Pathophysiology - 03 - Cancer

7/30/2019 Pathophysiology - 03 - Cancer

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APPLIEDPATHOPHYSIOLOGYAPPLIEDPATHOPHYSIOLOGY

PHRM315PHRM315

Lecture1Lecture1

AN ERAN ER

p.11p.111919

PowerPointLecture Slide Presentation prepared by

Dr. Ashraf Kamel,Associate Professor of Anatomy and Physiology,Riyadh College of Dentistry and Pharmacy, KSA


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Cancer is a disease that results from abnormal

growth and differentiation of tissues.

the United. States (see Table 2.1).

are the prostate, breast, lung and colon.

oug cancer can ar se a any age, eincidence of cancer increases proportionallywith increasing age.

Copyright 2008 Dr. Ashraf KamelRiyadhCollegeofDentistryandPharmacy


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Tumor or neo lasm A mass of tissue in which the

growth rate is excessive and uncoordinated whencompared with normal tissues (see Table 2.2).

Benign neoplasm Tumor cells that tend to he

clustered in a single mass and are not malignant.Benign tumors usually will not cause death unless

they interfere with vital function.

Specific names end with oma e.g. osteoma is abenign tumor of bone, whereas osteosarcoma is a

Copyright 2008 Dr. Ashraf Kamel

.

RiyadhCollegeofDentistryandPharmacy


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Abnormal gene expression



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Mali nant neo lasm Tumors that have the

ability to metastasize or break loose and spreadto other areas of the body. If untreated, such

tumors can cause great suffering and death.

S ecific exam les:

Carcinoma Malignant tumor of epithelial

.

Sarcoma Malignant tumor of skeletal or


connective tissue origin.



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MetastasisMetastasis

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The ability of tumor cells to spread to other parts of the body andestablish secondary tumors.

Malignant tumor cells can break off and utilize blood vessels or lymphaticvessels to spread to other areas of the body.

umor ce s en ance t e r potent a or metastat c sprea y re eas ngprotease enzymes that digest the extracellular matrix surrounding

adjacent cells.

Malignant tumor cells may also produce growth factors that stimulate theformation of new blood vessels (angiogenesis), which in turn support the

rapid growth of tumor cells.

Certain organs such as the lungs are prime locations for the formation ofmetastases because of the large amount of blood flow they receive from

the body. The liver is also a common site of metastasis for tumors


intestines must first pass through the liver via the hepatic portal system.

Common sites of metastasis for various cancers are listed in Table 2.3.RiyadhCollegeofDentistryandPharmacy


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Th ri f Th ri f n n in n i

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AbnormalitiesofAbnormalitiesoftumourtumour suppressor/inducergenessuppressor/inducergenes

Several proteins produced within cells such as the pp5353proteinprotein are known to limit cellular division by regulating

certain parts of the normal cell cycle.

The genes that code for these proteins are referred to as

antiantioncogenesoncogenes since they suppress cell growth.

Failure of these antioncogenes may lead to the unregulatedcellular division that is characteristic of cancer cells.

In contrast, other groups of genes are classified as protoprotooncogenesoncogenes since they produce proteins and substances that


enhance cellular growth and proliferation.


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TheoriesofTheoriesofOncogenesisOncogenesis10

MutationofDNAMutationofDNA

Numerous chemical, physical d biologic agents have been shownto be carcinogenic, meaning they can induce the formation of

cancers (see Table 2.4).

any o t ese agents can amage ce u ar , e t er rect y orthrough the production of toxic intermediates such as free

radicals.

Certain viruses are also oncogenic in that they may inducemutations in host cell DNA or alter rates of cellular transcription

see Table 2.5 .

Mutations of cellular DNA can lead to the formation of cells withabnormal growth and differentiation patterns.



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for a number of cancers including:

1. Colon cancer

.

3. Retinoblastoma

4. Certain forms of leukemia and lymphoma.



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Many cancers may be asymptomatic in the early stages. Asthe tumors continue to grow, they affect local tissues as

well as the overall body.

Local effects of cancer:

1. Compression of blood vessels2. Ischemia

3. Pain

. ee ng5. Infection


.



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S stemic effects of cancer:

1. Fatigue

.

3. Bleeding and hemorrhage

4. Anemia due to chronic bleedin or bonemarrow destruction; this anemia may beexacerbated by chemotherapy

.6. Abnormal hormone production from an

affected gland or directly from certain types


of hormoneproducing tumors



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A complex syndrome characterized by anorexia, weight loss andlean body (muscle) wasting seen in a significant percent of

patients with cancer and AIDS.

num er o meta o c a norma t es ave een emonstratein patients with cachexia that lead to poor utilization of nutrients

and overall malnutrition.

A key factor in cachexia appears to be the production ofcytokines such as tumor necrosis factor and interleukins in

res onse to the resence of cancer. These substances are

produced by many cells within the body and appear to beprotective against bacterial and viral infections as well as

malignant cells. Unfortunately, these substances also appear to


be responsible for cachexia.


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TumorStagingTumorStaging17

Tumors are classified or staged based upon the TNM system

that includes a description of tumor size (T), involvement of

lymph nodes (N) and metastasis (M).



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CancerDetectionCancerDetection18

Tumorcell

markersTumor

cell

markers

cells.

presence of tumor cells in the body.

diagnosis:

a) Not specific for cancer as certain noncancerous

conditions may also be associated with theappearance of some of these markers in the blood.


cell markers are detected.



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VisualizationVisualization

o en y e presence o a umor anevaluate metastasis:

Radiography, computer tomography

,

imaging.

Endoscopy may also be utilized tovisually detect tumors in the bronchi


and gastrointestinal tract.


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BiopsyBiopsy

histologic or histochemical analysis.

May be accomplished:

1. Surgically.

2. by a needle biopsy.

. .4. by endoscopic biopsy.



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Cancer treatment can he multifaceted and may include:

1. Surgical removal of tumors

2. Chemotherapy

3. Radiation therapy

tokillorarrestrapidlyrowingtumorcells

4. Immunebased treatments are currently under

investigation as alternatives to toxic chemotherapy and

radiation therapy.

5. Hormonal therapy has also been shown to inhibit the


growth of certain types of cancers.


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If accessible tumors should be sur icall removed.

Often accompanied by chemotherapy or radiationtherapy to kill any cancer cells that are not removed

or ave me as as ze .

ChemotherapyChemotherapy

Drugs used for chemotherapy of cancer fall intoseveral categories (see Table 2.8).



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in breast,breast, prostateprostate and uterineuterine cancercancer.

The estrogen inhibitor tamoxifen is effective in

the treatment ofbreastbreast cancercancer.

The androgen inhibitor flutamide is effective in

..



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Radiation therapy is used to destroy cancer cells that are highlymitotic and most susceptible to the lethal effects of radiation.

Radiation therapy side effects include alopecia, diarrhea, tissueirritation and organ inflammation.

Immunebased

TherapiesImmune

based

Therapies

Biologic response modifiers such as interferons, immunomoduIators, tumor antigens and lymphokines/cytokines are

response of individuals with cancer.

Monoclonal antibodies have also been studied as a hi hl


specific means of delivering chemotherapeutic drugs directly to

and only to cancer cells.RiyadhCollegeofDentistryandPharmacy

Pathophysiology - 03 - Cancer

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