Exam #2: Neoplasia VI Flashcards Preview

General Pathology > Exam #2: Neoplasia VI > Flashcards

Flashcards in Exam #2: Neoplasia VI Deck (66):
1

What is the mechanism of UVB tumorigenesis?

- UVB (280-320 nm) causes the formation of pyrimidine dimers
- Pyrimidine dimers cause DNA damage

2

What is the pathway of DNA repair following UVB damage?

NER pathway i.e. nucleotide excision repair

3

What is Xeroderma Pigementosum?

This is a condition in which infected individuals have enzyme defect in DNA repair (NER pathway), making the patient highly susceptible to radiation damage

4

What is ionizing radiation?

Ionizing radiation is radiation with enough energy so that during an interaction with an atom, it can remove tightly bound electrons from the orbit of an atom, causing the atom to become charged or ionized. Types of ionizing radiation include:
- Alpha rays
- Beta rays
- Gamma rays
- Neutrons
- X-ray

Note that alpha, beta, and neutrons are worse than gamma & x-rays; these are particulates

5

What are the two ways that ionizing radiation can cause DNA damage?

1) Direct effect i.e. direct damage to DNA
2) Indirect effect= free radical generation, which then damage DNA

6

What are the mechanisms of DNA damage that lead to tumorigenesis in ionizing radiation?

1) Chromosome breakage
2) Translocation
3) Point mutation

7

What are the most common cancers caused by radiation?

Leukemia, except CLL
Thyroid papillary cancer
Breast/ lung

8

In response to atomic bomb radiation, is skin cancer likely?

No--skin is most sensitive to UV radiation

9

What cancers are associated with x-rays workers?

Radiation dermatitis
Skin cancer

10

For workers that commonly work with radium, what cancer is most common? What occupation is associated with radium exposure?

Osteosarcoma

--This is associated with factory workers that dials of watches that contain "luminous radium"

11

How do Hepatitis B & C lead to liver cancer?

Chronic liver damage leads to chronic regeneration and regenerative hyperplasia, which can transform to dysplasia & eventually malignancy

B= Hepatitis B also produces HBX protein
- Stimulates insulin-like growth factor
- Binds & inhibits p53

12

What cancers are associated with EBV?

- Burkitt Lymphoma
- Hodgkin Lymphoma
- B-cell Lymphoma in immunosuppressed patients
- Nasopharyngeal carcinoma

13

Which subtypes of HPV are associated with cancer? What are the mechanisms of carcinogenesis?

- HPV 16, 18, & 31 are "high risk" b/c they INTEGRATE their DNA into host DNA
- E6= p53 inhibitor
- E7= Rb, p53, & p21 inhibitor

14

What subtypes of HPV are "low risk" & why?

- HPV 6 & 11 only cause benign tumors
- These subtypes of HPV do NOT integrate into the genome of the host

Not integrated= "episomal"

15

What is the primary cancer causing RNA virus?

Human T-cell Leukemia Virus Type 1 (HTLV-1)

HTLV-1 is a retrovirus of the human T-lymphotropic virus (HTLV) family that has been implicated in several kinds of diseases including very aggressive adult T-cell lymphoma (ATL)

16

Where is HTLV-1 endemic?

Japan
Caribbean basin

17

What is the mode of transmission for HTLV-1?

Intercourse
Blood
Breast feeding

18

What is the mechanism of HTLV-1?

Virus contains Tax gene that:
1) Stimulates transcription of viral mRNA
2) Activates c-FOS, IL-2, and GM-CSF in the host
- IL-2 is a growth factor for T-cells that is activated by the virus
- c-FOS 7 GM-CSF are both growth factors
3) Inactivates p16INK4a

19

What is p16INK4a?

Tumor suppressor

20

What is HHV-8 & what cancer is it associated with?

HHV-8= Human Herpes Virus; this is an HIV-associated virus that leads to the development of Kaposi sarcoma

21

What are the symptoms of Kaposi Sarcoma?

Red-purple macules, papules, or nodules

22

What tumors are associated with H. pylori infection?

1) Gastric carcinoma
2) Gastric Lymphoma (MALT)

23

How does H. pylori cause cancer?

H. pylori encodes CagA (Cytotoxin associated gene A), which is a toxin stimulates growth factor pathways

24

What hormones are carcinogeneic?

Estrogen
Contraceptive hormones
Anabolic steroids

25

What cancers is estrogen associated with?

First, remember that estrogen can BOTH initiate AND promote cancer
- Breast
- Squamous cell carcinoma of the cervix
- Leiomyoma of uterus

26

What are the contraceptive hormones associated with?

- Breast cancer
- Benign/malignant liver tumors

27

What cancers are associated with anabolic steroids?

Benign & malignant liver tumors

28

What are the three general clinical manifestations in a patient with a tumor?

1) Local or hormonal effects
2) Cancer cachexia
3) Para-neoplasic syndrome

29

What is cancer cachexia & what causes cancer cachexia?

Loss of body fat, wasting & profound weakness; caused by loss of appetite, metabolic changes, and TNF-a

The key point here is TNF-a

30

What are para-neoplastic syndromes?

Distant effects of a tumor unrelated to the primary tumor or metastasis i.e. the tumor produces a hormone; that hormone secretes in the body and has a generalized effect


*****Note that this may represent the earliest manifestation of a cancer

31

List examples of para-neoplastic syndromes.

1) ACTH/ Cushing Syndrome
2) SIADH/ hyponatremia
3) Acanthosis nigricans

32

What cancer is SIADH associated with? What does SIADH lead to & why?

Small cell carcinoma of the lung
- Tumor secretes ADH
- Causes water retention
- Leads to dilution of Na+ in the blood

33

What is Acnathosis nigricans? What cancer is this associated with?

- This is a black, verrucoid appearing lesion in the skin, usually the axilla
- Gastric carcinoma

34

What is the second skin lesion associated with gastric carcinoma?

Lesser-Trelat sign

****This is an explosive onset of multiple seborrheic keratoses[1] (many pigmented skin lesions), often with an inflammatory base

35

What is Carcinoid Syndrome? What cancers is this associated with?

- This is a syndrome associated with neuroendocrine tumors
- Tumor is located in the appendix or small intestine & overproduces 5-HT
- Causes flushing, diarrhea, bronchospasm and tachycardia esp. on palpation of the abdomen

36

How is Carcinoid Syndrome diagnosed?

Urinary excretion of 5-hydroxyindoleacetic acid (5-HIAA) --a metabolite of 5-HT

37

What is the cause of nearly 40% of all clinical cases of hypercalcemia?

Malignancy

38

What are the causes of hypercalcemia in malignancy?

1) Release of PTH-like peptide
2) Osteolytic effect of bony metastasis
- Breast cancer

****Note that breast cancer can also have osteoblastic effects as well

39

What cancers are associated with the release of PTH?

- Squamous cell carcinoma of the lung
- Renal cell carcinoma

*****Note that these patients may have LOW levels of PTH; PTH-like peptide is causing the symptoms, NOT PTH, & Ca++ has a negative feedback on PTH

40

What causes hypocalcemia seen in cancer? What cancers is hypocalcemia associated with?

Medullary cancer of the thyroid
- Tumor releases calcitonin

41

What cancer is associated with gynecomastia? What hormone is causing gynecomastia?

Choriocarcinoma of the testis
- B-HCG

42

What is Eaton-Lambert Syndrome? What cancer is associated with Eaton-Lambert Syndrome?

Eaton Lambert Syndrome is a Myasthenia Gravis-like syndrome i.e. neuromuscular disease that leads to fluctuating muscle weakness and fatigue
- Eaton Lambert Syndrome is associated with Small Cell Cancer of the Lungs

43

What are the three general methods for diagnosing cancer?

1) Morphology
2) Molecular methods
3) Biochemical assay i.e. tumor markers

44

What are the different techniques used for morphological diagnosis of cancer?

Biopsy
Frozen section
FNAC--Fine needle aspiration cytology
Cytology
IHC

45

What are the molecular methods used for cancer diagnosis?

Flow cytometry
DNA probe analysis

46

When should you use immunohistochemistry (IHC) for cancer diagnosis?

- Diagnosis of undifferentiated tumors i.e. this is how you find the origin
- Categorization of leukemias and lymphomas

47

How would you know that a tumor is epithelial in origin (marker)?

Positive for cytokeratin or EMA i.e. epithelial membrane antigen

48

How would you know that a tumor is mesenchymal in origin?

Vimentin

49

What does desmin positive marker tell you?

Muscle specific origin

50

What is LCA? What does an LCA positive tumor indicate?

Leukocyte common antigen
- Leukocyte origin

51

What are the three markers associated with neuronal tumors?

1) Neuron-specific enolase
2) Chromogranin
3) Synaptophysin

52

What types of tumors aside from strictly neuronal tumors will be positive for the marker, NSE?

Neuroendocrine tumors e.g.
- Small cell carcinoma of the lung
- Carcinoids

53

What is Thyroglobulin a marker for?

Thyroid cancer

54

What is CD10 (CALLA) a marker for?

Acute Lymphoblastic Leukemia (ALL)

55

What is Placental Alkaline Phosphatase a marker for?

Seminoma i.e. germ-cell tumor of the testicles

56

What are vWF & CD31 markers for?

Vascular neoplasms

57

What is a tumor marker?

Substance found in the blood, urine, or body tissue that can be elevated in cancer

58

What is CEA? What is this a tumor marker for?

CEA= Carino-embryonic antigen that is a tumor marker for:
- Colon
- Pancreas
- Stomach
- Breast*

59

What is PSA & what is PSA a marker for?

PSA= Prostate-Specific Antigen, which is a tumor marker for prostate cancer

60

What is B-HCG? What is B-HCG a marker for?

B-HCG= beta-Human Chorionic Gonadotropin, which is a tumor marker for trophoblastic tumors i.e. choriocarcinoma

61

What is CA-125 a tumor marker for?

Ovarian carcinoma

62

What is AFP? What is AFP a tumor marker for?

AFP= alpha-fetoprotein, which is a tumor marker for
- Heptaocellular carcinomas
- Germ cell tumors of testes or ovaries

63

What is NSE a tumor marker for?

Small cell carcinoma of the lung

64

What is calcitonin a tumor marker for?

Medullary thyroid carcinoma

65

What is CA 19-9 a tumor marker for?

Colon & pancreatic cancer

66

What is CA 15-3 a tumor marker for?

Breast carcinoma