Biology of cancer & Tumor Spread: Chap 9: Class 2 Flashcards
Cycline Dependent Kinases
- Control transitions between cell cycle
Cell cycle
- There are checkpoints that allow the transitions between the phases of the cell cycle.
- Proteins called CYCLINE DEPENDENT KINASES control the transitions
Cell Cycle
-Cancer Cells
- Cancer cells enter the cell cycle more frequently than normal cells
- Commonly found in the SYNTHESIS & MITOSIS PHASE of the cell cycle
- Cancer cells spend little time in the resting phase
Growth Factors
- Signals outside the cell that may ignite the cell cycle
- Activates transmembrane proteins called TYROSINE KINASES. This allows signal transduction for DNA replication
Genetic Mutations
- Mutations in cancer causing genes accumulate w/ age increasing risk
Benign Tumors
-Characteristics
- Grow Slowly
- Have a well-defined capsule
- Are not invasive
- Are well differentiated
- Have a low mitotic index
- Do not metastasize
Malignant Tumors
-Characteristics
- Grow rapidly
- Are not encapsulated
- Invade local structures and tissues
- Poorly differentiated
- Have a high mitotic index
- Can spread distantly
Anaplasia
- The lost ability of a cell to differentiate
- resemble the original cell - Cancer cells look like other cancer cells, not like the tissue from which they arose
Cancer Cells
-Characteristics
- Contact inhibition
- Anchorage independent
- Immortal
START ON POWERPOINT PG 6
-INTRACELLULAR CHANGES
=)
Carcinoma
Arise from:
- Epithelial & Squamous tissue
- Conjunctiva
Adenocarcinoma
Arise from
1. Ductal or Glandular structures
Ex.
Papilla Vater
Lymphoma
Arise from
1. Lymphatic tissue
Ex
Non-Hodgkin’s Lymphoma
Leukemia
Arise from
1. Blood forming cells
Ex
B-Cell acute lymphoblastic leukemia
Sarcoma
Arise from Mesenchymal tissue
-Connective Tissue , muscles, bones
Abnormal Cells
-Grade 1
- Cells differ slightly from normal cells and are well differentiated
Abnormal Cells
-Grade 2
- Cells are more abnormal and moderately differentiated
2. Increasingly harder to tell the difference between normal/abnormal cells
Abnormal Cells
-Grade 3
- Cells are very abnormal; poorly differentiated
Abnormal Cells
-Grade 4
- Cells are Immature / undifferentiated
- Origin of cell is difficult to determine
- Whole part/organs need to be removed
Stage 0 cancer
- Cancer in Situ
- Early stage growths localized to the epithelium but have not penetrated the local basement membrane or invaded surrounding stroma
- Non-malignant
Carcinoma in Situ
- Early stage growths localized to the epithelium
- Have not penetrated local basement membrane
- Non malignant
- Found in:
- Oral cavity, cervix, skin, esophagus, and bronchus
Stage 1 Cancer
- Tumor is limited to the tissue of origin
- Localized tumor growth
- All cells are still on one area
Stage 2 Cancer
- Limited local spread (further outgrowth)
Stage 3 Cancer
- Extensive local and regional spread
2. Local lymph node involvement
Stage 4 Cancer
- Metastasis
- Moving to a new location
Tumor Markers
- Substances produced by both benign and malignant cells that are either present in or on tumor cells or found in blood, spinal fluid, or urine
Tumor markers include:
- Hormones
- Enzymes
- Genes
- Antigens
- Antibodies
Alpha fetoprotein (AFP)
Genetic Marker
-Secreted by LIVER and GERM CELL TUMORS
Prostate Specific Antigen (PSA)
Genetic Marker
-Secreted by prostate tumors into the blood
Carcino Embryonic Antigen (CEA)
Genetic Marker
-Secreted by BREAST or LUNG.
further investigation is needed
Tumor markers Help with…
- Screen and ID individuals w/ high risk for cancer
- Help Diagnose specific type of tumor
- Follow clinical course
- Determine efficiency of treatment
Viral Causes of Cancer
-Epstein-Barr Virus (EBV)
- Burkitt’s lymphoma
Viral Causes of Cancer
-HIV
Kaposi’s Sarcoma
Viral Causes of Cancer
-Hepatitis B
- Hepatocellular Carcinoma
Viral Causes of Cancer
-HPV
- Squamous Cell Carcinoma
Inflammation and Cancer
- Inflammation turns on the switch of oncogenes
2. Overtime this can result in the wrong cells getting growth factors needed to grow and multiply
Bacterial Causes of Cancer
-H. pylori
- Peptic ulcer disease
- Gastric lymphomas
- Gastric Carcinomas
Chemotherapy
-Immediate effects
- Extravasation
- Hyperkalemia
- Hyperphosphatemia
- Hypocalcemia
- Renal impairment
W/in 24 hrs of treatment N/Emesis
Cancer Risk Factors
- Tobacco
- Alcohol
- UV and Ionizing radiation
- Obesity
Lung Carcinoma
-Preferred treatment
- For all types of EARLY-STAGE lung carcinoma, the preferred treatment is SURGICAL RESECTION
Chemotherapy
-10-14 days after administration
- Blood count falls
- Mouth ulcers occurs
- Taste changes
- Diarrhea
Chemotherapy
-Several months later
- Heart/ kidneys mostly affected
Chemotherapy
-Late toxicities
- Infertility/ early menopause
Radiotherapy
- Used to damage and/or kill cells in a SPECIFIED treatment area
- Commonly administered over a period of SIX WEEKS
- Can cause localized and systemic side effects
Origin of Cancer may be?
- Genetic
- Chemical
- Environmental
- Viral or Immunologic
- May arise from causes not yet identified
DNA and Cancer Development
- It is believed that at least 4 to 5 changes in the genes of DNA are needed over years for cancer to develop
Cancer Cells and the Cell Cycle
- Cancer spends more time in the MITOTIC phase
- High mitotic index
Angiogenesis
- Tumor can’t grow beyond 2-3 mm square w/out new blood supply
- Cancer cells produce angiogenic growth factors such as endothelial growth factors and basic fibroblast growth factors
- Provide mechanism of nutrition and escape from original site
Metastasis
-What it needs to occur?
- In order for metastases to occur you need the right cells (seeds) and the right organ (soil) in which to grow
- Easier to go through lymphatic system then the blood system
Chemotherapy Drugs Affect?
- All cells that are dividing at the time
- Bone Marrow
- Hair Follicles
- Mucosal Cells
Chemotherapy & Urine
80% of chemotherapy is unchanged in urine
