11/2: Anticancer Therapies: Radiation and Drugs

Question 1

What are key properties of cancer cells?

Answer 1

• They reproduce without regard to the normal restraints on cell
  growth and cell division
  – They invade and colonize areas normally reserved for other cells

Question 2

What are abnormal cells that grow (increase in mass) and proliferate (divide)?

Answer 2

Tumors or neoplasms

Question 3

When are tumors considered benign?

Answer 3

If the neoplastic cells do not
become invasive

Question 4

When are tumors considered cancerous?

Answer 4

If it acquires the ability to invade surrounding tissue at which point it is has become malignant

Question 5

Malignant tumors often, as a consequence of
their invasiveness, produce cells that break
out of their primary site and form secondary
tumors at other sites called…

Answer 5

Metastases

Question 6

Is a single mutation sufficient to cause cancer?

Answer 6

No - inherited mutations offer increased risk

Question 7

What are potential risk factors for cancer?

Answer 7

– Radiation exposure
– UV light from the sun
– Chemicals (carcinogens)
– Life-style (smoking, certain diets)
– Viruses (EBV, HIV, HPV)

Question 8

The overall incidence of cancer increases with ______

Answer 8

age

Question 9

During the cell-cycle, the cell has scanning mechanisms to do what?

Answer 9

Detect DNA damage and either repair the damage or result in cell-cycle arrest or cell death (apoptosis)

Question 10

What protein is a key mechanism in the cellular response to DNA damage?

Answer 10

p53

Question 11

What is the basic strategy for treating cancer?

Answer 11

To induce so much damage to
the tumor cells via DNA damage (primarily) to
prevent them from dividing and induce cell death

Question 12

What are the types of radiation therapy?

Answer 12

External beam therapy
Internal Radiation therapy
Photon Therapy
Charged particle or proton therapy

Question 13

What therapy uses a machine to send high energy beams from outside the body to the tumor area?

Answer 13

External beam therapy

Question 14

What therapy uses radioisotope given internally, radiation generally only travels a short distance depending upon the isotope and its energy?

Answer 14

Internal radiation therapy

Question 15

What therapy works either by direct ionization of atoms in the DNA chain or indirectly by ionization of water to form hydroxyl radicals that can then damage DNA?

Answer 15

Photon therapy

Question 16

What therapy uses a particle accelerator to beam high-energy particles (protons or carbon, boron or neon nuclei). Better ability to precisely localize the radiation
dosage and less damage to surrounding, healthy tissue?

Answer 16

Charged particle or proton therapy

Question 17

How does doxorubicin hydropcholride (adriamycin) work?

Answer 17

Intercalates between base pairs in the DNA helix,
thereby preventing DNA replication and ultimately inhibiting protein synthesis

Question 18

How does bleomycin sulfate work?

Answer 18

forms complexes with iron that reduce molecular oxygen to superoxide and hydroxyl radicals which cause single- and double-stranded breaks in DNA

Question 19

How does cisplatin work?

Answer 19

inducing intrastrand and interstrand DNA cross-links, as well as DNA-protein cross-links, which induce apoptosis

Question 20

How does methotrexate work?

Answer 20

Inhibition of DNA and RNA syntheses

Question 21

How does vinblastine work?

Answer 21

inhibits microtubule formation, resulting in disruption of mitotic spindle assembly and arrest of tumor cells

Question 22

What is a treatment designed to induce, enhance or suppress the immune response. Most applications are designed to stimulate a person’s own immune response to destroy cancer cells that have escaped normal immune surveillance?

Answer 22

Immunotherapy

Question 23

What is leukemia characterized by?

Answer 23

Increased production/growth of granulocytes in the bone
marrow that then circulate in the blood

Question 24

What is leukemia caused by?

Answer 24

A chromosomal translocation called the Philadelphia chromosome

Question 25

What does the translocation of the philadelphia chromosome cause?

Answer 25

A fusion gene/protein
between the BCR gene and the ABL gene

Question 26

What is the fusion protein in a philadelphia chromosome?

Answer 26

Tyrosine kinase

Question 27

What is the parent drug used to treat CML?

Answer 27

Gleevec (imatinib)

Question 28

What is the mechanism of action WITHOUT Gleevec to induce leukemia?

Answer 28

BCR-ABL active -> signal for cell proliferation and survival -> leukemia

Question 29

What is the mechanism of action of Gleevec to NOT induce leukemia?

Answer 29

BCR-ABL blocked with gleevec -> no signal -> no leukemia

Question 30

What are the treatment phases for leukemia?

Answer 30

1. induction therapy
2. consolidation/intensification therapy
3. maintenance therapy

Question 31

What is the goal of induction therapy?

Answer 31

Kill the leukemia cells in the blood and bone marrow
This puts the leukemia into remission

Question 32

What is the goal of consolidation therapy?

Answer 32

Kill any remaining leukemia cells that may not be active but could begin to regrow and cause a relapse

Question 33

What is the goal of maintenance therapy?

Answer 33

Kill any remaining leukemia cells that may regrow and cause a relapse
*cancer treatments are given in lower doses than those used for induction and consolidation therapy

Question 34

Where does acute lymphoblastic leukemia start?

Answer 34

Lymphoid cells of the bone marrow

Question 35

What occurs in lymphoblastic leukemia?

Answer 35

Bone marrow produces too many immature lymphocytes

Question 36

What are risk factors of ALL?

Answer 36

• Being exposed to x-rays before birth.
• Being exposed to radiation.
• Past treatment with chemotherapy.
• Having certain changes in the genes.
• Having certain genetic conditions that include the following:
  – Down syndrome, Ataxia telangiectasia, Bloom syndrome, Neurofibramatosis,
  Schwachman Syndrome

Question 37

What are possible signs and symptoms of ALL?

Answer 37

Fever; foul smelling urine; easy bruising or bleeding; petechiae (flat, pinpoint, dark-
red spots under the skin caused by bleeding); bone or joint pain; painless lumps in
the neck, underarm, stomach or groin; pain or feeling of fullness below the ribs;
weakness, feeling tired, or looking pale; loss of appetite

Question 38

What is the diagnosis of ALL?

Answer 38

Blood CBC (complete blood count), bone marrow analysis, cytogenetic analysis

Question 39

What is ALL prognosis?

Answer 39

• Age at diagnosis, gender, and race.
• The number of white blood cells at diagnosis.
• Whether the leukemia cells began from B lymphocytes or T lymphocytes.
• Whether there are certain changes in the chromosomes of lymphocytes.
• Whether the child has Down syndrome.
• Whether the leukemia has spread to the brain, spinal cord or testicle.
• How quickly and how low the leukemia cell count drops after
  initial treatment.

Question 40

What are low risk ALL groups?

Answer 40

Includes children aged 1 to
younger than 10 years who have a WBC count of less
than 50,000/μL at diagnosis

Question 41

What are high risk ALL groups?

Answer 41

children younger than 1 year or 10 years and older and children who have a white blood cell count of 50,000/μL or more at diagnosis