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Neoplasms. Definitions:. Neoplasm New growth No new purpose Tumor Swelling, enlargement, mass. Types of Neoplasm. Benign vs. Malignant Varies with: Cell characteristics Potential for spread Local , regional, distant spread Degree of anaplasia Cellular differentiation and specificity.
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Definitions: • Neoplasm • New growth • No new purpose • Tumor • Swelling, enlargement, mass
Types of Neoplasm • Benign vs. Malignant • Varies with: • Cell characteristics • Potential for spread • Local , regional, distant spread • Degree of anaplasia • Cellular differentiation and specificity
Benign Neoplasms • Slow growing • Well defined, less anaplastic cells • Often encapsulated • No infiltration of local tissue • Unlikely recurrence
Malignant Neoplasms • Rapidly growing • Anaplastic • Metastasize via blood or lymphatics • May/often recur after excision • Fatality possible • Called cancers
Cancer Growth & Spread • Localized • Stays at the site of the original tumor (primary) • Invades the local tissues • Metastases • Spreads beyond the site of the primary tumor • Regional spread (local lymph nodes often) • Distant mets (other organs or organ systems)
Risk Factors & Prevention • No single cause of malignancy • Some risk factors: • Carcinogen exposure • Substance that increases the risk of cancer development • Radiation, chemicals, tobacco, sun exposure • Genetics • Diseases that increase cancer risk • Example: ulcerative colitis, familial adenomatous polyposis
General Preventative Measures • Stop smoking • Limit alcohol consumption • Protect skin from UV exposure • Limit X-rays • Limit exposure to harmful chemicals • Asbestos, aniline dyes, vinyl chloride, benzene • Limit HRT (estrogen therapy)
General Preventative Measures • Limit exposure to air pollution, solvent cleaners, paint thinners, pesticides, etc. • Eat diet rich in fibrous fruits & vegetables, bran, whole grains. Moderate caloric intake. • Exercise • Regular medical screening exams • Limit salt- & nitrate-cured & smoked foods.
Medical Screening Exams and Tests • Rectal exams (prostate Ca) • Colonoscopy (colon Ca) • Mammography (breast Ca) • Pap smear (cervical Ca) • PSA (prostate specific antigen) • CEA (carcinoembyronic antigen)(colon cancer) • Skin exam
Cancer Stats (2008) US cancer deaths: 565,650 -Decreasing 1.1%/yr from 1993-2002 -Decreasing 2.1%/yr from 2002-2004 New cases: 1,437,180 (not including nonmelanoma skin cancers)
Cancer Stats (2008) • Most common Ca types in US (new cases per year): • Nonmelanoma skin cancer (over 1 million) • About 50% all Ca diagnosed in US • Lung (215,000) • Prostate (186,000) • Breast (182,000 females) • Colorectal (148,000)
Classification of Neoplasms • According to type of body tissue involved • Carcinomas • Sarcomas • Blood and lymph neoplasms
Carcinomas • Most common type • Solid tumors of epithelial origin • Examples: adenocarcinoma
Sarcomas • Less common than carcinomas • Cancers of connective and supportive tissues • Examples: osteosarcoma
Blood & Lymph Neoplasms • Leukemias • Hodgkin’s Disease • Non-Hodgkin’s lymphoma
Leukemias • Not a solid tumor • Increased number of abnormal WBC • Acute Type • Acute myeloblastic leukemia • Chronic Types • Chronic myelocytic leukemia • Chronic lymphocytic leukemia
Hodgkin’s Disease • A type of lymphoma • Painless enlargement of lymph nodes in neck at first • Reed-Sternberg cell is characteristic giant cell in this disease
Non-Hodgkin Lymphoma • Malignant lymphomas • More common than Hodgkin’s • Increasing in incidence • Also has painless LN enlargement • May involve other non-lymphatic tissues • No Reed-Sternberg cells
Etiology of Neoplasms • No single etiology • Reflects a change in chromosomal material • Cell growth is independent & uncontrolled • Generally considered a failure of immune system
Etiology of Neoplasms • Heredity • Breast cancer (female relatives) • Colon carcinoma (polyposis coli) • Retinoblastoma (dominant trait) • Most neoplasms are not inherited disorders
Etiology • Viral etiology • Epstein-Barr virus (Burkitt’s lymphoma) • Herpes simplex virus (cervical Ca) • Human papilloma virus (cervical Ca) • Carcinogens • UV light, X-rays, radiation therapy, tobacco smoke, chewing tobacco, formaldehydes, asbestos, nickel & zinc ores, pesticides, etc.
Cancer Progression • Hyperplasia • Increased growth of cells • Dysplasia • Cells become abnormal in appearance • Carcinoma in situ • Remains in one place, a primary • Metastases • Distant spread via the circulation
Grading and Staging • Grading • Describes the degree of anaplasia • Grade I (well differentiated cells) to Grade IV (difficult to tell tissue of origin) • Staging • Degree to which a cancer has spread • TNM system • Tumor size, # regional LN, metastases
Treatments • Surgery • Specific, palliative, preventative • Radiation Therapy • Electromagnetic type (x-rays, gamma rays) • Particle type (electrons, neutrons, protons, etc) • Given externally or internally • Radioisotopes • Radiation affects DNA & cell replication of both cancer and normal cells
Treatments • Chemotherapy • Most effective against cancers that spread widely • Affect both cancer & normal cells • Frequent adverse effects on bone marrow, GI tract, and skin • Most common side effects: nausea, vomiting, anemia, leukopenia, alopecia
Treatments • Immunotherapy (Biotherapy) • Stimulation & strengthening of immune system • Used early in the course of the disease • Examples: interferon, bone marrow & stem cell transplantation, cord blood transfusion • Hormonal Therapy • Adds, blocks, or removes hormones that affect the growth of certain cancers (breast, prostate)