Sperm cryopreservation of male cancer patients for fertility preservation : 10-year monocentric experience

Background: Semen cryopreservation is an effective method to preserve fertility, which is very important for male cancer patients. Unfortunately, due to unaware of the opportunities for sperm cryopreservation for both physicians and cancer patients, not a lot of data on evaluating the semen parameters and dispositions of the cryopreserved samples of Chinese cancer population are available in the literature. Methods: We retrospectively reviewed semen parameters as well as the clinical outcomes of assisted reproductive treatments (ART) of 339 male cancer patients of Chinese population who were referred to our center from 2010 to 2019 for fertility preservation. Results: We rst classify the male tumors into six major types according to body regions. The most prevalent cancer patients who came from our cohort for sperm banking were hematological neoplasms patients, and the second cancers were germ cell tumors. Patients with germ cell tumors had the lowest pre-thaw and post-thaw concentration among the six major cancer types. However, we separately compared among testicular tumors, lymphoma and leukemia, it turned out that leukemia had the lowest pre-thaw concentration. Most cancer patients (58%) chose to go on keeping their specimens in storage. The second proportion selected to discard their specimens electively (31%). Over the years, there were only 13 patients (4%) returned to use their sperm by ART. In the storage samples, germ cell tumors were the most proportion ones (29.3%). Moreover, in the unfrozen samples, the percentage of hematological neoplasms were the most (45.5%). Conclusions: To our knowledge, we had owned the most numbers of male cancers who came to sperm bank for fertility conservation in the southwest of China. In our study we suggested that sperm quality could decrease even before antineoplastic treatment and sperm banking prior to treatment should be strongly recommended for male cancer patients. outcomes 13 patients used their banked samples for 15 assisted reproductive cycles.


Introduction
According to World Health Organization (WHO) report, infertility will become the third largest disease after tumors and cardiovascular diseases affecting human life and health in the 21st century [1]. Studies have reported that distress about infertility was more prevalent among male survivors of cancer than unaffected men [2][3][4]. With the increasing number of patients surviving cancer, there is interest in long-term quality of life for cancer patients and reproductive physicians, especially with respect to cancer-related infertility [5,6]. Therefore, Attaches great importance has been placed on studying the potential negative effects of cancer therapies: chemotherapy and radiotherapy, even malignancy itself on fertility [7]. At present, sperm banking before cancer treatment for male cancer patients is considered the most effective method to preserve fertility [8,9].
In China, a few articles have been published regarding fertility preservation about male cancer patients [10]. There was one report performed a retrospective review of sperm cryopreservation for 143 male cancer patients about the Human Sperm Bank of the National Research Institute for Family Planning in Beijing [11]. Due to its late starting this program in China, man fertility preservation awareness is weak and we need to develop a systemic and patient-centered program for offering cryopreservation to all male cancer patients.
Human Sperm Bank, West China Second University Hospital, Sichuan University, has been offered sperm banking to patients for 10 years. Compare to other sperm banks in China, our unit own relatively more populations in which received 1039 men to cryopreserve sperm for birth demand and cancer patients was 339. In this study, the primary aim of our study was to evaluate semen parameters and the dispositions of the cryopreserved samples among the various types of cancer in our 10-year experience of sperm banking. We simultaneously focused on the reproductive outcomes used cryopreserved semen by ART.

Patients
The study was approved by the Ethics Committee of the West China Second University Hospital, Sichuan University. Informed written consent was obtained from all patients prior to their enrollment in this study. In accordance with the guidelines and processes established by our sperm bank, all cancer patients seeking fertility preservation were counseled by an andrology physician and fully informed about the procedure. The information provided included the different methods for fertility preservation, and the procedures for future use of the specimens. All the patients received a physical examination. Medical records of all cancer patients who attempted sperm cryopreservation at Human Sperm Bank, West China Second University Hospital, Sichuan University from

Statistical analysis
The statistical methodology consisted of One-way analysis and Kruskal-Wallis tests. In all cases, p < 0.05 was considered statistically signi cant.

Population studied
There were 339 male cancer patients who attempted sperm cryopreservation from January 2010 to December 2019 (Fig. 1A). The cancer diagnoses of the 339 included patients were germ cell tumors (26%), hematological neoplasms (28%), head and neck cancers (19%), thoracic tumors (4%), abdominal tumors (10%), and other tumors (13%) (Fig. 1B). Germ cell tumors included testicular tumors and extragonadal germ cell tumors. Hematological neoplasms included lymphoma and leukemia. The "other" group was composed of skin, sarcoma and peripheral schwannoma. In our unit, we found not only testicular tumors but also extragonadal germ cell tumors had need for fertility preservation. This classi cation that cancers were devised into six major tumors by body parts was the rst showed. The age of patients was 26.7 ± 6.8 years old, among whom 31 patients (9.9%) were adolescents under the age of 18 years.

Semen parameters
Median sexual abstinence was in the range of a minimum of 2 days and a maximum of 7 days [12]. While a few of the patients had a longer period of sexual abstinence than one week, due to emergency treatment (data not shown). The mean semen volume was 3.4 ± 1.5 mL and a median number of straws stored was 4 per patient among different cancer groups. Before cryopreservation, the overall median sperm concentration was 47×10 6 /mL and progressive motility (a + b %) of 49%. Post-thaw analyses after cryopreservation revealed a median concentration of 30×10 6 /mL and motility (a + b %) of 28%. There was no difference in change from pre-to post-thaw motility and recovery rate between the various cancer groups. A statistically signi cant lower sperm pre-and postthaw concentration was observed in germ cell tumors compared to the other ve cancers (Table 1). When comparing the data of leukemia, lymphoma and testicular cancer group, patients with leukemia had the poorest samples, with lower pre-thaw concentration ( Table 2).

Disposition of cryopreserved sperm
We elaborated the cryopreserved sperm states to analyze the further study of improving the utilization. Disposition of cryopreserved sperm categories included ongoing storage (58%), discarded (31%), failure to bank (6%), death (1%) and used (4%) (Fig. 2). Twenty-two patients (6%) failed the sperm cryopreservation due to poor quality (azoospermia, oligoasthenozoospermia, and received chemotherapy). Moreover, we furtherly analyzed the details of men using cryopreserved sperm and their reproductive outcomes. The results showed that leukemia was the most cancers failed cryopreservation (45.5%). We concluded the urgent treatment time for further treatment might be the most reason for this result. The phenomenon needed we communicate with clinicians in a timely manner to ensure leukemia cancers bank sperm before cancer treatment. In the ongoing storage semen, germ cell tumors (29.3%) and hematological neoplasms (26.8%) were the higher proportion (Table 3). The outcome of ART with cryopreserved semen As of December 31, 2019, only 3.8% (13 out of 339) of patients returned to use their cryopreserved semen for ART. Conceptions were achieved in 66.7% (10 out of 15), with 50% (5 out of 10) of pregnancies resulting in delivery, 20% of pregnancies spontaneous abortions (2 out of 10) and 30% (3 out of 10) clinical pregnancies. There were two couples failed concept, and one embryo cryopreservation. The details of these cases are listed in Table 4. Reproductive outcomes of 13 patients who used their banked samples for 15 assisted reproductive cycles.

Discussion
As cancer survival rates improve, more attention is being directed from issues of cancer treatment toward enhancing quality-of-life issues related to long-term survivorship for cancer patients. Cryopreservation of semen samples is a noninvasive procedure and is the main option for male cancer patients [13].
In our study, we demonstrating that male cancer patients in the Sichuan, China, use sperm banking for fertility preservation. During the 10 years of our study, there were 339 male cancer patients attempted to conduct fertility preservation, the most population at present reported in China. To our knowledge, this is the rst report demonstrating that sperm parameters of different cancers types according to body regions. We divide into six portions: germ cell tumors, hematological neoplasms, head and neck cancers, thoracic tumors, abdominal tumors and other tumors. We found that men with germ cell tumors (including testicular cancer and extragonadal germ cell tumor) had an inferior pre-and post-concentration compared with men with other types of cancer. However, when we separately compared testicular cancer, leukemia, and lymphoma we found that leukemia showed the lowest sperm concentration among them. Although there were reported that sperm count and motility was signi cantly lower in testicular tumors in some prior studies [14][15][16][17]. There are several causes of semen quality decline before cancer treatment, such as disruption of the blood-testis barrier and endocrine derangements [18,19]. Some studies show that cancer patients especially leukemia patients have an innate suppression of spermatogenesis, but the mechanism for suppression is under studied [15,20,21]. So, not should be discussed with cancer patients about sperm preservation as early as possible. All ways of oncological therapy, including surgical procedures, chemotherapy and radiotherapy have some risk to fertility [4]. We are all talking about adults that can cryopreserve sperm by masturbation. To date, for the prepubertal male patients especially the patients that cannot masturbate to obtain sperm, cryopreservation of sperm is impossible. When it is not possible to obtain sperm, testicular tissue containing spermatogonia stem cells (SSCs) can be obtained by biopsy. Exciting basic science work in under way that addresses the unmet fertility preservation and may expand fertility options for men in the future.

Conclusion
In conclusion, our study supports studies that sperm banking is an effective way of fertility preservation in cancer patients. Fertility preservation utilization is very low among Chinese male cancer patients. Therefore, reproductive physicians and oncologists are required to discuss fertility preservation before gonadotoxic therapy with all male cancer patients. Sperm cryopreservation is a quick and effective technique that can preserve fertility. Development of local clinical guidelines and the organization of conference to promote the fertility preservation should be encouraged.  Outcomes for the cancer patients who attempted banking