Pd. Inskip et al., SERUM ESTROGEN AND ANDROGEN LEVELS FOLLOWING TREATMENT FOR CERVICAL-CANCER, Cancer epidemiology, biomarkers & prevention, 3(1), 1994, pp. 37-45
Endogenous sex hormones seem to influence the risk of several common a
nd debilitating diseases. With a view toward better understanding the
effects of surgical removal of the ovaries and high-dose pelvic radiot
herapy on plasma sex hormone levels, we measured estrogen and androgen
concentrations cross-sectionally among 147 women who had been treated
for cervical cancer 0.3-18.5 years previously. Pelvic radiotherapy (m
ean dose to ovaries, 50 Gy) and bilateral ovariectomy were associated
with similarly reduced hormone concentrations relative to levels among
nonirradiated women with intact ovaries, most of whom had had early-s
tage disease and were treated by hysterectomy. There was little eviden
ce that radiotherapy in addition to ovariectomy further lowered concen
trations below levels associated with ovariectomy alone, such as might
be expected if radiation was suppressing adrenal endocrine function.
Among women age 50 years or older at the time of blood drawing, the re
moval or irradiation of the ovaries was associated with approximately
45% lower concentrations of estradiol (mean ratio [MR], 0.55; 95% conf
idence interval [CI], 0.32-0.95) and testosterone (MR, 0.57; 95% CI, 0
.32-0.99), and 25-30% lower concentrations of estrone (MR, 0.69; 95% C
I, 0.44-1.09) and androstenedione (MR, 0.76; 95% CI, 0.47-1.23), relat
ive to the hysterectomy-only group. Among women younger than 50, ovari
ectomy and radiotherapy, alone or in combination, were associated with
83% lower estradiol concentrations (MR, 0.17; 95% CI, 0.09-0.31), 46%
lower estrone concentrations (MR, 0.54; 95% CI, 0.37-0.81), 23% lower
androstenedione concentrations (MR, 0.77; 95% CI, 0.57-1.04), and 14%
lower testosterone levels (MR, 0.86; 95% CI, 0.64-1.15). A possible m
echanism for the reductions among postmenopausal women involves effect
s on androgen-producing cells in the ovary, which retain secretory fun
ction after menopause.