Oncology Flashcards
What proportion of oncology patients say they never want to hear about palliative?
10%
What are 3 temporal models of
oncology/palliative integration?
- Sequential (“hand over”)
- Oncology-provided
- Concurrent
List 4 barriers to onco/pal cooperation
- Conflicting cultures of care
a. biomedical vs. patient-centred - Delays in referral
a. overoptimistic prognosis
b. fear of losing hope - Patient fear of abandonment
- Territoriality
Per ESMO, are oncologists taught
adequate palliative care?
42% say no
42% also disagree that their colleagues are skilled at it
Per ESMO, do oncologists routinely stay involved in patients’ EOL courses?
No–88% say they should
42% actually do
Per ESMO, what % of oncologists
believe they have no role in PC?
10-20%
What % of oncologists discussed no-treatment in one study?
50%
only 25% explained >1 sentence
What % of phase 1 trials
lead to tumour response?
<5%
What % of participants
understand the role of phase I trials?
<50%
What simple options can improve patient
understanding/satisfaction with MD visits?
audio recordings
lists of suggested questions
What are 7 features of cancer cells?
- Avoid apoptosis
- Resist aging process
- Replicate despite control mechanisms
- Dissolve connective tissue (MMPs)
- Angiogenesis
- Metastasis
- Avoid immune system
What are the 2 primary cell phases at which chemotherapy drugs can act?
S phase (DNA synthesis)
M phase (mitosis)
What are the two types of actions of
cytotoxic chemotherapy?
Phase specific (usu. S phase)
“Cycle”-specific (i.e. any dividing cell)
How can you improve efficacy of
phase-specific chemo?
Longer exposure (e.g. continuous infusions)
What is the role of breaks between
cycles of chemotherapy?
Normal cells have better DNA repair
- this allows rest of body time to heal
What are the 4 classes of chemotherapy mechanisms?
Alkylating agents
* platinums
* cyclophosphamide
Antibiotics
* bleomycin
* doxirubicin
Antimetabolic agents
* 5-FU
Plant alkaloids
List 4 cancers that can be cured
with chemotherapy alone
- Germ cell tumours
- Chorioncarcinoma
- Non/Hodkgin Lymphoma
- ALL
List 2 cancers resistant to chemotherapy
RCC
Endometrial ca
Describe the 3 phases of clinical trials
Phase I: dosing/toxicity
Phase II: finding where drug works
Phase III: assessing clinical benefits
What are the 4 outcomes assessed
when studying chemotherapy?
- Absolute survival time
- Time to disease recurrence
- Cancer response (total, >50%, <50%, none)
a. or at worst, growth - QOL
What is an alternative to transfusions
for chronic chemotherapy anemia?
EPO/darbopoetin
Target Hb >90
What is the usual neutrophil cutoff
for cytotoxic chemotherapy?
> 1.5
Which chemo agents are esp.
associated with alopecia?
Cyclophosphamide
-rubicins
-taxels
What agents are NOT associated
strongly w. marrow toxicity?
Gemcitabine
Vincristine
- all others have moderate to severe toxicity
Which chemo agents are associated
with renal failure?
Platinums, esp. cisplatin
What chemotherapy agents can cause cognitive impairment?
Methotrexate
Ifosfamide
Which agent can cause cerebellar problems?
5-FU
Which agents are associated
with peripheral neuropathy?
Methotrexate
Platinums
Taxols
Vin- (vinca alkaloids)
Which 2 drugs may cause
pulmonary toxicity?
Bleomycin
Methotrexate
Cyclophosphamide
- esp. w. XRT
- bleomycin dangerous with high-flow/hyperbaric O2
Which class of agents is most
associated with cardiotoxicity?
-rubicins, esp. doxirubicin
List some blood markers and their cancers
- CEA: colon ca
- CA 19-9: pancreatic ca
- CA 125: ovarian ca
- CA 15-3: breast ca
- PSA: prostate ca
- LDH: lymphoma
- AFP/HCG: Germ cell ca
- IGs: myeloma
What is aromatase?
Adrenal androgens → estrogen
- exists in fat, sexual organs
- exists in 70% of breast cas
List 3 aromatase inhibitors
Letrozole (protein, reversible)
Anastrozole (protein, reversible)
Exemestane (steroid, irreversible)
- some evidence that exemestane can help when patients progress on others
Which 2 hormones regulate testosterone?
LHRH → LH → testosterone
peripherally, testosterone → DHT
What is the primary site of action
for prostate ca hormone therapy?
Inhibiting GNRH
either drugs (e.g. goserelin) or castration
What are 2 peripheral testosterone-conversion inhibitors?
Bicalutamide
Enzalutamide
Cyproterone acetate
What is the role of tyrosine kinase?
Transmits signals from surface receptors into cell
What are the 2 most common sites of action of biological cancer treatment?
EGFR (epidermal growth factor receptor)
TK (tyrosine kinase)
What setting is hormone therapy for
breast cancer used first-line?
In non-life-threatening disease
i.e. no liver/lung mets
What is the role of hormone therapy
in life-threatening breast ca?
Adjuvant therapy following chemo
e.g. tamoxifen x 5 years
What is the typical response rate for first-line hormone monotherapy in breast ca?
30%
60% in well-selected patients
much lower as second-line treatment
What is the role of hormone therapy for breast ca in relapsed disease?
If < 1 year since tx, likely hormone resistant
If >1 year + on tamoxifen, aromatase inhibitor
If >1 year + done tamoxifen, restart tamoxifen
What 3 paraneoplastic syndromes
are associated with SCLC?
SIADH
ACTH secretion
myasthenia syndrome
What is the only curative tx
in non-small-cell lung ca?
Surgery (60% 5-year)
only true in early-stage disease, obvs
What % of NSCLC are metastatic at dx?
50%
What is the median survival of
un-tx stage IV NSCLC?
6 months
What % of cancers cannot have
a primary tumour identified?
3%
What % of cancers of unknown primary have a primary identified at autopsy?
66%
What are common primaries discovered
at autopsy for adenocarcinoma?
lung
pancreas
stomach
prostate
What are common primaries discovered
at autopsy for squamous carcinoma?
skin
ENT
esophagus
lung
What are common primaries discovered at autopsy for undifferentiated tumours?
germ cell
lymphoma
melanoma
neuroendocrine
What 3 ways does radiation directly
damage DNA?
single-strand breaks
double-strand breaks
base deletions
What is the mechanism of indirect DNA damage by radiation?
Splitting H2O → free radicals
(majority of XRT-induced DNA damage)
What 3 factors determine tumour radiosensitivity?
- Intact repair mechanisms (less in cancer)
- Perfusion (hypoxia → radioresistance)
- Rate/number of dividing cells (dividing tissues more sensitive)
After how many XRT fractions is the majority of tumour killed?
Why does this matter?
1-2
:. in palliative settings can get excellent effect from short XRT courses
More doses matter when aiming for cure
What 3 ways can radiation be given?
External beam
Brachytherapy
Systemic radioisotopes
List examples of radioisotope therapy
- Radium-223 for prostate metastases
- Strontium for bone mets
- Radioiodine for thyroid ca
- Iridium in hollow viscuses
a. uterus/vagina
b. esophagus/intestines
c. bronchi
At what rate to typical linear
accelerators generate radiation?
1 Gy/min
What is the mechanism of early RT toxicity?
Death of rapidly-dividing epithelium
→ mucositis
→ cystitis
→ gastritis/colitis
What is the mechanism of late RT toxicity?
Endothelial damage → radionecrosis
→ skin atrophy
→ bowel fibrosis or perforation
→ fistula formation
How do we define the maximum dose of XRT for a given tissue?
Dose at which late radiation damage is NOT expected to occur in a typical patient
What topical treatments need to be avoided for radiation-induced skin damage?
- Talc
- Gentian violet
- Creams with metallic salts
- can worsen reaction
Which 3 antinauseants are preferred
for radiation-induced nausea?
- Metoclopramide
- -setrons
- Steroids
What are tips for managing acute
radiation-induced diarrhea?
Avoid fruit sugars
Avoid fibre
Antidiarrheals
What are some tips for managing
radiation-induced cystitis?
Potassium citrate
Cranberry juice
a-blockers
Rule out infection
Systemic analgesia
How to prevent/manage radiation-induced
oropharyngeal mucositis?
- Chlorhexidine rinses regularly
- Preventative nystatin
- Dental hygiene with fluoride
- Reduce smoking (anything) + EtOH
Treatment:
- NSAID or ASA rinses
- Saliva replacement
What is the likelihood that 8Gy x 1 will improve a patient’s bone pain?
80% response rate
- most within 4 weeks
- small few more within 8 weeks
What is the likelihood that re-treatment with 8Gy x 1 will improve a patient’s bone pain?
80%
not predicted by initial response
What is the primary concern with radiation to the spine?
Late radiation myelitis, c. 6-9mo
Do large radiation fields offer more pain relief?
Mixed
- earlier onset (c. 7 vs. 21 days)
- at 4 weeks response equalises
- more toxicity with larger fields
What are 3 relative contraindications
for systemic radioisotope therapy?
- Incontinent of urine (req. catheter)
- Renal failure
- Pre-existing marrow failure
all radioisotopes are renally cleared
What is the role of XRT in preventing bone mets?
Limited–it works but risk:benefit poor
Where do SCCs happen in the spine?
- C-spine: 20%
- T-spine: 70%
- L/S-spine: 30%
If clinical picture consistent with SCC but MRI remains negative, what is the next test?
Lumbar puncture to r/o leptomeningeal dz
What 3 cancers make up ⅔ of spinal cord compressions?
Breast
Prostate
Lung
What % of patients who present ambulatory
remain ambulatory after SCC treatment?
80%
What % of patients who present paraparetic
regain walking after SCC treatment?
20-40%
Which SCC-causing cancers respond best
to radiation?
myeloma + lymphoma
>
breast
>
lung
What % of cancers will met. to brain?
10%
Most will be multifocal
What proportion of patients with multifocal brain mets respond to whole-brain RT?
80% see some neurological improvement
20% will not finish tx 2* decline
What are positive prognostic features in patients treated with RT for brain mets?
- Brain as first or only site of relapse
- Brain primary
- Long disease-free interval
- ECOG 0-1
- <60yo
What are negative prognostic factors in patients treated with RT for brain mets?
- 2+ lobes involved
- meningeal mets
- extracranial mets
- poor performance status
- advanced age
Which 1* brain tumours are potentially curable?
- Meningioma
- oligodendroglioma
- Astrocytoma, grade I-II
- Ependymoma
What are typical presenting sx
of meningeal carcinomatosis?
- Multilevel spinal symptoms
- Multiple facial nerve palsies
- Sx of increased ICP
Which cancers like the meninges?
- Breast
- Lung
- CNS lymphoma
What is the prognostic sig. of
meningeal metastases in solid tumours?
Grim–short weeks median survival
with intensive tx, short months
What are expected response rates
to XRT for malignant neuropathic pain?
55% any response
25% total response
What part of the eye do cancers met to?
Choroid plexus
(bresst/lung are 80%)
Which 2 eye structures are vulnerable
to radiation damage?
Cornea (keratitis)
Lens (delayed cataract)
Which two cancers cause SVCO?
Primary lung (75%)
Mediastinal lymphoma (15%)
Which vein marks the line where SVCO tends to be more severe?
Above/below azygous v
Is SVCO an emergency?
Not usually–take the time to identify the causative tumour to allow targeted treatment
Which SVCO-causing tumours respond
best to chemotherapy?
- Lymphomas (NHL/Hodkgin)
- Germ-cell tumours
- Small-cell lung ca
Which SCVO-causing tumour
responds best to RT?
Non-small-cell lung
accounts for basically all other SVCOs
Describe approach to brachytherapy
in a hollow organ
- Endoscopic localisation of lesion
- Insertion of hollow plastic tube at desired site of treatment
- Insertion of radioactive source into tube to be held near lesion for a short period
Can be done as an outpatient procedure
What is the most common malignant cause of dysphagia?
Tumour in the esophagus (⅘)
What proportion of malignant cases of
dysphagia respond to XRT?
80%, persistent at 6mo
What is the response rate to RT
for malignant hemoptysis in 1* lung ca?
80%
What is the response rate to RT
for malignant hemoptysis in lung mets?
Minimal unless you can identify a specific site of bleeding on bronchoscopy to target
What are non-tumour causes of hematuria in cancer patieints?
- Cyclophosphamide s/e
- Delayed radiation response
- Thromboytopenia
Which two organs are particularly
radiosensitive, even at low doses?
Kidney
Liver
Which GI organs are harder to radiate?
Stomach
small intestine
- more mobile
- stomach near liver, kidneys
- small intestine ++ symptomatic to tx
Why may it be OK to oversaturate the chest wall with RT in breast cancer recurrence?
Fungating tumours are worse than late radiation damage
Which organ is exquisitely sensitive to RT
when infiltrated by cancer?
Splenic lymphoma/leukemia
- high risk of TLS
- treated with 1Gy weekly or less
