Neoplasms. Definitions: Neoplasm New growth No new purpose Tumor Swelling, enlargement, mass.
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Transcript of Neoplasms. Definitions: Neoplasm New growth No new purpose Tumor Swelling, enlargement, mass.
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
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.ExerciseRegular medical screening examsLimit 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)