Chapter 3: Ignorance is NOT Strength

For the past few weeks, we have been focusing on more of the theoretical portion of genetic testing, and I thought it would be a good idea to change gears and look at (and critique)  an article that focuses on the controversy on whether women should or should not get genetic testing for breast cancer.

Here is the link for the article:

http://health.usnews.com/health-news/news/articles/2013/04/01/breast-cancer-gene-tests-wont-help-most-women-report

Summary of  "Breast Cancer Gene Tests  Won't Help Most Women"

The article focuses on a study conducted by the U.S. Preventative Task force. It states that there is virtually no benefit for women who get genetic testing for  BRCA 1&2 who do  not  have a family history of  breast cancer. They later state that only women who have a family history of breast cancer should get the genetic testing for breast cancer done.

Oh, boy... where do we begin. Well let's start at the beginning. A title like, "Breast Cancer Gene Tests Won't Help Most Women" is quite the statement. With there still being so much on-going research about genetic testing (in general), it is too much of a bold and vague statement to be made. Just stating that most women won't need genetic testing without any information is not helpful. It is extremely misleading to the public.

Next, genetic testing for BRCA 1& 2 isn't offered to women unless they have a family history of breast cancer.  While, I agree that women who do not have a history of breast cancer should not get the genetic testing done, the wordiness of the article (although very short), it is extremely confusing for anyone to read. 

I am one of those people who is very detail oriented, and even if the information that is presented is actually accurate, the WAY the information is presented to makes more of a difference.

News articles like this are the reason why there is a lot mis-communication between the world of science and the general public. The information that is given is usually watered down, or exaggerated and not explained.

Some details about the study and test the this "task force" conducted would have been nice. A title that did not just let the reader assume things without actually reading the article would have also been nice.

So, next time you read a publication in the science or health section, make sure your keep your eyes open for unclear and misleading statements. Ask yourself questions like, " does this make sense?' or "how can they prove this?' Often times, this media publications write articles like this to conjure up a dramatic response instead of one that is actually there to notify, and empower the public with the right facts to make informed decisions about their lives. Knowledge is Power!!



References: 
http://www.peoplefluent.com/blog/knowledge-is-power-and-relief-thank-you-mayo-clinic

Chapter 2: How is Genetic testing done?

In my last post, I gave a brief introduction as to what SNPs (single Nucleotide Polymorphisms) are. Please enjoy this short video to give you a better understanding of SNPs

Now that you understand what SNPs are, let’s delve a little deeper in to how geneticists look at the DNA during the genetic testing. 

SNP Chips

A sample of the patients DNA must first be taken. This can be done by either a blood test (usually) or a simple swab of saliva. Once that is done, next the scientist will use a something called a micro-array chip, or as I like to call them SNP chips. With these chips, they apply the DNA onto the chip. The strands of DNA separate, and each segment of DNA has a specific part of the chip that it will bind to. This is known as hybridization in the world of genetics. Once the DNA is hybridized to the SNP chip, they will add outside DNA (called probes) that are tagged with fluorescents. These florescent DNA probes will bind to the patients DNA if they are complementary. It’s like a game of playground tag, except the probes can only "tag" DNA that it is exactly complementary to. 

 This allows the geneticists to compare DNA between healthy patients and sick ones. Because each segment of DNA has specific spot on the SNP chip, it allows the geneticist to see what part of the DNA is mutated. If someone has a mutation in either the BRCA 1&2 gene, the part of the DNA that has the instructions for those cells will light up a different color than the rest of the DNA.

Here is an example of that:

What Kind of Genes are BRCA 1&2?

BRCA 1 & 2 are tumor suppressor genes. As the name suggests, these are genes that help prevent the tumors for growing in our cells. When a mutation occurs in the instructions of the BRCA 1&2 gene, it changes how they work. In breast cancer, they are turned off. When they are turned off, the cell loses its control on growth.  

References:

http://www.mdanderson.org/education-and-research/departments-programs-and-labs/labs/brown-lab/research-projects/transcription-factors.html

http://www.cancer.gov/cancertopics/factsheet/Risk/BRCA

http://www.nejm.org/doi/pdf/10.1056/NEJMoa0907727

https://www.23andme.com/health/BRCA-Cancer/

http://www.youtube.com/watch?v=tJjXpiWKMyA&list=PL4CwdpuBkK81c77rb5GqPDoh3D6trHl3-

http://www.mun.ca/biology/scarr/DNA_Chips.html

http://www.lookfordiagnosis.com/mesh_info.php?term=Genes%2C+Tumor+Suppressor&lang=1

Chapter 1: Introduction to Breast Cancer and Genetic Testing

What is Breast Cancer?

Breast cancer is the uncontrolled growth of cells in the breast. This uncontrolled growth is caused by mistakes (mutations) in the genes of these cells. These genes act as a set of instructions for the cell to follow. When these "instructions" are changed by the mutations it completely switches how the cell can work. In cancer, the set of instructions on when to grow and divide is changed, and the cells go on a growth frenzy! 

A collection of cancer cells is called a tumor. Breast cancer is defined when someone has a malignant (dangerous) tumor located in the part of the breast that is responsible for making milk. Malignant tumors are considered dangerous because they can invade other parts of the body and grow there. This is called metastasis. 

What genetic testing can someone get for Breast Cancer?

While mammograms are used to diagnose women above the age of 50 for breast cancer, now, younger women are going to geneticists, to see if they are more likely (predisposed) to have cancer. To be genetically predisposed for breast cancer means that you have inherited one gene 

that has mistakes (mutations) in its instructions. These mutations are usually found in the BRCA 1 & 2 (BReast CAncer genes 1&2).  Scientists can now do genetic testing to determine whether someone has received one of the faulty genes from their parents, and is now more likely to be diagnosed with breast cancer. This is done with Single Nucleotide Polymorphisms (SNPs) .SNPs is when there is a change in one of the nucleotides in the gene.

How often are these mutations passed on from parent to child?

These abnormalities are sometimes passed on from mother/father to their children. This is rather rare, accumulating only 5-10% of all breast cancer patients. This still means that there is a change in the genes for the patient, the only difference is HOW the change occurred, whether is an inherited mistake from their parents, or a mistake by the cells themselves.

References:

http://www.hopkinsmedicine.org/avon_foundation_breast_center/treatments_services/breast_cancer_diagnosis/breast_ovarian_surveillance_service_genetic_testing/faqs.html

http://www.cancer.gov/cancertopics/factsheet/Risk/BRCA

http://www.webmd.com/breast-cancer/guide/genetic-testing

http://www.broadinstitute.org/education/glossary/snp

http://www.chabad.org/theJewishWoman/article_cdo/aid/337762/jewish/Breast-Cancer-Genetics-and-the-Jewish-Woman.htm

http://www.abraxane.com/mbc/patients/About-Metastatic-Breast-Cancer/

http://www.hindawi.com/journals/bmri/2010/460607/fig2/