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Neoplasms
Tumor Nomenclature
• Key: carcinoma vs. sarcoma
Leading sites of new cancer cases & deaths
Benign vs. Malignant Tumors
• Key differences:
• Encapsulation vs. infiltration
• Differentiated cells vs. undifferentiated cells
Benign vs. Malignant
Malignant Tumors -- Pathophysiology
• Staging vs. grading
– Staging = describes the extent of the disease at the diagnosis time
• In-situ = malignant cells in pre-invasive stage
• Usually I through IV ( higher = worse)
• T, N, M system
– T = tumor; N = involvement of lymph nodes; M =
metastasis
– Grading = describes the degree of differentiation of the malignant
cells
• Usually I through IV (higher = more undifferentiated)
• Local Effects
– Pain
– Not an early sx
– Infection
– From tissue necrosis and ulceration
– From destruction of normal flora
– Obstruction
– When growth of the tumor compresses a duct or passageway
• Systemic effects
– Weight loss
– Cachexia = severe tissue wasting
– Anemia
– Causes = anorexia, chronic bleeding, & bone marrow depression
– Infections
– Especially pneumonia
» Reason = stasis of secretions & weaker cough efforts
– Paraneoplastic syndromes
– Substances released from certain tumors have effects on:
» Endocrine system (e.g. ACTH-like effect & ADH-like effect)
• Diagnostic tests
• Blood tests
– General = CBC (esp. when undergoing chemo or radiation)
– Specific = called tumor markers
» Exp = PSA
• Imaging techniques
– CAT, MRI, nuclear scanning (includes PET)
• Exfoliative cytology
• Biopsies
• Spread of malignant tumors
– Primary tumor = parent tumor; initial site & cell type
– Secondary tumor =other sites of identical tumor cells
– 3 basic mechanisms
» (1) invasion into adjacent tissue
» (2) metastasis via blood and/or lymphatics
» (3) seeding = spread of tumor cells along serous membranes
and in body fluids within serous body cavities
• Staging correlates with degree of spread
Etiology of Cancer
• Carcinogenesis = process when normal cells transformed into cancer cells
• Factors in carcinogenesis are multiple & include:
–
–
–
–
–
Changes in DNA (mutations)
Genetic oncogenic factor
Radiation (gamma rays, X-rays, & ultraviolet rays)
Chemicals --- called carcinogens
Biological factors
– Chronic irritation
– Hormonal excess
– Diet
– Pathogens --- primarily viruses
• Host defenses
– Immune system has 3 types of cells that are “killers” (cytotoxic)
– NK lymphocytes (NK = natural killer)
– Killer T-lymphocytes
– Macrophages
Stages in
carcinogenesis:
1.
2.
3.
Initiating
factors --- get
irreversible
DNA changes
Promoters ---repeated
exposure to
carcinogens
Promoters --- continued
exposure to
carcinogens
Cancer Treatment
• 3 basic modalities
• (1) surgery
(2) chemotherapy
• Curative treatment
• Palliative treatment
• Prophylactic adjunct therapy
• Radiation therapy
(3) radiation
– Especially affects cells that rapidly reproduce
» Epithelium, bone marrow, gonads
– Adverse effects
– Bone marrow depression
– Epithelial tissue inflammation & ulceration --- get stricture & fibrosis
– Ovarian or testicular damage
– Non-specific fatigue & lethargy
• Chemotherapy’s adverse effects
• Hair loss, breakdown of mucus membranes, N&V, bone marrow depression
• Newer treatment modalities
• Angiogenesis inhibitor drugs
– These block endothelial cell regeneration
• Anti- telomerase
• Immunotherapy (biologic response modifiers)
• Radioimmunotherapy (monoclonal antibodies & radioactive isotopes
• Prognosis
• Cure = 5 year survival without recurrence
• Follow-up for metastasis
– Key = Bone, Brain, Liver, & Lungs
•
Treatments
– Curative
– Palliative
– Prophylactic
• Adjuvant
therapy