Neoplasia III

Question 1

What are carcinogens?

Answer 1

Carcinogens are agents that inflict genetic damage by damage to DNA

Question 2

Direct-Acting Carcinogens

Answer 2

They require no metabolic conversion to enact their negative effects.

Question 3

Indirect Acting Carcinogens

Answer 3

They require metabolic conversion to become ultimate

carcinogens.

Question 4

What are promoters?

Answer 4

Promoters are compounds, which themselves are nontumorigenic, however they facilitate the induction of cell proliferation.

Question 5

Carcinogen: Vinyl chloride

Answer 5

Angiosarcoma of the liver

Question 6

Carcinogen: Nitrosamine in smoked foods

Answer 6

Stomach cancer

Question 7

Carcinogen: Asbestos

Answer 7

Mesothelioma and bronchogenic carcinoma

Question 8

Carcinogen: Arsenic

Answer 8

Squamous cell carcinoma of the skin

Question 9

Carcinogen: Aflatoxin B

Answer 9

Hepatocellular carcinoma

Question 10

Carcinogen: Cigarette smoke

Answer 10

Carcinoma of the oropharynx, lung, esophagus, kidney, bladder

Question 11

What are some radiation carcinogens?

Answer 11

• Ionizing radiation (X-rays)

- UV light

Question 12

What does Human T-cell lymphotropic virus (HTLV-1) cause?

Answer 12

T cell leukemia/lymphoma

Question 13

What does Human papillomavirus (HPV) cause?

Answer 13

Cervical cancer

Question 14

What does Epstein Barr Virus (EBV) cause?

Answer 14

Burkitt Lymphoma and nasopharyngeal carcinoma

Question 15

What does Hepatitis B and C virus cause?

Answer 15

Hepatocellular carcinoma

Question 16

What are some mechanisms that tumors enact to evade the immune system?

Answer 16

 Failing to express HLA class I and escaping CTL attack
 Eliminating strongly immunogenic subclones
 Suppressing the host immune response; examples: by secreting TGF-beta
 Expressing FasL and inducing immune cell apoptosis
 Producing a thicker coat of glycocalyx molecules blocking access to immune cells

Question 17

What is cancer cachexia?

Answer 17

This results on the loss of body fat, lean body mass, weakness, anorexia, anemia.

Question 18

What are Paraneoplastic Syndromes?

Answer 18

They are symptom complexes that cannot be readily explained by local or distant spread of the neoplasms. They may be mediated by hormone elaboration which is not indigenous to the tumor parenchyma.

Examples are Cushing’s Syndrome from a tumor cells in the lung producing ACTH

Question 19

How does grading of cancer work?

Answer 19

Based on the cytologic differentiation (anaplasia, pleomorphism, loss of normal architecture, mitoses) of the tumor cells

Well-differentiated = low grade; poorly differentiated = high grade

Question 20

How does the staging of cancer work?

Answer 20

Staging of a cancer is based on the size of the primary tumor, extent of spread to regional lymph nodes, and the presence or absence of metastases.

Question 21

What is “homing?”

Answer 21

Specific cancers have shown an ability to metastasize to areas of the body far away that show no direct path