Unit XXI Cancer

Question 1

What is cancer?

Answer 1

A group of diseases characterized by uncontrolled growth and spread of abnormal cells.​

Question 2

Prevalence / estimated new cancer cases

Answer 2

Females - Breast
Males - Prostate

both with lung being second next

Question 3

Mortality

Answer 3

Lung and bronchus causing the most deaths in both males and females

Question 4

Prognosis of new cancer in adults (cases and deaths)

Answer 4

Lung cancer

Question 5

Mortality

Answer 5

The number of deaths due to cancer per 100,000 population. That is, Mortality Rate = (Cancer Deaths / Population) × 100,000​

Question 6

Morbidity

Answer 6

Proportion of illness in a population

Question 7

Incidence rates in children and adults

Answer 7

Highest in 15-19 years olds in all sites (including benign brain)

Question 8

Reality & stigma

Answer 8

• One of the leading cause of death worldwide​
• Second leading cause of death in the US​

Question 9

Normal cells

Answer 9

Grow to a certain volume at an established rate & then stabilize​

There is a limit to the number of times it can double​

Question 10

cancel cells

Answer 10

• Continue to expand without boundaries & divide indiscriminately and haphazardly​
• Continue to replicate indefinitely (continuously)​
• The time it takes for a tumor to double in size is known as the “doubling time”​

Question 11

what are cancer cells characterized by

Answer 11

Cancer cells are characterized by uncontrolled cell growth and altered cell differentiation ​

Question 12

what is contact inhibation

Answer 12

There is a built-in mechanism to control cell proliferation​

Normal cells respect the boundaries and territory of the cells around them​

Physical contact with other cells inhibits their growth “contact inhibition”​

Cancer cells do not exhibit “contact inhibition”​

Grow on top of one another and on top of or between normal cells​

Question 13

Proto-oncogenes ​

Answer 13

Regulate normal cellular processes such as promoting growth​

Genetic “lock” that keep cells functioning normally.​

Question 14

Oncogenes

Answer 14

Exposure to carcinogens or oncogenic viruses can “unlock” the gene which can cause the development of an Oncogene (Tumor inducing) ​

Question 15

Hyperplasia

Answer 15

refers to an abnormal increase in the number of cells​

Question 16

Dysplasia

Answer 16

refers to the replacement of one mature cell type with a less mature cell type.​

Question 17

Neoplasia

Answer 17

is the uncontrolled, abnormal growth of cells or tissues in the body, and the abnormal growth itself is called a neoplasm or tumor. It can be benign or malignant.​

Question 18

What is common in hyperplasia and dysplasia

Answer 18

Hyperplasia and dysplasia are reversible because they are results of a stimulus.

Question 19

what is important about neoplasia

Answer 19

Neoplasia is irreversible because it is autonomous.​

Question 20

what is metastasis

Answer 20

The spread of cancer cells from the place where they first formed to another part of the body. Also referred to as METS, or metastatic disease. ​

Question 21

NED

Answer 21

No evidence of disease

Question 22

3 stage theory of causation

Answer 22

1. Initiation: exposure to radiation, a chemical or viral agent known as a “carcinogen” Initiation also occurs when there is a mutation or disruption in the normal cell development cycle.​
2. Promotion: Increased risk of developing cancer due to the presence of promoting factors- tobacco, obesity, physical inactivity, diet.​
3. Progression: Increased growth rate of tumor; invasiveness.​

• Cells can detach from the primary tumor, invade the tissue surrounding the tumor, penetrate the walls of lymph and blood vessels and metastasize (spread) to a different organ or tissue​
• Tumor cells can evade the cells of the immune system​
• Angiogenesis secures a blood supply to the tumor to support growth​

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