of chemotherapy?
- most target DNA indirectly or directly
- agents are preferentially toxic towards actively proliferating cells
- thus rapidly dividing tumours respond best
7 indications/ settings of chemotherapy?
- radical- curative intent
- primary- alone for cure
- neo-adjuvant
- adjuvant
- chemoradiation
- palliative
- high dose- with bone marrow transplant for stem cell support
What does the term ‘cycle’ mean in chemotherapy?
e.g. docetaxel IV day 1 every 21 days
What does the term ‘course’ mean in chemotherapy?
the planned number of cycles
How do you calculate the dose for chemotherapy?
- using body surface area most commonly
- DuBois formula
- also according to renal function
immediate side effects of chemotherapy?
- nausea and vomiting
- myelosuppression
- diarrhoea and constipation
- alopecia
- ototoxicity
- neuropathy
- nephrotoxicity
- arrhythmia
- transient rise in LFTs
- skin changes (pigmentation)
- lethargy
- myalgia
long term complications of chemotherapy?
- second malignancies
- reduced fertility
- pulmonary fibrosis
- cardiac fibrosis
What is the definition of neutropenic sepsis?
- absolute neutrophil count of <1 x10 9 /L
AND
- single temperature over 38.5 OR
- sustained temperature over 38 OR
- clinical signs
How many days post chemo is neutropenic sepsis more common?
7-14 days post chemo
Which examinations should you avoid in a person with suspected neutropenic sepsis?
- rectal
- vaginal
Investigations for a person with suspected neutropenic sepsis?
- BUFALO
- FBC, U and Es, LFTs
- paired blood cultures (x2 anaerobes and aerobes, culture all lines or if no lines –> 2 peripheral cultures)
- swabs
- sputum culture
- urinalysis and MSU
- stool analysis and culture
- CXR if respiratory signs (? atypical pneumonia serology)
Which type of organism is more likely to cause neutropenic sepsis (70%)?
Gram positive
Give three examples of gram positive organisms that may cause neutropenic sepsis?
- staph aureus
- coagulase negative staph
- alpha and beta haemolytic strep
What is the management of neutropenic sepsis?
Broad spec antibiotics (trust guidelines) within 1 hr
- e.g. tazocin (tazobactam and piperacillin)
- continue until afebrile for 72 hours OR
- 5 days course and neutrophils >0.5 x 10 9
What is the MASCC score?
a scoring system for identifying low-risk (of complications) cancer patients with febrile neutropenia
Which 5 cancers are more commonly associated with metastatic cord compression?
- prostate
- breast
- lung
- myeloma
- lymphoma
Which region of the spinal cord does metastatic cord compression most commonly affect?
2/3 in the thoracic spine
Presentation of MSCC?
- back pain (alone in 90%)
- leg weakness
- sensory loss
- bowel/bladder dysfunction (incontinence or retention)
- saddle anaesthesia
- loss of anal tone
Management of metastatic spinal cord compression?
- lie flat
- 16mg dexamethasone (PPI cover)
- urgent MRI full spine within 24hrs
- contact local spinal cord co-ordinator
- consider neurological intervention
- ? radiotherapy
3 broad causes of superior vena cava obstruction?
- extrinsic compression
- thrombosis
- invasion
What is the most common cause of SVCO and by which two types of cancer?
- extensive lymphadenopathy in upper mediastinum
- lung and lymphoma
5 benign causes of SVCO?
- goitre
- mediastinal fibrosis
- infection (TB)
- aortic aneurysm
- thrombus
Presentation of SVCO?
- breathlessness
- headache - worse on coughing, “fullness”
- facial/ neck/ arm swelling
- distended neck and chest veins
- cyanosis
- visual disturbance
Investigations for SVCO?
- CXR
- contrast CT
- consider: tumour markers, bronchoscopy, OGD (if oesophageal cancer suspected, biopsy)
Management of SVCO?
- 16mg dexamethasone (PPI cover)
- depending on the cause (stenting under radiological guidance, radiotherapy, chemotherapy, LMWH if thrombosis)
why do you get hypercalcaemia in cancer?
- cancer of bones or bone mets
- due to an imbalance between bone resorption and calcium excretion
What is the most common cause of hypercalcaemia (before cancer)?
primary hyperparathyroidism
Cancers that cause hypercalcaemia?
- NSCLC
- breast
- prostate
- renal cell carcinoma
- myeloma/ lymphoma
Key investigation for hypercalcaemia?
- serum calcium
- CORRECTED FOR SERUM ALBUMIN
Presentation of hypercalcaemia?
General
- dehydration
- weakness
- fatigue
- bone pain
CNS
- confusion
- seizures
- proximal neuropathy
- hyporeflexia
- coma
GI
- weight loss
- N and V
- abdo pain
- constipation
- ileus
- dyspepsia
