10.2 pathways

Question 1

1) Some disorders, such as ____________, are associated with high rates of cancer
2) These individuals have an increased risk of __________ and have defects in their ______ system
3) This predisposition may result from the presence of an initial what?

Answer 1

1) Down syndrome
2) leukemia; immune
3) mutation or genetic imbalance that moves cells closer to a cancerous state

Question 2

Environmental factors

Answer 2

Chemical carcinogens
Natural and artificial radiation
Viruses
Certain foods
Behaviors

Answer 3

Some chemicals cause nucleotide substitutions or change the number of nucleotides in DNA

Other chemicals structurally change the bases in DNA, causing a base pair change after replication

Question 4

DNA Damage from UV Light

Answer 4

Thymine dimer
Chemical bonds formed between a pair of adjacent thymine bases in a DNA molecule
Distorts the DNA molecule and affects replication

Answer 5

Viruses have been determined to be the cause of a few cancers
The Epstein-Barr virus causes Burkitt’s lymphoma
The Hepatitis B and C viruses cause hepatocellular carcinoma
Human Papillomaviruses cause cervical cancer
HPV 16 and HPV 18 – 70% of cervical cancers
(HPV 6 and HPV 11 – 90% of genital warts)

Question 6

Viruses have been determined to be the cause of a few cancer; give at least 4 examples

Answer 6

The Epstein-Barr virus causes Burkitt’s lymphoma
The Hepatitis B and C viruses cause hepatocellular carcinoma
HPV 16 and HPV 18 – 70% of cervical cancers
(HPV 6 and HPV 11 – 90% of genital warts)

Question 7

1) Social behavior contributes to approximately ____% of all cancer cases in the United States
2) Smoking accounts for _____ to _____% of all cases of lung cancer
3) Smoking accounts for ______% of all cancer deaths

Answer 7

1) 50%
2) 75-85%
3) 30%

Question 8

Skin cancer cases related to ________ exposure are increasing (one million new cases per year in the United States)

Answer 8

UV

Answer 9

Grading
Cytological evaluation of tumor
Mitoses, pleomorphism, necrosis, other variables
Grading criteria vary with each type of cancer
Staging
Size of primary lesion and extent of metastases
Clinical evaluation of patient (imaging and surgery)
Greater clinical value than grading
TNM staging system

Answer 10

Clinical methods to quantify the aggressiveness of cancer
Useful for determining treatment and prognosis

Answer 11

Some cancers are grouped into five stages (0-IV)
0 – abnormal cells, not cancer yet
1 – small, only in initial organ
2 – larger, +/- lymph nodes
3 – larger + lymph nodes
4 – metastasis