Our genes are responsible for the functioning of the cells in the body. One of their major roles includes controlling how cells divide and grow. Malfunctioning among one or more genes in the body can cause a lot of serious problems such as cancer.
Changes in the genes which lead to further abnormal alterations are usually referred to as mutations or faults. Although a person’s way of living and choices are commonly the reason for cancer in the majority of the cases, it can also be linked to faults and mutations.
This means that cancer can be genetically passed down. In other words, a person can inherit cancer from grandparents and parents as well as pass it on to future generations.
How can Genetic Changes Lead To Cancer?
A cell which has to have at least six or more faults has the highest risk of becoming cancerous. The mutations can affect the normal functioning of the cell, become cancerous and result in dividing and growing in an abnormal way.
This can also happen during the process of aging due to some mistake in cell division. In addition, exposure to specific substances can also change the cells and make them cancerous. Such substances are known are carcinogens and include cigarettes and even sunlight.
The changes in the genes may increase the risk of cancer but they do not affect all of the cells in the body. These are neither inherited nor can be passed on to future generations.
Cancer has become so prevalent today that there are some cancer patients in every other family. Sometimes, there are particular types of cancers that affect several members of a family. However, only a very few of the cancers out of all types are inherited.
How Is the Risk of Cancer Passed On?
Mutated genes that carry the danger of causing cancer can be passed on from parents to their children. These genes are often cited as inherited cancer genes and are created when the egg or the sperm cell contains some mistake.
The genes that can potentially accelerate the chances of developing cancer are also known as cancer susceptibility genes whose typical job is actually the opposite or avoiding cancer by managing the DNA damage that occurs naturally during cell division.
If a person inherits these faulty genes, he/she might be at a much higher risk of cancer since the DNA damage in cell division is not corrected. Genes from both of the parents are inherited by the child.
If both of the parents have a faulty gene, the child has 1 in 2 chance of inheriting the gene. Some children might have a higher risk of developing cancer at any stage of life while others would not.
Which Types of Cancer Can Be Passed On?
The cases of cancer due to an inherited faulty gene are much less common than cancer caused by aging, changes in the genes, exposure to specific substances, and other reasons. In fact, the majority of people have cancer due to both life choices and environmental factors.
On the other hand, it should also be noted that 5 to 10 percent of the cancer cases are of people who have inherited genetic mutations that have the ability to cause cancer.
The mutations and syndrome which might increase the chances of developing cancer include:
- Cowden syndrome
Cowden syndrome increases the risk of three types of cancer including thyroid, breast, and uterine cancer.
- BRCA1 and BRCA2 genetic mutations
Both of the mutations increase the risk of developing prostate, breast, and ovarian cancer.
- Von Hippel-Lindau disease
This disease raises is said to raise the risk of a number of cancers including kidney cancer. More research is needed to see exactly how many types is the disease actually linked to.
- Li-Fraumeni syndrome
This syndrome was linked to raising many different kinds of cancers.
- Familial adenomatous polyposis
This mutation increases the risk of colorectal cancer and brain and soft tissue tumors
- Multiple endocrine neoplasias
This mutation was linked to higher chances of endocrine cancers.
- Lynch syndrome
The syndrome was seen to raise the risk of brain tumors, some skin cancers, and colorectal cancer
What is the Genetic Test for Cancer?
Fortunately, the advancements in medical science today have also led to the creation of genetic testing for cancer. There are tests available for gene faults that are linked with ovarian, breast, womb, bowel, and prostate cancer.
In addition, there are also tests for some genetic faults that can raise the risk of developing kidney, thyroid, and skin cancers as well as retinoblastoma which is a type of eye cancer.
Tests for other types of cancer genes are unfortunately not available yet but the research on the matter continues.
The tests conducted to detect genes that increase the risk of cancer is also known as predictive genetic testing. These tests can be useful in identification of mutation but they do not give precise results. Hence, they cannot indicate if cancer is present or not.
Getting a positive result would mean that there is a comparatively higher chance of having cancer. It does not assure that cancer is there or will develop in the future. A faulty gene may be spotted through this test but there is no way to be sure that it will cause cancer.
Putting it simply, genetic testing can only predict something that can happen but they cannot be relied on to show what exactly will happen.
This also means that negative results do not always mean there is no chance of having cancer since the risk can increase with aging, due to exposure, choices and other environmental factors.
There might be chances of the tests being flawed or being interpreted in a wrong way. Although it is rare, some labs have different ways of interpreting the tests as the regulation of genetic testing is not very strict.
Some people claim that makers of the tests make the test sound more reliable and helpful than it is in real during its advertisement and promotion. However, reputable genetic counselors are often able to aid in interpretation and what to expect from the test.
Who Should Get Genetic Testing?
Genetic counselors and doctors often suggest genetic testing to people who have a family history of cancer. In accordance with Cancer Research UK, the following cases are considered as ‘strong family history of cancer’:
- One relative has a faulty gene detected by the genetic test
- If more than two relatives from the same side have or had cancer
- The cancers were detected when the relatives were under the age of 50
- The relatives have or had the same type of cancer or different cancers that are caused by the same gene
What Can You Do to Avoid Cancer?
People who think they might have higher chances of hereditary cancer are suggested to consult their family doctor or specialist who can help in determining whether a genetic test is needed or not. If a test is needed, the doctor will refer the person to a genetic clinic.
Other forms of cancer can be avoided by making certain lifestyle changes. According to the American Cancer Society, the best ways to cut down the risk of cancer are:
- Staying safe in the sun
- Avoiding smoking (and second-hand smoke)
- Eating a healthy and well-balanced diet
- Maintaining a healthy weight
- Exercising regularly