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Aim. Several
studies have shown a
negative correlation
between cancer and
atopy-related
diseases. There are
also a few reports
of a positive
relationship. We
wanted to further
evaluate these
relationships in a
prospective study.
Subjects and methods.
The incidence of
malignant diseases
among adult patients
with atopy-related
diseases (asthma,
rhinitis, urticaria,
eczema etc;
n=13811), who had
been skin prick
tested in 1976-1999
was compared with
the incidence in the
general population.
Expected cancer
incidence from the
date of skin prick
testing up to 1999
was obtained from
cause-, sex-,
calendar-year-, and
5-year-age-group
specific incidence
rates for the county.
These rates were
calculated from
cancer incidence and
population counts
obtained from the
Swedish Cancer
Register. The
95% confidence
intervals (CIs) for
cause-specific
standardized
incidence ratios (SIRs)
were calculated.
Skin prick tests
were performed with
Dermatophagoides
pteronyssinus, horse,
dog, cat, timothy,
mugwort, birch, and
Cladosporium.
Patients having one
or several positive
skin prick test
reactions (≥2+) were
regarded as atopics.
Results. 119
cases of cancer
occurred among 6224
atopic individuals
(SIR 1.0) compared
with 216 cases (SIR
0.94, CI 0.82-1.08)
among 6358 non-atopics.
There was a slight
excess of Hodgkins
lymphoma cases among
atopic men (SIR
4.03, 95% CI
1-10.3), and of non
Hodgkin lymphoma
cases among atopic
women (SIR 4.52,
95% CI 1.23-11.6).
However, a large
number of
comparisons were
made which can have
caused random
findings.
Conclusions.
The results showed
no associations
between atopy or
allergic symptoms,
and subsequent
cancer risk, but
supported the theory
that type-I allergy
is not related to
cancer risk.
Key words.
Allergy, asthma,
allergic rhinitis,
atopy-related
diseases, cancer,
malignancies, skin
prick test. |
