principles of oncology pt 2 Flashcards
If this primary tx goal cannot be accomplished, the goal of cancer treatment shifts to:
1) palliation
2) treatment of symptoms
3) preservation of quality of life
difference between cure to cancer vs palliative care
cure = cancer treatments may be undertaken despite the certainty of severe and perhaps life-threatening toxicities
palliative = minimizing the toxicity of potentially toxic treatments becomes a significant goal
4 cancer tx types
- Surgery
- Radiation therapy (including photodynamic therapy)
- Chemotherapy
- Biologic therapy (including immunotherapy and gene therapy)
which type of cancer treatment is considered a local tx
- surgery
- radiation
which type of cancer tx is considered systemic tx
- Chemotherapy
- biologic therapy
which cancer tx is the most effective means of treating cancer
surgery
why is surgery used for cancer tx
- Cancer prevention (prophylactic mastectomy/colectomy)
- Diagnosis
- Staging
- Treatment (for both localized and metastatic disease)
- Palliation
?% of cancer patients cured by surgery
40%
However, 60% of solid tumors have metastasized and are not accessible for removal
what are the benefits of surgical tx for cancer even if it’s not fully curable with it
- Local control of tumor
- Preservation of organ function
- Debulking for subsequent treatments
- Palliative/Supportive care
- Placement of lines
- Control of effusions and ascites
- Removal of adhesions/strictures
- Reconstructive surgery
a physical agent that destroys cancer cells
radiation
The main goal of radiation therapy is to ?
deprive cancer cells of their cell division potential
how does radiation damage the cancer cells?
breaks in DNA that prevent replication and generates hydroxyl radicals from cell water
Cancer cells are not as efficient as normal cells in repairing the damage caused by radiation resulting in ?
differential cancer cell killing
Radiation therapy is most often administered locally, but systemic effects may develop depending on:
- volume of tissue irradiated
- dose fractionation,
- radiation fields
- individual susceptibility
The features that determine cell sensitivity to biologic effects of radiation is influenced by: (3)
- total absorbed dose
- number of fractions (delivering radiation in repeated doses to maximize exposure during cell division)
- time of treatment
Therapeutic radiation is delivered in 3 ways:
- teletherapy - focused beams of radiation generated at a distance and aimed at the tumor within the patient
- brachytherapy - encapsulated/sealed sources of radiation implanted directly into or adjacent to tumor tissues
- systemic therapy - radionuclides targeted in some fashion to a site of tumor……radioactive iodine for thyroid cancer
what is the most commonly used form of radiation therapy
Teletherapy with x-ray or gamma ray photons
what is the most commonly used form of radiation therapy
Teletherapy with x-ray or gamma ray photons
a component of curative therapy for several cancers:
Breast cancer, Hodgkin’s disease, head and neck cancer, prostate cancer, and gynecologic cancers.
Radiation therapy
what type of therapy can also be used for palliation such as relief of bone pain from metastatic disease, control of brain metastases
radiation therapy
what toxicities can happen from radiation therapy
-
Acute toxicities include mucositis, skin erythema (ulceration in severe cases), and bone marrow toxicity.
- Often these can be alleviated by interruption of treatment. -
Chronic toxicities are more serious
- Radiation carcinogenesis with secondary malignancy; pericarditis; myocardial infarction; thyroid failure; cataracts; lung fibrosis; arteritis; spinal cord transection
Though radiation therapy is most often administered to a local region, what other toxic effect can happen
systemic effects, including fatigue, anorexia, nausea, and vomiting, may develop
focused microwave radiation to induce thermal injury within a volume of tissue
Radiofrequency ablation
use of extreme cold to sterilize lesions in certain sites
Cryosurgery
Infusion of chemotherapeutic agents directly into the target area via vascular catheters
Chemoembolization
what agent may be used for the treatment of active, clinically apparent cancer
chemotherapy
can be administered in addition to surgery or radiation, after all clinically apparent disease has been removed
chemotherapy
Cancer drug treatments are of four broad types:
- Conventional cytotoxic chemotherapy agents - target DNA structure
- Targeted agents - molecular target important in either maintaining the malignant state or selectively expressed by the tumor cells.
- Hormonal therapies - work on the biochemical pathways underlying estrogen and androgen function
- Biologic therapies - induce a host immune response to kill tumor cells.
chemotherapy agents have what type of therapeutic index
narrow
Useful cancer drug treatment strategies have one of two valuable outcomes:
- induce cancer cell death
- tumor shrinkage with corresponding improvement in patient survival, or increase the time until the disease progresses. - induce cancer cell differentiation or dormancy
- loss of tumor cell replicative potential and reacquisition of phenotypic properties resembling normal cells.
Methotrexate
Antimetabolites - chemotherapy
5-fluorouracil (5-FU)
Antimetabolites - chemotherapy
MOA of Antimetabolites
Cause DNA damage indirectly
which antimetabolite prevents thymidine formation (required for DNA replication)
5-FU
which antimetabolite competes and counteracts folic acid, causing folic acid deficiency in cancer cell and cell death
Methotrexate
SE of antimetabolites
stomatitis, diarrhea, and myelosuppression
Vincristine, Vinblastine
Mitotic Spindle Inhibitors
Paclitaxel
Mitotic Spindle Inhibitors
SE of mitotic spindle inhibitors
alopecia, neuropathy, and myelosuppression.
which chemotherapy as a class are cell cycle phase–nonspecific agents
Alkylating Agents
what chemotherapy agents has MOA of covalently modify bases in DNA leading to cross-linkage of DNA strands or the appearance of breaks in DNA as a result of repair efforts
Alkylating Agents
Cyclophosphamide
Alkylating Agents
Chlorambucil
Alkylating Agents
Cisplatin
Alkylating Agents
which specific chemotherapy agent has SE of neuro-toxicity (stocking-glove), hearing loss, renal failure
Cisplatin
which chemotherapy agent:
- Produced by bacteria
- bind to DNA directly and can undergo electron transfer reactions to generate free radicals in close proximity to DNA
Doxorubicin (Anthracyclines)
which chemotherapy drug has a common SE of cardiotoxicity
Doxorubicin (Anthracyclines)
MOA of Topoisomerase inhibitor
inhibits DNA synthesis by forming a complex with topoisomerase II and DNA, causing breaks in DNA