Cancer treatment

Question 1

surgery

Answer 1

-oldest effective cancer therapy
-it can be used alone or in combination with other modalities
-technqiues include resection of metastases, tumor debulking, paliative and reconstructive surgery

Question 2

primary tumor resection

Answer 2

If tumor has not metastasized
-Chemotherapy and radiation therapy must be given before to reduce cancer size, limit extent of surgery and increase success rate

Question 3

Radiation therapy

Answer 3

-mainly cures localised cancer that can be completely encompassed within a radiation field
-radiation + surgery for head, neck, laryngeal or uterine
Radiation+surgery+chemotherapy for sarcomas, breast, oesophageal, lung or rectal
-Types include photons, electrons, protons, alpha particle, radionuclides

Question 4

Neoadjuvant therapy

Answer 4

Given before surgery or chemo

Question 5

Adjuvant therapy

Answer 5

After surgery or chemo

Question 6

How radiation works

Answer 6

It damages DNA of cancer cells and causes mitotic catastrophe via single or double stranded breaks. This can be direct DNA damage or indirect via the formation of reactive oxygen species like hydroxyl radicals that do damage
-Normal cells have DNA repair mechanisms while cancer does not

Question 7

Gamma Knife

Answer 7

Directs highly precise dose of radiation to tumor and avoids healthy tissue around

Question 8

Brachytherapy

Answer 8

-It involves placing radioactive material inside the body to treat certain cancers

Question 9

next generation therapy

Answer 9

uses nanoparticles and non-ionising radiation

Question 10

Nano particles

Answer 10

-The surface of the particle is coated with a molecule that binds to the surface of cancer which facilitates endocytosis
-The particles contain molecules that generate reactive oxygen species or heat when exposed to light
-Not as effective in hypoxic tissue
-Can also be radioactive which allows for far more directed doses as the use of radioisotopes such as alpha emmiters has the potential to limit death of healthy cells surrounding tumor

Question 11

chemotherapy

Answer 11

-Use cytotoxic drugs that damage DNA (crosslinkers) or inhbit DNA synthesis (anti-metabolites)
-Causes death due to non DNA repair mechanisms
-P53 mutations make cells less sensitive to these drugs as P53 is needed

Question 12

E.crosslinkers

Answer 12

cisplatin
nitrogen mustards
mitomycin C

Question 13

E.DNA intercalaters

Answer 13

doxorubicin
(topoisomerase inhibitor)

Question 14

E.Antimetabolites

Answer 14

fluorouracil (thymidylate synthetase inhibitor)
Methotrexate (tetraydrofolate synthesis inhibitor)

Question 15

Endocrine therapy

Answer 15

-uses drugs that inhbit cancer growth for cancers that overexpress hormone (androgens) receptors and respond to hormones in a way that promotes survival and growth such as prostate and breast cancers

Question 16

E.Endocrine

Answer 16

Tamoxifen is a drug that was developed in 1960s and acts as oestrogen antagonist and blocks hormone from binding to cell to reduce oestrogen dependant cancer
Bicalutamide is a testosterone anatagonist for prostate cancer

Question 17

Immune therapy

Answer 17

Active
Adoptive

Question 18

Active immunotherapy

Answer 18

Treatment is mediated by active immunity and aims to provoke or amplify a patient’s anticancer immune response
eg: Vaccines, modified T-cells from patient, monoclonal antibodies

Question 19

Adoptive immunotherapy

Answer 19

Treatment is mediated by passive immunotherapy and involves anticancer antibodies or T cells from healthy individuals that target cancer cells

Question 20

Car-T Cells

Answer 20

CAR T-cell therapy is used to eradicate very advanced leukemias and lymphomas and to keep cancer at bay for many years
-cytotoxic T cells are removed from cancer patients blood and genetically engineered to express a CAR receptor (chimeric antigen receptor) that targets cancer cells and are returned to patient intravenously

Question 21

CAR

Answer 21

chimeric antigen receptor

Question 22

Checkpoint inhibitors

Answer 22

PD1 is a checkpoint receptor on the surface of immune cells that prevents them from attacking self-antigens and causing autoimmune disease
-Cytotoxic T cell with PD1 will engage with ligand PD-L1 and become inactivated
-Tumor cells express large amounts of PD-L1 to inactivate cytoxic T cells
-Monoclonal antibodies bind to PD-L1 which allows T cells to ignore PD1 signal and attack cancer cells

Question 23

Monoclonal antibody therapy

Answer 23

-targets specific cancer receptors
-HER2 protein is over expressed on breast carcinoma cells and these cells are typically aggressive and have a poor prognosis
-Trastuzumab is a monoclonal antibody that targets Her2 as Herceptin

Question 24

Anti-angiogenesis drugs

Answer 24

-Monoclonal antibodies that block VEGF

Question 25

differentiating promoting drugs

Answer 25

include hypo-methylating drugs such as azacitidine which treats leukaemias

Question 26

Targeted drug therapies

Answer 26

-inhbit overexpressed or overactive proteins
-Eg: Gleevac which is a tyrosine kinase inhibitor

Question 27

Oncolytic viruses

Answer 27

-viruses are designed to preferentially infect and lyse cancer cells
-it is designed to activate the immune system against a tumor which results in cancer eradication and immune system memory
-it was noted in 20th century
-Hepatitis was used in 1950-1980 as a simplistic approach
-Now use genetically engineered viruses