NeoplasmsNeoplasms

Tumor NomenclatureTumor Nomenclature

• Key: carcinoma vs. sarcoma

Leading sites of new cancer cases & deaths

Benign vs. Malignant TumorsBenign vs. Malignant Tumors• Key differences:

• Encapsulation vs. infiltration

• Differentiated cells vs. undifferentiated cells

Benign vs. Malignant

Malignant Tumors -- PathophysiologyMalignant 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 CancerEtiology 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. Initiating factors --- get irreversible DNA changes

2. Promoters ----repeated exposure to carcinogens

3. Promoters ---- continued exposure to carcinogens

Cancer TreatmentCancer Treatment• 3 basic modalities

• (1) surgery (2) chemotherapy (3) radiation

• Curative treatment

• Palliative treatment

• Prophylactic adjunct therapy

• Radiation therapy– 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