Cancer Care - Cancer Management

Question 1

Chemotherapy

Pathophysiology
Classes of Cytotoxic Chemotherapy
Indications for Chemotherapy
Prescribing Chemotherapy

Answer 1

1. ) Pathophysiology - systemic drug therapy used to kill cancer cells by causing lethal cytotoxicity or apoptosis
   - traditional chemo target rapidly dividing cells so they also kill normal cells e.g. GI tract, bone marrow, hair
   - targeted therapies are more precise as they target specific molecules and receptors e.g. monoclonal antibodies and protein kinase inhibitors (e.g. imatinib)
   - hormonal therapies are used in hormone-dependent cancers of the breast and prostate
2. ) Classes of Cytotoxic Chemotherapy - attack DNA by interfering with cell division or metabolism
   - alkylating agents: cisplatin, cyclophosphamide
   - antimetabolites: methotrexate, 5-fluorouracil
   - cytotoxic antibodies: doxorubicin, bleomycin
   - plant derivatives: docetaxel, vincristine
3. ) Indications for Chemotherapy
   - neoadjuvant, adjuvant, palliative (sx control, ↑QoL )
   - induction: of remission for disseminated disease
   - ‍maintenance: lower doses to prolong remission
4. ) Prescribing Chemotherapy - by medical oncologist
   - must take into account patient factors (age, co-morbidities), tumour factors (stage, tumour type), and treatment factors (associated morbidities w/ chemo)
   - consist of single or multiple drugs used in combo
   - dosing based off the patient’s body surface area
   - often given in multiple cycles to kill as many cancer cells as possible and allow for recovery in between
   - regimens are shorter when there is curative intent and can be longer when there is palliative intent

Question 2

Side Effects of Chemotherapy

Nausea and Vomiting
Neutropenia 
Alopecia 
Oral Mucositis
Weight Loss
Peripheral Neuropathy
Infertility
Secondary Cancer

Answer 2

1. ) Nausea and Vomiting - affects 70-80% of patients
   - associated with traditional systemic agents
   - onset: acute (within a few hours), delayed (>24 hrs), anticipatory (conditioned response before treatment)
   - non-pharmacologic Mx: smaller meals, dry starchy foods, behavioural therapy for anticipatory vomiting, avoiding vestibular stimulation by resting, sleep
   - Dx: ondansetron, aprepitant, dexamethasone, metoclopramide, olanzapine
2. ) Neutropenia - due to myelosuppression
   - typically associated with traditional systemic agents
   - definition: neutrophil count <1.5, <0.5 if severe
   - Mx: consider g-CSF as prophylaxis in high-intensity chemo, Abx in neutropenic sepsis
3. ) Alopecia - onset usually 7-10 days after chemo
   - typically associated with traditional systemic agents
   - Mx: wigs, shave remaining hair from head, reassurance as it will grow back
4. ) Oral Mucositis - acute inflammation or ulceration of the oral or oropharyngeal mucosal membranes
   - pain and discomfort can affect eating, swallowing
   - increased risk in combined chemo and radiotherapy
   - can be worsened by drugs that lead to a dry mouth
   - should complete major dental work before chemo
   - non-pharmacological Mx: ↑fluid intake, avoid spicy or acidic foods, alcohol, cigarette smoking, maintain good oral hygiene, chewing gum, cryotherapy (ice chips, popsicles)
   - Dx: mouth rinses with normal saline, ‘magic mouthwash’, lidocaine mouthwash, benzydamine hydrochloride mouthwash or spray, avoid alcohol containing mouthwashes
5. ) Weight Loss
   - poor nutrition due to N+V, anorexia, change in taste
   - cachexia: hypercatabolic state leading to weight loss despite nutritional supplementation may occur in 80% of patients with advanced cancer
6. ) Others
   - peripheral neuropathy: symmetric distal “stocking and glove” distribution, ↑incidence w/ vincristine
   - infertility: counselling, offer sperm/egg harvest and storage, counselling females on contraception
   - secondary cancer: most commonly leukaemia (AML) and myelodysplastic syndromes

Question 3

Radiotherapy

Pathophysiology
Side Effects
Brachytherapy

Answer 3

1. ) Pathophysiology - lasers emitting gamma radiation are fired at the tumour to damage cells, angled to avoid heathy tissues as much as possible
   - can be used w/ radiosensitisers: chemo which stimulates the uptake of radiation into targeted tissues
   - can be adjuvant, neoadjuvant, curative (low grey high fractions), palliative (high grey, low fractions/at once)
2. ) Side Effects - localised and depends on the area
   - skin: radiation dermatitis, pigmentation, necrosis, telangiectasia, ulceration, moist desquamation
   - H+N: alopecia, xerostomia, oral mucositis, loss of taste, thick/sticky saliva, sore throat, dysphagia, osteonecrosis of the mandible, hypothyroidism, hypopituitarism,
   - cardio/resp: pneumonitis, pulmonary fibrosis, cardiomyopathy, pericardial fibrosis
   - GI/GU: radiation cystitis, diarrhoea, bowel strictures or adhesions, impotence, infertility, menopause
   - lymph nodes: can cause lymphoedema
   - general: fatigue, N+V, myelosuppression
   - secondary cancer: often leukaemia

4.) Brachytherapy - localised internal radiation therapy, can be temporary, permanent (long half-life) or systemic (radioactive iodine for thyroid disease)

Question 4

Common Side Effects of Immunotherapy

Digestive System
Endocrine System
MSK 
Respiratory System
Skin

Answer 4

1. ) Digestive System
   - colitis: abdo pain, diarrhoea, black or bloody stools
   - mild hepatitis
2. ) Endocrine System - inflammation
   - pituitary gland: headaches and fatigue
   - adrenal gland: fatigue, muscle weakness, loss of appetite, weight loss, and abdominal pain
   - thyroid gland: hypothyroidism or hyperthyroidism
   - pancreatitis: severe abdominal pain, N+V

3.) MSK - joint and muscle (myositis) inflammation can cause pain and weakness

4. ) Respiratory System
   - pneumonitis: SOB, cough
5. ) Skin
   - rashes, itchy skin, blisters, and sores