Chapter 7: Malignant Neoplasms (Cancer)

Question 1

How does a malignant tumor start?

Answer 1

Starts from a single cell that has sustained damage to its genome that causes it to proliferate abnormally.

Question 2

Malignant tumors secrete ________ that break down normal cell tissue barriers, allowing the tumor to _______ adjacent tissues, invade ________ and _______, and _________ throughout the body.

Answer 2

enzymes; infiltrate; lymphatic channels; blood vessels; metastasize

Question 3

True or false: Malignant tumors become immortal and can proliferate indefinitely.

Answer 3

True

Question 4

What are the steps of carcinoma development?

Answer 4

1) Normal epithelium
2) Dysplasia (abnormal appearing cells, but not yet malignant)
3) Carcinoma in situ (bound by basement membrane, but is now malignant)
4) Early invasive carcinoma (penetrates basement membrane)
5) Invasion of blood and lymphatic vessels with distant metastasis.

Question 5

True or false: Carcinoma in Situ is fully curable by surgery.

Answer 5

True; it remains localized in the epithelium.

Question 6

True or false: Carcinoma in Situ is benign.

Answer 6

False; it has the potential to invade because it has the same DNA abnormalities as invasive cancer.

Question 7

What is the longest stage of tumor development?

Answer 7

From a normal cell to a malignant cell

Question 8

How many cell duplications are needed for a tumor to grow to the size of a grape.

Answer 8

30

Question 9

True or false: A tumor has lived most of its life before it is large enough to be detected.

Answer 9

True

Question 10

What is the measurement of how many cells within a tumor are growing at one time?

Answer 10

Tumor growth fraction

Question 11

What does tumor growth primarily depend on?

Answer 11

The tumor growth fraction (i.e., how many cells in the tumor are dividing at one time)

Question 12

True or false: Tumor growth primarily depends on how rapidly cells in a tumor are dividing.

Answer 12

False; primarily depends on the tumor growth fraction.

Question 13

Why are targeted therapies a challenge with malignant tumors?

Answer 13

Due to the heterogeneity of the cells that comprise the tumor, some cells in a group of tumor cells may not respond to a treatment.

Question 14

What are CSCs? Why are they difficult to treat?

Answer 14

Cancer Stem Cells (cells that arise due to a mutation in a stem cell); They do not divide frequently, and this makes them difficult to treat with chemotherapy (which targets quickly dividing cells)

Question 15

What determines tumor size?

Answer 15

Their blood supply.

Question 16

What is the limit of how much a tumor can grow if it does not increase its blood supply?

Answer 16

2-3 mm

Question 17

Process by which malignant tumors induce the generation of new blood vessels

Answer 17

Angiogenesis

Question 18

What happens if a tumor outgrows its blood supply?

Answer 18

The parts with poorest blood supply will necrose.

Question 19

What can oozing small blood vessels in the ulcerated base of a tumor lead to?

Answer 19

Anemia and even, perhaps, severe hemorrhage