Cancer therapy and side effects Flashcards
Which type of cancers have available screening programmes and who is eligible for them?
Cervical cancer
Smear tests are offered every three years to females between the ages of 25-49 and every 5 years to those between the ages of 50-64.
Breast cancer
Mammograms are offered every 3 years to females from 50-71 years.
Bowel cancer
Males and females aged between 60-74 years are sent a home test kit every 2 years to collect feces for testing.
What are some of the patient factors that would help you decide which route and regime of treatment is most appropriate?
Age of the patient
Previous treatment
Other conditions or medications they are taking (Diabetes, monitoring blood glucose levels)
Health and fitness status of the patient (Pregnant)
Hepatic and renal conditions
Performance status (0-5), 4 not well enough to be treated, 2 or 3 dose needs to be adjusted
Polypharmacy and drug interactions
What are some of the cancer factors that would help you decide which route and regime of treatment is most appropriate?
Location of the tumor (is it operable)
Size of the tumour
Type of tumour (sub-class)
Grading of the tumour (has it metastasized)
What are some of the factors that determine patient specific dosing and examples?
Body surface area (mg/m2) classic chemotherapies
Dosing per weight (mg/kg)
Flat dosing (standard dose for all) lot of newer drugs
Dose adjustment according to renal function
Entirely determined by renal function (Carboplatin)
When are you able to have chemotherapy at home?
- If you are prescribed capsules of tablets to take (Tamoxifen for breast cancer, prescribed for 5 or 10 years)
-If your hospital has home-care chemotherapy nurses
-Low dose, continuous (24 hr) chemotherapy that can be given in a pressure pump
How is chemotherapy normally administered in a day centre?
If the chemotherapy is to be administrated intravenously.
Can be given via:
Cannula
Central line
PICC (peripherally inserted central catheter)
Portacath or port- (chamber at the end of the central line)
What is a PICC line?
Peripherally inserted central catheter, consists of a long, thin, hollow, tube which is inserted into the arm and then to where the tumour is or was, so it is a bit more targeted treatment.
What are some of the issues that can arise with a PICC line?
May get an infection
Blood clot can develop
The line can split
Line can become blocked
How are some of the problems associated with a PICC line overcome?
After administration of the chemotherapy, the lines are often rinsed with water to ensure the line isn’t blocked and all the drug has been administered.
The line is washed every week or so with a saline rinse to prevent an infection developing
Line is also rinsed with heparin (anti-clotting agent) to prevent a blood clot.
When do you have to stay in hospital with chemotherapy?
Doctor wants to monitor you in case of a reaction developing
You require fluids before or after the treatment via a drip
The drug needs to be administered in a slow, controlled way
The drug needs to be administered a number of times a day for a couple of days in a row
Aside from cancer cells, which other cells does chemotherapy drugs target?
Chemotherapeutic drugs are non-specific and target cells with a high turnover rate which aside from cancer cells include:
Hair follicles (resulting in hair loss)
Blood cells in the bone marrow (resulting in anaemia, increased bruising and bleeding, more prone to infection)
Reproductive cells (infertility)
Cells in the digestive tract
What does the two week wait refer to in cancer treatment?
In the UK, two week wait means that anybody who has presented symptoms that could be indicative of cancer are seen within two weeks by a specialist to be checked over, confirm diagnosis or discharged.
What are some of the scans used to confirm the diagnosis of cancer?
Scans including:
MRI
X-ray
PET-scan
Ultrasounds
Bone scan
CT-scans
Aside from scans which additional tests are used to diagnose cancer?
Biopsy (piece of abnormal is taken are examined by a pathologist)
Tumour marker tests
Sputum cytology
Blood chemistry tests
Full blood count (white, red and platelets)
Cytogenic analysis (looking for changes in chromosomes)
Immunophenotyping (using antibodies to identify antigens on cell-surface)
Liquid biopsy
Urinalysis (describes the colour of urine, contents in urine)
Urine cytology (looking for traces of cancer cells shed from the urinary tract)
Why is histology so important?
Analysing genes to determine the type of cancer present and hence which treatments would be most effective (not reasonable to give hormone therapy to a triple negative breast cancer).
Also good for identifying patients who are at risk of developing certain types of cancer (if they possess the BCR-ABL gene Philadelphia chromosome).
If a patient possesses the BCR-ABL gene which type of cancer are they at risk of getting?
Leukemia (95% of patients with chronic myeloid leukaemia possess the gene).
Describe the different stages of cancer?
Stage 0- cancer is where it started and hasn’t spread
Stage 1- cancer is small and hasn’t spread
Stage 2- cancer is large but hasn’t spread
Stage 3- cancer is large and may have spread to surrounding tissue or lymph nodes
Stage 4- cancer has spread to at least one other organ (it has metastasized)
Describe the different grades of cancer.
Grade 1- cancer cells resemble normal ones and aren’t growing quickly
Grade 2- cancer cells do not look like normal cells and are growing faster than normal cells
Grade 3- cancer cells that look abnormal and may grow or spread more aggressively
What does the T in the TNM grading system stand for?
T - size of the tumour (scale is 1-4)
T1- less than 3cm
T2 - more than 3cm
T3 - near the airways
T4- invaded local structures
What does the N in the TNM grading system stand for?
N- whether the cancer has spread to lymph nodes or other tissue
N (0)- no spread
N1- nearby lymph nodes
N2- lymph nodes on the same side of the body
N3- spread to lymph nodes across the body, not on the same side
What does the M in the TNM grading system stand for?
M1- has not metastasised
M2- it has metastasised
What is the main role of chemotherapy in the treatment of cancer?
Can be used pre-operatively to shrink the tumour size before surgery or post-operatively to ‘scoop up’ any remaining cancer cells that were not able to be removed and to prevent the cancer from returning.
What does curative treatment involve?
Aimed to cure the cancer and is decided based upon the type of cancer, grading, stages etc.
Normally involves high dose, aggressive chemotherapy. Normally followed up with scans and regularly monitoring afterwards to ensure relapse does not occur.
What is the difference between neoadjuvant and adjuvant?
Neoadjuvant- chemo is given before surgery to shrink the tumour
Adjuvant- chemo is given after surgery to scoop up remaining cells(micro metastasises)
These are curative treatments
What does palliative care involve?
When you are not able to cure the cancer, chemo and radiotherapy to reduce symptoms, making the patient comfortable
What is concomitant treatment?
Drugs to make cells more sensitive to other types of treatment for example radiotherapy.
What is subsequent line therapy?
When a patient is started on one line of therapy and then is switched over to another type due to either the cancer progressing or patient can’t tolerate the side effects or risk of sepsis.
What are the four systemic therapies?
Oral
IV
Intramuscular
Subcutaneously
What are the three regional therapies?
Intrathecal (methotrexate) into the spine
Intra-arterial
Intra-vesical
What is the lifetime limit of anthracyclines and why is it in place?
Lifetime limit is different for each but for example Doxorubicin has a cumulative lifetime limit of 400-500mg/m2 and it has implemented due to the risk of cardiotoxicity of the drugs as they causes damage to the myocardial tissue by reactive free radicals.
Total exposure needs to be calculated for each treatment as a percentage of what they are allowed.
What kind of supplement reduces platelet count and what is the increased risk with chemo?
Garlic, chemo can target blood cells in the bone marrow and increases the risk of bruising and bleeding even more due to reduced platelet count.
What are some of the ways the response to treatment is monitored?
External examination
X-rays, CT scans
Blood tests for organ function
Tumour marker test (PSA rise during prostate cancer indicates progression of the disease)
How are the responses defined?
Complete- cured
Partial
Stable
Progression- relapse
What are the different types of chemo-therapies and what are their drug targets?
Alkylating agents - two alkylating groups causes cross linking preventing replication and transcription
Anthracyclines - stabilises the DNA and topoisomerases 2 which induces apoptosis
Antimetabolites-mimic the enzymes needed for the cancer cells to replicate
Taxanes- interfere with microtubules which are needed to move structures in mitosis
Vinca alkaloids- interfere with the M-phase of mitosis, depolymerize microtubules and destroy mitotic spindles.
What are some of the benefits of using combination therapies for chemotherapy?
Different mechanisms, reducing potential for resistance
Reduced side effects (in comparison to high doses of one drug)
Increased efficacy
How does drug resistance of chemotherapies arise?
Decreased drug influx (reduced amount of drug getting into the cell)
Increased drug efflux (more drug being pumped out of the cell)
Inactivation of apoptotic pathways
Altered drug targets (receptor desensitization)
Mutation of targets
Increased metabolism (drug is broken down quicker)
Which type of cancers are hormone therapy an option for?
Certain types of breast cancer or ovarian cancer which are known as estrogen receptor positive or progesterone receptor positive as the cancer cells over-express hormones for these receptors and induce their growth.
Prostate, progesterone receptors
What are some examples of hormone receptor antagonists?
Tamoxifen (selective estrogen receptor modulator) and enzultamide (nonsteroidal antiandrogen medicine).
Are hormone therapies cytotoxic?
No but they are anti-cancer drugs
How do monoclonal antibodies work?
Prevent angiogenesis, by inhibiting the vascular endothelial growth factors
What are some examples of monoclonal antibodies?
Avastatin
