EMBARGOED UNTIL 11 AM EASTERN TIME, WEDNESDAY, DEC. 7, 2016
Novel test enables earlier detection of Merkel cell carcinoma, Fred Hutch scientists report
New research findings show how an immune system marker can outperform and supplement imaging studies for recurrence of Merkel cell carcinoma
Scientists
have found a way to detect earlier if a deadly cancer, Merkel cell carcinoma
(MCC), is recurring in patients, according to a paper to be published 11 a.m.
Eastern time, Dec. 7, in the journal Cancer.
The
test works by measuring the presence of a novel marker – an antibody to a
cancer-driving protein from the virus that causes MCC. It enables
clinicians to identify which of the patients who successfully undergo treatment
for MCC are most at risk of recurrence and to it makes it easier, more
effective and less costly to see when the cancer is just starting to return.
The
paper’s senior author is Dr. Paul Nghiem, a member of Fred Hutchinson
Cancer Research Center, the head of the Division of Dermatology at the
University of Washington medical school and a clinician at the Seattle Cancer Care Alliance. Its 18
co-authors are from Fred Hutch, UW medical school and SCCA.
The
research builds on a key discovery revealed earlier this year in another study by
Nghiem
and colleagues —that the immune system can be mobilized to effectively attack
MCC, a rare cancer that kills one of every three who develop it.
The
reason the new blood test matters is that detecting MCC early can be the
difference between life and death. The cancer has an extremely high recurrence
rate: It is several times more likely to recur than melanoma and hundreds of
times more likely than basal cell carcinoma; even patients who have the
earliest, lowest-risk stage of this cancer have a 20 percent risk of it coming
back. “Catching and treating the recurrence before it has a chance to grow
large – the difference between a cancer the size of a grape and one the size of
a grapefruit –enhances the chances that immune therapy will work,” said Nghiem.
The
latest study involved 219 patients whose initial MCC had been effectively treated with surgery and or radiation.
The researchers examined how well the test detected MCC compared with
radiologic imaging, which is the prevailing practice. The findings show that
over a five-year period, the test was better at picking up small traces of the
cancer when it first returns. In many cases, the blood test suggested the
cancer was recurring well before tumors were visible by imaging.
Compared
with traditional imaging, the test is also much less expensive and spares
patients exposure to the radiation and contrast dye associated with imaging.
Nghiem
says that all of his MCC patients now get the test at the time of diagnosis.
Clinicians can get the test for their patients by sending blood samples to a
clinical lab at the University of Washington. Physicians at Mayo Clinic,
Stanford and UC San Francisco as well as in individual practices around the
country are already frequently using the test. This study documents the strengths and limitations of the blood test and will likely lead to it being offered to MCC patients more broadly.
The
new test costs about $200, and the UW lab does not expect to profit from it.
(At present they are not fully covering their costs.)
The
researchers say that the test is not practical for the initial diagnosis of MCC
because the disease is so uncommon; instead, its main use is in detecting recurrence earlier.
The
test has different implications for MCC patients who do not produce these
antibodies – nearly half of those in the study. The test doesn’t track Merkel
cell carcinoma recurrence in this group, because such patients will not
produce these antibodies even when the cancer returns. Still, getting the test done once is useful for all patients, including those found not to produce the antibodies. This is because those who test negative are 42 percent more likely to have a recurrence, meaning that doctors should order more frequent imaging done for them.
The
importance of this test goes beyond the improvement in treatment for patients
with MCC. “The findings highlight how monitoring the robustness of the immune
system provides key insights into cancer treatment, and they are emblematic of
a broader shift in how physicians can track disease,” said Nghiem. “It
underscores a key tenet of immune therapy – that your immune system is
naturally attuned to fighting cancer and the challenge is how best to harness
that.”
The
research was supported by grants from the National Institutes of Health and the
National Center for Advancing Translational Sciences and by the Merkel Cell
Carcinoma Patient Gift Fund at the University of Washington.
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Media Contact:
At Fred Hutchinson Cancer Research Center, home to three Nobel laureates, interdisciplinary teams of world-renowned scientists seek new and innovative ways to prevent, diagnose and treat cancer, HIV/AIDS and other life-threatening diseases. Fred Hutch’s pioneering work in bone marrow transplantation led to the development of immunotherapy, which harnesses the power of the immune system to treat cancer with minimal side effects. An independent, nonprofit research institute based in Seattle, Fred Hutch houses the nation’s first and largest cancer prevention research program, as well as the clinical coordinating center of the Women’s Health Initiative and the international headquarters of the HIV Vaccine Trials Network. Private contributions are essential for enabling Fred Hutch scientists to explore novel research opportunities that lead to important medical breakthroughs. For more information visit fredhutch.org or follow Fred Hutch on Facebook, Twitter or YouTube.
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