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)