Literature Scan
to a group of cancer cells from the initial
diagnosis. They also identified new genetic
changes that had arisen.
The culprit and common genetic
lineage linking the original and relapsing
leukemia in this patient? The BCR-ABL1
mutation.
“Limited prior research assumes that
late, recurring cancer is a derivative of the
original clone at diagnosis, with the exception of some acute leukemia cases where
physiologic rearrangement of immunoglobulin (IGH and IGK) genes provide
clone-specific markers,” the authors wrote.
“Our data provide unambiguous evidence
that leukemia-propagating cells, most
probably pre-leukemic stem cells, can
remain covert and silent, but potentially
reactivatable, for more than two decades.”
These findings apply to only one case
study, representing an extremely rare situation. “In the future, it might be possible to
speed up the growth of these precancerous
dormant cells so that they can be targeted
and killed using chemotherapy, to reduce
the risk of relapse even further,” the authors
added. ●
REFERENCE
Ford AM, Mansur MB, Furness CL, et al. Protracted dormancy of
pre-leukaemic stem cells. Leukemia. 2015 May 28. [Epub ahead
of print].
For Perioperative Anticoagulation in Atrial
Fibrillation: Burn Those Bridges
When patients with atrial fibrillation (AF)
being treated with warfarin need to interrupt anticoagulation to undergo an elective
operation or invasive procedure, the common practice is to “bridge” the patient with
low-molecular-weight heparin (LMWH)
during the perioperative period. According
to a recent study published in New England
Journal of Medicine, that practice is not only
unnecessary, but it may be dangerous.
In a randomized, double-blind, placebocontrolled trial, James D. Douketis, MD,
from St. Joseph’s Healthcare Hamilton and
the Department of Medicine at McMaster
University in Hamilton, Ontario, and colleagues found that bridging anticoagulation
offered no benefit over no bridging, but it
actually increased the risk of major bleeding
nearly threefold.
“Each year, this common clinical scenario affects approximately one in six warfarintreated patients with atrial fibrillation,” Dr.
Douketis and co-authors wrote. “Multiple
observational studies have assessed the
timing and dosing of perioperative bridging
with low-molecular-weight heparin. However, the fundamental question of whether
bridging anticoagulation is necessary during
perioperative warfarin interruption has
remained unanswered.”
The Bridging Anticoagulation in
Patients who Require Temporary Interruption of Warfarin Therapy for an Elective
Invasive Procedure or Surgery (BRIDGE)
trial compared the risk of arterial thromboembolism or bleeding events with bridging
anticoagulation or no anticoagulation in
1,884 patients – 950 assigned to the bridging
therapy group and 934 to the no-anticoagulation group.
Patients were enrolled from 108 sites in
the United States and Canada between July
2009 and December 2014. All patients had
chronic AF or atrial flutter, had received
warfarin therapy for three or more months,
were undergoing an elective operation or
invasive procedure, and had at least one of
the following CHADS2 stroke risk factors:
platelet drug, in addition to the warfarin.
Patients in the bridging therapy group
received either LMWH or dalteparin sodium (in the no-anticoagulation group) at a
dose of 100 IU/kg of body weight administered subcutaneously twice daily. Warfarin was discontinued five days before the
procedure and two days before the bridging
therapy was administered. Patients received
bridging treatment for three days prior to 24
hours before the procedure and then for five
to 10 days following the procedure.
A total of 1,813 completed the study, and
follow-up assessments wer