Neoplasms

Definitions: Neoplasm Tumor New growth No new purpose 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 Metastases 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 Carcinogens 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 Dysplasia Carcinoma in situ Metastases 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 Staging 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 Radiation Therapy 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) Hormonal Therapy 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)