lunes, 5 de marzo de 2012

Screening for Lynch Syndrome Varies Among Hospitals

Screening for Lynch Syndrome Varies Among Hospitals

From Reuters Health Information

Screening for Lynch Syndrome Varies Among Hospitals

By Genevra Pittman

NEW YORK (Reuters Health) Feb 23 - Hospitals and cancer centers inconsistently screen tumors from colon cancer patients for Lynch syndrome, a new survey suggests.

Those that do have screening protocols have different policies on whether all patients, or just younger ones, get the tests, and whether they're given a chance to opt out. None of the hospitals surveyed require written informed consent, researchers reported February 21 in the Journal of Clinical Oncology.

Experts say there's still no evidence that immunohistochemistry (IHC) or microsatellite instability (MSI) testing saves lives, and their effectiveness likely depends on patient follow-up after testing.

"These are not generally diagnostic, they are suggestive," said Dr. Michael Hall, head of gastrointestinal risk assessment at the Fox Chase Cancer Center in Philadelphia.

Still, he told Reuters Health, "Many of these patients are frankly unaware that (tumor) testing will be done."

If tests are positive for one of the inherited defects in mismatch repair genes that cause Lynch syndrome, patients meet with a genetic counselor before going ahead with diagnostic germ line testing.

Some may be taken by surprise at the possibility of having a genetic condition that predisposes them -- and some family members -- to cancer, whereas for others without prior counseling, "that information from their doctor may go in one ear and out the other," said Dr. Hall, who wasn't involved in the new study.

To get a sense of how IHC and MSI are currently being used in patients with colorectal cancer, researchers from City of Hope in Duarte, California surveyed 139 national cancer centers and community hospital programs about their routine use of tumor testing.

Of the 69 institutions that responded, 29 said they automatically screen at least some of their colon cancer patients with IHC and/or MSI. Less than half of those test tumors from all new patients (38%), whereas others only screen patients younger than 50 (27%) or 60 years old (14%), or use another convention to select which cases to test.

National Cancer Institute-designated Comprehensive Cancer Centers (71%) were more likely to report doing reflex testing than Community Hospital Comprehensive Cancer Programs (36%) and Community Hospital Cancer Programs (15%).

True estimates may be lower, researchers said, as the survey's 50% response rate suggests that hospitals already doing the testing were more likely to be included.

Only four of the 29 hospitals offer patients an opt-out option from testing, and none of them require written informed consent before IHC or MSI, senior author Dr. Deborah MacDonald and her colleagues reported.

Part of that is a feasibility and cost issue, researchers said.

"Removing that barrier of the genetic counseling before doing this really does open the door to many more patients doing that initial screening and getting that message out to patients that they may be at risk," Dr. Hall said.

Still, some controversy remains.

There has been "concern that testing the tumors is the same thing as genetic testing, which I really don't think it is," said Dr. Sapna Syngal from Harvard Medical School in Boston, who co-wrote an editorial on the study.

"This just happens to be a subset of patients who, if you look at the tumors and look at these features, you're able to tell who has a genetic syndrome," Dr. Syngal told Reuters Health.

Dr. Hall said that about 15-20% of patients with colon cancer will screen positive on IHC or MSI, and another 15-20% of those will have a MLH1, MSH2, MSH6, or PMS2 mutation.

Will more hospitals and cancer centers routinely screen for Lynch syndrome mutations in the coming years? Dr. Hall pointed out that IHC and MSI won't prove cost-effective and widely applicable "until we can see evidence that this approach is actually identifying more patients, that these patients are taking that information and going into a genetic clinic and getting genetic testing, and (that they are) sharing that information with family members who can also determine if they have Lynch."

The multi-institutional Lynch Syndrome Screening Network, he said, should help answer those questions in the future.


J Clin Oncol 2012.

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