Oncology Flashcards
How to approach the cancer patient client?
Compassionate Facts and evidence not opinions Knowledgable Honest Communication
What is cancer?
Persistent purposeless proliferation of host cells malignant tumour
Define Tumour Neoplasia Malignant Benign Metstasis Oncology
Tumour-a swelling
Neoplasia- a new growth
Malignant-Neoplasm with the capacity for local invasion and metastasis
Benign- Neoplasm forms solid cohesive tumour that does not metastasises
metastatic- development of a tumour remote from the primary tumour
Oncology-the study of any of the above
Nomenclature tumours are described according to two features
Benign Oma Malignant carcinoma sarcoma Tissue origin Epithelial Squamous, glandular (adenoma) Mesenchymal Fibro Lipo Haemangio Osteo Lymphoma
Discuss the characteristics of a benign tumour
Non invasive into local tissue No metastasis Capsulated Slow rate of growth Minimal effects on adjacent tissues Minimal effects on host(depends on anatomical location) Pareneoplastic effects can occur
Discuss the characteristics of a malignant tumour
Rapid growth Invades local tissue Metastasis occurs Effects local tissues (ulceration lysis of bone) Life threatening distrust give nature Paraneoplastic effects possible
When is a tumour detectable?
1cm in diameter already done the majority of its growing by that point. Not as susceptible to drugs when not rapidly dividing
Describe the two clinically important features of cancer
Effect on the host
Effects of cancer treatment on the host
What is metastatic potential and describe how it may take place?
The ability to spread to distant tissues.
Via the blood (liver and lungs)
Via the lymphatics ( first to local then regional lymph nodes)
Transcoelomic across pleural or peritoneal space
Iatrogenic FNA or tru cut biopsy bleeding
What characteristics grade a tumour?
Growth rate, ability to metastasise, location is it close to lymph nodes, location, cellular and nuclear characteristics
What are paraneoplastic effects?
The production of physiological substances that effect distant organs
Name the four types of paraneoplastic effects and describe each of them
Haematological
Non regenerative anaemia
Leukopenia
Thrombocytopenia
Hyperhistaminaemia Mast cell tumours release histamine, heparin, pro teases when handled Local effects-swelling pruritus Localised bleeding(heparin) Delayed wound healing (proteases) Systemic effects-anaphylactic shock Gastroduodeanl ulceration
Immune mediated reactions
iMHA ITP(immune mediated thrombocytopenia)
Neuropathies and myasthenia graves
Skin disease
Hypercalcemia
Parathormone-like substance increases calcium concentrations
Tumours that cause these include-lymphosarcoma, anal sac adenocarcinoma, multiple myleoma
What are the aims of diagnostic investigations?
Grade tumour and type (histological)
Has it spread where to how far
Treat and investigate tumour related or concurrent complications
Inflated radiographs should be taken to rule out lunge metastasis
Why is microspoci evaluation so important?
Do not know the diagnosis of malignant or begnin, or type of tumour until evaluation using this method
What are the three possible aims of cancer treatment?
Cure-all cancer cells eradicated
Remission-more achievable all clinical evidence of cancer gonesome cancer cells remain
Palliative- reduce pain/improve sense of wellbeing and correct physiological malfunction
What are the three main methods of cancer treatment and what do they involve?
Surgical complete removal of the tumour or debulking(encourages proliferation)
Radiation two types Brachytherapy- radioactive substance emits gamma or beta particles directly next to the tumour
Teletherapy- applied externally beam directed at tissue either from fixed radioactive source or linear accelerator
Chemotherapy- cytotoxic drugs kill cancer cells
Best methods often use a combination
What are the main principles of chemotherapy?
Highest possible dose that has the maximal acceptable side effects to effect maximum fraction.
Repeated dosing as will not kill all cancer cells on first does
Institute treatment when tumour burger is lowered
Unlikely to be effective in advanced disease
Combination chemotherapy is more effective
Name the types of alkylating agents and there mode of action
Cyclophosphamide chlorambucil melphalan
Cross link DNA stop jreplication
Name the types of anti-metabolites and their mode of actions
Cytarabine 5-Fluorouracil Methotrexate Azathioprine
Stop single stranded DNA from replication
Anti-tumour antibiotics (chemotherapy)
Doxorubicin Epirubicin
Name the types of Vinca alkaloids and describe their mode of action
Vincristine Vinblastine
Interfere with microtubules during division
Name the types of tyrosine kinase inhibitors
Martinib Torecarnib
Platinum compounds (chemotherapy)
Cisplatin Carboplatin act at cell surface receptors to block signals
Enzymes (chemotherapy)
L-asaraginase damages DNA
Response to chemotherapy depends on two factors?
Growth rate and drug resistance
WHich tumours are responsive to chemotherapy?
Lymphoma myeloma leukaemia
Moderately sensitive- scar I as mast cell tumours
Poorly sensitive- carcniomas melanomas sarcomas slow growing
How is dosing calculated for chemotherapy?
Calculated using surface area rather than weight as dosing is very sensitive
What is the time period between chemotherapy dosing and why is it set this way
3 weekly treatment cycles as myleosupression lasts for 7-10 days with recovery at 21 days
What are the three phases of the chemotherapy protocol dedcribe the aims of each of them
Induction-reduce tumour burden to undetectable levels, very rarely a cure
Maintenanc- less intensive regime to maintain remission (debatable)
Rescue- resources to more aggressive chemotherapy regime
When is first line chemotherapy used?
Rapidly dividing cancers
Lymphosarcoma
Leukemia
Systemic cancers
What types of combination chemotherapy regimes used for lymphosarcoma?
COP Cyclophosphamide Vincristine Predinsalone CHOP Cyclophosphamide Doxorubicin Vincristine Prednisalone
Side effects of chemotherapy?
Effects normal tissues with high turnover skin intestine bone marrow
GI chemotherapy toxicity; how is it treated?
Antiemetics iv fluids
Gastroprotectants Chlorhexidine mouth wash
Parental antibiotics if haemorrhaging diarrhoea and myleosupressed
Phlebitis and tissue necrosis and perivascualr leakage treatment chemotherapy
Adequate restraint of patient, administration through iv catheter and flushing with saline before and after Perivascular leakage: Stop infusion(do not remove catheter) Aspirate drug give intralesional saline Draw back blood then remove catheter Iv hydrocortisone Cold compress Dexarazoxane (specific antidote for doxorubicin)
Name the specific drug toxicities generate from cyclophosphamide Doxorubicin
Cisplatin, carboplatin
Cyclophosphamide Sterile haemorrhagic cystitis Doxorubicin Cardiotoxicity (cumulative dose) Cisplatin carboplatin nephrotoxicity
What is the response to chemotherapy like for lymphosarcoma?
High growth rate no plateau very susceptible to chemotherapy
Resistance may develop
Smaller percentage of cats respond than dogs
Treatment options for canine multicenteric lymphoscarcoma
No treatment-live 4-6 weeks
Palliative prednisalone-may induce partial or complete remission 2-3 months may induce resistance
Prednisalone and cyclophosphamide
No survival advantage over pred alone
Single agent- doxorubicin every 3 weeks similar 6-12 month survival
Multi drug chemotherapy COP CHOP 6-12 months depending on protocol
What does rescue of lymphosarcoma entail?
Repeating induction regime use of additional agents not used during induction
Use of rescue protocols with novel cytotoxic
What happens when resistance occurs in lymphosarcoma chemo treatment?
All cases patient will come out of remission and is resistant to all treatment
Euthanasia
