Cancer

ClassificationCausesDiagnosis

GradingStaging

Effects/Surgical Tx

Objectives Discuss the pathophysiology of cancer. Differentiate between benign and malignant

neoplasms Discuss causes of cancer Describe the lab and diagnostic tests used to

diagnose cancer

Pathophysiology

Normal cell growth review The Cell Cycle: 4 phases A malfunction of any of the

regulators of cell growth can result in rapid proliferation of immature cells

Differentiation Etiology

Known Causes Viruses Drugs and

Hormones Chemical Agents Physical Agents

Benign Neoplasms

Localized growths Form a solid mass

Well-defined borders Frequently encapsulated

Response to homeostatic controls Grow slowly; same size Destructive with crowding/pressure

Malignant Neoplasms

Grow aggressively Response to homeostatic controls Noncohesive; irregular shape Cut through surrounding tissues; Rapid Cells may travel thru blood or lymph Not always easy to remove Can recur

Characteristics of Malignant Cells Loss of regulation of mitotic rate Loss of cell specialization Loss of contact inhibition Progressive acquisition of the cancerous

phenotype & immortality Irreversibility of cancerous phenotype to greater

aggressiveness Altered cell structure; diff in cell nucleus &

cytoplasm Simplified metabolic activity Transplantability (metastasis) Ability to promote own survival

How Cancer Invades Normal Tissue

Diagnostics X-ray imaging Computed Tomography Ultrasonography Magnetic Resonance Imaging Tissue Samples Screening: PSA

Grading and Staging Grading

Amt of differentiation (level of functional maturity) of the cell

Estimates rate of growth based on the mitotic rate

Staging Use to classify solid tumors Refers to relative size of tumor and extent of

disease TNM classification system

TNM Classification SystemTumor To

TisT1, T2,T3,T4

No evidence of primary tumorTumor in situAscending degrees of tumor size and involvment

Nodes NoN1a, N2aN1b, N2b, N3bNx

No abnormal regional nodesRegional nodes-no metastasisRegional lymph nodes-mets suspected; Regional nodes cannot be assessed clinically

Metastasis MoM1, M2, M3

No evidence of distant metastasisAscending degrees of metastatic involvement of host including distant nodes

Effects of Cancer Disturbed or loss of physiologic functioning, from

pressure to obstruction Hematologic Alterations: Impaired function of

Blood Cells Infections: Fistula development & tumors may

become necrotic; erode skin surface Hemorrhage: Tumor Erosion, bleeding, severe

anemia Anorexia-Cachexia Syndrome: wasting away

Effects of Cancer Paraneoplastic Syndromes: ectopic sites

w/excess hormone production Pain: major concern Physical Stress: body tries to respond and

destroy neoplasm Psychological Stress

Surgical Tx Surgical Tx isused for Dx and staging of more than 90% of

all cancers and for primary TXx of more than 60% of cancers

If possible, tumor is removed in entirety; may necessitate mutilation of body

Less distressing results Remove nonessential portion of organ or tissue containing

tumor, such as in situ bowel tumors Remove organ whose function can be replaced chemically,

such as thyroid Resect a pair of organs when the unaffected organ can take

over the function of the missing one, such as a lung