Patho - Lect 5: Cancer II

What are role of genes in cancer?

Most of the mutations of cells do not affect genes that regulate growth and stability. As a result these mutations are of no consequence.

Genes that can cause cancer are:

Mutator genes, oncogenes, tumor suppressor genes.

Mutator Genes

Genes that repair __ and protect the __.

mutated DNA, genome.

Mutator Genes

Over time affected cells with disable mutator genes __.

allow mutations go unrepaired.

What are oncogenes?

Genes that code for proteins involved in cells growth or regulation.

Oncogenes

Affected cells will __ and inhibit cell death.

allow unregulated growth

What are tumor suppressor genes?

Genes that prohibit over proliferation of cells and regulate apoptosis.

Tumor Suppressor Genes

Affected cells will not go through __ and become __.

apoptosis, ‘immortal’.

What are tumor markers?

Antigens present on the surface of tumor cells or substances released by normal cells in response to the presence of tumor cells.

Tumor Markers Examples

__ - normally present during fetal development but have been induced to reappear.

Ex: Primary liver cancer, cancer of the testes.

Alpha-fetoprotein

Tumor Markers Examples

__ - specific antigen from epithelial cells lining the ducts of prostate gland.

Prostate

Tumor Markers Examples

__ - 125 glycoprotein produced in the ovary.

CA

Which cancer is most common in men?

Prostate cancer, lung cancer, colorectal cancer

Which cancer is most common in women?

Breast cancer, lung cancer, colorectal cancer

What is prognosis?

A cancer-free state generally defined as 5 years survival without recurrence.

Prognosis

__ - no clinical signs of cancer. Client may experience several remissions.

Remission

Cancer Deaths

Among men, __ is by far the leading cause of cancer death (28%), followed by __ (10%) and __ (8%) cancers.

lung cancer, prostate, colon & rectal

Cancer Deaths

Among women, __ (26%), __ (15%), and __ (9%) cancers are the leading causes of cancer death.

lung, breast, colon & rectal

Treatment

Many treatments will result in __.

long term remission and some in cure.

Treatment

__ - to reduce pain in late stage cancers is commonly done.

Palliative treatment

What are treatments of cancer?

Chemotherapy, radiation, surgery, hormonal therapy, monoclonal antibodies, immunotherapy.

Cancer Treatments Chemotherapy

Use of __ that target vital cellular function or metabolic pathways critical to both malignant & normal cell growth and replication.

nonselective cytotoxic drugs

Cancer Treatments Chemotherapy

Principle of __ - (usually mg/wk) correlation between dose and kill the tumor cells.

Dose Intensity

Cancer Treatments Chemotherapy

__ - maximum dose to kill the tumor but not harm normal tissue, (quite low).

Therapeutic index

Classifications of chemotherapy includes:

Antimitotics, antimetabolites, alkylating agents, antibiotics.

Which adverse effects of chemotherapy:

• Limiting factor with chemotherapy

• Blood test taken before each treatment

• Nadir is point of lowest cell count

Bone marrow depression

Which adverse effects of chemotherapy:

• May occur prior to, during, or shortly after treatment

• Antiemetic drugs helpful for decreasing nausea

Nausea

Which adverse effects of chemotherapy:

• Occurs easily

• Hair loss

• Breakdown of skin and mucosa

Epithelial cell damage

Which adverse effects of chemotherapy:

• Fibrosis in the lungs

• Damage to myocardial cells

• Kidney damage

Damage to specific areas with some antineoplastic drugs

Other Drugs

• Act to block receptors for growth promoters on cancer cells

Blocking agents

Other Drugs

• Augment the natural immune response

Biological response modifiers (BRMs)

Other Drugs

• Inhibit the stimulus for growth of blood vessels

Angiogenesis inhibitors

Other Drugs

• Prescribed to alleviate pain

• May be used in high dosages

Analgesics

How is radiation used in cancer treatments?

It use ionizing radiation to eradicate cancer without producing excessive toxicity.

Which type of cancer treatment:

• Causes mutations or alterations in target DNA

• Most effective in rapidly dividing cells

• Some types of cancers are radioresistant

Radiation Therapy

Methods of administration for Radiation Therapy

• Radiation for a short time to specific site in the body

• Requires multiple treatments (gold flake, background)

External sources - cobalt machine

Methods of administration for Radiation Therapy

• Treat specific cancers (e.g., cervical or oral tumors)

Internal Insertion of radioactive material at the tumor site

Methods of administration for Radiation Therapy

• Monitor to ensure that there is no leakage

• Radioisotopes may be given by injection for specific tumors

Instill radioisotope in a solution into a body cavity

Which adverse effects of radiation:

• Decreased leukocytes - increase risk of infection

• Decreased erythrocytes - fatigue, tissue breakdown

• Decreased platelets - excessive bleeding

Bone marrow depression (if bone specific)

Which adverse effects of radiation:

• Damage to blood vessels and skin, hair loss

Epithelial cell damage

Which adverse effects of radiation:

• Caused by abdominal radiation

Infertility

Which adverse effects of radiation:

• Can lead to mental depression

Nonspecific fatigue and lethargy

Which cancer treatment:

• Biopsy of the tumor - Dx

• Sentinel (central) node - staging

• Removal of tumor and surrounding tissue - (healthy margins)

Surgery

Cancer Treatments

• Has been one of the first cancer treatments used

• Action is used for receptor activation of blockage

  • Block Estrogen or Testosterone

• Interferes with cell growth and proliferation

Hormonal therapy

Cancer Treatments

• Highly specific to cancer antigens (flags cells)

• Can be used bound to radioactive material

• Can cause tumor rejection without affecting healthy tissue

Monoclonal antibodies

Cancer Treatments

• The use antitumor immune rejection responses

• Selectively eliminate cancer cells while sparing normal tissue

• Memory cells would give extended protection against reemergence

• Cytotoxic effect on cancer cells

Immunotherapy

What are immunomodulating agents?

Nonspecific stimulation to enhance the immune response, tumor is injected with bacteria.

What are these characteristics of:

• Inhibits tumor growth

• Enhances natural killer cell activity

• Increases cancer cell expression of tumor antigens (flags cancer cells)

Interferons

What does antigens do in immunotherapy?

They uses DNCB inducing a contact hypersensitivity response at the tumor site - restricted to superficial tumors of the skin.

What are these characteristics of:

• Transfer or augmentation of a cytotoxic T cell

• Specific for antigens of the tumor cell

• Known as Lymphokine-Activated Killer (LAK) Cell therapy

Effector Cells & Lymphokines