oncology: study of cancer. when normal cells go “rogue” cancer is a disease by unrestrained and...

ONCOLOGY: STUDY OF CANCER

When Normal Cells go “Rogue” Cancer is a disease by unrestrained and

excessive multiplication of body cells

Or in simpler terms

Cancer is normal cells that have begun to divide at a rapid and non organized rate

Rogue cell division

Put another way

Cancer is a group of disease in which cells are: aggressive (grow and divide without respect for

normal cellular limits) invasive (invade and destroy adjacent tissues) sometimes metastatic (spread to other location

in the body

Nearly all cancers are caused by abnormalities in the genetic material of the transformed cell

Cancer cells compared to Normal

Breast Cancer cells

Probability of Developing or Dying from cancer Increase with age

43% of new cancer cases and 60% of deaths will occur among those who are at least 70 years of age

40% of women and 45% of men will develop cancer in their life time 1 in 4 Canadians will die of cancer

62% of those diagnosed will survive for 5 years

(depends on the type of cancer)

Definitions: sorry there are a few Anaplasia:

Loss of differentiation of cells Return to a more primitive cell type Lack of orderly arrangement

Tumors Masses or growths that arise from normal

tissue Neoplasm

New growth, benign or malignant tumors

Sorry still on Definitions

Remissions Lessening of Symptoms of a disease

Carcinogens: agents that cause cancer Chemicals, drugs, radiation, viruses

Mutations Change in the DNA of a cell May be caused by exposure to a carcinogen or

spontaneously

And two more

Differentiation Specialization of cells

Prognosis Expected outcome of disease Mortality Morbidity

Now we can move into our discussion on Cancer

Defining a Tumor

Malignant Tending to become worse and results in

death Benign

Non cancerous still can cause death depending on location ie in the brain, heart, kidney

Defining a Tumor Encapsulated (Good)

Surrounded by a capsule

Infiltrative (Bad) Extending beyond normal tissue boundaries

Invasive (Very Bad) Having the ability to enter and destroy

surrounding tissue

Metastases (Worst) Spread of malignant tumor to a secondary

site

Causes of Cancer: not well understood Environmental Heredity: Retinoblastoma Viruses: HPV, HIV Spontaneous

Retinoblastoma

Environmental

Chemicals & Drugs Hydrocarbons

(Smoke) Insecticides Industrial cleaners Insulations Hormones Steroids Mercury

Radiation UVA,UVB

Skin cancer X-rays

Damage to cell DNA

Nuclear fusion Chernobyl in the

Ukraine Hiroshima Result: Leukemia

Viruses

HIV AIDs Kaposi Sarcoma

Human Papilloma Virus Four strains 6,11,16,18 that cause cervical

cancer

Epstein-Barr virus Causes Burkitt’s lymphoma

Classification of Cancers

Types of tumors Malignant Benign

Types of Cancers1. Carcinomas2. Sarcomas3. Mixed-tissue tumors

Benign

Grows slowlyEncapsulated

Fibrous capsule

Differentiated cells Resemble normal mature tissue

Do not metastasis Do not form secondary tumors

Malignant: usually grows rapidlyInfiltrative & Invasive

May be initially encapsulated

Anaplasia Resemble primitive or embryonic cells Not capable of mature cellular function Lack orderly arrangement

Metastasis Travel through bloodstream or lymphatic

system Create secondary tumors

Carcinomas vs Sarcomas

Epithelial tissue Lining of external &

internal body surfaces

Skin Glands Digestive, urinary Reproductive

50% of tumors in women are carcinomas

Supportive & connective tissue Bone Adipose Muscle Cartilage Bone marrow Lymphatic/immune

Rare form of cancer Is increasing

Carcinomas: Solid tumors Sarcomas

Mixed Tissue Tumors

Can contain both epithelial and supportive and connective tissue

Kidney Ovaries Testes

Factors to determine Prognosis1. Location of tumor2. Microscopic appearance

Grading Degree of differentiation

3. Extent of spread Metastases

Number of secondary tumors Location of secondary tumors

Microscopic Grading: Four gradesGrade I

well differentiated closely resembles original tissue cells

Grade II less differentiated still can determine parent cells

Grading:III-IV

Grade III Even less differentiated

Grade IV Anaplasia Difficult to determine tumor tissue site of

origin

Example is used in Papanicolaou tests (Pap smears)

Degree of Spread Staging 0-5Stage I

very early cells localized to few cell layers

Stage 2 spread to deeper cell layers ? Infiltrate to surrounding tissue

Stage 3-4

Stage 3 infiltrated surrounding tissue contained in the primary cancer site

Stage 4 invasive to near by sites

Stage 5-recurrences

Stage 5 metastases to other organs of the body via

the bloodstream or lymphatic system

Recurrent cancer cells have reappeared after

treatment

In Canada stage 5

Lymphatic Involvement

Spread to lymph nodes is indicated by the number of nodes involved

N1 infiltrate one lymph node

N3 infiltrate three lymph nodes

Metastases

M1: one site of metastasis M2: two sites of metastasis M3: three sites of metastasis Mx: more than four sites

Tumor size can also by stagedT1 small tumor presentT2 larger tumorT3 progressive increase in tumor

sizeTx tumor so invasive unable to

determine size

Cancer Coding

Grade 3 Stage 4 N3 Tx M3What does this mean?What is the prognosis?

Grade I Stage 2 N0 TI M0What does this mean?What is the prognosis?

Treatment

1. Surgery2. Radiation3. Chemotherapy4. Biological Therapy

Surgery

Encapsulated with limited infiltration and limited metastases

Example: stomach, breast, uterus, prostrate

Sometimes done to decrease the size of the tumor for palliative reasons

Example: decrease pain from tumor pressing on nerve

Radiation Therapy

Maximal dose of ionizing radiation to the tumor cells

Minimal dose to the surrounding cells Targeted at non-differentiated cells

What is the difficulty?Where would this be difficult to do?Solution can be pellets. Say what?

Chemotherapy

Drugs target rapidly dividing cells (non differentiated)

Block replication to decrease growth Given by Intravenous (IV) and oral route Often used with other treatments Used in T1-4N1-4M1-3 Carcinomas, Sarcomas & Mixed-Tissue

TumorsWhich body system has cells that normal

divide rapidly? (hint SE of chemo)

Biological Agents

Using immune cells to target and fight tumor cells

Researchers are focusing on NKC and T-cells

Hormones: Estrogen is used to treat prostate cancer

Creating vaccinations ie Gardasil to boost the immune response

Utilizing the MHC on phage cells to create antibodies against cancer cells