severe failure in the regulation of genes (mutations) that code for cell division

Severe failure in the regulation of genes (Mutations) that code for cell division

Cancer Characteristics• Lack Differentiation

– “Immortal” due to repeated division, normal cells do not repair the mutation

– Not Specialized = No purpose to any body part, does use nutrients from the body

• Have Abnormal Nuclei– - Genes are mutated and contain excessive number of

chromosomes• Form Tumors

– Abnormal mass of cells that invade surrounding tissues and disrupt normal cellular mitosis

Microscopic Appearance of Cancer Cells

Loss of Normal Growth Control

Cancer cell division

Fourth orlater mutation

Third mutation

Second mutation

First mutation

Uncontrolled growth

Cell Suicide or Apoptosis

Cell damage—no repair

Normal cell division

Hyperplasia

HyperplasiaNormal

Dysplasia

Hyperplasia Mild dysplasiaNormal

Carcinoma in Situ

Milddysplasia

Carcinoma in situ (severe

dysplasia) Cancer(invasive)

Normal Hyperplasia

Example of Normal Growth

Dermis

Dividing cells in basal layer

Dead cells shed from

outer surface

Epidermis

The Beginning of Cancerous Growth

Underlying tissue

Tumors (Neoplasms)

Underlying tissue

Invasion and Metastasis

3Cancer cells reinvade and grow at new location

1Cancer cells invade surrounding tissues and blood vessels

2Cancer cells are transported by the circulatory system to distant sites

Cancer• Cells divide uncontrollably and produce an excess of

tissue– Benign Tumors

• NOT cancerous. • Does not spread to other parts of the body or invade and

destroy nearby tissue. • Benign tumors usually grow slowly.• Generally, not harmful. However, this is not always the case.

If a benign tumor is big enough, its size and weight can press on nearby blood vessels, nerves, or organs, or otherwise cause problems

– Malignant tumor can be fatal• Cancer cells compete with normal cells for nutrients, blood,

and energy eventually causing normal cells to atrophy• The spreading of cancer is known as Metastasis which allows

cells to spread to other parts of the body Cancer cells usually spread via the bloodstream or the lymph system

Causation

Environmental & Genetic

Chromosomes are DNA molecules

Heredity

RadiationChemicals

Viruses

Chemicals & Radiation-Damage the genes

Virus -Introduces own genes

Heredity-Passes on alterations in genes

Mutations and Cancer

Genes Implicated in Cancer

Oncogenes are

Mutant Forms of Proto-Oncogenes

Cell proliferation driven by internal oncogene signaling

Transcription

Activated gene regulatory protein

Inactive intracellular signaling protein

Signaling protein from active oncogene

Inactive growth factor receptor

DNA Repair Genes

Cancer

No cancer

No DNA repair

Normal DNA repair

Base pair mismatch

T CATC

A GTCG

T CAGC

A GTCG

A GTG A GTAG

T CATCT CATC

Cancer Causing Viruses• HTLV-1

– Attacks killer T-cells in leukocytes and impairs Lymphatic system T-Cell Leukemia

• HIV– Directly attacks Helper T cells which are

responsible for stimulating B Lymphocytes antibody production

Epstein Barr (EBV)– Hodgkin’s Lymphoma– Burkitt’s Lymphoma

• Hepatitis B (HBV)– Liver Cancer

• Human Papillomavirus (HPV) • Cervical Cancer

• Herpes Simplex 2– Cancer of the cervix

Different Kinds of Cancer

Lung

Breast (women)

Colon

BladderProstate (men)

Some common sarcomas:Fat

Bone

Muscle

Lymphomas:Lymph nodes

Leukemias:Bloodstream

Some common carcinomas:

Naming Cancers

Prefix Meaning

adeno- gland

chondro- cartilage

erythro- red blood cell

hemangio- blood vessels

hepato- liver

lipo- fat

lympho- lymphocyte

melano- pigment cell

myelo- bone marrow

myo- muscle

osteo- bone

Cancer Prefixes Point to Location

Necrosis – Death of a cell or a group of cells

Atrophy – Decrease in cellular size and corresponding organs or tissuesNeoplasm – Abnormal formation or

growth

Common Cancer Terms

MelanomaDestruction melanocytes

LymphomaDestruction of lymph nodes

CarcinomaMalignant tumor hat arises from epithelial cells

SarcomaMuscle or connective tissue cancer

LeukemiaDestruction of Leukacytes (WBC)

Signs / Symptoms

Got Pain?1.Nerve Pressure2.Passageway Obstruction

3.Vital Organ Malfunction

• Problems with Diagnosing Cancer– Vague

• See next slide for common symptoms

– Depends on size, location, and which organs are being affected

– Asymptomatic– Symptoms can be misleading

Symptoms of CancerSubjective

Common Symptoms

• Fever• Aches• Weakness• Weight Loss• Cough• Pain• Headaches• Irritable

• Behavior Change• Inconsistent Digestion• Rash• Lumps• Skin Color Change• Mental Problems• Abnormal CBC

Signs of CancerObjective

Diagnosis• Biopsy• X-Ray• CBC• Angiography• Pap Smear• Mammogram• Colonoscopy/Endoscopy• Fecal Occult Blood Test

Biopsy – Removal and microscopic examination of tissues from the body

After cancer has been diagnosed, doctors ask the following three questions to determine how far the disease has progressed:1. How large is the tumor, and how deeply

has it invaded surrounding tissues?2. Have cancer cells spread to regional

lymph nodes?3. Has the cancer spread (metastasized)

to other regions of the body?

After cancer has been diagnosed, doctors ask

the following three questions to determine how

far the disease has progressed:1. How large is the tumor, and how deeply

has it invaded surrounding tissues?2. Have cancer cells spread to regional

lymph nodes?3. Has the cancer spread (metastasized) to

other regions of the body?

• Stage 0 – carcinoma in situ.

• Stage I – cancers are localized to one part of the body.

• Stage II – cancers are locally advanced.

• Stage III – cancers are also locally advanced. Whether a cancer is

designated as Stage II or Stage III can depend on the specific type of cancer; for example, in Hodgkin's Disease, Stage II indicates affected lymph nodes on only one side of the diaphragm, whereas Stage III indicates affected lymph nodes above and below the diaphragm. The specific criteria for Stages II and III therefore differ according to diagnosis.

• Stage IV – cancers have often metastasized, or spread to other

organs or throughout the body

Treatments

Common Cancer Treatments

• Chemotherapy• Radiation Therapy• Bone Marrow Transplant• Targeted Therapy• Immunotherapy