BIO 302 - Exam 3 - Systemic Treatment of Cancer PowerPoint Flashcards
What is systemic therapy? What is the delivery route?
Any therapy delivered to the entire body for:
* Carcinoma is known to be disseminated
* Carcinoma is likely to be disseminated but undetectable
* Adjuvant or neo-adjuvant use
* Leukemia/lymphoma
Uses the blood stream as the delivery route
* Direct intravenous injection (most common)
* Given orally, absorbed through the gut into the blood
What are 6 normal physiological and anatomical limitations to delivery?
A
B
C
J
Pe
Pl
Avascular spaces
Blood-brain barrier
Cerebrospinal fluid spaces
Joint spaces
Peritoneal cavity
Pleural spaces
What are 3 tumor-related limitations to delivery of the therapeutic agent?
- Tumor neovasculature is disorganized
- Dense sclerotic tumor stroma may prevent diffusion
- High interstitial fluid pressure in tumor stroma hampers diffusion.
What are the 4 classes of Systemic therapy?
(1) Cytotoxic chemotherapy – most common
(2) Biological therapy – monoclonal antibodies
* The active agent in many targeted and immunotherapies
* Can also be used as a “smart bomb” to deliver an attached toxic agent.
(3) Targeted therapy - single or multiplex targeting of molecular aberrations and molecular pathways
* Antibodies (biologic therapy) or small molecules
(4) Immunotherapy
* Vaccines
* Immune stimulation (cytokines, etc.)
* Cell-based (T cell) therapies (in vitro manipulations of various sorts including genetic engineering)
* Checkpoint inhibition
Biggest challenge with finding a cure are related to limited effectiveness due to?
TUMOR CELL HETEROGENEITY WITH THERAPY-RESISTANCE in advanced stage disease.
Other 4 problems limiting success of treatment include:
Treatment toxicities and complex clinical care
Treatment cost (can be VERY high)
Quality-of-life in-treatment and post-treatment.
Secondary cancers
Systemic therapy is often used in the face of ______ or ______ disease when the chances of benefit are very low.
Sometimes ______ therapy makes no sense - offers no upside, only a downside.
Issue of timing of recommendation for palliative care (versus interventional care) is difficult and signals an end to hope for any positive effect.
This is end of life reality.
In an effort to “buy time”, the quality of remaining life may be sacrificed.
advanced / recurrent / anti-cancer
(1) All forms of systemic therapy have adverse systemic effects on normal cells and tissue.
(2) Side effects can be severe and debilitating, even life-threatening
(3) Patient’s ability to tolerate the therapy may require modifying or stopping the therapy before the treatment goal can be reached
(4) 10 Examples of common side effects of cytotoxic systemic therapy:
Bl
Bl
Bo
D
F
E
H
N
M
S
- Bleeding or clotting
- Blood disorders (bone marrow suppression): infection; anemia.
- Bone density loss
- Diarrhea, nausea and vomiting
- Fatigue, pain
- Emotional distress
- Heart damage
- Nervous system effects (e.g., neuropathies)
- Memory loss
- Skin and hair changes
Successful therapies must address what 3 things? Are these challenges met?
(1) Complexity of the cancer
(2) Adaptive evolution
(3) Rx escape
THESE CHALLENGES ARE NOT YET MET!
Types of Systemic Therapy: Chemotherapy
What does the treatment Cytotoxic chemotherapies do?
Toxicity is i______ and p______.
kill dividing cells (cancer or normal) / inevitable / predictable
What is the action of Alkylating agents in Cytotoxic chemotherapy?
What part of the cell cycle does this affect?
What are they used to treat?
What could they cause?
- Crosslink and/or damage DNA; work at all phases of the cell cycle.
- Used to treat lymphoma, leukemia, Hodgkin lymphoma, multiple myeloma, and sarcoma, as well as carcinomas of the lung, breast, ovary
- Alkylating agents may cause leukemia later
What are Platinum drugs in Cytotoxic chemotherapy?
What part of the cell cycle does this affect?
Directly damage DNA and work at all phases of the cell cycle but are less likely to cause post-Rx leukemias
What is the action of Anti-metabolites in Cytotoxic chemotherapy? BCDbIDS
What part of the cell cycle does this affect?
What cancers does this treatment affect?
Block cell division by interfering with DNA synthesis (the “anti-metabolite” is inserted instead of the normal nucleotide)
Cells damaged during the S (synthesis) phase, when the cell’s chromosomes are being copied
Commonly used to treat leukemias, cancers of the breast, ovary, and the intestinal tract.
What is the action of Topoisomerase inhibitors in Cytotoxic chemotherapy?
What part of the cell cycle does this affect?
Topoisomerases are enzymes that relax the supercoiling of DNA to allow the enzyme helicase to separate the strands of DNA so they can be copied during S phase.
When topoisomerases are inhibited, helicase can’t separate the strands.
What is the action of Anti-neoplastic antibiotics?
What part of the cell cycle does this affect?
- Either break up DNA strands or stop DNA synthesis
- May work in any of the phases of the cell cycle
- Made by micro-organisms
- Do not act like the antibiotics used to treat infections
What does Plant alkaloids and naturally occurring products
in Cytotoxic chemotherapy do? BCDbDMF
What part of the cell cycle does this affect?
- Block cell division (mitotic inhibitors) by disrupting microtubule formation.
- The spindle that is required for separation of the chromosomes into two cells during mitosis is made of microtubules
- Stop mitosis in M phase
Drug resistance: major challenges for systemic therapies
Most resistance mechanisms accomplished through ______ ______.
Compensatory modifications of an existing mechanism also may occur.
new mutation
Hormone therapy ______ ______ kill cancer cells: used in combination with other chemotherapies that do kill cancer cells.
does not
What are the two types of hormonal agents? What reasons are they used for?
(1) Antagonists of sex hormones are anti-tumor.
* Artificial sex hormones block hormone receptors (if present) and control growth of tumors driven by hormone stimulation.
* Prostate cancer: androgen deprivation therapy (“ADT”).
* Breast cancer: block estrogen .
(2) Corticosteroids (prednisone, dexamethasone) –are not tumor-directed.
* Used to reduce inflammation, reduce swelling, boost appetite, help relieve side effects of other chemotherapies.
Surgical removal of natural sources of sex hormone
______ (remove testes)
______ (remove ovaries)
______ (remove adrenal glands)
Orchiectomy (remove testes)
Oophorectomy (remove ovaries)
Adrenalectomy (remove adrenal glands)
Other systemic therapies
What are Proteasome inhibitors?
Block the action of proteasomes, cellular complexes that break down (degrade) proteins
Build-up of unwanted proteins causes the cancer cell to die
Other systemic therapies
What are Cell differentiation agents?
Induce terminal differentiation to non-replicating state (leukemias/lymphomas but not solid tumors to date)
Customized, “targeted”, and precise
Molecular profiling of tumors to facilitate the right Rx choice for right disease subtype or to identify futile Rx choices (increase efficacy)
Molecular profiling of the patient to facilitate the right Rx choice for right patient (pharmacogenomics to increase efficacy and decrease toxicity)
Concept of “precision medicine” matches the biology of the tumor and the biology of patient to the most rationale treatment approach
What are targeted therapies?
Targeted therapy is a type of cancer treatment that targets proteins that control how cancer cells grow, divide, and spread.
- Agents that target specific molecular aberrations or pathways.
- Requires the presence of the molecular “target” in the tumor.
- A “companion diagnostic” test may be required to demonstrate that the target of a therapy is present before administering that therapy.