Family history of cancer

A small number of families have a greater risk of breast cancer, ovarian cancer, bowel cancer and melanoma, because they carry a changed gene.

What constitutes a family history of cancer? Consider contacting your doctor or a Family Cancer Centre if, on the same side of the family (but only blood relatives), you have any of the following:

Breast and ovarian cancer

  • Three or more close blood relatives on the same side of the family with breast or ovarian cancer
  • Two or more close blood relatives on one side of the family with breast or ovarian cancer who have one or more of the following features on the same side of the family:
    • cancer in both breasts
    • onset of breast cancer before the age of 40
    • onset of ovarian cancer before the age of 50
    • breast and ovarian cancer in the same relative
    • breast cancer in a male relative
    • Jewish ancestry
  • A relative diagnosed with breast cancer at or before 45 years of age plus a relative on the same side of the family diagnosed with bone or soft tissue cancer at or before 45 years of age
  • Three or more close relatives on the same side of the family with cancer of the bowel or uterus
  • A family member who has had a genetic test that has shown that they have an inherited change in a gene associated with breast or ovarian cancer

See also familial breast cancer and familial ovarian cancer.


Bowel cancer

Three or more close relatives on the same side of the family with bowel cancer.

  • Two or more close relatives on the same side of the family with bowel cancer who have any of the following:
    • more than one bowel cancer in the same relative
    • onset of bowel cancer before the age of 50
    • a relative who has had endometrial, ovarian, stomach, small bowel, renal pelvis or ureter, biliary tract or brain cancer
    • a close relative who has had bowel cancer with a large number of benign (not cancer) tumours, called adenomas, throughout the bowel
  • A family member who has had a genetic test that has shown that they have an inherited change in a gene associated with bowel cancer

See also familial bowel cancer.


Melanoma

A personal history of:

  • melanoma at an early age (average age of familial melanoma is 33 years)
  • more than one primary melanoma
  • a large number of moles (more than 10 on the arms and 200 on the body)
  • multiple atypical moles

A family history of:

  • multiple cases of melanoma on the same side of the family
  • melanoma occurring at an early age
  • ocular (eye) melanoma
  • pancreatic cancer in more than one family member

See also familial melanoma.  


Other cancers

  • several relatives who have the same type of cancer
  • a relative who has been found to carry a changed gene
Updated: 07 Aug, 2013