Cancer and Your Genes

Cancer and Your Genes - NHMC

Various cancers tend to run in families. The pattern for this may be as simple as one family member getting diagnosed, and finding out that someone closer to you has it, too. Or it can be that the cancer appears at least once or twice every generation. Whatever the case, there are various cancers which are hereditary in nature.

Yet that does not mean that a family with a history of the cancer already has it mapped into their genes. Sometimes, while the cancer do tend to occur in families, they are actually environmental in nature. An example of this is a family of smokers; while lung cancer may run in the family, this is actually because they are all smoking.

How would you determine if the streak of cancer in your family is actually genetic, which means there is nothing you can do about it, or environmental in nature, in which case you can do something about it? Here’s what you need to know about cancer and your genes.

The relationship between cancer and your genes

Medical News Today defines cancer as “a class of diseases characterized by out-of-control cell growth. There are over 100 different types of cancer, and each is classified by the type of cell that is initially affected.” The same source goes on to say that the disease “harms the body when altered cells divide uncontrollably to form lumps or masses of tissue called tumors.” These tumors can grow significantly and interfere with the normal functions of the body, as well as spread to other parts of the body.

These tumors grow when the cell’s ability to grow and die naturally is hindered. Multiple studies have pinpointed out several genetic mutations that are linked with the growth of certain kinds of cancer. Your genes, as you probably know, are the “blueprint” of your cells. The American Cancer Society (ACS) explains, “A gene mutation can affect the cell in many ways. Some mutations stop a protein from being made at all. Others may change the protein that is made so that it no longer works the way it should or it may not even work at all. Some mutations may cause a gene to be turned on, and make more of the protein than usual. Some mutations don’t have a noticeable effect, but others may lead to a disease.”

That means then that if you have a genetic predisposition towards a certain cancer, you are more likely to get it than another person who does not have that genetic marker. Common genetic markers associated with cancers are as follows:

  • APC gene – those with mutations in the APC gene are at an increased risk of developing colorectal cancer, as well as soft tissue and brain tumors.
  • BRCA1 and BRCA2 Genetic Mutations – these mutations are commonly associated with breast and ovarian cancer in women. On the other hand, men with these genetic mutations are at risk of breast and prostate cancer.
  • Lynch Syndrome – commonly referred to as hereditary nonpolyposis colorectal cancer (HNPCC), this type of cancer is led by several genetic mutations particularly in the PMS2, MLH1, MSH2 or MSH6. Other variations of the mutation can lead to Turcot syndrome (brain tumors) and Muir Torre syndrome (skin cancers).
  • MEN1 and RET gene – Mutations in these genes can result to multiple endocrine neoplasia (MEN), or cancers of the endocrine system.
  • PTEN gene – people with the PTEN gene mutation may have Cowden syndrome, which is associated with breast, uterine, and thyroid cancer.
  • TP53 gene – also known as the Li-Fraumeni syndrome, people with this genetic mutation are at an increased risk of developing several forms of cancer, including soft tissue sarcomas, leukemia, breast cancer, lung cancer, adrenal gland cancer, and brain tumors.
  • VHL gene – mutations in this gene increases the risk of kidney cancer and a predisposition towards Von Hippel-Lindau Disease, which is the abnormal growth of blood vessels.

How knowing these markers help

The genetic markers mentioned above are just some of the more common genetic mutations known to be linked with various cancers. However, it is worth pointing out that having a certain mutation does not already mean you will have the cancer later on in life. Yet for many cancer patients, knowing these genetic markers and being tested for them made a difference between early diagnosis, preventing cancer, and beating cancer once and for all.

How so? Through genetic testing, they were able to see if they were at risk of the popular cancers. For example, people who tested positive for both BRCA1 and BRCA2 genetic mutations can decide to have mastectomy, which is a plastic surgery procedure wherein the breasts and their underlying structures are removed. This then would minimize the risk of breast cancer from developing, since the breast tissues are already removed.

On the other hand, knowing that you have a predisposition towards a certain cancer can also make you more aware of the risk. For example, people who may have the TP53 gene mutation can opt to never start smoking, to exercise regularly, and to eat healthy, to avoid developing certain kinds of cancer. Knowing these markers would be influential into making the active decision to be healthier and to live a better lifestyle than to put themselves at risk of getting the disease in the long run.

What’s next?

If you have noticed that certain cancers seem to run in your family, do not be afraid to consult a physician and tell them your concerns. You can be referred to a genetic counselor who will talk to you about your family’s medical history, particularly concerning the cancer you were worried about. You would be assessed if you are at risk of getting the disease, and all your concerns about testing would be responded to.

Once you are scheduled for a genetic test, remember not to be overly anxious as all that would be needed from you is oftentimes a small blood sample or a sample of your saliva, taken from a cotton swab to the inside of your mouth. The testing should be a fuss-free, non-invasive procedure that gives you minimal discomfort.

After the testing, your genetic counselor can still walk you through the results and help you understand the next steps you may need to take.

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