DNA damage in patients with untreated cancer as measured by the sperm chromatin structure assay

Cancer risk and male Infertility: Unravelling predictive biomarkers and prognostic indicators

In recent years, there has been a global increase in cases of male infertility. There are about 30 million cases of male infertility worldwide and male reproductive health is showing rapid decline in last few decades. It is now recognized as a potential risk factor for developing certain types of cancer, particularly genitourinary malignancies like testicular and prostate cancer. Male infertility is considered a potential indicator of overall health and an early biomarker for cancer. Cases of unexplained male factor infertility have high levels of oxidative stress and oxidative DNA damage and this induces both denovo germ line mutations and epimutations due to build up of 8-hydroxy 2 deoxygunaosine abase which is highly mutagenic and also induces hypomethylation and genomic instability. Consequently, there is growing evidence to explore the various factors contributing to an increased cancer risk. Currently, the available prognostic and predictive biomarkers associated with semen characteristics and cancer risk are limited but gaining significant attention in clinical research for the diagnosis and treatment of elevated cancer risk in the individual and in offspring. The male germ cell being transcriptionally and translationally inert has a highly truncated repair mechanism and has minimal antioxidants and thus most vulnerable to oxidative injury due to environmental factors and unhealthy lifestyle and social habits. Therefore, advancing our understanding requires a thorough evaluation of the pathophysiologic mechanisms at the DNA, RNA, protein, and metabolite levels to identify key biomarkers that may underlie the pathogenesis of male infertility and associated cancer. Advanced methodologies such as genomics, epigenetics, proteomics, transcriptomics, and metabolomics stand at the forefront of cutting-edge approaches for discovering novel biomarkers, spanning from infertility to associated cancer types. Henceforth, in this review, we aim to assess the role and potential of recently identified predictive and prognostic biomarkers, offering insights into the success of assisted reproductive technologies, causes of azoospermia and idiopathic infertility, the impact of integrated holistic approach and lifestyle modifications, and the monitoring of cancer susceptibility, initiation and progression. Comprehending these biomarkers is crucial for providing comprehensive counselling to infertile men and cancer patients, along with their families.

Severe sperm DNA fragmentation may persist for up to 3 years after cytotoxic therapy in patients affected by Hodgkin lymphoma and non-Hodgkin lymphoma

STUDY QUESTION

Does sperm DNA recover from damage in all men after 2 years from the end of cytotoxic treatments?

SUMMARY ANSWER

The current indication of 2 years waiting time for seeking natural pregnancy after cytotoxic treatment may not be adequate for all men, since severe sperm DNA damage is present in a proportion of subjects even after this timeframe.

WHAT IS KNOWN ALREADY

Data in the literature on sperm DNA fragmentation (SDF) in lymphoma patients after cytotoxic treatments are scarce. The largest longitudinal study evaluated paired pre- and post-therapy (up to 24 months) semen samples from 34 patients while one study performed a longer follow-up (36 months) in 10 patients. The median/mean SDF values >24 months after therapy did not show significant differences but the studies did not explore the proportion of patients with severe DNA damage and the analysis was done on frozen-thawed samples.

STUDY DESIGN, SIZE, DURATION

In this study, 53 Hodgkin lymphoma (HL) and 25 non-Hodgkin lymphoma (NHL) post-pubertal patients were included over a recruitment period of 10 years (2012-2022). Among them, 18 subjects provided paired semen samples for SDF analysis at the three time points. SDF was evaluated in patients before (T0) and after 2 (T2) and 3 years (T3) from the end of, cytotoxic treatments (chemotherapy alone or in combination with radiotherapy). A cohort of 79 healthy, fertile, and normozoospermic men >18 years old served as controls (recruited between 2016 and 2019).

PARTICIPANTS/MATERIALS, SETTING, METHODS

SDF was evaluated on fresh semen samples (i.e. spermatozoa potentially involved in natural conception) from patients and controls using TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assay coupled with flow cytometry. SDF median values were compared between groups: (i) HL and NHL patients versus controls at the three time points; (ii) HL versus NHL patients at baseline; and (iii) patients at T0 versus T2 and T3. Severe DNA damage (SDD) was defined for SDF levels above the 95th percentile of controls (50%) and the proportion of patients with SDD at all time points was established.

MAIN RESULTS AND THE ROLE OF CHANCE

At T0, patients displayed higher median SDF than controls, reaching statistical significance in the NHL group: 40.5% [IQR: 31.3-52.6%] versus 28% [IQR: 22-38%], P < 0.05. Comparing SDF pre-treatment to that post-treatment, HL patients exhibited similar median values at the three time points, whereas NHL showed significantly lower values at T3 compared to T0: 29.2% [IQR: 22-38%] versus 40.5% [IQR: 31.3-52.6%], P < 0.05. The proportion with SDD in the entire cohort at T2 was 11.6% and 13.3% among HL and NHL patients, respectively. At T3, only one in 16 NHL patients presented SDD.

LIMITATIONS, REASONS FOR CAUTION

TUNEL assay requires at least 5 million spermatozoa to be performed; hence, severe oligozoospermic men were not included in the study. Although our cohort represents the largest one in the literature, the relatively small number of patients does not allow us to establish precisely the frequency of SDD at T2 which in our study reached 11-13% of patients.

WIDER IMPLICATIONS OF THE FINDINGS

Our data provide further insights into the long-term effects of cytotoxic treatments on the sperm genome. The persistent severe DNA damage after 2 years post-treatment observed in some patients suggests that there is an interindividual variation in restoring DNA integrity. We propose the use of SDF as a biomarker to monitor the treatment-induced genotoxic effects on sperm DNA in order to better personalize pre-conceptional counseling on whether to use fresh or cryopreserved spermatozoa.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by grants from the Istituto Toscano Tumori (ITT), Fondazione Ente Cassa di Risparmio di Firenze, the European Commission-Reproductive Biology Early Research Training (REPROTRAIN). C.K., G.F., V.R., and A.R.-E. belong to COST Action CA20119 (ANDRONET) which is supported by the European Cooperation in Science and Technology (www.cost.eu). The authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Fifteen Year Regional Center Experience in Sperm Banking for Cancer Patients: Use and Reproductive Outcomes in Survivors

Simple Summary

Sperm cryopreservation before gonadotoxic iatrogenic treatments is the only method currently available to preserve fertility in men with cancer. The aims of this study were to report our 15 years of experience, the clinical outcomes of assisted reproductive treatments as well as neonatal characteristics of babies born. We retrospectively reviewed 682 oncological patients who were referred to our center from 2004 to 2019 for fertility preservation. Data regarding cancer diagnosis, age, and the use of frozen semen were analyzed. The cumulative live-birth delivery rate per couple was 35%. No stillbirths, as well as no malformations in the babies born, were recorded. These successful findings demonstrated that pregnancy could be safely achieved using frozen-thawed sperm of cancer survivors who cryopreserved before gonadotoxic therapies.

Abstract

Cancer treatments frequently impair the reproductive ability of patients by damaging spermatogenesis. International guidelines recommend semen cryopreservation to preserve the fertility of oncological adult males and pubertal boys. However, due to the low usage rate of banked samples, not a lot of data on assisted reproductive treatments (ART) success rates in this population and follow-up data for children born are available in the literature. The aims of this study were to report our 15 years of experience, the clinical outcomes of ART as well as neonatal characteristics of babies born. We retrospectively reviewed 682 oncological patients who were referred to our center from 2004 to 2019 for fertility preservation. Over the years, only 26 patients (4%) returned to use their sperm by ART. They were survivors of leukemia and lymphomas (52%), testicular cancer (20%), and other malignant diseases (28%). These couples performed 45 cycles: 34 intracytoplasmic sperm injection (ICSI) plus 11 frozen embryo transfers. A total of 13 children were born, with 35% of the cumulative live-birth delivery rate per couple. No stillbirths or malformations were recorded. These successful findings demonstrated that pregnancy could be safely achieved using frozen-thawed sperm of cancer survivors who cryopreserved before gonadotoxic therapies.

Dysregulation of Key Proteins Associated with Sperm Motility and Fertility Potential in Cancer Patients

Cancer has adverse effects on male reproductive health. Conventional semen analysis does not explain the molecular changes in the spermatozoa of cancer patients. Currently, proteomics is being widely used to identify the fertility-associated molecular pathways affected in spermatozoa. The objective of this study was to evaluate the sperm proteome of patients with various types of cancer. Cryopreserved semen samples from patients (testicular cancer, n = 40; Hodgkin’s disease, n = 32; lymphoma, n = 20; leukemia, n = 17) before starting therapy were used for proteomic analysis, while samples from fertile donors (n = 19) were included as controls. The proteomic profiling of sperm was carried out by liquid chromatography-tandem mass spectrometry, and differentially expressed proteins involved in the reproductive processes were validated by Western blotting. Bioinformatic analysis revealed that proteins associated with mitochondrial dysfunction, oxidative phosphorylation, and Sirtuin signaling pathways were dysregulated in cancer patients, while oxidative phosphorylation and tricarboxylic acid cycle were predicted to be deactivated. Furthermore, the analysis revealed dysregulation of key proteins associated with sperm fertility potential and motility (NADH:Ubiquinone oxidoreductase core subunit S1, superoxide dismutase 1, SERPINA5, and cytochrome b-c1 complex subunit 2) in the cancer group, which were further validated by Western blot. Dysfunctional molecular mechanisms essential for fertility in cancer patients prior to therapy highlight the potential impact of cancer phenotype on male fertility.

Diagnostic value of advanced semen analysis in evaluation of male infertility

Conventional semen analysis is the standard of care to initially evaluate the fertility status of a male patient. However, it has some limitations and among these are failure to correctly identify the aetiology underlying fertility problems, intra- and inter-observer variability and incomplete information about sperm function. Considering these drawbacks, advanced semen tests have been developed to assess male infertility, including sperm function tests, oxidative stress (OS) and sperm DNA fragmentation (SDF) tests. This review illustrates the commonly utilised sperm function techniques, along with the assays used to assess SDF and OS and their diagnostic value.

Alterations of Spermatozoa Proteomic Profile in Men with Hodgkin's Disease Prior to Cancer Therapy

Purpose

Hodgkin's disease (HD) is a type of cancer affecting men in the reproductive age with potential consequences on their fertility status. This study aims to analyze sperm parameters, alterations in proteomic profiles and validate selected protein biomarkers of spermatozoa in men with HD undergoing sperm banking before cancer therapy.

Materials and Methods

Semen analysis was carried out in healthy fertile donors (control, n=42), and patients diagnosed with HD (patients, n=38) before cancer therapy. We compared proteomic profiles of spermatozoa from donors (n=3) and patients (n=3) using LTQ-Orbitrap Elite hybrid MS system.

Results

A total of 1,169 proteins were identified by global proteomic in both groups. The ingenuity pathway analysis revealed that differentially expressed proteins involved in capacitation, acrosome reaction, binding of sperm to the zona pellucida, sperm motility, regulation of sperm DNA damage, and apoptosis were significantly downregulated in HD patients. Validation of proteins implicated in sperm fertility potential by Western Blot demonstrated that peroxiredoxin 2 (PRDX 2) was underexpressed (p=0.015), and transferrin (p=0.045) and SERPIN A5 (p=0.010) protein levels were overexpressed in spermatozoa of men with HD.

Conclusions

Findings of this study indicates that the key proteins involved in sperm fertility potential are significantly altered in men with HD, which provides substantial explanation for the observed low sperm quality in HD subjects prior to cancer therapy. Furthermore, our results suggest PRDX 2, transferrin and SERPIN A5 as possible candidate proteins for assessing sperm quality in HD patients prior to cancer therapy.

Reproductive toxicity of manganese dioxide in forms of micro- and nanoparticles in male rats

BACKGROUND

Manganese Dioxide (MnO2 ) has long been used in industry, and its application has recently been increasing in the form of nanoparticle. Objective: The present study was an attempt to assess the effects of MnO2 nanoparticles on spermatogenesis in male rats.

MATERIALS AND METHODS

Micro- and nanoparticles of MnO2 were injected (100 mg/kg) subcutaneously to male Wistar rats (150 ± 20 gr) once a week for a period of 4 weeks, and the vehicle group received only normal saline (each group included 8 rats). The effect of these particles on the bodyweight, number of sperms, spermatogonia, spermatocytes, diameter of seminiferous tubes, testosterone, estrogen, follicle stimulating factor, and the motility of sperms were evaluated and then compared among the control and vehicle groups as the criteria for spermatogenesis.

RESULTS

The results showed that a chronic injection of MnO2 nanoparticles caused a significant decrease in the number of sperms, spermatogonia, spermatocytes, diameter of seminiferous tubes (p < 0.001) and in the motility of sperms. However, no significant difference was observed in the weight of prostate, epididymis, left testicle, estradiol (p = 0.8) and testosterone hormone (p = 0.2).

CONCLUSION

It seems that the high oxidative power of both particles was the main reason for the disturbances in the function of the testis. It is also concluded that these particles may have a potential reproductive toxicity in adult male rats. Further studies are thus needed to determine its mechanism of action upon spermatogenesis.

Suitability of the hemi-zona assay for the evaluation of the effect of the length of the equilibration period before cryopreservation

The aim of this study was to test the suitability of the interspecific hemizona assay (HZA) to predict the fertilizing capacity of bovine sperm after modifying the length of the equilibration period before freezing and thawing. Ejaculates from 10 proven fertile bulls were split after dilution, equilibrated at 4 °C for either 24 h (control sperm = CS) or 6, 48, 72 or 96 h (test sperm = TS) and cryopreserved. Hemizona (HZ) pairs from in vitro matured pig oocytes were used for the heterologous HZA: After thawing and swim-up (1 h) CS and TS were co-incubated with matching HZ (125,000 S/HZ in 25 μL Fert-TALP) for 4 h. Spermatological analyses (progressive motile sperm (PMS), plasma membrane- and acrosome-intact sperm (PMAI), sperm showing a high degree of DNA fragmentation (%DFI)) were performed after 0 and 3 h of incubation after thawing. After an equilibration time of 48 h and 72 h values for PMAI0h were higher (P < 0.05) compared to PMAI0h values of sperm equilibrated for 6 h, and %DFI3h values were higher after 96 h (P < 0.05) compared to 6 h equilibration. Between 12 and 90 TS and 13-97 CS were tightly bound to each HZ, respectively. The mean Hemizona Index (HZI) after a sperm equilibration for 48 h (HZI = 92.3 ± 12.7) or 72 h (HZI = 98.9 ± 16.23) was higher (P < 0.01) than after an equilibration for 6 h (HZI = 73.3 ± 13.93) or 96 h (HZI = 81.3 ± 11.41). The HZI for 96 h equilibration was moderately negatively related to PMS0h and PMS3h (r < -0.35, P < 0.05). Furthermore the HZI for 6 h equilibration was highly negatively correlated with DFI0h (r = -0,46, P < 0.01). On the basis of these results it can be concluded that the hemi-zona assay is a suitable test to detect alterations in the fertilizing capacity of bovine sperm after modifying the equilibration period.

Fatherhood and Sperm DNA Damage in Testicular Cancer Patients

Testicular cancer (TC) is one of the most treatable of all malignancies and the management of the quality of life of these patients is increasingly important, especially with regard to their sexuality and fertility. Survivors must overcome anxiety and fears about reduced fertility and possible pregnancy-related risks as well as health effects in offspring. There is thus a growing awareness of the need for reproductive counseling of cancer survivors. Studies found a high level of sperm DNA damage in TC patients in comparison with healthy, fertile controls, but no significant difference between these patients and infertile patients. Sperm DNA alterations due to cancer treatment persist from 2 to 5 years after the end of the treatment and may be influenced by both the type of therapy and the stage of the disease. Population studies reported a slightly reduced overall fertility of TC survivors and a more frequent use of ART than the general population, with a success rate of around 50%. Paternity after a diagnosis of cancer is an important issue and reproductive potential is becoming a major quality of life factor. Sperm chromatin instability associated with genome instability is the most important reproductive side effect related to the malignancy or its treatment. Studies investigating the magnitude of this damage could have a considerable translational importance in the management of cancer patients, as they could identify the time needed for the germ cell line to repair nuclear damage and thus produce gametes with a reduced risk for the offspring.

Semen quality of 4480 young cancer and systemic disease patients: baseline data and clinical considerations

Background

Except for testicular cancer and Hodgkin’s disease, baseline data on semen quality in case of cancers as well as systemic pathologies of the young adult are scarce or based on low sample size.

Methods

Semen quality in patients having testicular cancer (TGCT, n = 2315), Hodgkin’s disease (HD, n = 1175), non-Hodgkin’s lymphoma (NHL, n = 439), leukemia (L, n = 360), sarcoma (S, n = 208), brain tumour (BT, n = 40), Behcet’s disease (Behcet’s, n = 68) or multiple sclerosis (MS, n = 73) was studied and compared to that of 1448 fertile men candidates for sperm donation (CSD) and 208 partners of pregnant women (PPW). All samples were studied following the same methodology in a single laboratory. Post freezing and thawing semen characteristics were also studied.

Results

The percentage of normozoospermic men was only 37 % for L patients and lower than 60 % for TGCT, NHL, S and BT. The level of sperm production was differently decreased according to pathologies, the median total sperm count in TC and L patients being four times lower (p < 0.01 when compared to CSD and PPW). The lowest percentage of progressively motile spermatozoa was found for L and BT patients (both, p < 0.01 compared to CSD and PPW). The percentage of morphologically normal spermatozoa was also reduced in cancer patients, especially in BT patients. Progressive motility after thawing in patients was about half that observed among candidates for sperm donation. In almost half of the semen of patients with testicular cancer or leukemia, the total number of motile spermatozoa per straw was less than 0.5 × 10⁶ compared to 4.3 × 10⁶ in CSD.

Conclusions

The present data confirm on large series the deleterious impact of various cancers of the young adult on semen quality, establishing thus baseline data for future studies. Owing to the post-thaw quality of the frozen straws, future fertility projects for the majority of the patients studied (in case there is no post-treatment recovery of spermatogenesis) should necessitate an ICSI to provide the best chance of paternity whatever the fertility check-up in the female partner.

Impact of lymphoma treatments on spermatogenesis and sperm deoxyribonucleic acid: a multicenter prospective study from the CECOS network

OBJECTIVE

To determine consequences of lymphoma treatments on sperm characteristics and sperm DNA, and to evaluate predictors of sperm recovery.

DESIGN

Multicenter prospective longitudinal study of patients analyzed before treatment and after 3, 6, 12, and 24 months.

SETTING

University hospitals.

PATIENT(S)

Seventy-five Hodgkin lymphoma and non-Hodgkin lymphoma patients and a control group of 257 fertile men.

INTERVENTION(S)

Semen analyses, and sperm DNA and chromatin assessments.

MAIN OUTCOME MEASURE(S)

Comparisons of sperm characteristics before and after treatment.

RESULT(S)

Patients already had altered sperm characteristics before lymphoma treatment, with no identified risk factor. Sperm count, total sperm count, motility, and vitality decreased after treatment, with lowest values at 3 and 6 months. Twelve months after treatment, mean sperm count recovered to pretreatment values after doxorubicin, bleomycin, vinblastine, darcarbacine (ABVD) or ABVD+radiotherapy, but not after doxorubicin, cyclophosphamide, vincristine, prednisone (CHOP) or mechlorethamine, oncovin, procarbazine, prednisone (MOPP) chemotherapies. It was noteworthy that 7% of patients remained azoospermic at 24 months. After 24 months, Kaplan-Meier estimates showed that more than 90% of patients will recover normal sperm count after ABVD or ABVD+radiotherapy vs. 61% for CHOP chemotherapies. In multivariate analyses including diagnosis and treatment protocol, only pretreatment total sperm count was related to recovery. Compared with a control group, lymphoma patients had higher sperm chromatin alterations and DNA fragmentation before any treatment. After treatment, DNA fragmentation assessed by TUNEL assay and sperm chromatin structure assay decreased from 3 and 6 months, respectively, while remaining higher than in the control group during follow-up.

CONCLUSION(S)

Lymphoma patients had altered sperm DNA and chromatin before treatment. Lymphoma treatment had damaging effects on spermatogenesis. These data on both the recovery period according to treatment modalities and the pre- and post-treatment chromatin status of sperm are useful tools for counseling patients wishing to conceive.

Sperm cryopreservation before testicular cancer treatment and its subsequent utilization for the treatment of infertility

Aims. In this study we report our results with storage of cryopreserved semen intended for preservation and subsequent infertility treatment in men with testicular cancer during the last 18 years. Methods. Cryopreserved semen of 523 men with testicular cancer was collected between October 1995 and the end of December 2012. Semen of 34 men (6.5%) was used for fertilization of their partners. They underwent 57 treatment cycles with cryopreserved, fresh, and/or donor sperm. Results. A total of 557 men have decided to freeze their semen before cancer treatment. Azoospermia was diagnosed in 34 men (6.1%), and semen was cryopreserved in 532 patients. Seminoma was diagnosed in 283 men (54.1%) and nonseminomatous germ cell tumors in 240 men (45.9%). 34 patients who returned for infertility treatment underwent 46 treatment cycles with cryopreserved sperm. Totally 16 pregnancies were achieved, that is, 34.8% pregnancy rate. Conclusion. The testicular cancer survivors have a good chance of fathering a child by using sperm cryopreserved prior to the oncology treatment, even when it contains only limited number of spermatozoa.

Recovery, Preparation, Storage and Utilization of Spermatozoa for Fertility Preservation in Cancer Patients and Sub-Fertile Men

Sperm cryopreservation is an important part of an infertility program for patients undergoing infertility treatments, fertility assurance for vasectomy cases, and for fertility preservation due to cancer or other medical conditions. With recent developments in reproductive technology, even men with severely impaired sperm parameters can benefit from cryopreservation as procedures such as intra-cytoplasmic sperm injection (ICSI) require only a few sperm to achieve fertilization and pregnancy. The increasing success of cancer treatment and concerted efforts to ensure quality of life after successful treatment have placed great emphasis on the need to preserve the reproductive capability of young men. It is a highly effective method of protecting male fertility potential, and involves collection, freezing, and long-term storage of sperm. Based on the etiological condition of the patients, sperm can be collected by ejaculation or by surgical retrieval from epididymis or testes. The option to bank sperm should be offered systematically to all patients who may benefit. However, this is not a standard of practice yet; it may be overlooked due to lack of physician awareness regarding the need for fertility preservation and the effectiveness of this option, and/or overestimating the limitations of poor baseline sperm quality leading physician to view cryopreservation as futile. Failure to offer cryopreservation ignores the only possible reproductive option available to certain patients.

Sperm DNA damage in male infertility: etiologies, assays, and outcomes

Male factor infertility is the sole cause of infertility in approximately 20% of infertile couples, with an additional 30% to 40% secondary to both male and female factors. Current means of evaluation of male factor infertility remains routine semen analysis including seminal volume, pH, sperm concentration, motility, and morphology. However, approximately 15% of patients with male factor infertility have a normal semen analysis and a definitive diagnosis of male infertility often cannot be made as a result of routine semen analysis. Attention has focused on the role of sperm nuclear DNA integrity in male factor infertility. Here we review the structure of human sperm chromatin, the etiology and mechanisms of sperm DNA damage, current tests available to assess sperm DNA integrity, and effect of sperm DNA integrity on reproductive outcomes.

Impact of chemotherapeutics and advanced testicular cancer or Hodgkin lymphoma on sperm deoxyribonucleic acid integrity

OBJECTIVE

To determine the impact of combination chemotherapy on the quality of newly generated spermatozoa from patients with advanced testicular cancer and patients with Hodgkin lymphoma (HL).

DESIGN

Prospective longitudinal study.

SETTING

Academic facility.

PATIENT(S)

Patients with newly diagnosed metastatic testicular cancer and with HL that required chemotherapy were compared with age-matched healthy community volunteers.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Semen parameters, hormone levels, testis volume, and presence of sperm DNA strand breaks in patients with cancer and in healthy community volunteers were compared before and after the patients' chemotherapy at 6, 12, 18, and 24 months.

RESULT(S)

Before chemotherapy, both cancer groups had poorer semen quality compared with community volunteers. Among patients with testicular cancer and HL, 67% and 60%, respectively, had <5x10(6) sperm/mL at 6 months after chemotherapy. At 24 months, 60% and 57% of patients with testicular cancer and HL, respectively, had normal sperm concentrations. Level of FSH was significantly higher in the cancer group compared with community volunteers at 6 to 12 months after chemotherapy. Before chemotherapy, sperm DNA damage was higher in the cancer group than in community volunteers; this damage was increased further at 6 months and remained elevated 24 months after treatment.

CONCLUSION(S)

Sperm generated after chemotherapy maintain a significant degree of chromatin damage. Therefore, survivors of testicular cancer and HL are at risk of having abnormal reproductive outcome. Proper counseling to these patients on reproductive risks and fertility preservation before chemotherapy is recommended.

Sperm DNA fragmentation in a random sample of the Spanish boar livestock

A collection of 180 chilled boar semen samples, randomly chosen from stocks currently used for routine characterization of standard seminal quality, were studied for DNA fragmentation status using the sperm chromatin dispersion test and the DNA fragmentation index (DFI: percent of abnormal cell versus normal cells for DNA fragmentation) was determined. Values for sperm motility, acrosome status, coiled tails and abnormal head morphology, including presence and position of cytoplasmic droplets were also obtained. The DFI in the whole sample presented a wide range of variation with values oscillating between practically 0% and 47.95% and do not fit to a normal distribution. The most frequent classes (83.3%) presented a DFI lower than a 5%. Significant correlations between sperm DNA fragmentation and sperm motility, acrosome status, frequency of distal droplets, coiled tails and abnormal head morphology, were not observed. However, the presence of proximal cytoplasmic droplets showed a significant correlation with the level of DNA fragmentation observed in the ejaculated spermatozoa.

[Assessing sperm DNA damage]

Infertility affects almost 20% of couples in reproductive age and the male factor being responsible of 50% of this infertility. Among the classic parameters that determine a good seminal quality such as sperm motility, sperm morphology or the quality of the of acrosomes and/or sperm membranes, the integrity of the DNA molecule is crucial to carry out a successful fertilization. Nevertheless, the study of this parameter has not been straightforward approached. This fact has shunned its incorporation, as a routine technique, within a standard seminogram. The aim of the present review is to summarize and update those technologies that are considered more successful to study sperm DNA fragmentation with special emphasis to: 1) the levels of technological complexity and the possibility of its use in laboratories of andrology, according with the equipment and the resources available, and 2) the effects and possible implications of high level of sperm DNA fragmentation for fecundation, embryo development and fertility.

Differential contribution of poly(ADP-ribose)polymerase-1 and -2 (PARP-1 and -2) to the poly(ADP-ribosyl)ation reaction in rat primary spermatocytes

Poly(ADP-ribose)polymerases (PARP-1 and -2) are activated by DNA strand breaks to synthesize protein-bound ADP-ribose polymers from NAD+. The two enzymes are overexpressed in rat spermatocytes and are likely to play a role in meiosis. Indeed parp-2-/- mice, but not parp-1 knockouts, show hypofertility. Aside, PARP-1 and PARP-2 are both involved in DNA damage repair and signalling, but their relative contributions to such processes remain as yet unknown, largely because of the lack of PARP isoform-specific inhibitors that has precluded in vivo studies. Here, we used permeabilized rat primary spermatocytes or isolated spermatocyte nuclei and radiolabelled NAD+ to investigate potential isoform-specific effects on basic features of the poly(ADP-ribosyl)ation reaction, including size of ADP-ribose polymers at different NAD+ concentrations, extent of auto- versus etheromodification, and modulation of such reactions by the PARP inhibitor, PJ34. We found that PARP-1 automodification prevailed over PARP-2 modification. In addition, over 50% of cellular poly(ADP-ribose) was covalently bound to histones H1 and H2. The inhibitory effect of PJ34 appeared to be targeted mainly to the elongation step of the reaction. We propose that a different propensity of PARP-1 and PARP-2 to undergo automodification and/or catalyze etheromodification, both in terms of number of enzyme molecules being involved and amount of bound poly(ADP-ribose), may underlie distinct roles in the regulation of spermatocyte functions.

Sperm DNA integrity in testicular cancer patients

BACKGROUND

We evaluated the impact of testicular germ cell cancer (TGCC), its treatment and length of follow-up on sperm DNA integrity.

METHODS

In 96 TGCC patients, semen was collected at specific intervals until 5 years after treatment. Sperm DNA integrity was assessed by the sperm chromatin structure assay (SCSA, n = 193) and by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL, n = 159) assay. Results were expressed as DNA fragmentation index (DFI). Controls comprised of 278 military conscripts.

RESULTS

Post-surgery testicular cancer (TC) patients did not differ from controls. Compared with pretreatment values, radiotherapy induced a transient increase in SCSA(DFI) (medians: 12 versus 19%; P = 0.03), normalizing after 3-5 years. One year or more after therapy, 5/13 (38%) of normozoospermic, irradiated patients had SCSA(DFI) >27% compared with 7% of normozoospermic controls (P = 0.002). More than two cycles of chemotherapy decreased DFI 3-5 years post-therapy (median SCSA(DFI): 12 versus 9.1%, P = 0.02; median TUNEL(DFI): 11 versus 7.5%, P = 0.03).

CONCLUSION

Irradiation increases sperm DNA damage 1-2 years after treatment, and 38% of irradiated patients with normozoospermia had high (>27%) DNA damage, which may affect the sperm-fertilizing ability. TC per se is not associated with an increase of DFI, and DFI is reduced by three or more cycles of chemotherapy.

American Society of Clinical Oncology recommendations on fertility preservation in cancer patients

PURPOSE

To develop guidance to practicing oncologists about available fertility preservation methods and related issues in people treated for cancer.

METHODS

An expert panel and a writing committee were formed. The questions to be addressed by the guideline were determined, and a systematic review of the literature from 1987 to 2005 was performed, and included a search of online databases and consultation with content experts.

RESULTS

The literature review found many cohort studies, case series, and case reports, but relatively few randomized or definitive trials examining the success and impact of fertility preservation methods in people with cancer. Fertility preservation methods are used infrequently in people with cancer.

RECOMMENDATIONS

As part of education and informed consent before cancer therapy, oncologists should address the possibility of infertility with patients treated during their reproductive years and be prepared to discuss possible fertility preservation options or refer appropriate and interested patients to reproductive specialists. Clinician judgment should be employed in the timing of raising this issue, but discussion at the earliest possible opportunity is encouraged. Sperm and embryo cryopreservation are considered standard practice and are widely available; other available fertility preservation methods should be considered investigational and be performed in centers with the necessary expertise.

CONCLUSION

Fertility preservation is often possible in people undergoing treatment for cancer. To preserve the full range of options, fertility preservation approaches should be considered as early as possible during treatment planning.

Flow cytometry applications in the evaluation of sperm quality: semen analysis, sperm function and DNA integrity

Flow cytometry (FCM) has been extensively used to study mammalian sperm in the areas of reproductive toxicology (to monitor effects from environmental, occupational and therapeutic exposures), veterinary science (to preselect the gender of offspring by sorting X- and Y-chromosome-bearing sperm) and clinical andrology (to assess individual fertility potential). Using FCM, a variety of sperm features can now be rapidly measured on a cell-by-cell basis such as sperm count, viability, acrosomal integrity, mitochondrial function and DNA integrity; the last one is involved in postfertilization failure and embryo toxicity. It is foreseen that only a multiplex approach, which includes FCM assays together with the new genomics/proteomics methods, could increase the predictive power of fertility status and help identify susceptible subpopulations of men at risk for infertility, spontaneous abortions and birth defects.

Semen quality before and after gonadotoxic treatment

BACKGROUND

The aim of this study was to analyse the semen quality of patients before and after gonadotoxic therapy.

PATIENTS AND METHODS

We evaluated semen quality in 314 patients over a 26 year period. The diagnostic categories were leukaemia (n = 13); lymphoma (n = 128); testicular cancer (n = 102); benign conditions (n = 13); and other malignant neoplasms (n = 58). The degree of azoospermia or oligozoospermia for each disease category was recorded. We then analysed the recovery in semen quality over time for each disease category.

RESULTS

The mean patient age was 27.9 years (range 13-65 years). A total of 1115 post-treatment semen samples were analysed from 314 patients. There was a significant reduction in the post-treatment sperm concentration, sperm motility and semen volume compared with pre-treatment levels (P < 0.05) in the entire cohort. However, the sperm movement and motility grade remained unaffected. Patients with testicular carcinoma had the lowest pre-treatment sperm concentrations but also the lowest incidence of azoospermia after cancer treatment. Patients with lymphoma and leukaemia had the highest incidence of post-treatment azoospermia and oligospermia. Patients having the largest reductions in their sperm concentration after treatment required the longest recovery period for spermatogenesis. The diagnostic category was the only significant predictor of post-treatment azoospermia.

CONCLUSION

Gonadotoxic treatment results in a significant reduction in sperm quality. The type of cancer or disease, and the pre-treatment sperm concentrations were found to be the most significant factors governing post-treatment semen quality and recovery of spermatogenesis. All categories of patients displayed varying degrees of azoospermia and oligozoospermia, and recovery of gonadal function from these states was not significant. This highlights the importance of ensuring sperm banking before treatment, including for patients with benign conditions. Several factors and associations are discussed further in order to give an insight into the pre- and post-gonadotoxic treatment effects.

Preserving the reproductive potential of men and boys with cancer: current concepts and future prospects

The introduction of ICSI has totally changed the reproductive prospects for boys and men who are treated for cancer. With post-pubertal boys and adult men, semen cryopreservation should be offered to every patient undergoing a cancer treatment since preservation of fertility cannot be guaranteed for an individual patient and treatment may shift to a more sterilizing regimen. In the ICSI era, all semen samples, even those containing only a few motile sperm, should be accepted for cryopreservation. Patients who are azoospermic at the time cancer is diagnosed may be offered testicular sperm extraction and cryopreservation of testicular tissue. With pre-pubertal boys, no prevention of sterility by sperm banking is possible since no active spermatogenesis is present. However, in the next decade, prevention of sterility in childhood cancer survivors will become a major challenge for reproductive medicine. In theory, testicular stem cell banking is the only way of preserving the future fertility of boys undergoing a sterilizing chemotherapy. In animal models, testicular stem cell transplantation has proved to be effective; however, it remains to be shown that this technique is clinically efficient as well, especially when frozen-thawed cells are to be transplanted. Malignancy recurrence prevention is an important prerequisite for any clinical application of testicular stem cell transplantation. Although still at the experimental stage, cryobanking of testicular tissue from pre-pubertal boys may now be considered an acceptable strategy.

Sperm chromatin structure assay (SCSA) parameters are related to fertilization, blastocyst development, and ongoing pregnancy in in vitro fertilization and intracytoplasmic sperm injection cycles

OBJECTIVE

To determine the relationship between sperm chromatin structure assay (SCSA) parameters (DNA fragmentation index [DFI] and high DNA stainability [HDS]), and conventional IVF and IVF/intracytoplasmic sperm injection (ICSI) outcomes.

DESIGN

Retrospective review and prospective study.

SETTING

Private IVF clinic.

PATIENT(S)

Two hundred forty-nine couples undergoing first IVF and/or ICSI cycle.

INTERVENTION(S)

IVF, ICSI, blastocyst culture.

MAIN OUTCOME MEASURE(S)

DFI, HDS, conventional semen parameters, IVF, ICSI.

RESULT(S)

IVF and ICSI fertilization rates were not statistically different between high- and low-DFI groups. More men with > or =15% HDS had lower (<25% and <50%) IVF fertilization rates. High DNA stainability was not related to ICSI fertilization rates. High DNA stainability did not affect blastocyst rates or pregnancy outcomes. Men with > or =30% DFI were at risk for low blastocyst rates (<30%) and no ongoing pregnancies. Men with > or =30% DFI had more male factors. World Health Organization thresholds were not predictive of ongoing pregnancy.

CONCLUSION(S)

The relationship between HDS and poor IVF fertilization rates provides preliminary evidence that ICSI may be indicated in men with > or =15% HDS. Men with high levels of DNA fragmentation (> or =30% DFI) were at greater risk for low blastocyst rates and failure to initiate an ongoing pregnancy. The SCSA provides valuable prognostic information to physicians counseling couples before IVF and/or ICSI cycles.

Implications of systemic malignancies on human fertility

Cancer patients have now longer life expectancy due to improved treatment modalities. As the mortality rate decreased and the survival rate increased, the consequences of cancer treatment in terms of impaired fertility became more frequently encountered. The objective of this review is to highlight fertility issues associated with systemic malignancies. Systemic malignancies lead to deterioration of human fertility directly or indirectly as a result of cytotoxic treatment regimens. A variety of measures may be used to decrease the incidence of fertility decline that occurs. Gamete cryopreservation represents a widely accepted method for fertility preservation in cancer patients. In addition, other procedures such as germ cell transplantation and ovarian cryopreservation, which are currently being developed, are expected to make significant contribution in these cases. However, there are some ethical issues that should be considered before offering patients any of these options.

Correlation between sperm motility and sperm chromatin structure assay parameters

OBJECTIVE

To evaluate the association between chromatin structure and sperm motility.

DESIGN

Cross-sectional prospective study.

SETTING

Scanian Andrology Centre, Malmö, Sweden; ENEA Casaccia, Rome, Italy; and Department of Occupational Medicine, Aarhus University, Aarhus, Denmark.

PATIENT(S)

One hundred seventy-one males from Danish first pregnancy planner couples (group 1) and 278 Swedish military conscripts (group 2).

MAIN OUTCOME MEASURE(S)

Sperm chromatin structure assay (SCSA) parameters, DNA fragmentation index (DFI), high DNA stainable (HDS), and sperm motility, which was evaluated manually and by use of computer-aided sperm analysis (CASA).

RESULT(S)

A statistically significant negative correlation between DFI and the CASA percentage of motile sperms (group 1: r = -0.53; group 2: r = -0.38) was found. For the manual motility assessment, the correlation coefficients were slightly lower. Furthermore, HDS correlated negatively with CASA sperm motility (group 1: r = -0.39; group 2: r = -0.36) and percentage of World Health Organization category A motile sperm. In multiple linear regression analysis, concentration and SCSA parameters, but not the time of abstinence, were statistically significant predictors of sperm motility.

CONCLUSION(S)

There is a moderate correlation between sperm motility and SCSA parameters. The study supports the assumption that both SCSA and motility can be relatively independent predictors of male fertility.

Cryopreservation of sperm: indications, methods and results

PURPOSE

We review the history of the cryopreservation of human sperm. The current methods of cryopreservation and indications are highlighted, and the success rates of the various uses of cryopreserved sperm are reviewed. Potential adverse sequelae of human cryopreservation are also discussed.

MATERIALS AND METHODS

Indications for cryopreservation include several applications, namely homologous and donor insemination, cryopreservation prior to surgical infertility treatment, intraoperative cryopreservation, postoperative cryopreservation, cryopreservation prior to treatment for malignancies and nonmalignant diseases, as well as premortem and postmortem cryopreservation.

RESULTS

With the use of intracytoplasmic sperm injection, open microsurgical epididymal sperm aspiration and testicular sperm extraction with cryopreserved sperm in men with obstructive azoospermia yields pregnancy rates similar to those using fresh sperm. Intraoperative cryopreservation is recommended for complex reconstructive cases with lower patency rates, including vasoepididymostomy and vasoepididymostomy to the efferent ductule. In addition, sperm banking is strongly recommended for all patients with malignant disease who may wish to have children, since a small but significant percent of these men later use their banked semen. Although there is concern about the transfer of genetically damaged sperm after cryopreservation, no proven increase in genetic or phenotypic abnormalities in offspring has been identified.

CONCLUSIONS

Sperm cryopreservation has revolutionized the field of assisted reproduction. Cryopreserving sperm avoids the need for additional surgery in couples undergoing repeated in vitro fertilization/intracytoplasmic sperm injection cycles. Moreover, it provides hope for men undergoing chemotherapy, radiation or radical surgery who once had no chance for future fertility.

Sperm DNA damage and cancer treatment

Cancer treatments are well known to adversely affect male fertility. Reduction of sperm output arises from the cytotoxic effects of chemo- or radiotherapy upon the spermatogenic epithelium. However, if the epithelium survives there is a hazard to reproduction as the treatments are also mutagenic. The presence of DNA damage in the male genome is shown in animal experiments where there is transgenerational expression as a variety of effects ranging from miscarriage to carcinogenesis. The application of DNA damage methodology to sperm provides the opportunity for direct assessment. The Comet and Chromatin structure assays (SCSA) measure DNA damage by different principles, however, conclusions arising from the data are similar. DNA damage is present in sperm from fertile and infertile men and there is some association with infertility. Both assays detect sperm DNA damage after in vivo treatment with genotoxic agents. In a man treated with chemotherapy for cancer there was increased and persistent DNA damage in sperm. This information is consistent with the generation of human genetic diseases after conception with sperm carrying high loads of DNA damage. Whilst studies have not supported any association between paternal cytotoxic cancer therapy and genetic disease in their children, it would be unwise to discount these observations. The institution of better surveillance of genetic disease in the offspring of men surviving cytotoxic therapies may provide more robust risk assessment.

Oncologists' attitudes and practices regarding banking sperm before cancer treatment

PURPOSE

The goal of this study was to survey oncologists in three different practice settings to determine their knowledge, attitudes, and practices regarding referring patients to bank sperm before cancer treatment.

METHODS

A postal survey about knowledge, attitudes, and practices regarding banking sperm before cancer treatment was sent to 718 oncology staff physicians and fellows at two cancer centers and at sites in a Community Clinical Oncology Program.

RESULTS

The return rate was 24% and did not differ by institution, oncologic specialty, or sex. Fellows were significantly more likely to participate (37%) than staff physicians (20%). Ninety-one percent of respondents agreed that sperm banking should be offered to all men at risk of infertility as a result of cancer treatment, but 48% either never bring up the topic or mention it to less than a quarter of eligible men. Neither greater knowledge about sperm banking nor seeing large numbers of eligible men yearly increased the likelihood of discussing the option. Barriers cited included lack of time for the discussion, perceived high cost, and lack of convenient facilities. Oncologists reported they would be less likely to offer sperm banking to men who were homosexual, HIV-positive, had a poor prognosis, or had aggressive tumors. Oncologists overestimated the costs of sperm banking and the number of samples needed to make cryopreservation worthwhile.

CONCLUSION

Sperm banking should be offered as an option to all men at risk of infertility because of their cancer treatment. Clearer practice standards could help oncologists increase their knowledge about sperm banking and avoid dependence on biased patient selection criteria.