Family Cancer History Should be Updated to ID Need for More Screening
Study finds substantial changes occurring between ages 30 and 50 - see video
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July 13, 2011 First, everyone should accept the need to maintain a family cancer history, but a new study adds that we
should also commit to updating this history at least every five to ten years. Researchers found substantial changes occurring between the ages
of 30 and 50 for colorectal, breast and prostate cancer, which could result in recommendations for earlier or more intense cancer screening.
"One of the most effective tools to identify individuals at increased risk of cancer is to ascertain their family
history. For example, having one or more close relatives with colorectal cancer increases risk from 2-fold to 6-fold, according to the report
in todays issue of the Journal of the American Medical Association (JAMA).
Individuals at increased risk of colorectal, breast, or prostate cancer due to family history are recommended to begin
screening for these cancers earlier and in some cases using more sensitive methods than average-risk individuals," according to background
information in the article.
It is recommended that primary care clinicians collect a detailed family cancer history including age at diagnosis for
affected first- and second-degree relatives. Little is known about how often clinically important changes in cancer family history occur over
time that could change individual's risk and the need for earlier or intensive screening.
This study to quantify how often clinically significant changes in family history of breast, colorectal, or prostate
cancer occur throughout adulthood was conducted by Argyrios Ziogas, Ph.D., of the University of California-Irvine, and colleagues.
It included an examination of baseline and follow-up family history data from participants in the Cancer Genetics Network
(CGN), a U.S. national population-based cancer registry, between 1999 and 2009. Participants included adults with a personal history, family
history, or both of cancer enrolled in the CGN through population-based cancer registries.
Retrospective colorectal, breast, and prostate cancer screening-specific analyses included 9,861, 2,547, and 1,817
participants, respectively; prospective analyses included 1,533, 617, and 163 participants, respectively. Median (midpoint) follow-up was 8
years.
The primary outcomes measured included percentage of individuals with clinically significant family histories and rate of
change over 2 periods: (1) retrospectively, from birth until CGN enrollment and (2) prospectively, from enrollment to last follow-up.
The researchers found that retrospective analysis indicated that the percentages of participants who met criteria for
high-risk screening based on family history at ages 30 and 50 years, respectively, were as follows:
● for colorectal cancer, 2.1 percent and 7.1 percent;
● for breast cancer, 7.2 percent and 11.4 percent; and
● for prostate cancer, 0.9 percent and 2.0 percent.
"In prospective analysis, the numbers of participants who newly met criteria for high-risk screening based on family
history per 100 persons followed up for 20 years were 2 for colorectal cancer, 6 for breast cancer, and 8 for prostate cancer. The rate of
change in cancer family history was similar for colorectal and breast cancer between the 2 analyses," the authors write.
"Both analyses demonstrate that clinically relevant family history changes substantially during early and middle
adulthood, particularly for colorectal and breast cancer, for which the percentage recommended for high-risk screening increases 1.5- to
3-fold between ages 30 and 50 years."
The researchers recommend that family cancer history should be updated at least every 5 to 10 years to appropriately
inform recommendations for cancer screening.
Editorial: Updating the Family History of Cancer
In an accompanying editorial, Louise S. Acheson, M.D., M.S., of Case Western Reserve University School of Medicine,
Cleveland, writes that studies regarding screening must take into account risks, benefits, costs, and lead time issues.
"It is plausible but still unknown whether family history increases the likelihood that breast cancers, prostate cancers,
or colon adenomas found by screening are clinically significant, he writes.
An increase in the incidence of false-positive results and test-associated complications is a cost and potential harm of
increased screening based on familial risk. Although some prospective data on the benefits of cancer screening based on familial risk are
available, many estimates rely on extrapolation from small studies of patients with high-penetrance hereditary cancer susceptibility or from
screening older patients at equivalent levels of risk."
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