Diagnosis and management of the growing teratoma syndrome: A single-center experience and review of the literature

Growing teratoma syndrome in children and adolescents: Prevalence and surgical outcome

INTRODUCTION

Patients affected by metastatic germ cell tumors may occasionally experience enlargement of masses with concurrent normalization of tumor markers during or after chemotherapy. This phenomenon is described as growing teratoma syndrome (GTS). The aim of the pre sent study is to assess the prevalence of GTS in the pediatric population and its implications in terms of surgical outcome.

PATIENTS AND METHODS

The clinical notes of patients diagnosed with stage III and IV malignant germ cell tumors from January 2010 until December 2020 at our Institution were retrospectively reviewed. The prevalence of GTS, treatment strategies, survival, and outcome were analyzed.

RESULTS

Thirty-three patients with high-stage malignant germ cell tumors were diagnosed in our institution in the analyzed period. Nine patients (28%) had radiologic evidence of enlargement of persistent masses with normal markers after chemotherapy; these patients were classified as GTS patients. All nine patients underwent resection of metastatic lymph nodes, and six had surgery on visceral metastases. In six patients, radical excision of all metastatic sites was achieved; five patients are alive and in complete remission, while one died because of peri-operative complications. Out of the three patients who could not achieve radical excision of the metastases, two died of progressive disease, and one is alive with progressive disease.

CONCLUSIONS

Patients affected by GTS have a risk of progression of chemotherapy-resistant disease and death. Radical surgical excision is essential to achieve disease control and long-term survival.

Regionalization of Testis Cancer Care-Is It Necessary?

Testicular germ cell tumors are rare genitourinary malignancies, but they represent the most common malignancies in men aged 15 to 30 years. Whereas the initial steps of management such as staging imaging studies, inguinal orchiectomy, and tumor marker can be performed elsewhere, the surgical and cytotoxic therapy needs to be done at reference centers. Regionalization of testis care has been shown to result in superior oncological outcome.

Assessing the risk to develop a growing teratoma syndrome based on molecular and epigenetic subtyping as well as novel secreted biomarkers

In germ cell tumors (GCT), a growing teratoma during chemotherapy with decreasing tumor markers was defined as 'growing teratoma syndrome' (GTS) by Logothetis et al. in 1982. So far, its pathogenesis and specific treatment options remain elusive. We aimed at updating the GTS definition based on molecular and epigenetic features as well as identifying circulating biomarkers. We selected 50 GTS patients for clinical characterization and subsequently 12 samples were molecularly analyzed. We further included 7 longitudinal samples of 2 GTS patients. Teratomas (TER) showing no features of GTS served as controls. GTS were stratified based on growth rates into a slow (<0.5 cm/month), medium (0.5-1.5) and rapid (>1.5) group. By analyzing DNA methylation, microRNA expression and the secretome, we identified putative epigenetic and secreted biomarkers for the GTS subgroups. We found that proteins enriched in the GTS groups compared to TER were involved in proliferation, DNA replication and the cell cycle, while proteins interacting with the immune system were depleted. Additionally, GTSrapid seem to interact more strongly with the surrounding microenvironment than GTSslow. Expression of pluripotency- and yolk-sac tumor-associated genes in GTS and formation of a yolk-sac tumor or somatic-type malignancy in the longitudinal GTS samples, pointed at an additional occult non-seminomatous component after chemotherapy. Thus, updating the Logothetis GTS definition is necessary, which we propose as follows: The GTS describes a continuously growing teratoma that might harbor occult non-seminomatous components considerably reduced during therapy but outgrowing over time again.

The potential role of miRNAs in the pathogenesis of testicular germ cell tumors - A Focus on signaling pathways interplay

Testicular germ cell tumors (TGCTs) are the most common testicular neoplasms in adolescents and young males. Understanding the genetic basis of TGCTs represents a growing need to cope with the increased incidence of these neoplasms. Although the cure rates have been comparatively increased, investigation of mechanisms underlying the incidence, progression, metastasis, recurrence, and therapy resistance is still necessary. Early diagnosis and non-compulsory clinical therapeutic agents without long-term side effects are now required to reduce the cancer burden, especially in the younger age groups. MicroRNAs (miRNAs) control an extensive range of cellular functions and exhibit a pivotal action in the development and spreading of TGCTs. Because of their dysregulation and disruption in function, miRNAs have been linked to the malignant pathophysiology of TGCTs by influencing many cellular functions involved in the disease. These biological processes include increased invasive and proliferative perspective, cell cycle dysregulation, apoptosis disruption, stimulation of angiogenesis, epithelial-mesenchymal transition (EMT) and metastasis, and resistance to certain treatments. Herein, we present an up-to-date review of the biogenesis of miRNAs, miRNA regulatory mechanisms, clinical challenges, and therapeutic interventions of TGCTs, and role of nanoparticles in the treatment of TGCTs.

Metastatic Mature Teratoma and Growing Teratoma Syndrome in Patients with Testicular Non-Seminomatous Germ Cell Tumors

Metastatic mature teratoma is a common radiologic and histopathologic finding after chemotherapy for metastatic non-seminomatous germ cell tumors. The leading theory for these residual tumors is the selective chemotherapy resistance of teratomas versus the high chemotherapy sensitivity of the embryonal components. Growing teratoma syndrome is a relatively rare phenomenon defined as an enlarging residual mass histologically proven to be a mature teratoma in the setting of normal serum tumor markers. Metastatic mature teratomas should be resected because of their malignant potential and occasional progression to growing teratoma syndrome with the invasion of the surrounding structures. CT is the preferred imaging modality for post-chemotherapy surveillance and should cover all sites of potential metastatic disease. This article reviews the clinical, pathologic, and multimodality imaging features of metastatic mature teratomas in patients with primary testicular non-seminomatous germ cell tumors.

Growing Teratoma Syndrome: A Rare Outcome

Growing teratoma syndrome is a rare condition described in both testicular and ovarian cancer. We present a case of a 26-year-old male with known mixed germ cell tumor which exhibited new and progressive secondary lesions during imaging surveillance, later to be histologically characterized as teratomas.

Systemic treatment options for growing teratoma syndrome: A single-center experience with a comprehensive review of the literature

Background

Growing teratoma syndrome (GTS) is a very uncommon phenomena. Given its lower prevalence, there is little data about clinichopathological features and management of GTS. Literature about disease mostly composed of case reports. In this study, we aimed to report patients characteristics and treatment modalities in our center within a relatively large cohort.

Patients and Methods

We retrospectively reviewed the clinical records 21 patients who fulfilled criteria of GTS. Survival analysis was performed by using the Kaplan-Meier method with the Long-rank test. p<0.05 was considered statistically significant.

Results

The median age at diagnosis was 25 (range 17-51). A total of 12 patients could have undergone surgery. Of patients who underwent surgery, 5 patients remained fully disease free, and 7 patients had experienced disease recurrences. Nine patients had unresectable disease, and treated with either platin-based chemotherapy or interferone α2b. Of those, 5 patients eventually had undergone autologous stem cell transplantation (ASCT) with surprisingly promising response rates. One patient had complete response and three patients had partial response. One patient died soon after ASCT due to infectious complication.

Conclusion

GTS is an unique entity with regard to its clinicopathological features and available treatment options as we mentioned in the text. Despite various agents reported to have efficacy in case reports, surgery remains as the mainstay of treatment. According to result of our study, ASCT and platin-based chemotherapy regimens may be feasible options for patients with unresectable disease.

Short-term and long-term outcomes after resection of thoracic growing teratoma syndrome

PURPOSE

Thoracic growing teratoma syndrome (TGTS) is a rare disease in patients with germ cell tumors. Other than a few case reports and a limited number of case series, studies of this topic are not available.

METHODS

We retrospectively analyzed the data from our patients who received surgery for TGTS between 1999 and 2016. Descriptive statistical analyses were performed to analyze the characteristics of the patients, tumors, and short-term outcomes. Furthermore, the long-term outcomes and survival curves were analyzed using the Kaplan-Meier method.

RESULTS

Twenty-nine patients underwent surgery for TGTS. The median age was 32 years (range: 19-50 years). All patients received cisplatin-based chemotherapy. Many of the patients had multilocalized TGTS (n = 10). The median tumor size was 64.5 mm (range 10-210 mm). In all cases, R0 resection was achieved. The minor morbidity, major morbidity, and mortality rates were 3.4%, 6.9%, and 0%, respectively. Altogether, 28 patients were included in the long-term follow-up analysis, with a median follow-up time of 94 months (13-237 months). The 5-, 10-, and 15-year survival rates were 93%, 93%, and 84%, respectively.

CONCLUSIONS

TGTS may occur in multiple localizations and grow to a large tumor size. The resection of TGTS can be performed with low morbidity and mortality rates and is associated with good overall survival after complete resection. Important are an early detection and knowledge of the systemic treatment options by the oncologist and urologist, as well as a thoracic surgeon with a large experience in extended thoracic resections.

Cisplatin Resistance in Testicular Germ Cell Tumors: Current Challenges from Various Perspectives

Testicular germ cell tumors share a marked sensitivity to cisplatin, contributing to their overall good prognosis. However, a subset of patients develop resistance to platinum-based treatments, by still-elusive mechanisms, experiencing poor quality of life due to multiple (often ineffective) interventions and, eventually, dying from disease. Currently, there is a lack of defined treatment opportunities for these patients that tackle the mechanism(s) underlying the emergence of resistance. Herein, we aim to provide a multifaceted overview of cisplatin resistance in testicular germ cell tumors, from the clinical perspective, to the pathobiology (including mechanisms contributing to induction of the resistant phenotype), to experimental models available for studying this occurrence. We provide a systematic summary of pre-target, on-target, post-target, and off-target mechanisms putatively involved in cisplatin resistance, providing data from preclinical studies and from those attempting validation in clinical samples, including those exploring specific alterations as therapeutic targets, some of them included in ongoing clinical trials. We briefly discuss the specificities of resistance related to teratoma (differentiated) phenotype, including the phenomena of growing teratoma syndrome and development of somatic-type malignancy. Cisplatin resistance is most likely multifactorial, and a combination of therapeutic strategies will most likely produce the best clinical benefit.

Application of miRNAs in the diagnosis and monitoring of testicular germ cell tumours

Testicular germ cell tumours (TGCTs) are the most frequent cancer type in young men and originate from the common precursor germ cell neoplasia in situ (GCNIS). For decades, clinical management of patients with TGCT has relied on classic serum tumour markers: α-fetoprotein, human chorionic gonadotropin subunit-β and lactate dehydrogenase. In the past 10 years, microRNAs have been shown to outperform classic serum tumour markers in the diagnosis of primary tumours and in follow-up monitoring and prediction of relapse. miR-371a-3p is the most consistent marker and exhibits >90% diagnostic sensitivity and specificity in TGCT. However, miR-371a-3p cannot be used to diagnose GCNIS or mature teratoma. Future efforts must technically standardize the microRNA-based methods internationally and introduce miR-371a-3p as a molecular liquid biopsy-based marker for TGCTs in the clinic.

Postchemotherapy Resection of Residual Mass in Nonseminomatous Germ Cell Tumor

The introduction of cisplatin-based chemotherapy has revolutionized the care of patients with disseminated testicular germ cell tumors. Although a majority are cured with chemotherapy alone, surgical resection continues to play a role because one-third will have residual mass after chemotherapy. In this article, we review the current indications for postchemotherapy resection in nonseminomatous germ cell tumors, including masses greater than 1 cm, resection after salvage chemotherapy, with elevated markers, after late relapse, and for growing teratoma syndrome. We also highlight technical considerations of this often-challenging surgery, including the need for adjunctive procedures, extraretroperitoneal resections, and modern techniques to minimize morbidity.