Family History

Risk factors, or red flags, for hereditary cancer can help identify individuals and families who may be at increased risk for hereditary cancer. These risk factors include:

  • Cancer in two or more close relatives on the same side of the family
  • Rare cancers (e.g., male breast cancer, paragangliomas)
  • Cancers at unusually young ages (e.g., breast cancer under 45)
  • Individuals with bilateral or multiple primary cancers
  • Multiple generations affected with cancer exhibiting an autosomal dominant inheritance pattern
  • Constellation of tumors consistent with a hereditary cancer syndrome (e.g., breast, ovarian, colorectal, and uterine)
  • More than 20 cumulative colon polyps (particularly adenomatous or mixed histologies)
  • Ashkenazi Jewish ancestry in addition to personal/family history of cancer

American College of Medical Genetics (ACMG) and National Society of Genetic Counselors (NSGC) released Practice Guidelines pertaining to referral indications for hereditary cancer risk assessment (September 2014).

Capturing Family History

A detailed family history is an essential component of risk assessment. A three-generation history includes information about:

  • Patient
  • First-degree relatives (parents, siblings, and children)
  • Second-degree relatives (grandparents, aunts, uncles, nieces, and nephews)
  • Third-degree relatives (great-grandparents, great-aunts, great-uncles, and cousins)

The history provides medical professionals with important information, such as:

  • Vital status
  • Age (current or at time of death)
  • Cancer diagnoses
  • Age at diagnosis

The number and ages of unaffected relatives are also important in cancer risk assessments. Please note that some people might not know all their family history for a variety of reasons, such as adoption, limited contact, and geographic separation.

There are multiple resources available to aid with the collection of detailed histories, including:

Updating Family Histories

Family histories change as years go by, so medical providers should update their patients’ family histories on a regular basis.

As they do, physicians should remember that families with hereditary cancer often have an increased psychological burden. The psychosocial implications of testing to clarify hereditary cancer risk should be addressed before, during, and after the genetic testing process.

Several initiatives emphasize the importance of integrating family history collection into medical practice: