Chemo (Exam 4) Flashcards
Goals of Anti-cancer Regimen
Kill every CA cell and produce a cure
Cannot cure:
Control growth
Offer palliation
Treatment is often complex involving several therapies
Cell Cycle Review
GO - Rest
G1 - Cell growth
S - DNA synthesis
G2 - Prepare to divide
M- Mitosis (division
Growth Fraction
The ratio of proliferating cells to resting cells
3 cells in the cycle are proliferation and one cell is in GO = Ratio = 3:1
The higher the growth fraction the likely chemo is to
work because most chemo works better on cells that are actively moving
Growth Fractions and Tumor Growth
Malignant tumors grow very rapidly initially
Malignant tumors = high growth fraction
As tumor increases in size, rate of proliferation decreases
= low growth fraction
-Large tumors have a necrotic core (slowing)
-Decreased nutrient supply at core
-More cell in resting phase (G0)
-More difficult to treat
Barriers to Success with Cancer Treatment
100 to kill
Toxicity to normal tissues
Late detection
Tumor response
Drug resistance (Tumor cell mutate)
Cell heterogeneity
Cannot kill the patient to cure the patient
Have to use same dose therapy to prevent it from coming back
Hard for patient to keep going long term
Consequences of late detection
- Metastasis
- Less responsive (larger tumor = lower growth fraction)
- Patient more Debilitated by disease (Patient can not tolerate chemo)
Solid tumors respond poorly because
Low growth fraction
Limited blood supply (Especially the core)
Resistance
CA cells constantly mutate
Natural selection - drug - resistant mutant flourish
Intermittent Chemo: Goal
100% cell death with limited normal cell injury
Strike a balance: Let normal cells recover but not too long
Nadir
Combination Therapy
Using multiple drugs
Reduces:
Drug resistance
Normal cell injury
Increases:
Cancer cell kill
Example of combination therapy
Cyclophosphamide + Vincristine
Optimal Dosing
Dosing schedule depends on the agent being used. Try to maximize results using cell-cyle specific agents. Try to keep active drug present in body
Regional Drug Therapy
Access to tumors
High drug concentration
Decrease systemic toxicity
Examples of Regional Drug Therapy
Intraarterial
Intrathecal
Intraperitoneal
Intravesical
Chemo Usual Toxicities
Nausea and Vomiting for several days after chemo (CTZ Zone)
1-2 weeks after first round:
Decrease WBC - RBC - Platelets
Diarrhea (Kills gut bacteria)
Alopecia (7-14 days)
Fatigue (Drained)
Other Toxicity Chemo Drugs
Bone Marrow:
-Neutropenia
-Erythrocytopenia
-Thrombocytopenia
Digestive Tract Injury
-Stomatitis (Oral pain)
-Inflammation
-Nutrition problems (Pain)
Magic Mouthwash
Prescription cocktail for stomatitis
Magic Mouthwash Instructions
Swish gargle spit 5-10 ml every six hours PRN
May be swallowed if esphoageal involvement
Magic Mouthwash Contains
Lidocaine
Mylanta
Diphenhydramine
Nystatin
Prednisolone
Other Toxicites 2 Chemo
Reproductive:
-Developing fetus
-Germinal Epithelium of testes
Hyperuricemia:
-Def: Excessive level of uric acid in blood
-Cause: Cell death destruction of DNA
Last of Toxicity Chemo
Extravasation: Vesicant
Carcinogenesis: Normal Cells transformed into cancer cells
Organ damage
