Robot-assisted versus three-dimensional laparoscopic radical prostatectomy: 12-month outcomes of a randomised controlled trial

OBJECTIVES

To compare functional and oncological outcomes of robot-assisted laparoscopic prostatectomy (RALP) to three-dimensional laparoscopic radical prostatectomy (3D-LRP) at 12 months after surgery.

PATIENTS AND METHODS

Prospective randomised single-centre study of 145 consecutive men referred to radical prostatectomy in a tertiary referral centre in Finland. Patients were randomised 1:1 to the RALP (N = 75) and 3D-LRP (N = 70) groups. The primary outcome was urinary continence evaluated with the Expanded Prostate Cancer Index Composite 26-item version (EPIC-26) incontinence domain score at 12 months after surgery. Secondary outcomes included the use of protective pads at 12 months after surgery, EPIC-26 domain scores of irritative/obstructive, bowel, sexual and hormonal symptoms, positive surgical margin (PSM) rate, and biochemical recurrence (BCR). Complication frequency within the 3-month period after surgery was evaluated according to Clavien-Dindo classification. Statistical significance between groups was analysed using Mann-Whitney, chi-square and Fisher's exact tests. The trial was terminated after interim analysis based on no statistically significant difference in EPIC-26 urinary incontinence domain scores. Altogether 145 patients of the target accrual of 280 patients were recruited.

RESULTS

Postoperative continence at 12 months after surgery according to the EPIC-26 incontinence domain was 79.25 in both groups (P = 0.4). Between group difference was -5.8 (95% confidence interval -15.2 to 3.6). There was no statistically significant difference in the rates of PSM or BCR between the two surgical modality groups.

CONCLUSION

We were unable to demonstrate a difference between the RALP and 3D-LRP groups for functional and oncological outcomes at 12 months after surgery.

Randomised double-blind phase 3 clinical study testing impact of atorvastatin on prostate cancer progression after initiation of androgen deprivation therapy: study protocol

INTRODUCTION

Blood cholesterol is likely a risk factor for prostate cancer prognosis and use of statins is associated with lowered risk of prostate cancer recurrence and progression. Furthermore, use of statins has been associated with prolonged time before development of castration resistance (CR) during androgen deprivation therapy (ADT) for prostate cancer. However, the efficacy of statins on delaying castration-resistance has not been tested in a randomised placebo-controlled setting.This study aims to test statins' efficacy compared to placebo in delaying development of CR during ADT treatment for primary metastatic or recurrent prostate cancer. Secondary aim is to explore effect of statin intervention on prostate cancer mortality and lipid metabolism during ADT.

METHODS AND ANALYSIS

In this randomised placebo-controlled trial, a total of 400 men with de novo metastatic prostate cancer or recurrent disease after primary treatment and starting ADT will be recruited and randomised 1:1 to use daily 80 mg of atorvastatin or placebo. All researchers, study nurses and patients will be blinded throughout the trial. Patients are followed until disease recurrence or death. Primary outcome is time to formation of CR after initiation of ADT. Serum lipid levels (total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and trigyserides) are analysed to test whether changes in serum cholesterol parameters during ADT predict length of treatment response. Furthermore, the trial will compare quality of life, cardiovascular morbidity, changes in blood glucose and circulating cell-free DNA, and urine lipidome during trial.

ETHICS AND DISSEMINATION

This study is approved by the Regional ethics committees of the Pirkanmaa Hospital District, Science centre, Tampere, Finland (R18065M) and Tarto University Hospital, Tarto, Estonia (319/T-6). All participants read and sign informed consent form before study entry. After publication of results for the primary endpoints, anonymised summary metadata and statistical code will be made openly available. The data will not include any information that could make it possible to identify a given participant.

TRIAL REGISTRATION NUMBER

Clinicaltrial.gov: NCT04026230, Eudra-CT: 2016-004774-17, protocol code: ESTO2, protocol date 10 September 2020 and version 6.

Men's experiences of the impact of penile cancer surgery on their lives: A qualitative study

OBJECTIVE

Surgery is the primary treatment for invasive penile cancer (PC). Postoperative changes in genital anatomy and function may lead to altered body and self-image, compromised sexual function and subsequent psychological problems. The aim of this study is to describe men's experiences of the impact of PC surgical treatment on their lives.

METHODS

The institutional databases of two Finnish university hospitals were searched for patients who underwent surgery for invasive PC between 2009 and 2019. Of 107 men, 29 agreed to an interview or a response letter. The data were analysed by thematic analysis.

RESULTS

The men experienced that their self-image had changed after PC diagnosis and treatment to a 'cancer-modified me'. They also experienced that physical symptoms after surgery defined their everyday, as well as sexual, lives and that the whole content of life changed.

CONCLUSION

Support and counselling for physical, mental, sexual and social factors should be part of the treatment of men with PC.

Number of screening rounds attended and incidence of high-risk prostate cancer in the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC)

BACKGROUND

The European Randomized Study of Screening for Prostate Cancer has shown a 20% reduction in prostate cancer (PC) mortality by prostate-specific antigen-based screening. In addition, screening has been shown to reduce the risk of advanced PC. The objective of the current study was to analyze the impact of screening participation on the incidence of PC by risk group.

METHODS

The participants in the screening arm of the Finnish trial (31,867 men) were classified according to screening attendance in a time-dependent fashion. Initially, all men in the screening arm were regarded as nonattenders until the first screening attendance; they then remained in the once-screened group until the second screen and similarly for the possible third round. The control arm formed the reference group. Follow-up started at randomization and ended at the time of diagnosis of PC, emigration, or the end of 2015. PC cases were divided into risk groups according to European Association of Urology definitions.

RESULTS

The incidence of low-risk PC increased with the number of screens, whereas no clear relation with participation was noted in the intermediate-risk and high-risk cases. For patients with advanced PC, attending screening at least twice was associated with a lower risk.

CONCLUSIONS

Screening reduces the risk of advanced PC after only 2 screening cycles. A single screen demonstrated no benefit in terms of PC incidence. Repeated screening is necessary to achieve screening advantages.

Urine colour as an indicator for anastomotic leakage after robot-assisted radical prostatectomy

Objectives: To determine whether macroscopic haematuria predicts urethrovesical anastomotic leakage after robot-assisted laparoscopic radical prostatectomy (RALP) as well as a cystogram.Patients and methods: Participants were recruited before cystogram and catheter removal 5-14 days after RALP surgery. Urine colour in the collection bag was classified according to a three-step scale (clear, light red and dark red) and leakages in cystogram were graded with a four-step scale (Grade 0-3). Diagnostic accuracy parameters were calculated for urine colour. A multivariate logistic regression model was used to evaluate other leakage risk factors.Results: Of 214 patients, 201 (94%) had clear, six (3%) had light red and seven (3%) had dark red coloured urine. In the cystogram, 20 (9%) patients had leakage; 14 had Grade 1, five Grade 2 and one Grade 3 leakage. Overall, specificity and sensitivity of urine colour in predicting anastomotic leakage were 0.97 (95% CI = 0.95-100) and 0.38 (95% CI = 0.17-0.59), respectively. Negative and positive predictive values were 94% and 62%, respectively. Other significant risk factors for anastomotic leakage were previous transurethral resection or radiation therapy to the prostate, non-waterproof anastomosis at surgery, postoperative pelvic haematoma, long catheterization and surgeon's inexperience. In patients with no other risk factors, test sensitivity improved to 0.80 (95% CI = 0.45-1.15) and negative and positive predictive values to 99% and 44%, respectively.Conclusion: This prospective single-arm trial indicates that in patients with clear urine and no other risk factors for anastomotic leakage, a cystogram examination before urethral catheter removal can be safely omitted.

Expression of LHCG receptors in the human penis

The aim of this study is to investigate the expression of the luteinizing hormone/choriogonadotropin (LHCG) receptor in the human penis to see, if the luteinizing hormone (LH) effects are possible in the spongious and cavernous tissue of the penis. The number of men with erection disturbances increases significantly simultaneously with the elevated LH concentrations between 40 and 70 years. It is possible that the elevated LH concentrations may influence locally the erectile mechanisms. The precondition for this is the expression of LHCG receptors in the penis. Penile tissue was obtained from three patients undergoing total or partial penectomy due to a rectal cancer with secondary penile metastasis or squamous cell carcinoma of the penis. Immunohistochemistry was used for the detection of the LHCG receptor. Positive immunoreaction for LHCG receptors was discovered in the endothelial cells of cavernous spaces in the corpus cavernosum and corpus spongiosum penis, also in the endothelial cells of the capillary walls in all patients. Our results show that LHCG receptor is expressed in the spongious and cavernous tissue of the human penis. This finding suggests that LH can affect the spongious and cavernous tissue in human and play a significant role in the development of erectile dysfunction among the aging men.

Atorvastatin Versus Placebo for Prostate Cancer Before Radical Prostatectomy-A Randomized, Double-blind, Placebo-controlled Clinical Trial

We tested whether intervention with atorvastatin affects the prostate beneficially compared with placebo in men with prostate cancer in a randomized clinical trial. A total of 160 statin-naïve prostate cancer patients scheduled for radical prostatectomy were randomized to use 80mg atorvastatin or placebo daily from recruitment to surgery for a median of 27 d. Blinding was maintained throughout the trial. In total, 158 men completed the follow-up, with 96% compliance. Overall, atorvastatin did not significantly lower tumor proliferation index Ki-67 or serum prostate-specific antigen (PSA) compared with placebo. In subgroup analyses, after a minimum of 28 d of atorvastatin use, Ki-67 was 14.1% lower compared with placebo (p = 0.056). Among high-grade cases (International Society of Urological Pathology Gleason grade 3 or higher), atorvastatin lowered PSA compared with placebo: median change -0.6 ng/ml; p = 0.024. Intraprostatic inflammation did not differ between the study arms (p = 0.8). Despite a negative overall result showing no effect of statins on Ki67 or PSA overall, in post hoc exploratory analyses, there appeared to be benefit after a minimum duration of 28 d. Further studies are needed to verify this. PATIENT SUMMARY: Cholesterol-lowering atorvastatin does not lower prostate cancer proliferation rate compared with placebo overall, but exploratory analyses suggest a benefit in longer exposure.

Abstract CT133: Atorvastatin and prostate cancer - a phase 2 clinical trial

Background: Use of cholesterol-lowering statin drugs has been linked to lowered risk of advanced prostate cancer (PCa) and improved PCa-specific survival. However, statins’ efficacy against specifically against PCa has not been tested in a prospective randomized clinical trial.

Materials and methods: A total of 160 men with PCa and scheduled for radical prostatectomy were randomly allocated 1:1 to receive either 80 mg atorvastatin or placebo from recruitment to surgery. The study inclusion criteria included 1) histologically confirmed adenocarcinoma of the prostate, 2) radical prostatectomy selected as the first-line treatment and 3) signing of informed consent. Exclusion criteria were 1) previous oncological treatments 2) previous usage statins, finasteride or dutasteride within a year of inclusion, 3) clinically significant liver or kidney insufficiency, 4) previous adverse effects from cholesterol-lowering drugs and 5) use of drugs that might interact with statins Serum PSA was measured at recruitment and at the time of surgery. After prostatectomy, intraprostatic inflammation was quantified according to international consensus criteria. PSA change, calculated by subtracting PSA value at recruitment from PSA before prostatectomy, was compared between the trial arms using Man-Whitney U test. Extent and amount of intraprostatic inflammation were compared using linear regression and ANOVA. Separate comparisons were made for inflammation in glandular, periglandular and stromal compartments as well as for combined inflammation score. All analyses were performed for all cases combined, and separately for low-grade (prostatectomy Gleason score 3+4 or lower) and high-grade (Gleason score 4+3 or higher) cases.

Results: In total 160 men were recruited and randomized. Of these 158 completed the follow-up. Median time from recruitment to surgery was four weeks. Compliance to assigned treatment was excellent, 96%. Four men in the atorvastatin arm, none in the placebo arm discontinued the study drug due to side effects. They were analyzed in their assigned study arm according to the intention-to-treat principle. Overall, the median PSA change after the intervention did not differ between the atorvastatin and placebo arms (median change -0.4; IQR -1.4-0.1 and -0.2; IQR -1.1-0.4 in the atorvastatin and placebo arm, respectively), p for interaction 0.150. However, among the high-grade cases (n=35), PSA decreased among all men in the atorvastatin arm (median change -0.6, IQR -2[[Unsupported Character - Codename ­]]- -0.2), but not in the placebo arm (median change 0, IQR -0.6-0.4); p for interaction 0.024. Overall, intraprostatic inflammation score did not differ between the study arms (p for difference 0.772). Result was similar for separate tissue compartments.

Conclusions: Short-term high-dose atorvastatin therapy before radical prostatectomy lowers serum PSA values in high-grade cases but not in low-grade cases, indicating that atorvastatin intervention affects the prostate in such cases. Future clinical trials testing statins in prostate cancer patients should aim to enroll patients with Gleason score at least 4+3.

Citation Format: Teemu J. Murtola, Jarno Riikonen, Heimo Syvälä, Teemu Tolonen, Juha Koskimäki, Tomi Pakarainen, Antti Kaipia, Taina Isotalo, Paula Kujala, Teuvo Tammela. Atorvastatin and prostate cancer - a phase 2 clinical trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT133. doi:10.1158/1538-7445.AM2017-CT133

Delay of postnatal maturation sensitizes the mouse prostate to testosterone-induced pronounced hyperplasia: protective role of estrogen receptor-beta

The role of estrogens in the etiology of prostate cancer is controversial. To demonstrate the specific effects of estrogens and androgens on the development of the prostatic epithelial hyperplasia, we used luteinizing hormone receptor knockout mice (LuRKO), which are resistant to pituitary regulation mediated by luteinizing hormone, lack postnatal androgen production, and have rudimentary accessory sex glands, the growth of which can be induced with exogenous androgen replacement. This model is thus ideal for the investigation of direct hormonal effects on the prostate. Testosterone, but not 5alpha-dihydrotestosterone, replacement from 21 days of life for 8 weeks induced pronounced hyperplasia and inflammation in the prostates of LuRKO mice. Interestingly, 5alpha-dihydrotestosterone combined with 17beta-estradiol did not induce hyperplasia or inflammation, and treatments with inhibitors of estrogen action, aromatase inhibitor, and ICI 182780 further exacerbated testosterone-induced hyperplastic growth. However, the activation of estrogen receptor (ER)-beta with a specific agonist, DPN [2,3-bis(4-hydroxyphenol)-propionitrile], prevented the development of prostatic hyperplasia and inflammation in testosterone-treated LuRKO mice. Thus, it seems that in the presence of sufficient androgenic stimulation, it is the balance between ER-alpha- and ER-beta-mediated signaling that determines whether estrogens promote hyperplasia or protect the prostate against hyperplastic changes.

Male pheromone-stimulated neurogenesis in the adult female brain: possible role in mating behavior

The regulation of female reproductive behaviors may involve memories of male pheromone signatures, formed in part by neural circuitry involving the olfactory bulb and hippocampus. These neural structures are the principal sites of adult neurogenesis; however, previous studies point to their independent regulation by sensory and physiological stimuli. Here we report that the pheromones of dominant (but not subordinate) males stimulate neuronal production in both the olfactory bulb and hippocampus of female mice, which are independently mediated by prolactin and luteinizing hormone, respectively. Neurogenesis induced by dominant-male pheromones correlates with a female preference for dominant males over subordinate males, whereas blocking neurogenesis with the mitotic inhibitor cytosine arabinoside eliminated this preference. These results suggest that male pheromones are involved in regulating neurogenesis in both the olfactory bulb and hippocampus, which may be important for female reproductive success.

Extragonadal LH/hCG action--not yet time to rewrite textbooks

Gonadotropins are indispensable in both sexes in the regulation of gonadal sex steroid production and gametogenesis. In addition to their well-established classical actions, numerous recent publications have indicated the presence and function of luteinizing hormone/chorionic gonadotropin receptors (LH/hCG-R) in a variety of extragonadal tissues. However, the physiological significance of such effects has remained unclear. We have generated two genetically modified mouse models, one with excessive production of hCG and the other with targeted disruption of LH/hCG-R gene, and used them to address the functions of LH and hCG. Numerous gonadal and extragonadal phenotypes were found in the models with the two extremes of LH/hCG action. However, when the extragonadal effects were scrutinized in greater detail, they all appeared to arise through modification of gonadal function, either through enhanced or inhibited response to LH/hCG stimulation. Hence, further evidence is needed before the extragonadal LH/hCG-R expression can be considered functionally significant.

Phenotypic characterisation of mice with exaggerated and missing LH/hCG action

In order to study the physiology and pathophysiology of gonadotrophin action, we have produced transgenic (TG) mice overexpressing human chorionic gonadotrophin (hCG) alpha and beta subunits (hCG+ mice) and knockout (KO) mice for the luteinising hormone receptor (LHR; LuRKO mice). The two extremes in LH function, i.e. strong LH/hCG stimulation and total blockade of this action, confirm numerous earlier concepts about LH function, but they also reveal new aspects about gonadal function during excessive LH production and in the absence of this trophic stimulus. The purpose of this review is to summarise the key findings on these two genetically modified mouse models.

Genetically modified mouse models in studies of luteinising hormone action

Numerous genetically modified mouse models have recently been developed for the study of the pituitary-gonadal interactions. They include spontaneous or engineered knockouts (KO) of the gonadotrophin-releasing hormone (GnRH) and its receptor, the gonadotrophin common-alpha(Calpha), luteinising hormone (LH) beta and follicle-stimulating hormone (FSH) beta subunits, and the two gonadotrophin receptors (R), LHR and FSHR. In addition, there are also transgenic (TG) mice overexpressing gonadotrophin subunits and producing supraphysiological levels of these hormones. These models have offered relevant phenocopies for similar mutations in humans and to a great extent expanded our knowledge on normal and pathological functions of the hypothalamic-pituitary-gonadal (HPG) axis. The purpose of this article is to review some of our recent findings on two such mouse models, the LHR KO mouse (LuRKO), and the hCG overexpressing TG mouse (hCG+).

Knockout of Luteinizing Hormone Receptor Abolishes the Effects of Follicle-Stimulating Hormone on Preovulatory Maturation and Ovulation of Mouse Graafian Follicles

It is considered a dogma that a secretory peak of LH is indispensable as the trigger of ovulation. However, earlier studies on hypophysectomized rodents have shown that stimulation with recombinant FSH, devoid of any LH activity, is able to boost the final stages of follicular maturation and trigger ovulation. As the expression of ovarian LH receptors (LHRs) still persists after hypophysectomy, such studies cannot totally exclude the possibility that LHR activation is involved in the apparently pure FSH effects. To revisit this question, we analyzed in LHR knockout (LuRKO) mice the progression of folliculogenesis and induction of ovulation by human chorionic gonadotropin and human recombinant FSH treatments. The results provide clear evidence that follicular development and ovulation could not be induced by high doses of FSH in the absence of LHR expression. Ovarian histology and oocyte analyses indicated that follicular maturation did not advance in LuRKO mice beyond the antral follicle stage. Neither were ovulations detected in LuRKO ovaries after any of the gonadotropin treatments. The ovarian resistance to FSH treatment in the absence of LHR was confirmed by real-time RT-PCR and immunohistochemical analyses of a number of gonadotropin-dependent genes, which only responded to the treatments in wild-type control mice. Negative findings were not altered by estradiol priming preceding the gonadotropin stimulations. Hence, the present study shows that, in addition to ovulation, the expression of LHR is essential for follicular maturation in the progression from antral to preovulatory stage.

Fertility in luteinizing hormone receptor-knockout mice after wild-type ovary transplantation demonstrates redundancy of extragonadal luteinizing hormone action

The luteinizing hormone receptor (LHR), mainly expressed in gonads, is essential for normal reproduction. However, numerous recent studies have also demonstrated LHR expression in multiple extragonadal reproductive and nonreproductive tissues. Although some effects of luteinizing hormone (LH) or its agonist, human chorionic gonadotropin, have been shown in extragonadal sites, their physiological significance remains open. In the present study, we have addressed the function of the extragonadal LHR using LHR-KO mice (LuRKO mice), in which the ovaries of prepubertal mice were orthotopically replaced with pieces of WT ovary using similarly transplanted WT mice as controls. Most ovarian transplants attained normal endocrine function in both groups of mice, as demonstrated by normal age at vaginal opening, estrous cycles, and sexual behavior. Both the LuRKO and WT mice repeatedly became pregnant (9/16 vs. 16/20 after first mating; difference not significant) and delivered similarly sized litters, which grew normally after birth, indicating normal lactation. In conclusion, fertility is restored in LuRKO mice by transplantation of WT ovarian tissue. This is achieved in the absence of extragonadal LHR expression, which indicates physiological redundancy for such receptor sites.

Testosterone replacement therapy induces spermatogenesis and partially restores fertility in luteinizing hormone receptor knockout mice

Testosterone (T) is essential for spermatogenesis, fertility, and maintenance of the male phenotype. We analyzed in hypogonadal LH receptor knockout (LuRKO) male mice whether T treatment can restore their phenotype, spermatogenesis, and fertility. In LuRKO mice, spermatogenesis is arrested at round spermatids, adult-type Leydig cells are absent, T production is dramatically decreased, the animals are cryptorchid, and their accessory sex organs are atrophic. T replacement therapy from 21 d of life for 60 or 120 d in LuRKO mice induced a male phenotype macroscopically indistinguishable from that of wild-type littermates as well as full spermatogenesis and testicular descent. Thus, the absence of LH-dependent prepubertal androgen priming is not necessary for subsequent maturation of the male phenotype. Conspicuously, some abnormalities remained in epididymal histology after T treatment despite normal expression of several epididymis-specific genes in caput epididymis. The mice displayed normal mating behavior, although at lower frequency than wild-type controls. The spermatozoa were able to fertilize oocytes, but their impaired passage from epididymis to uterus was apparent. The mice remained subfertile, because only 9% of all breedings resulted in pregnancy, and only two of 13 mice (15%) were fertile. Moreover, inflammation in epididymides and prostate was found in many T-treated LuRKO mice, which probably impaired sperm transport and contributed to their high rate of subfertility. In conclusion, T replacement initiated prepubertally only partially restores the fertility of LuRKO mice, even though most features of the male phenotype recover. Full fertility may require higher and/or earlier postnatal T exposure or production of other Leydig cell factors lacking in this model.

Molecular characterization of postnatal development of testicular steroidogenesis in luteinizing hormone receptor knockout mice

We recently demonstrated that the sexual development of LH receptor (LHR) knockout mice is normal until birth, but is totally arrested thereafter. To study further the functional defects of LHR knockout mice, the expression of selected Leydig cell-specific genes was studied in (-/-) and control (+/+) mice between birth and adulthood. Testis weights were similar at birth in both types of mice, but after about 3 wk, the (-/-) testes remained significantly lighter, weighing only 18% of (+/+) testes on d 70. Testicular testosterone (T) content on d 1 was also similar in (-/-) and (+/+) testes, but it was 97% reduced by d 70 in the former. Likewise, testicular T production in vitro was similar in neonatal (-/-) and (+/+) testes, but became undetectable in adult (-/-) testes. The mRNA expression of cytochrome P450 side-chain cleavage, 17 alpha-hydroxylase cytochrome P450, 17 beta-hydroxysteroid dehydrogenase type III, 3 beta-hydroxysteroid dehydrogenase I (3 beta HSDI), steroidogenic acute regulatory protein, and relaxin-like factor were similar in newborn (-/-) and (+/+) testes, but became gradually very low/undetectable in (-/-) mice. The only exception was the persistently high expression of 3 beta HSDI in peritubular Leydig precursor and mesenchymal cells of the (-/-) testes at all ages. Immunohistochemistry and Western hybridization studies confirmed the above findings. In conclusion, LH action is not essential for the differentiation and function of mouse fetal Leydig cells, but, with the exception of 3 beta HSDI, the expression of the key genes of endocrine function of adult Leydig cells is dependent on LH signaling.

The low gonadotropin-independent constitutive production of testicular testosterone is sufficient to maintain spermatogenesis

Spermatogenesis is thought to critically depend on the high intratesticular testosterone (T) levels induced by gonadotropic hormones. Strategies for hormonal male contraception are based on disruption of this regulatory mechanism through blockage of gonadotropin secretion. Although exogenous T or T plus progestin treatments efficiently block gonadotropin secretion and suppress testicular T production, only approximately 60% of treated Caucasian men reach contraceptive azoospermia. We now report that in luteinizing hormone receptor knockout mice, qualitatively full spermatogenesis, up to elongated spermatids of late stages 13-16, is achieved at the age of 12 months, despite absent luteinizing hormone action and very low intratesticular T (2% of control level). However, postmeiotic spermiogenesis was blocked by the antiandrogen flutamide, indicating a crucial role of the residual low testicular T level in this process. The persistent follicle-stimulating hormone action in luteinizing hormone receptor knockout mice apparently stimulates spermatogenesis up to postmeiotic round spermatids, as observed in gonadotropin-deficient rodent models on follicle-stimulating hormone supplementation. The finding that spermatogenesis is possible without a luteinizing hormone-stimulated high level of intratesticular T contradicts the current dogma. Extrapolated to humans, it may indicate that only total abolition of testicular androgen action will result in consistent azoospermia, which is necessary for effective male contraception.