Endocrine profiles in tamoxifen-induced conception cycles

Transcription

1 FERTILITY AND STERILITY Copyright" 1984 The American Fertility Society Printed in U.S A. Endocrine profiles in tamoxifen-induced conception cycles Choshin Tajima, M.D. Department of Obstetrics and Gynecology, Kumamoto University Medical School, Kumamoto, Japan Twenty-five infertile women conceived while taking tamoxifen (TMX). Daily serum profiles of 5 of the 25 TMX -induced conception cycles were elucidated and compared with those found in 5 normal cycles. In spite of lower levels of follicle-stimulating hormone and luteinizing hormone during the follicular phases, estradiol concentrations were higher in the TMX-induced conception cycles. It is suggested that this may be due to a direct ovarian effect of TMX as one of its major mechanisms in the course of folliculogenesis. On the other hand, progesterone concentrations on days 6 and 7 during the luteal phases were also higher in the TMX -induced conception cycles. It is suggested that this may be due to a luteotropic influence at the blastocyst stage. Fertil Steril 42:548, 1984 Some information on hormone profiles in spontaneous pregnancy cycles is available, 1, 2 but detailed data have not been provided. Lenton et al. 3 elucidated the hormone profiles in spontaneous conception cycles in normal women, spontaneous conception cycles in subfertile women, conception cycles following clomiphene treatment, and conception cycles during bromocriptine treatment, and compared them with those of cyclic nonpregnant women. Mean concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and estradiol (E 2 ) were generally very similar to those of normal control cycles, which suggests that a conception cycle even in previously infertile women is likely to conform closely to normal conception cycles. Although there were no significant differences in progesterone (P) secretion among the conception cycles, there were highly significant differences between the conception cycles and the nonpregnant cycles. Mean P concentrations in the conception group were high- Received March 19, 1984; revised and accepted June 6, Reprint requests: Chosin Tajima, M.D., Assistant Professor, Department of Obstetrics and Gynecology, Kumamoto University Medical School, Kumamoto 86, Japan. er than those in the control women from days 3 to 8 following the LH peak. We have been studying the hormonal profiles of infertile patients treated with tamoxifen (TMX). In a previous article,4 we elucidated the endocrine profiles in TMX-induced ovulatory cycles. We fortunately obtained daily blood samples in five TMX treatment cycles during which conception occurred. In an attempt to elucidate the hormonal profiles in the TMX-induced conception cycles, daily FSH, LH, E 2, and P concentrations were examined. The hormone levels obtained were compared with those of normal cycles. MATERIALS AND METHODS Twenty-five infertile patients conceived in our clinic after taking to mg oftmx daily for 5 consecutive days from the fifth day of menses. These patients consisted of 1 with secondary amenorrhea in which withdrawal bleeding by P had occurred, 3 with oligomenorrhea, 4 with anovulatory cycles, and 17 with luteal phase deficiency (LPD). Endometriosis, hyperprolactinemia, and androgen excess could not be found in these patients. Five of the 25 patients who con- 548 Tajima Tamoxifen-induced conception cycles Fertility and Sterility

2 Table 1. Clinical Information of Test Group 1 2 Test group Mean ± SEMa Age (yr) Menarche (yr) Parity Height (em) Weight (kg) Duration of infertility (yr) Previous clinical diagnosis LPD b LPD LPD Anovc GO, PO Anov 26.6 ± ± ± ± ±.22 astandard error of the mean. blpd, luteal phase deficiency. canov, anovulatory cycle. ceived while taking TMX were subjects for this study. Previously, two of the patients were amenorrheic, and three with LPD had been ovulatory regularly. Clinical information about the test group is shown in Table 1. Clinical assessment of anovulatory cycles was made on the basis of (1) a low monophase with regular cyclic menses, according to basal body temperature (BBT), and (2) anovulation confirmed by endometrial biopsy performed prior to the onset of menses. An LPD was assumed when the BBT pattern was typical of that of a shortened luteal phase «12 days as the mean length of three consecutive cycles) and, in addition, when the histologic pattern of the endometrium was at least 2 days out-of-phase. The control group consisted of five cycles from normal menstruating volunteers with biphasic BBT and luteal phases lasting for 14 days or more. Previously they conceived at least more than one time, but they did not conceive in present control cycles. Their age, menarche, height, and weight ranged from 24 to 29 years of age, 12 to 14 years, 15 to 16 cm, and 45 to 53 kg, respectively. There were no significant differences between the groups with respect to age, menarche, height, and weight. In the test group, venous blood samples were obtained between 8: A.M. and : A.M. daily from the first day of TMX administration; and in the control group, they were taken daily throughout the cycle. The serum was separated and stored at - C until the assays could be performed. Serum concentrations of LH, FSH, E 2, and P were determined with radioimmunoassay kits obtained from Daiichi Radioisotope Laboratories, Ltd., Tokyo, Japan. The intraassay variations of LH, FSH, E 2, and P were 3.8%, 5.1%, 9.9%, and 8.%, respectively. The interassay variations were 4.2%, 7.9%,.9%, and 9.1%, respectively. All samples were assayed in duplicate. RESULTS Data on daily serum concentrations were obtained from 5 of the 25 TMX-induced conception cycles. The data were synchronized on the midcycle day of the LH surge, and therefore LH midcycle peaks have been designated as day o. Figures 1 through 4, respectively, show the patterns of serum concentrations of LH, FSH, E 2, and P in FSH mlu ml Case I tamo"fel'l 1 Omll: day ~ ~ H ~.JA~J--- j ~-... '_... C.Sf! 2 tame.,fen ~ day H~JJ Case 3 tamo)(lfen 1 Omg dily HHJ Case 5 A _J 1\ II I I I \ o days from LH peak Figure 1 The patterns of serum concentrations of FSH during TMX therapy. The normal range is shown in the background (mean ± standard deviation). Tajima Tamoxifen-induced conception cycles 549

3 LH mlu mi. eo. Co... Co.., tamolufen IO",&ct.y HW Co... Co.., lamo.. fen 1'" day -'5 -' di,s from LH puk LUTEINIZING HORMONE The serum concentration patterns of LH were similar in the five cases and similar to those in the control group, excluding those on days 14 and 15, which showed apparent differences from those in the control group (Fig. 2). Mean concentrations oflh during the follicular phases in the five individual cases were lower than those of the control group (Table 2). ESTRADIOL As shown in Figure 3, elevated E2 concentrations were observed during the follicular phases after TMX treatment. The mean E2 concentrations during the follicular phases in the five individual cases were higher in the TMX-induced conception cycles than in the normal cycles (Table 2). A secondary rise in E2 was observed between days 9 and 12 (Fig. 3). PROGESTERONE There were no apparent differences in the follicular phase P between the TMX-induced conception cycles and normal cycles, but the differences '" Case, PO ml 6 tamoll.fen IOmg day J, J., Case 2 6 tamoll.fen mg d.ly ~Hj, Figure 2 The patterns of serum concentrations of LH during TMX therapy. The normal range is shown in the background (mean ± standard deviation). Case J 6 tamox.fen IOmg day JW~ each cycle following TMX administration. Serum hormone concentrations were plotted against the normal ranges, shown in the background (mean ± standard deviation). FOLLICLE-STIMULATING HORMONE As shown in Figure 1, the serum concentration patterns of FSH in each case following TMX administration were similar to those of the control group, shown in the background, although the late luteal rise in FSH seen in the control group was absent. 55 Tajima Tamoxifen-induced conception cycles Case 4 6 tamoll.fen rng day m~~ Case 5 6 t.amo~,ten mg day ~W~ -'5 -' days trom LH peak Figure 3 The patterns of serum concentrations of E2 during TMX therapy. The normal range is shown in the background (mean ± standard deviation). Fertility and Sterility

4 p ng ml 15 Case 1 Case 2 15 Case 1 15 o tamo",fen 1('1",1" rlav ijhj tamo)"fen 1 Omg day jjjjj tamo~lfen mg day Hjjj ~ ~ c tamolll'en mg day mh o r Cas tamoa,fen,", cyiy JWJ o o 15 days from LH pmk Figure 4 The patterns of serum concentrations of P during TMX therapy. The normal range is shown in the background (mean ± standard deviation). in P profiles were pronounced in the luteal phase (Fig. 4). P concentrations during the luteal phases after day 2 were higher than normal in cases 4 and 5, but in cases 1, 2, and 3, those after day 5 or 6 were higher. The mean and integrated P concentrations during the luteal phases in each case were higher in the TMX-induced conception cycles than in normal cycles (Table 2). MEAN HORMONE CONCENTRATIONS Table 3 shows the mean and integrated hormone concentrations during the follicular and luteal phases and the LH and E2 peak concentra- tions at midcycle in the three TMX-induced conception cycles (cases 1, 2, and 3). The mean FSH and LH concentrations during the follicular phases were.9 ±.21 miulml and 17.9 ±.81 miu/ml, respectively, which were significantly lower than those of the normal cycles. The mean and integrated follicular phase E2 concentrations were 17 ± 7.8 pg/ml and 2482 ± pg/ml, respectively, which were significantly higher than those of the normal cycles. The mean E2 peak concentration at midcycle was 578 ± 74.1 pg/ml, which was significantly higher than that of the normal cycles of 318 ±.8 pg/ml; whereas the mean LH peak concentration was 3 ± 15. miulml, which was not significantly different from normal concentrations. The mean FSH and LH concentrations during the luteal phases were 8.6 ±.22 miulml and 26.5 ± 2.59 miu/ml, respectively, which were not significantly different from normal concentrations. The mean and integrated luteal phase E2 concentrations during both cycles were 3 ± 36.3 pg/ml and 4949 ± pg/ml and 156 ± 19.7 pg/ml and 2293 ± pg/ml, respectively; and there were significant differences between the groups. The mean luteal phase P and integrated luteal phase P concentrations were 18.8 ± 1.47 ng/ml and 282 ± 22.1 ng/ml, respectively, which were significantly higher than those of the normal cycles of 9.7 ±.76 ng/ml and 1 ± 13. ng/ml, respectively. The mean daily concentrations on days 6 and 7 were significantly higher in the TMX-induced conception cycles than in normal cycles. DISCUSSION Although some information on the hormone consequences of TMX therapy in anovulatory or ovulatory infertile women is available,4-9 the endocrine profiles in TMX-induced conception cycles were not clear because of the difficulty in obtaining daily blood samples in TMX treatment cycles during which conception occurred. In the present study, the mean E2 concentration during the follicular phase after TMX treatment was significantly higher than those of normal cycles. By contrast, the concentrations of serum FSH and LH were not higher. These findings support the results reported by other investigators9-11 that TMX may act directly on the ovary to stimulate E2 release without intermediate gonadotropin stimulation. Tajima Tamoxifen-induced conception cycles 551

5 Table 2. Serum Hormone Concentrations During the Follicular Phase, at Midcycle, and During the Luteal Phase 1 2 Mean of follicular phase FSH (mlulml) LH (mlulml) E2 (pg/ml) Integrated follicular phase E2 (pg/ml) Midcycle peak LH (mlu/ml) E2 (pg/ml) Mean of luteal phase (days 1 to 15) FSH (mlulml) LH (mlu/ml) E2 (pg/ml) P (ng/ml) Integrated luteal phase (days 1 to 15) E2 (pg/ml) P (ng/ml) amean ± standard error of the mean. Case Normal women a ± ± ± ± ± ± ± ± ± ± ± ± 13. Lenton et al. 3 reported that the clomiphene-induced elevations of follicular phase gonadotropin concentrations in the conception cycles following clomiphene treatment were associated with large and variable increases in preovulatory and luteal phase E2 secretion. In the present study, elevated E2 production during the follicular phase exerted its negative feedback on LH secretion. The reason that this' effect is not seen with clomiphene citrate, as mentioned in the articles of Lenton et al. 3 and WU,12 seems to be that clomiphene citrate enhances the gonadotropin-releasing hormonestimulated release of gonadotropin, whereas TMX does not. 13 In spite of the decreased LH production during the follicular phase based on the negative feedback of elevated E2 production, an early follicular rise in LH was observed in the TMX-induced ovulatory cycles, as reported in our previous article, in which we described the mech- anism of TMX action on the hypothalamic-pituitary axis as well as on the human ovary. However, this was not seen in the present study. This difference may not be attributable to whether the cycles are TMX-induced ovulatory cycles or TMXinduced conception cycles, but may rather be attributable to previous menstrual history or the dosage of TMX or both. The data presented strongly support a direct ovarian effect oftmx as one of its major mechanisms in the course of ovulation induction. In the present study, the serum P concentrations on days 6 and 7 were significantly higher in the TMX-induced conception cycles than in the normal cycles. The apparent differences in serum P concentrations between days 12 and 15 may be due to recovery of the corpus luteum after implantation, but the observation of higher levels of serum P on days 6 and 7 was the most interesting Table 3. Serum Hormone Concentrations During the Follicular Phase, at Midcycle, and During the Luteal Phase Intepated follicular Integrated luteal Mean of follicular phase phase Midcycle peak Mean of luteal phase phase Luteal phase P FSH LH Ez Ez LH Ez FSH LH Ez P Ez P Day 6 Day 7 miulml pglml pglml mlulml pglml mlulml pglml nglml pglml nglml nglml LPD group (cases 1. 2, and 3) Mean SEM Normal women Mean SEM Significant difference P value < NS a.5 NS NS ans, not significant. 552 Tajima Tamoxifen-induced conception cycles Fertility and Sterility

6 feature of the present study. These increased P concentrations on days 6 and 7 may be due to the TMX effect on the luteal function, as mentioned in our previous article. 7 Another possible explanation is that luteotropic influences from the products of the preimplantation embryo contribute to stimulation of P secretion. Fuchs and Beling14 reported that serum P concentrations, as well as the rate of rise in P levels, are greater in pregnant than in pseudopregnant does on days 5 to 8 after mating. They suggest that in the rabbit the maternal ovary recognizes the presence of blastocysts prior to implantation, and that the fertilized ova already exert a luteotropic influence at the blastocyst stage. Lenton et al. 3 studied hormonal profiles obtained throughout 26 conception cycles and 27 nonconception control cycles and observed mean P concentrations in the conception group to be higher than those in the control women from days 3 to 8 after the LH peak. They suggest that the higher conception cycle P concentrations during the early part of the luteal phase may be due to a preimplantation component of the maternal recognition pregnancy in women. Haour and Saxena 15 and Fujimoto et al. 16 demonstrated a substance immunologically and biologically similar to chorionic gonadotropin in rabbit preimplantation blastocysts. However, further investigations are needed to confirm these observations. Acknowledgments. I am grateful to lei, Osaka, Japan, for providing tamoxifen, and to Daiichi Radioisotope Laboratories, Ltd., Tokyo, Japan, for providing radioimmunoassay kits. I am indebted to Professor Masao Maeyama for his support and to Miss Sono Nanaki for her technical assistance. REFERENCES 1. Mishell DR, Thorneycroft IH, Nagata Y, Murata T, Nakamura RM: Serum gonadotropin and steroid patterns.in early human gestation. Am J Obstet Gynecol 117:631, Thomas K, De Hertogh R, Pizarro M, Van Exter C, Ferrin J: Plasma LH-HCG, 17f3-oestradiol, oestrone and progesterone monitoring around ovulation and subsequent nidation.int J Fertil 18:65, Lenton EA, Sulaiman R, Sobowale, Cooke ID: The human menstrual cycle: plasma concentrations of prolactin, LH, FSH, oestradiol and progesterone in conceiving and non-conceiving women. J Reprod Fertil 65:131, T~ima C, Fukushima T: Endocrine profiles in tamoxifeninduced ovulatory cycles. Fertil Steril :23, Gerhard I, Runnebaum B: Comparison between tamoxifen and clomiphene therapy in women with anovulation. Arch Gynecol 227:279, Senior BE, Cawood ML, Oakey RE, McKiddie JM, Siddle DR: A comparison of the effects of clomiphene and tamoxifen treatment on the concentrations of oestradiol and progesterone in the peripheral plasma of infertile women. Clin Endocrinol (OxO 8:381, Fukushima T, Tajima C, Fukuma K, Maeyama M: Tamoxifen in the treatment of infertility associated with luteal phase deficiency. Fertil Steril 37:755, Tajima C: Tamoxifen in the treatment of infertile patients associated with inadequate luteal phase. Fertil Steril 41:47, Fukushima T, Maeyama M: Action oftamoxifen on folliculogenesis in the menstrual cycle of infertile patients. Fertil Steril :2, Sherman BM, Chapler FK, Crickard K, Wycoff D: Endocrine consequences of continuous antiestrogen therapy with tamoxifen in premenopausal women. J Clin Invest 64:398, Groom GV, Griffiths K: Effect of the anti-oestrogen tamoxifen on plasma levels of luteinizing hormone, folliclestimulating hormone, prolactin, oestradiol and progesterone in normal premenopausal women. J Endocrinol 7: 421, Wu CH: Plasma hormones in clomiphene citrate therapy. Obstet Gynecol 49:443, Adashi EY, Hsueh AJW, Bambino TH, Yen SSC: Disparate effect of clomiphene and tamoxifen on pituitary gonadotropin release in vitro. Am J PhysioI2:E125, Fuchs AR, Beling C: Evidence for early ovarian recognition of blastocysts in rabbits. Endocrinology 95:54, Haour F, Saxena BB: Detection of a gonadotropin in the rabbit blastocyst before implantation. Science 185:444, Fujimoto S, Euker JS, Riegel GD, Dukelow WR: On a substance cross-reacting with luteinizing hormone in preimplantation blastocyst fluid of the rabbit. Proc Jpn Acad Sci 51;123, 19 Tajima Tamoxifen-induced conception cycles 553