Biology & Clinical Manifestations of Cancer

Tumor/Neoplasm: new growth

Cancer: only refers to malignant tumors

1. Antigens

2. Antibodies

3. Hormones

4. Enzymes

5. Genes

D: substances produced by cancer cells or that are found on plasma cell membranes inbthe blood, CSF, or urine

Used to....

Screen & identify individuals at high risk for cancer

Diagnose specific types of tumors

Observe clinical course of cancer

Problem: false positives/negatives

Changes in the DNA & chromosomes of the cell are what cause cancer to occur

Cancer is also a disease of aging

Cell damage accumulation

Mutations & future generations

Offsring may be effected by DNA damage of parents

Cancer cells like to use immune cells (neutrophils, lymphocytes, and macrophages) to help the cancer grow

Consequently, those with autoimmune diseases are at higher risk of developing cancer

In both cancer & inflammation, the site will be invaded by cells to stimulate cell & vessel growth

Damaged or suppressed immune system

About 15%nof cancers are viral related

Hepatitis B & C viruses

Epsein-Barr virus (EBV)

Kaposi sarcoma herpes virus

Human papilloma virus

Heliobacter pylori

Chronic infections associated with

Pepetic ulcer disease

Stomach carcinoma

Mucosa-associated lymphoid tissue lymphomas

Screening

Biopsies

Blood studies

Staging

Benign Tumor

Well differentiated

Well organized stroma (surrounding capsule)

Named according to the tissues from which they arise

Malignant tumors

Grow rapidly

Disorganized & lose normal tissue structure

Anaplasia: loss of differentiation

Pleomorphic: different size & shape from which they arise

Metastasis

Ability of a malignant tumor to spread to other parts of the body

Named according to tissue from which it arises

Carcinomas

Epithelial tissue

Lymphomas

Lymphatic tissue

Sarcomas

Connective, muscle, & bone tissue

Benign vs. Malignant

Benign

Grow slowly

Well-defined

Not invasive

Well differentiated

Low mitotic index

Do not metastasize

Malignant

Grow rapidly

Not encapsulated

Invasive

Poorly differentiated

High mitotic index

Can spread distantly (metastasis)

Mitotic index

How many cells are currently reproducing

Carcinoma in situ (CIS)

Area of abnormal cell growth in epithelial tissue that hasn't invaded the basement membrane

Has properties of malignant tumors, but is not consideed cancer because it has not invaded basement memberane

Could...

1. Remain stable

2. Progress

3. Disappear entirely

Pic: basement membrane

Cancer cells

Lack contact inhibition

Dont stop growing when come into contact with one another - pile up

Anchorage independence

Dont need to be anchored to something to grow

Immortal

Will live forever, until host dies

Normal cells

Have contact inhibition

Cells stop growing when they come into contact with each other

Anchorage dependent

Must be anchored to something to grow

Blood supply

Angiogenesis

Growth of new blood vessels

No need for external growth factors

Subtopic

Will grow in any environment (including high acid or hypoxic states), & will steal what they need from healthy cells

Characteristic sign of cancer

D: spread of cancer from a primary site of origin to a distant site

Seeding

Venous system

Lymphatic system

Pain

Little to no pain associated with early stages of malignancy

Occurs in 60-80% of terminally ill cancer patients

Influenced by fear, anxiety, sleep loss, fatigue, & overall physical deterioration

Mechanisms causing pain

1. Pressure

2. Obstruction

Inflammation

Tissue destruction

Infection

Cachexia

Most severe form of malnutrition

Results in wasting, emaciation, & decreased quality of life

Cancer cells stealing nutrition from normal cells

Leukopenia & thrombocytopenia

Direct tumor invasion to the bone marrow causes leukopenia & thrombocytopenia

Chemotherapy drugs are toxic to bone marrow

Anemia

Related to blood loss, malnutrition, or cancer in blood forming organs

Infection

Immune system suppression

GI Tract

Hair & skin

Hair loss

Two thirds of all cancers are caused by environmental/lifestyle factors & occupational exposure interacting with cell & its DNA

Multipotent carcinigenic mixture

Increases risknfor multiple cancers

Secondhand smoke (EST) contains many toxic chemicals

Cigar & pipe smokers also at risk

May account for 30% of the overall risk factors for cancer

Certain chemicals that can act like mutagens

Foods that increase your risk versus those that decrease your risk

Xenobiotics