Neoplasia

Question 1

What is a neoplasm

Answer 1

an abnormal mass of tissue usually referred to as a tumor

Question 2

How to neoplasms develop?

Answer 2

When cells fail to regulate their cell division resulting in growth that exceeds the normal rate of growth of the tissue

Question 3

Tumors can be divided into

Answer 3

Malignant and Benign

Question 4

Malignant tumor’s (cancerous)

Answer 4

can invade other tissues and metastasize (spread to remote areas)
have irregular borders
grow rapidly
cells are morphologically and functionally different from normal cells, cells less organized than in parent tissue
have abnormal nuclei
show necrosis

Question 5

Primary tumor vs secondary tumor

Answer 5

Primary tumor- original tumor

Secondary tumor- grow from metastatic deposits in distant organs

Question 6

Benign tumor (non-cancerous)

Answer 6

spread to other sites but they become large and put pressure on sensitive regions of the body causing problems
Do not invade beyond the tissue of origin
smooth boundaries
grow relatively slow
cells resemble normal cells of tissue of origin
bland nuclear features

Question 7

Malignant tumors can either be

Answer 7

carcinomas or sarcoma

Question 8

Tumorigenesis

Answer 8

process by which a tumor forms

Question 9

Oncogenesis

Answer 9

development of malignant tumor

Question 10

Genetic changes within cells can be due to a variety of causes including:

Answer 10

ionizing radiation
free radicals
chemicals
some viruses
inherited mutations
tobacco smoke
alcohol
chemotherapy drugs

Question 11

Four main stages in the development of malignant tumors

Answer 11

Transformation
Growth of transformed cells
Local invasion or infiltration
Metastasis

Question 12

Proto-oncogenes

Answer 12

essential genes that control normal cellular growth, differentiation and apoptosis
when it becomes an oncogene we say it is activated

Question 13

Oncogenes

Answer 13

mutated versions of proto-oncogenes resulting in the cell dividing when it should not
an oncogene is a dominant gene where only one mutated allele will produce the effect
These mutations are called gain of function mutations

Question 14

Activation on proto-oncogenes through

Answer 14

point mutation
translocation (gene product controlled by the wrong promoter)
amplification ( multiple copies of the gene)

Question 15

Examples of oncogenes

Answer 15

growth factors
growth factor receptors
proteins that promote cell division
anti-apoptotic proteins

Question 16

Tumor suppressor genes

Answer 16

normal genes that keep cells from overgrowing even when oncogenes are activated. Often called anti-oncogenes

Question 17

Examples of tumor suppressor genes are

Answer 17

genes that detect or repair damaged DNA

genes involved in promoting apoptosis

Question 18

How to tumour suppresor genes differ from oncogenes

Answer 18

for there to be an effect both alleles that code for a particular protein need to be mutated.

Question 19

P53

Answer 19

most frequently altered gene in human cancers. It is also one of the best studied TSDs. It regulates cell cycle and prevents excessive cell growth and therefore functions as a tumor suppressor

Question 20

Functions of P53

Answer 20

activates DNA repair proteins when DNA is damaged
stops cell cycle while the DNA is being repaired and allows it to continue if the DNA is fixed
initiates apoptosis if the DNA is impossible to repair , killing the cell

Question 21

Carcinomas

Answer 21

most common type of cancer occurring in humans.
They are malignant tumors of the epithelium and invade the underlying tissues
They have some features of the original tissue but the cells are disorganized and less well formed

Question 22

Three most common types of carcinomas

Answer 22

adenocarcinoma
squamous cell carcinoma
small cell carcinoma

Question 23

Numerous factors determine recovery from cancer

Answer 23

• stage
  -grade
  -tumor subtype
  -suitability of the organ for surgical removal of the tumor
  presence of receptor molecules for drug treatment
  immunosuppression
  cachexia (progressive weight loss)

Question 24

Difference between grade and stage

Answer 24

stage-describes how far the tumor has spread from the tissue of origin
grade- describe how much the tumor has changed from the tissue of origin (morphologically)