Transcript Testosterone and Breast Cancer

Testosterone
and
Breast Cancer
The “ABC Study”
This is a preliminary view of
data collected on women
receiving testosterone with
oestrogen replacement in the
menopause
These data are yet to be finally
analysed.
520 women received testosterone
and oestrogen by implant over
12 years.
The current population of
women receiving both
testosterone and oestrogen in my
practice at that time was:
1000+/- patients
Oestrogen was given at 6-12
month intervals.
Testosterone was given at 5-6
monthly intervals.
The dose of testosterone varied
between 50 and 100 mgm and
rarely 150 mgm.
The dose of implant was selected
on subjective response, checked
by objective measurement and
reduced if adverse side effects
emerged.
The measured total level would
often exceed the
premenopausal “normal
range”.
The relevant level would be the
bioavailable range
(testosterone / SHBG
“testosterone index”).
Originally the testosterone was
used in line with conventional
medical wisdom to improve
libido.
Quite quickly it became
apparent that this was not the
major benefit that the hormone
could confer on the woman.
As the years passed, it was noted
that the testosterone appeared to
have the capacity to reduce
oestrogen stimulated breast
soreness and the incidence of
abnormal mammograms was
reduced.
The only possible exception to
this would be when the woman
was inadequately replaced with
oestrogen.
Under these circumstances it is
believed that there may have
been increased aromatisation of
testosterone to oestrogen within
the breast tissue
The simplistic idea emerged that
if oestrogen was at least a
promoter of breast cancer, and if
testosterone reduced breast
stimulation, might it not be
shown to decrease the incidence
of breast cancer.
A retrospective data collection
was undertaken.
A list of patients receiving
testosterone were drawn from
the computer billing record and
contacted by telephone.
The interview was conducted by
a research assistant with a
standardised questionnaire.
The data included in addition to
basic clinical information,
benign breast disease
breast cancer
HDL/ LDL
hip and spine density
Total no. attempted contact
Successful contact
Unable to contact
Gone o/s or i/s
536
520
11
5
Date of Incidence of the Cancers
3.5
3
2.5
2
Cancer cases
1.5
1
0.5
0
0
5
10
15
Years
A survival analysis for the study group
was undertaken.
The starting date for the measurement
of survival time was the date of first
testosterone implant.
The end time was the date of last follow
up for those women not diagnosed with
breast cancer, and date of diagnosis for
those women diagnosed with breast
cancer.
The survival time was compared
with data taken from the S. A.
Cancer Registry.
There were 7 breast cancers in
the study group while on
testosterone plus oestrogen
compared with an expected
incidence of 12(14) on
conventional HRT alone,
but on analysis………………
The 10-year breast cancer free
survival rate for patients in the
trial was
97.41%.
(95% confidence interval of 95.53% to 99.29%.)
The expected 10-year breast
cancer free survival rate for
patients in the trial was
97.52%.
It would appear then that the
survival from the diagnosis
breast cancer did not differ
from that of the South
Australian population at
large of whom 44.3% were
taking oestrogens.
It would have been optimal to
compare the study group with
women taking oestrogen alone.
A statistical estimate was made
of expected rates if 100% of the
women in the Omnibus Study
had been taking oestrogen.
The R.R. of 1.35 (Beral et al)
was used in this exercise.
The S. A. Health Omnibus Study
tells us that in 1997 the current
use of oestrogen was a
maximum of 44.3% and the
‘ever use’ was 63.6%, and that
only 5.4% of these had ever used
testosterone.
The calculation shows that the expected
10-year breast cancer free survival rate
for patients in the trial was
?? 92%
??
It might therefore be suspected that if
the testosterone users were compared
with oestrogen only users, the
incidence of breast cancer would be
reduced.
Thank you
for your
attention.