CLINICAL NEWS
in a Different Vein
Research from ASH’s newest peer-reviewed
journal, Blood Advances
Study Finds Cancer Risk is Higher
Than Expected Among Patients With
Pregnancy-Related VTE
Venous thromboembolism (VTE)
is associated with an increased
prevalence of occult cancer. As
pregnancy is also associated with
an increased risk of VTE, it is
unknown whether VTE during
pregnancy or the postpartum
period is similarly associated with
an increased risk of a subsequent
malignancy.
Anette Tarp Hansen, PhD, of
the Department of Clinical Epi-
demiology at Aarhus University
Hospital in Denmark, and co-
authors conducted a, nationwide
study of nearly 4,000 pregnant
women who developed VTE
and found that VTE occurrence
during pregnancy or postpartum
appeared to be a marker of an
underlying occult cancer.
“[Our study] showed that
the risk of having a diagnosis of
malignancy in the first year after
a VTE episode during pregnancy
or the postpartum period was
higher than expected compared
with the general female popula-
tion of the same age and in [the]
same calendar years,” the authors
wrote of the findings, which were
published in Blood Advances.
The researchers used several
national Danish databases to
identify women without can-
cer who developed VTE (both
incident and recurring VTE,
TABLE .
including deep VTE and super-
ficial venous thrombosis) during
pregnancy or the 12 weeks after
delivery. They also assessed inci-
dence of occult cancer.
The authors identified any
VTE risk factors (including obe-
sity, smoking, surgery, fracture,
trauma, cesarean section, and
postpartum bleeding) and comor-
bid conditions (including diabetes,
chronic rheumatologic disease,
and inflammatory disease) related
to an increased risk of cancer.
assessed at three timepoints after
VTE diagnosis (<6 months, 6-12
months, and 1 year). Outcomes
were stratified based on patient
age, obesity at the time of VTE
diagnosis, and timing of the event
(antepartum or postpartum).
During a median follow-up of
14.8 years (range = 6.7-24.2 years),
3,934 women were diagnosed
with VTE during pregnancy or
postpartum, 8.8 percent of whom
had a prior history of VTE. A total
of 250 women were subsequently
“The risk of having a cancer
diagnosed within the first
months after a VTE episode in
relation to pregnancy seems
increased.”
—
ANETTE TARP HANSEN, PhD
The study included women
with VTE during pregnancy
or the postpartum period who
delivered a child between January
1, 1978, and November 20, 2013.
Patients were followed until can-
cer diagnosis, death, emigration,
or cutoff date (November 30,
2013), and cancer incidence was
diagnosed with cancer: 64 (25%)
after VTE during pregnancy and
186 (75%) after VTE during the
postpartum period.
“The number of cancer cases
observed within six months after
a VTE event was higher than
expected (absolute risk = 0.10%;
95% CI 0.04-0.25; standardized
incidence ratio [SIR] = 1.77;
95% CI 0.48-4.53), especially
after a postpartum VTE event
(SIR=2.86; 95% CI 0.78-7.33),”
the authors wrote. The increased
risk remained during the six to 12
months after VTE (SIR=3.27; 95%
CI 0.67-9.56), and cancer risk
was still moderately increased
after one year (SIR=1.23; 95% CI
0.94-1.58). The risk returned to
“expected levels” during the re-
maining follow-up (absolute risk
= 20.13%; 95% CI 16.55-23.98),
according to the authors. See
TABLE for more outcomes.
“The risk of having a cancer
diagnosed within the first months
after a VTE episode in relation to
pregnancy seems increased,” the
authors concluded.
The study is limited by its ret-
rospective design. In addition, the
data during the first year of follow-
up were “sparse, yielding imprecise
risk estimates for site-specific
cancers,” the authors noted.
The Lundbeck Foundation and
Novo Nordisk Foundation provided
financial support for the study.
The authors report no financial
conflicts.
REFERENCE
Hansen AT, Veres K, Horváth-Puhó E, et al. Pregnancy-
related venous thromboembolism and risk of oc