Testosterone Effect on Lipids,Bone Density and Breast Cancer Incidence The “ABC Study”
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Transcript of Testosterone Effect on Lipids,Bone Density and Breast Cancer Incidence The “ABC Study”
Testosterone Effecton
Lipids ,Bone Densityand Breast Cancer
IncidenceThe “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.
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.
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 5-12 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.
The data included in addition to basic clinical information,
benign breast disease
breast cancer
HDL/ LDL
hip and spine density
Total no. attempted contact 536Successful contact 520Unable to contact 11Gone o/s or i/s 5
Women receiving oestrogen replacement in the menopause
have been given the expectation that it will give a cardioprotective
effect at least in terms of the proxy markers of HDL and LDL
cholesterol.
It would be of concern if that protective effect was lost with
the introduction of testosterone.
HDL and LDL were followed over the 12 year span.
HDL Cholesterol
1.4
1.45
1.5
1.55
1.6
Year0-2
Year2-4
Year4-6
Year6-8
Year8-10
mean HDL
S.D. 0.3-0.5
LDL Cholesterol
3.45
3.5
3.55
3.6
3.65
3.7
3.75
3.8
3.85
Year0-2
Year2-4
Year4-6
Year6-8
Year8-10
mean LDL
SD 0.9-1.1
It would appear that there was no serious adverse effect by the
testosterone on these two markers.
The mean levels while varying over time, would be acceptable.
The addition of testosterone to conventional HRT has the
reputation for improving bone density.
This assertion was examined.
Change in Lumbar Density
1
1.01
1.02
1.03
1.04
1.05
1.06
1 2 3
Lumbar Spine Density
BM
D 123
Range0.77-1.60+3.1%
Change in Hip Density
0.72
0.73
0.74
0.75
0.76
0.77
1 2 2
Hip Density
BM
D
mean
Range0.77-1.37
+3.1%
Change in LS BMD over 3 years
0
2
4
6
8
LS1 LS2 LS3
BMD YEARS
% C
hang
e in
BM
D
Series1
The initial improvement in bone density of only 3.1% in either
area fell short of expectation as did the overall loss.
Declining densities in smaller numbers was attributed to non-
responders to HRT.
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 appeared to be 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?
Date of Incidence of the Cancers
0
0.5
1
1.5
2
2.5
3
3.5
0 5 10 15
Cancer cases
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.
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
It might therefore be suspected that if the testosterone users were compared
with oestrogen only users, the incidence of breast cancer would be
reduced.
?? 92%vs. 97.41%.(95% confidence interval of 95.53% to 99.29%.)
Thank you for
your attention.