Download 2. The histogram below shows the total estimated new breast cancer

Yeshua Lucombe
Activity Instructions
Analyze the data presented in the graph and table below. Then write a summary addressing the
following:
1. The results in this table below are from a 2007 study investigating BRCA mutations in women
diagnosed with breast cancer. All of the women in the study had a family history of breast
cancer.
BRCA Mutations in Women Diagnosed with Breast Cancer
BRCA1
mutation
BRCA2
mutation
No
BRCA
mutation
Total
Number of
patients
89
35
318
442
Average age at
diagnosis
43.9
46.2
50.4
Preventative
mastectomy*
6
3
14
23
Preventative
oophorectomy*
38
7
22
67
Number of
deaths
16
1
21
38
Percent died
18
2.8
6.9
8.6
2. The histogram below shows the total estimated new breast cancer cases diagnosed in 2003.
*A mastectomy is the surgical removal of one or both breasts, either partially of fully. An
oophorectomy is the surgical removal of an ovary or ovaries.
Please be sure to answer the following questions:
1. Describe how mutations lead to genetic variations.
Mutations happen when your genetic code gets altered or modified as an example if a
mother is addicted to smoking while pregnancy then her offspring will likely be born
with birth defects which are mutations which will lead to genetic variations.
2. Which appears to be more dangerous: the BRC1 or BRC2 mutation?
By analyzing the graph i can conclude that the BRC1 mutation is the most dangerous due
to the fact that it caused the most deaths on the chart.
3. Analyze a woman’s risk of dying of cancer if she carries a mutated BRC1 gene.
The risk is pretty high being 18% compared to the BRC2 gene being around 3%
4. How do heredity and inheritance relate to the data presented in these charts?
Because the gene seems to run in the woman’s family and it develops over time.
5. What data would you need to see in order to draw conclusions about the effectiveness
of preventive surgeries?
I would want to see the genetics of the patient’s families
6. What does the age at diagnosis tell you about the mutation?
It seems that the breast cancer risk is higher around the woman’s later years of her life
7. Explain how breast-cancer genes are still present in the population, despite cancerrelated surgeries and deaths.
Because the gene is carried by the patients reproductive cell so it is passed on ages