Clinically Relevant Family Histories of Cancer Change Over Time - July 12, 2011 • Volume 8 / Number 14

Clinically Relevant Family Histories of Cancer Change Over Time
July 12, 2011 • Volume 8 / Number 14

A person’s clinically relevant family history of certain cancers changes substantially between ages 30 and 50, particularly for colorectal and breast cancer, as more family members are diagnosed, a new study shows. The study highlights the importance of having an accurate, up-to-date family history.

The findings were reported July 12 in JAMA by investigators from the Cancer Genetics Network (CGN), a research resource that includes a national registry of people with a personal or family history of cancer. CGN is an NCI-funded project directed by Dr. Dianne Finkelstein of Massachusetts General Hospital and Harvard University.

“We wanted to find out how often changes in a person’s family history of cancer over time would affect the cancer screening schedule and tests recommended by standard guidelines,” said Dr. Sharon Plon of Baylor College of Medicine, the senior author on the paper.

The researchers examined family history data for colorectal, breast, and prostate cancer among 11,129 individuals enrolled in the CGN. Family history is an important predictor of risk for all three cancers. CGN investigators have followed registry participants for a decade with annual questionnaires on family history updates and other factors.

Using family history data that the participants provided when they entered the registry, investigators determined retrospectively the rate of change in each person’s family history from birth until the time of enrollment into CGN. They also examined the participants’ family history changes prospectively, from the time of their enrollment in the CGN to the time of their most recently completed questionnaire.

In particular, CGN investigators looked for changes in family history that would make someone a candidate for earlier or more intensive screening according to current American Cancer Society (ACS) guidelines. For individuals considered to be at high risk, ACS guidelines include earlier and more frequent screening for colorectal cancer and the addition of annual breast magnetic resonance imaging (MRI) for breast cancer.

The analyses showed that the participants’ clinically relevant family history changed substantially between the ages of 30 and 50, especially for colorectal and breast cancer. The proportion of individuals who should be recommended for high-risk screening for these two cancers increased 1.5 to 3-fold between ages 30 and 50.

“The results of this study could guide how often health care providers should ask their patients for an update in their family history,” said Dr. Finkelstein. “It is important to inform the physician of new diagnoses of cancer in family members at routine [annual] check-ups,” she added, noting that patients “should be aware of which of their close relatives have had cancer, the location or organ where the cancer started, and the age at which the relative was first diagnosed with cancer.”

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http://www.cancer.gov/ncicancerbulletin/071211/page3