Women with Turner’s syndrome may be at an increased
risk for various types of cancer, including bladder, melanoma and corpus uteri,
but are at decreased risk for breast cancer.
Researchers at the U.K. Clinical Cytogenetics Group in
Surrey, United Kingdom, developed a national cohort of 3,425 women diagnosed
with Turner’s syndrome between 1959 and 2002. They followed the patients
for cancer incidence for a mean 17 years per patient.
Not including non-melanoma skin cancer, researchers
found 73 malignancies (standardized incidence ratio 0.9; 95% CI, 0.7-1.2).
While the risk for breast cancer was lower in this population (n=10; SIR 0.3)
than in the general population, women with Turner’s syndrome had an
increased risk for central nervous system tumors, specifically meningioma (n=7;
SIR 12.0) and childhood brain tumors (n=3; SIR 10.3). Risks were also higher in
this population for cancers of the bladder, urethra and eye.
At ages 15 years to 44 years, the risk for corpus uteri
cancer was higher (n=3; SIR 8.0). Gonadoblastoma of the ovary was reported
during follow-up in five women with a Y-chromosome lineage. – by Stacey
The most important thing to note about this epidemiological study is
that overall cancers are not increased in Turner’s syndrome. Moreover,
risk for breast cancer was actually significantly reduced among women with
Turner’s syndrome compared to the general population. This is important
since patients and caregivers worry about reports of possible breast cancer
increase associated with hormone therapy for older women. This is the second
epidemiological study reporting no increase in breast cancer in women with
Turner’s syndrome. A small study was published in NEJM about
a year ago that reported no increase in estrogen-treated Polish women with
Turner’s syndrome, so this makes two studies with a fairly large number of
women and years of observation for this rare population, which is reassuring.
This study did find an increase in brain tumors, mainly meningiomas.
This reminds me of a study years ago that noted an increased prevalence of
neuroblastoma in girls with Turner’s syndrome. These reports might suggest
that practitioners need to be proactive in evaluating complaints of headache or
neurological symptoms in patients with Turner’s syndrome.
It is interesting to note that there were only five gonadoblastoma
diagnoses, all in individuals with Y chromosomes in their karyotype. Since
there were 441 subjects with Y-positive karyotypes in the study, this
represents a very low rate, in contrast to some estimates that have been as
high as 10%. The major limitation of the study is the lack of clinical
correlative information. For example, it is unknown if the gonadoblastomas
presented clinically or, more likely, were found as a result of standard
practice gonadectomy for girls with Y chromosome material. Nor do we know the
prevalence of estrogen and progestin use among the women. If there were a large
number of non-users, that would explain the reduced rate of breast cancer.
– Carolyn Bondy, MD
Chief, Developmental Endocrinology Branch,
Institute of Child Health and Human Development, NIH