The old adage that you can chose your friends but not your family holds true when looking at your cancer risks

Today people live for longer
In the 16 centuary,  more babies died of the plague, children died working in the mines, women died in childbirth, and 40 was considered ripe old age.

So yes there was cancer that killed people but it killed less people because people died of other things.

So today more people live to over 70 and 1 in 4 people over 70 will have a cancer, this is due to changes in cells and our bodies not being able to kill or vacuum clean these abnormal cells.

It is not uncommon for more than one member of a family to have cancer. Cancer can occur in families:

	just by chance (mostly the case)
	because family members have environmental and lifestyle influences in common (eg. too much sun or smoking)
	because there is an inherited faulty gene causing an increased chance of cancer (uncommon)

Trying to find information about cancers in your family and how to deal with them can be difficult.

Only a small percentage of certain cancers (up to 5%) are due to a faulty gene inherited from either the father or mother. This is what we call a familial or family cancer. This can also be referred to as an inherited predisposition to cancer. The faulty gene increases the risk of cancer, but even then it does not mean every family member will develop the cancer.

It is important to know your family history on both your mother and father side of the family.

The clues that cancers in the family may be due to an inherited faulty gene include:

Number of blood relatives* who have had cancer
The more blood relatives* who have had cancer (in particular breast, ovarian and/or bowel cancer), the more likely the cancer is due to an inherited faulty gene. *A blood relative is someone related by blood (eg. grandmother, father, sister), not marriage.

Ages at which cancers in the family developed
The younger people were when they developed cancer (compared to what is expected in the general community), the more likely it is to be due to inherited factors.

Pattern of cancer in the family
The type of cancer and who it affects in the family are important. In some families there are a number of blood relatives* who develop the same type of cancer, such as breast or bowel cancer. In other families there are some cancers that may run in the family (eg. breast, ovarian or bowel cancer and cancer of the uterus). This happens because some faulty genes can cause more than one type of cancer.

The more clues that are present, the more likely it is that there is an inherited faulty gene in the family causing a higher than usual chance of cancer. However, it is not definite. It is important to know that some people who inherit a faulty gene which causes an increased risk of cancer never go on to develop cancer.

What should I do if I have a family history of cancer?
Find out what types of cancer have occurred in your family and how old each person was when they developed cancer. It is also important to record the family members not affected by cancer. Talk to your doctor who can help you find out if your family history of cancer is of concern. If necessary, your doctor may refer you to a family cancer clinic or genetic counselling service.

Your family history of cancer can change over time, so it is important to keep your doctor updated about any new cancer diagnosed in your family. 

Family counselling and genetic counselling services
Genetic counselling services give people information about their chance of developing cancer based on their family history.

These services discuss ways that may help reduce the chance of cancer developing and methods of picking it up early. Sometimes genetic testing is possible, however it is only offered after the advantages and disadvantages of testing for the person and their family are discussed. Genetic testing is only useful if one of the family members with the cancer has been tested.

The following sites may help you determine your risk

Family History Initiative, U.S. Surgeon General, Department of Health and Family Services, My Family Health Portrait (Download) New 2004, includes an online tool, My Family Health Portrait, save information on multiple family members, and draw a family tree. Available as a web-based program to download or print, in English and in Spanish. The web-based tool can be completed on-line with data stored on your private computer. A printable report includes a table of family health history and a drawing of your family tree.

Construction of the Pedigree, General Principles of Medical Genetics (Inherited Disorders), Merck Manuel.

Does It Run in the Family? A Guide to Family Health History (PDF file), Genetic Alliance, printable guide, to gather, record and understand your family health history Added 2007.

Family Health Tree Guide, Centre for Genetics Education, Royal North Shore Hospital, Sydney, Australia, for professionals, "The Importance of the Family Health Tree' and for consumers, 'The Importance of Your Family Health Information".

Cancer History Guide, Myraid Genetic Laboratories, Inc. Online tool to organize personal and family history of cancer.  Data is not saved, so results should be printed

Family History Tools: The Importance of Gathering a Family History, American Medical Association (AMA), includes Prenatal Genetic Screening Questionnaire, Pediatric Clinical Genetics Questionnaire, Adult Family History Form, and Sample Pedigree, completed on-line and print.  Data not saved.  

Health Family Tree, University of Utah, Utah Department of Health: Pape.

Breast and ovarian cancer risk
Studies have clearly established the role of family history as an important risk factor for both breast and ovarian cancer. After gender and age, a positive family history is the strongest known predictive risk factor for breast cancer. In most cases an extensive family history (more than four relatives in the same biologic line affected) is not present. However, it has long been recognized that in some families, there is hereditary breast cancer, which is characterized by an early age of onset, bilaterality, and the presence of breast cancer in multiple generations through either the maternal or paternal lines in an apparent autosomal dominant pattern of transmission and familial association with tumors of other organs, particularly the ovary and prostate gland. We now know that some of these “cancer families” can be explained by specific mutations in single cancer susceptibility genes. The isolation of several of these genes, which when mutated are associated with a significantly increased risk of breast/ovarian cancer, makes it possible to identify individuals at risk. Although such cancer susceptibility genes are very important, only 5% to10% of individuals who develop breast cancer are known to carry highly penetrant gene mutations.

The identification of several susceptibility genes, including BRCA1, BRCA2, TP53, PTEN/MMAC1, and STK11
BRCA1 and BRCA2 are the genes most commonly tested for.

Clinical management of such patients needs to be highly individualized and must take into consideration factors such as the patient’s personal and family cancer history.

The prevalence of mutations by ethnic group was as follows:
BRCA1

3.5% Hispanic.

1.3% to 1.4% African American.

0.5% Asian American.

2.2% to 2.9% non-Ashkenazi Caucasian.

8.3 % to 10.2% Ashkenazi Jewish.[44,45]

BRCA2

2.6% African American.

2.1% Caucasian.[45]

Personal characteristics associated with an increased likelihood of a BRCA1 or BRCA2 mutation include the following:

	Breast cancer diagnosed at an early age.
	Bilateral breast cancer.
	A history of both breast and ovarian cancer.
	The presence of breast cancer in one or more male family members.
	Family history characteristics associated with an increased likelihood of carrying a BRCA1 or BRCA2 mutation include the following:
	Multiple cases of breast cancer in the family.
	Both breast and ovarian cancer in the family.
	One or more family members with two primary cancers.
	Ashkenazi Jewish background.
	Genetic testing for BRCA1 and BRCA2 mutations has been available to the public since 1996. As more individuals have undergone testing, risk assessment models have improved. This, in turn, gives providers better data to estimate an individual patient’s risk of carrying a mutation.