Through the Cancer Genetics Network, a United States population-based cancer registry, a team of statisticians, clinicians, oncologists and geneticists reviewed data on family history of cancer of more than 10,000 patients who were followed for almost 10 years.
Focusing on cancers of the breast, colon and prostate, the team looked at how clinically relevant changes in family cancer history changed over each individual’s lifetime.
Only first-and second-degree history (parents, siblings, grandparents and aunts and uncles) were noted in the analysis. Breast, colon and prostate were focused on because they have effective and proven methods of screening. They followed existing cancer screening guidelines developed by major cancer groups such as the American Cancer Society.
Changes most likely between 30-50
“We took data provided by people in the Cancer Genetics Network database that allowed us to determine their family of cancer literally from birth until entry into the network. To assess the need for screening, it’s crucial that a clinician has knowledge of how an individual’s family history changes over time,” said Dr. Sharon Plon, director of the Baylor College of Medicine Cancer Genetics Clinic and a professor of pediatrics and of molecular and human genetics at BCM, and senior author of the report. See video of Dr. Plon discussing this study.
The analysis revealed that the family cancer history was most likely to change between the ages of 30 and 50 but after age 50 there were fewer additional cancers that would put a person at a higher risk.
For example, Plon said a 30-year-old woman may not be eligible for a breast MRI (magnetic resonance imaging, used in high-risk women to detect cancer at earlier stages) but five years later, if there are changes in her family history, she may need to be placed in a higher risk category who needs this type of advanced screening earlier.
Dr. Dianne Finkelstein, a member of the Massachusetts General Hospital Biostatistics Center, professor of biostatistics at Harvard School of Public Health and a professor of medicine at Harvard Medical School, served as the principal investigator of the Cancer Genetics Network.
Updates needed every five to 10 years
Based on the analysis, the team concluded that a comprehensive family history should be taken from young adults and updated again about every five to 10 years until at least age 50.
Plon said the wider use and implementation of electronic health records could make this an easier task for physicians in the future.
“Our hope is that this new information will help educate physicians to more frequently ask patients these important questions,” said Plon, also a member of the NCI-designated Dan L. Duncan Cancer Center at BCM. “As most healthcare systems are moving toward the use of electronic health records, there is tremendous potential to ensure that people at higher risk of cancer are being screened earlier and using the best methods.”
The CGN is funded by the Epidemiology and Genetics Research Program in National Cancer Institute’s Division of Cancer Control and Population Sciences.
BCM has been a member of the Cancer Genetics Network since its inception in the late 1990s.
In addition to BCM and Massachusetts General Hospital, other institutions involved in the study include the University of California in Irvine; Huntsman Cancer Institute at the University of Utah in Salt Lake City; University of Colorado in Denver; University of Pennsylvania in Philadelphia; Georgetown University in Washington, D.C.; Johns Hopkins University in Baltimore; Duke University Medical Center in Durham N.C.; University of Washington in Seattle; University of New Mexico in Albuquerque; University of North Carolina at Chapel Hill; University of Texas Health Science Center at San Antonio; University of Texas Southwestern Medical Center; University of Texas M.D. Anderson Cancer Center; National Institute for Child Health and Development.