照這個邏輯，有病的家族，不是代代遺傳，也是隔代遺傳；沒病的家族，子女也永遠不會的這種病（沒有遺傳基因）。不消幾代，癌症和心血管病就可以從地球上消失了，因為後繼無人了。活著的也沒可能再得這種病。
太離譜了！
"Cancer that is not due to an obvious inherited pattern is called “sporadic cancer.” It is believed that most— perhaps 90%—of all cancers are sporadic."
From below...
_______________________________________________________
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Overview
All cancers are caused by changes to materials in our bodies called “genes.” These are units of information in every cell of our bodies. Everyone has two copies of each gene, one from each parent. During development, genes tell our cells what type of tissue to become—a skin cell vs. a muscle cell, for example—and in later life, when to divide and make more cells. Genes also determine which proteins to make based on the type of cell and its needs. Some genes tell our bodies how to repair damage from environmental toxins, sun exposure, dietary factors, hormones, and other influences, or tell our cells when to stop growing.
When changes called “mutations” occur in the genes, certain cells can grow out of control and cause cancer. Gene mutations that can lead to cancer usually happen later in life. Over time, these changes occur as a result of the aging process, from exposure to things such as smoke, hormones, certain viruses, certain chemicals or from dietary influences. Not all damage to our cells leads to cancer, however, because our bodies have many methods for repairing damage and because we are all born with two copies of these damage-repairing genes.
When mutations occur in both copies of a gene and cannot be repaired, the damage can lead to uncontrolled growth of the cell, which can lead to cancer. Cancer usually develops slowly, often involving multiple steps (damage to multiple genes), over a period of several years.
[Back to Top]
What is hereditary cancer?
Hereditary cancers occur when a person is born with a change or mutation in a single copy of a protective gene pair. Because people with an inherited mutation have only one working copy of a protective gene, damage to that remaining gene may occur in fewer steps and over a shorter period of time. This change can increase the risk for certain cancers in different parts of the body. The medical community uses the term "genetic susceptibility" to describe the fact that people with an inherited mutation have an increased risk for cancer.
The change does not increase the risk for every type of cancer and not everyone who is born with a gene change will develop cancer; risks vary according to the exact mutation that was inherited. Many other factors affect the risk of cancer in someone born with a gene mutation. Scientists do not know all the factors that determine whether or not a person with a gene change will develop cancer over the course of his or her lifetime.
The term “hereditary cancer syndrome” describes an inherited gene mutation that increases the chance to develop one or more types of cancer. For instance, the main hereditary breast cancer syndromes—caused by mutations in the BRCA1 or BRCA2 genes—are also associated with an increased risk for ovarian cancer. The main hereditary colon cancer syndrome, called Hereditary Nonpolyposis Colorectal Cancer (HNPCC), can also be associated with an increased risk for ovarian cancer or uterine cancer. Other, more rare cancer syndromes can be associated with a wide variety of cancers.
[Back to Top]
Hereditary vs. sporadic cancers
Cancer is a common disease, so most families will have some members who have had cancer. We don’t know the cause of most cancer, but we do know that most cancer is not due to a single inherited change in a gene. Cancer that is not due to an obvious inherited pattern is called “sporadic cancer.” It is believed that most— perhaps 90%—of all cancers are sporadic. This means even if cancer does not run in a family, a family member can still be at risk for some type of cancer in his or her lifetime.
Sporadic cancer and hereditary cancer differ in several ways that may affect health care decisions:
* Hereditary cancer tends to occur at an earlier age than the sporadic form of the same cancer, so screening and risk-lowering recommendations for cancer may be different and may begin at an earlier age for members of a family with an inherited gene mutation.
* Multiple family members may have inherited the same gene changes which raise the risk for certain cancers.
* Hereditary gene changes can be passed on to children.
* Individuals who have inherited a gene change may be at a higher risk for more than one type of cancer. In people who have already been diagnosed with a cancer, this may affect their cancer treatment or follow-up care.
* Specific screening or risk-lowering options exist for individuals who know they are at high risk for certain types of hereditary cancer.
[Back to Top]
Signs of hereditary breast and ovarian cancer (HBOC)
Most cancer is not due to inherited mutations. About 10-15% of cancers are hereditary, depending on the type of cancer. Therefore, one or two cases of cancer in a family does not necessarily mean that there is a hereditary cancer syndrome in that family.
Many factors can help determine if the cancer in a family is hereditary, including the presence of certain types of cancer occurring in the same family (for example breast cancer and ovarian cancer, or colon cancer and uterine cancer); the age of onset of cancer (particularly with breast cancer and colon cancer, cancer diagnosed before age 50 is considered more significant); and the number of relatives with cancer and their relationship to each other.
Hereditary cancer risk can be passed down from either side of the family, so when looking at your family medical history, you need to consider relatives on both your mother’s and your father’s sides of the family
太離譜了！
"Cancer that is not due to an obvious inherited pattern is called “sporadic cancer.” It is believed that most— perhaps 90%—of all cancers are sporadic."
From below...
_______________________________________________________
+++++++++++++++++++++++++++++++++++++++++++++++++++++++
Overview
All cancers are caused by changes to materials in our bodies called “genes.” These are units of information in every cell of our bodies. Everyone has two copies of each gene, one from each parent. During development, genes tell our cells what type of tissue to become—a skin cell vs. a muscle cell, for example—and in later life, when to divide and make more cells. Genes also determine which proteins to make based on the type of cell and its needs. Some genes tell our bodies how to repair damage from environmental toxins, sun exposure, dietary factors, hormones, and other influences, or tell our cells when to stop growing.
When changes called “mutations” occur in the genes, certain cells can grow out of control and cause cancer. Gene mutations that can lead to cancer usually happen later in life. Over time, these changes occur as a result of the aging process, from exposure to things such as smoke, hormones, certain viruses, certain chemicals or from dietary influences. Not all damage to our cells leads to cancer, however, because our bodies have many methods for repairing damage and because we are all born with two copies of these damage-repairing genes.
When mutations occur in both copies of a gene and cannot be repaired, the damage can lead to uncontrolled growth of the cell, which can lead to cancer. Cancer usually develops slowly, often involving multiple steps (damage to multiple genes), over a period of several years.
[Back to Top]
What is hereditary cancer?
Hereditary cancers occur when a person is born with a change or mutation in a single copy of a protective gene pair. Because people with an inherited mutation have only one working copy of a protective gene, damage to that remaining gene may occur in fewer steps and over a shorter period of time. This change can increase the risk for certain cancers in different parts of the body. The medical community uses the term "genetic susceptibility" to describe the fact that people with an inherited mutation have an increased risk for cancer.
The change does not increase the risk for every type of cancer and not everyone who is born with a gene change will develop cancer; risks vary according to the exact mutation that was inherited. Many other factors affect the risk of cancer in someone born with a gene mutation. Scientists do not know all the factors that determine whether or not a person with a gene change will develop cancer over the course of his or her lifetime.
The term “hereditary cancer syndrome” describes an inherited gene mutation that increases the chance to develop one or more types of cancer. For instance, the main hereditary breast cancer syndromes—caused by mutations in the BRCA1 or BRCA2 genes—are also associated with an increased risk for ovarian cancer. The main hereditary colon cancer syndrome, called Hereditary Nonpolyposis Colorectal Cancer (HNPCC), can also be associated with an increased risk for ovarian cancer or uterine cancer. Other, more rare cancer syndromes can be associated with a wide variety of cancers.
[Back to Top]
Hereditary vs. sporadic cancers
Cancer is a common disease, so most families will have some members who have had cancer. We don’t know the cause of most cancer, but we do know that most cancer is not due to a single inherited change in a gene. Cancer that is not due to an obvious inherited pattern is called “sporadic cancer.” It is believed that most— perhaps 90%—of all cancers are sporadic. This means even if cancer does not run in a family, a family member can still be at risk for some type of cancer in his or her lifetime.
Sporadic cancer and hereditary cancer differ in several ways that may affect health care decisions:
* Hereditary cancer tends to occur at an earlier age than the sporadic form of the same cancer, so screening and risk-lowering recommendations for cancer may be different and may begin at an earlier age for members of a family with an inherited gene mutation.
* Multiple family members may have inherited the same gene changes which raise the risk for certain cancers.
* Hereditary gene changes can be passed on to children.
* Individuals who have inherited a gene change may be at a higher risk for more than one type of cancer. In people who have already been diagnosed with a cancer, this may affect their cancer treatment or follow-up care.
* Specific screening or risk-lowering options exist for individuals who know they are at high risk for certain types of hereditary cancer.
[Back to Top]
Signs of hereditary breast and ovarian cancer (HBOC)
Most cancer is not due to inherited mutations. About 10-15% of cancers are hereditary, depending on the type of cancer. Therefore, one or two cases of cancer in a family does not necessarily mean that there is a hereditary cancer syndrome in that family.
Many factors can help determine if the cancer in a family is hereditary, including the presence of certain types of cancer occurring in the same family (for example breast cancer and ovarian cancer, or colon cancer and uterine cancer); the age of onset of cancer (particularly with breast cancer and colon cancer, cancer diagnosed before age 50 is considered more significant); and the number of relatives with cancer and their relationship to each other.
Hereditary cancer risk can be passed down from either side of the family, so when looking at your family medical history, you need to consider relatives on both your mother’s and your father’s sides of the family
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