Neoplasia Objectives

Question 1

Summarize the 3 fundamental and shared characteristics of cancers

Answer 1

1. Cancer is a genetic disorder caused by DNA mutations.
2. Genetic alterations in cancer cells are heritable, being passed to daughter cells upon cell division.
3. Mutations and epigenetic alterations impart “cancer hallmarks” to cancer cells.

Question 2

What is a neoplasia?

Answer 2

Neoplastic cells replicate without being constrained by regulating factors that affect normal cells.

Question 3

What is a papilloma?

Answer 3

Benign epithelial neoplasm

Question 4

What is a polyp?

Answer 4

Mass that projects above a mucosal surface

Question 5

What is a chondroma?

Answer 5

Benign cartilaginous tumor.

Question 6

What is a carcinoma?

Answer 6

Malignant neoplasm of epithelial cells

Question 7

What is a sarcoma?

Answer 7

Malignant neoplasms of the mesenchymal/connective tissue

Question 8

Compare and contrast benign and malignant tumors.

Answer 8

BENIGN: mass is mobile, smooth with surrounding fibrous capsule, slow growing, well circumscribed.
MALIGNANT: fixed or ulcerating, irregularly shaped with no capsule, fast growing, metastasis

Question 9

What are the two basic components of all tumors?

Answer 9

1. Parenchyma: determines tumor’s biological behavior.

2. Stroma: supporting non-neoplastic connective tissue such as connective tissue, blood vessels, inflammatory cells

Question 10

What are the 3 fundamental distinguishing features between benign and malignant tumors?

Answer 10

1. Differentiation and anaplasia: benign tumors are well-differentiated and resemble the normal cells, malignant lack differentiation.
2. Local invasion: Benign stay local within a capsule, malignant invade and lack capsules.
3. Metastasis: Metastasis unequivocally marks a tumor as malignant.

Question 11

Define anaplasia

Answer 11

“backward formation,” loss of structural and functional differentiation of normal cells

Question 12

What are the common morphological changes of anaplasia?

Answer 12

1. Pleomorphism: variation in size and shape.
2. Nuclear abnormalities
3. Tumor giant cells: considerably larger than neighboring cells and may include enormous or several nuclei
4. Atypical mitosis
5. Loss of polarity

Question 13

What is the difference between dysplasia and carcinoma in situ?

Answer 13

Dysplasia is disorderly proliferation/growth, loss of uniformity of individual cells and architectural orientation, and has possibility of returning to normal. Carcinoma in situ is a preinvasive stage of cancer when dysplastic changes are severe and involve the entire thickness of epithelium.

Question 14

What are features of invasiveness?

Answer 14

Lack of well defined borders, requires wide margins during surgical excision, allows penetration into blood vessels/lymph/body cavities for metastasis

Question 15

What are 3 mechanisms of metastasis?

Answer 15

1. Seeding within body cavities (e.g. spread over peritoneal surfaces).
2. Lymphatic spread
3. Hematogenous spread through blood vessels

Question 16

What is a sentinel lymph node?

Answer 16

First regional lymph node that receives lymph flow from primary tumor.
Identifiable by injecting blue dyes or radioactive tracers into primary tumor.
Sentinel lymph nodes indicate extent of metastasis

Question 17

What are 3 main factors that affect incidence of cancer?

Answer 17

1. Geographic & environmental
2. Age
3. Genetic/heredity

Question 18

What are four major classes of cancer genes?

Answer 18

1. Oncogenes: promote cell growth.
2. Tumor suppressor genes: Prevent uncontrolled growth.
3. Genes that regulate apoptosis.
4. Genes that regulate interactions between tumor cells and host cells: enhance or inhibit recognition by immune system.

Question 19

8 hallmarks of cancer?

Answer 19

1. Self-sufficiency of growth signals
2. Insensitivity to growth-inhibitory signals
3. Altered cellular metabolism.
4. Evasion of apoptosis.
5. Immortality.
6. Sustained angiogenesis.
7. Invasion and metastasis.
8. Evasion of immune surveillance.

Question 20

What is the RAS gene?

Answer 20

Most commonly mutated oncogene in tumors.
RAS gene encodes for RAS protein, which is activated by receptors turned on by growth factors. Mutated RAS gene creates RAS protein that is always turned “on”

Question 21

What is TP53?

Answer 21

Most commonly mutated gene in human cancer.
Tumor suppressor gene that functions by blocking progression from G1-S (for DNA repair), causing senescence (prohibiting cell division), or apoptosis

Question 22

What are 3 classes of carcinogenic agents?

Answer 22

1. Chemicals (causes lung cancer, leukemia, bladder cancer).
2. Radiant energy (causes skin, thyroid cancers).
3. Bacteria and viruses (HPV, EBV, H. Pylori)

Question 23

What are 5 most common effects of a tumor on the host?

Answer 23

1. Impingement on adjacent structures.
2. Paraneoplastic syndromes (e.g. tumors produce hormones)
3. Bleeding and infection.
4. Organ rupture or infarction.
5. Cachexia, weakness/wasting

Question 24

What are the 3 most common neoplastic syndromes?

Answer 24

1. HYPERCALCEMIA: Mechanism- PTH released by tumor cells.
2. CUSHING’S SYNDROME. Mechanism- ACTH releases by cancer cells.
3. HYPERCOAGUABILITY. Mechanism- cancer releases coagulating agents that cause embolisms and non-bacterial endocarditis.

Question 25

What is the difference between grading and staging?

Answer 25

Grading: measure of how abnormal cancer cells look under the microscope (differentiation and # of mitoses).
Staging: Size of primary lesion and where cancer is located/spread.