Residual tumor resection after high-dose chemotherapy in patients with relapsed or refractory germ cell cancer

European Association of Urology Guidelines on Testicular Cancer: 2023 Update

CONTEXT

Each year the European Association of Urology (EAU) produce a document based on the most recent evidence on the diagnosis, therapy, and follow-up of testicular cancer (TC).

OBJECTIVE

To represent a summarised version of the EAU guidelines on TC for 2023 with a focus on key changes in the 2023 update.

EVIDENCE ACQUISITION

A multidisciplinary panel of TC experts, comprising urologists, medical and radiation oncologists, and pathologists, reviewed the results from a structured literature search to compile the guidelines document. Each recommendation in the guidelines was assigned a strength rating.

EVIDENCE SYNTHESIS

For the 2023 EAU guidelines on TC, a review and restructure were undertaken. The key changes incorporated in the 2023 update include: new supporting text regarding venous thromboembolism prophylaxis in males with metastatic germ cell tumours receiving chemotherapy; quality of life after treatment; an update of the histological classifications and inclusion of the World Health Organization 2022 pathological classification; inclusion of the revalidation of the 1997 International Germ Cell Cancer Collaborative Group prognostic risk factors; and a new section covering oncology treatment protocols.

CONCLUSIONS

The 2023 version of the EAU guidelines on TC include the highest available scientific evidence to standardise the management of TC. Better stratification and optimisation of treatment modalities will continue to improve the high survival rates for patients with TC.

PATIENT SUMMARY

This article presents a summary of the European Association of Urology guidelines on testicular cancer published in 2023 and includes the latest recommendations for management of this disease. The guidelines are a valuable resource that may help patients in understanding treatment recommendations.

Postchemotherapy gross residual tumor in non-high-risk neuroblastoma: Clinical significance and the role of adjuvant therapy

BACKGROUND

Although survival rate among patients with non-high-risk neuroblastoma is excellent, a gross residual tumor (GRT) is often present at the end of treatment. However, reliable data do not exist on the relevance of a GRT for the risk of progression and the role of adjuvant therapy for patients with GRT.

METHODS

A retrospective review of 131 patients with non-high-risk neuroblastoma who underwent chemotherapy was performed. GRT was defined as >1 cm³ residual soft tissue density on end-of-chemotherapy scans. Progression-free survival (PFS) and overall survival (OS) rates were compared between patients with GRT and those without GRT. A proportional hazards model was also used to assess the effects of GRT and adjuvant therapies, including radiation and isotretinoin therapy on outcomes.

RESULTS

GRT was found in 52 (40%) patients in the study cohort. Correlation was not found between GRT and outcomes (PFS; p = .954, OS; p = .222). In multivariable analysis, GRT remained a nonsignificant predictor of outcome after adjusting for confounders. Local radiation and isotretinoin therapy did not affect outcome for patients with GRT. However, within GRT subgroups, the degree of volume reduction, as well as absolute residual volume in the primary tumor after induction treatment, were significantly associated with outcomes.

CONCLUSION

GRT in non-high-risk neuroblastoma may not indicate active disease that requires additional treatment. However, risk of progression is increased in patients with GRT whose response to treatment was less prominent, thus adjuvant therapy should be reserved only for those patients.

Post-treatment Residual Clinicopathological Outcomes in Testicular Germ Cell Tumours

Surgical resection is a generally accepted treatment for residual masses after chemotherapy for metastatic testicular germ cell tumour (GCT). About half the patients have necrosis in post-chemotherapy residual masses, whereas rest have viable tumour and teratoma. The likelihood of leaving behind teratoma with its subsequent complications such as growing teratoma syndrome necessitates resection outweighing its surgical complications. Ours is a retrospective observational study and aims at assessing post-chemotherapy residual masses in testicular GCTs and to predict importance of teratomatous and non-seminomatous components. A total of 62 cases of testicular GCTs resected after chemotherapy between January 2012 and June 2019 were included. Demographic, clinical, biochemical and imageological findings were noted and categorised according to WHO classification (2016). They were divided into two groups - those who underwent retroperitoneal lymph node dissection (RPLND) post-high inguinal orchidectomy (HIO) and chemotherapy (CT) as group 1 (n = 40) and those who underwent HIO and/or RPLND post-chemotherapy as group 2 (n = 22). The gross and microscopic examination was carried out to assess response to chemotherapy in terms of residual viable tumour, necrosis and teratoma. Viable tumour, necrosis and teratoma were 10%, 62.5% and 35% respectively in group 1 and in group 2, the same were 15%, 70% and 25% respectively in HIO specimen and 7%, 50% and 21% respectively in RPLND specimen. All the cases with viable tumour were proven to be yolk sac tumours (YST) based on morphology and immunohistochemistry (IHC).Twenty cases had teratoma in the post-CT residual masses out of which 11 cases had teratoma despite reduction in size. At a median follow-up of 47.85 months, 5 cases in group 1 and 2 cases in group 2 showed relapse and it was observed that group 1 had a prolonged relapse-free survival over group 2. Our study re-emphasises the importance of performing resection of residual mass post-CT irrespective of the size, imageological or biochemical evidence of tumour regression. There does not appear to be reliable predictors of post-chemotherapy histology of residual masses indicating the continued need for surgical resection in specialised centres.

A meta-analysis of clinicopathologic features that predict necrosis or fibrosis at post-chemotherapy retroperitoneal lymph node dissection in individuals receiving treatment for non-seminoma germ cell tumours

Purpose

Post-chemotherapy retroperitoneal lymph node dissection (pcRPLND) for residual nodal masses is a critical component of care in metastatic testicular germ cell tumour (GCT). However, the procedure is not of therapeutic value in up to 50% of individuals in whom histopathology demonstrates post-treatment necrosis or fibrosis alone. Improved diagnostic tools and clinicopathologic features are needed to separate individuals who benefit from pcRPLND and avoid surgery in those who do not.

Methods

A prospectively registered meta-analysis of studies reporting clinicopathologic features associated with teratoma, GCT and/or necrosis/fibrosis at pcRPLND for metastatic non-seminoma GCT (NSGCT) was undertaken. We examined the effect of various clinicopathologic factors on the finding of necrosis/fibrosis at pcRPLND. The log odds ratios (ORs) of each association were pooled using random-effects models.

Results

Using the initial search strategy, 4,178 potentially eligible abstracts were identified. We included studies providing OR relating to clinicopathologic factors predicting pcRPLND histopathology, or where individual patient-level data were available to permit the calculation of OR. A total of 31 studies evaluating pcRPLND histopathology in 3,390 patients were eligible for inclusion, including two identified through hand-searching the reference lists of eligible studies. The following were associated with the presence of necrosis/fibrosis at pcRPLND: absence of teratomatous elements in orchidectomy (OR 3.45, 95% confidence interval [CI] 2.94-4.17); presence of seminomatous elements at orchidectomy (OR 2.71, 95% CI 1.37-5.37); normal pre-chemotherapy serum bHCG (OR 1.96, 95% CI 1.62-2.36); normal AFP (OR 3.22, 95% CI 2.49–4.15); elevated LDH (OR 1.72, 95% CI 1.37-2.17); >50% change in mass during chemotherapy (OR 4.84, 95% CI 3.94-5.94); and smaller residual mass size (<2 cm versus >2 cm: OR 3.93, 95% CI 3.23-4.77; <5 cm versus >5 cm: OR 4.13, 95% CI 3.26-5.23).

Conclusions

In this meta-analysis, clinicopathologic features helped predict the presence of pcRPLND necrosis/fibrosis. Collaboration between centres that provide individual patient-level data is required to develop and validate clinical models and inform routine care to direct pcRPLND to individuals most likely to derive benefits.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42021279699

Current Status of Stem Cell Transplant in Treatment of Testicular Germ Cell Tumors

PURPOSE OF REVIEW

We aim to discuss the history of high-dose chemotherapy with autologous stem-cell transplant in testicular germ cell tumors, prognostic factors to consider prior to transplant, and issues both during and after transplant while also touching on the use of conventional-dose vs. high-dose chemotherapy for initial salvage treatment in patients with relapsed disease.

RECENT FINDINGS

The advancements in the treatment of testicular cancer have led to the majority of patients even with distant metastases being cured of their malignancy. Despite this, around 20% of patients with metastatic disease will relapse after first-line therapy, and the majority of these patients will go on to need further salvage chemotherapy, either with conventional-dose chemotherapy or high-dose chemotherapy. High-dose chemotherapy with autologous stem-cell transplant is an effective salvage therapy and will still remarkably result in cures for the majority of patients with relapsed disease. While patients receiving it as even third-line salvage therapy may achieve cures, earlier administration likely results in greater efficacy.

Salvage Resection of Mediastinal Nonseminomatous Germ Cell Tumor in a Patient with Extrathoracic Involvement upon Progression following High-Dose Chemotherapy

Primary mediastinal nonseminomatous germ cell tumor with extrathoracic metastases is associated with a very high mortality rate, and there is no consensus regarding optimal upfront therapy. Once patients fail the first-line treatment, salvage therapy often fails to effectively control the disease. Resection of the residual mediastinal mass does not appear to achieve long-term control in those who have extrathoracic metastases following conventional first-line systemic therapy. We report a case where a young man presented with symptomatic brain metastases as well as extensive visceral involvement of the liver, small intestine, and lungs. He was successfully managed with multimodality treatment including high-dose chemotherapy with hematopoietic stem cell support following standard first-line chemotherapy, resection of mediastinal disease, lung metastasectomy, and stereotactic brain radiation. He has achieved long-term survival.

Salvage management of patients with relapsing testicular germ cell tumors

PURPOSE OF REVIEW

This review aims to summarize the latest evidence of medical and surgical treatment options for patients with relapsing testicular germ cell tumors.

RECENT FINDINGS

Depending on International Germ Cell Cancer Classification Group risk classification 10-50% of patients with metastatic TGCT develop relapse which needs further multimodality treatment. With regard to therapy, early relapses are stratified according to their prognostic risk profile which results in a 3-year overall survival between 6% in the very high to 77% in the very low risk group. Prognostic risk score dictates systemic therapy which might be second line chemotherapy (TIP, PEI) or high dose chemotherapy. Any residual masses following salvage chemotherapy need to be completely resected due the presence of viable cancer and/or teratoma in more than 50% of cases. Targeted therapy in men with druggable mutations is for individualized cases only. Patients with late relapses developing more than 2 years after first-line chemotherapy are best managed by surgery. Desperation surgery is reserved for those patients with rising markers during or immediately after chemotherapy and good risk factors such as rising alpha-fetoprotein, <3 metastatic sites and complete resectability. Multimodality treatment will result in long-term cure of 25% to 60%. Due to the complexity of treatment, chemotherapy as well as surgery should be performed in highly experienced centres only.

SUMMARY

Multimodality treatment to salvage relapsing patients with metastatic testis cancer requires extensive experience for both systemic therapy and surgery. If done properly, it will result in moderate to high cure rates. Personalized therapeutic options are currently evaluated in clinical trials.

Thoracic Metastasectomy in Germ Cell Tumor Patients Treated With First-line Versus Salvage Therapy

BACKGROUND

Outcomes after thoracic metastasectomy in patients with testicular germ cell tumors (GCTs) who received first-line chemotherapy alone versus salvage chemotherapy remain unexplored.

METHODS

We conducted a retrospective review of patients who underwent thoracic metastasectomy for residual GCT between 1997 and 2019 at a single tertiary center. Factors associated with progression-free survival (PFS) and overall survival (OS) were assessed using multivariable Cox regression.

RESULTS

Of 251 patients, 191 received only first-line chemotherapy (76%) and 60 received salvage chemotherapy (24%). Median follow-up was 3.45 years (interquartile range, 1-7.93 years). Among first-line patients without teratoma in the primary tumor, with necrosis in the retroperitoneal nodes and normalized or decreasing serum tumor markers, 17 of 20 had intrathoracic necrosis (85%). Among first-line and salvage patients, respectively, 5-year OS was 93% (95% confidence interval [CI], 89%-98%) versus 63% (95% CI, 51%-78%; P < .001), and 5-year PFS was 69% (95% CI, 62%-77%) versus 40% (95% CI, 29%-56%; P < .001). On multivariable analysis, multiple lung lesions (hazard ratio [HR] = 3.01; 95% CI, 1.50-6.05; P = .002) and brain metastasis (HR = 4.51; 95% CI, 2.34-8.73; P < .001) at diagnosis, salvage chemotherapy (HR = 1.85; 95% CI, 1.10-3.13; P = .021), teratoma (HR = 2.68; 95% CI, 1.50-4.78; P = .001), and viable malignancy (HR = 4.34; 95% CI, 2.44-7.71; P < .001) were associated with worse PFS.

CONCLUSIONS

Although GCT patients treated with salvage chemotherapy followed by thoracic metastasectomy have more aggressive disease and poorer PFS, they can achieve encouraging OS. Our findings highlight the integral role of aggressive thoracic metastasectomy in the treatment of GCT patients with residual thoracic disease after first line-only or salvage chemotherapy.

Simultaneous Vs Sequential Retroperitoneal, Thoracic and Cervical Resection of Post Chemotherapy Residual Masses in Patients With Metastatic Nonseminomatous Germ Cell Tumors of the Testis

OBJECTIVE

To compare a simultaneous vs sequential approach to residual post chemotherapy mass resections in metastatic testis cancer.

METHODS

A retrospective review was performed of patients who underwent retroperitoneal and thoracic/cervical resection of post chemotherapy residual masses between 2002 and 2018. Group 1: "Simultaneous" (Combined Retroperitoneal and Thoracic/Cervical resections on the same date); Group 2: "Sequential" (Retroperitoneal and Thoracic/Cervical resections at separate dates).

RESULTS

During the study period, 35 simultaneous and 17 sequential resections were performed. The median age at surgery was 28 years (Range 16-61). The median follow-up from last surgical procedure was 62.7 months (Range 0.4-194). Histology revealed teratoma in 38 (73.1%) patients, necrosis in 8 (15.4%) and viable tumor in 6 (11.5%). Discordant pathology findings between thoracic/cervical and abdominal resections were noted in 16 (30.8%) patients. No differences were observed between the simultaneous vs sequential groups in median operating time (585 minutes vs 545 minutes, P = .64), blood loss (1300 vs 1300 mls, P = .42), or length of stay (9 vs 11 days, P = .14). There was no difference between the 5-year (65.7% vs 68.6%) relapse-free survival between the 2 groups (P = .84) or the 5-year (88.6% vs 100%) overall and disease-specific survival (P = .25).

CONCLUSION

Simultaneous resection of retroperitoneal and thoracic/cervical post chemotherapy metastases is a feasible in some patients. It requires multidisciplinary collaboration and a longer primary procedure.

Surgical salvage in patients with advanced testicular cancer: indications, risks and outcomes

The purpose of this review is to present a comprehensive and updated review of the literature and summary of the indications, risks and outcomes related to salvage, desperation and late relapse surgery for advanced testicular cancer. After completing a thorough review of the current literature, this review has attempted to provide an overview of the indications for salvage, desperation and late relapse retroperitoneal lymph node dissection (RPLND) followed by a summary of the histopathologic and clinical outcomes regarding each. Recent literature, combined with a significant contribution from historical studies suggest that while testicular cancer is a relatively uncommon malignancy overall, it represents the most common solid organ malignancy for young men. Although a significant number of men are cured with a combination of first-line treatments, the remaining men are a diverse and often challenging cohort who require the benefit of expertise to improve their outcomes. The role of surgical strategies in the salvage, desperation and late relapse settings is unquestionable, although the most important question remains who will benefit. This often requires a multi-disciplinary approach at centers specializing in this disease process in order to recognize who should get surgery, what surgery to do and how to minimize the potential morbidity associated with the operation.

[Management of residual masses of testis germ cell tumors]

A residual mass (RM) is an abnormal image with a transverse axis of more than 1cm trans that remains visible on the CT scan performed after chemotherapy for metastatic germ cell tumors. Their management depends on the histology of the initial tumor. In the case of a non-seminomatous germ cell tumor, all residual lesions must be resected if the tumor markers are negative. The surgery usually begins with a retroperitoneal lymphadenectomy. This lymphadenectomy is a programed regional surgery and not the only resection of visible masses. All RM must be resected, regardless of their location, and may require successive actions. In order to limit its morbidity, modifications on the extent of the lymphadenectomy and the use of minimally invasive approaches are proposed by some center. When the initial tumor is a pure seminoma the attitude is different: the decay of the masses in post chemotherapy is often postponed. If lesions less than 3cm can be monitored, the others benefit from 18FDG PET at the end of chemotherapy: a positive attachment to PET is suspected of the presence of residual active tissue. The surgery of these RM is curative. If its extent is precise in the case of non-seminomatous tumor, it is more controversial in the case of seminoma. In the case of residual markers, surgery has a place in very specific situations.

Surgical Management of Patients with Advanced Germ Cell Tumors Following Salvage Chemotherapy: Memorial Sloan Kettering Cancer Center (MSKCC) Experience

OBJECTIVE

To characterize clinical and pathologic outcomes of cisplatin-refractory or relapsed germ cell tumor (GCT) patients who underwent retroperitoneal lymph node dissection (RPLND) following salvage chemotherapy with either conventional or high dose regimens.

METHODS

Data were reviewed to identify all patients treated with TIP or TICE salvage chemotherapy between 1994 and 2011(n = 184) at our institution. We report clinicopathologic and outcomes data on 131 patients who were further managed with surgical resection. Using Cox-proportional hazards models, predictors of disease-specific survival (DSS) were analyzed.

RESULTS

Median follow-up was 7.3 years. Of the 112 patients who underwent postsalvage chemotherapy RPLND, histology was reported as viable GCT in 30 (27%), teratoma only in 26 (23%) and fibrosis in 56 (50%). 5-year DSS for the entire cohort was 74% (95% confidence interval 63%-80%). On multivariable analysis, viable GCT histology at RPLND or extra-RPLND resection predicted for worse DSS (hazard ratio 7.37, P = .003).

CONCLUSIONS

Our data suggest that approximately half of the patient with cisplatin-refractory or relapsed GCT salvaged with TIP or TICE chemotherapy and evidence of residual disease are at risk of harboring either viable GCT or teratoma. This finding underlines the critical role of surgery in the multimodality approach to the management of this advanced disease entity. If retroperitoneal disease exists prior to salvage chemotherapy, we recommend postchemotherapy resection in all eligible patients.

Management of Refractory Germ Cell Cancer

Over the past 5 decades, the use of well-validated, guideline-based strategies has resulted in high cure rates in newly diagnosed patients with germ cell cancer. However, about 30% of those with metastatic disease at initial presentation will experience refractory disease. Salvage treatment is far more complex and less validated than first-line treatment because it is rare, patient cohorts are more heterogeneous, and prognostic factors seem to have greater impact. Prior to the initiation of any salvage treatment, several considerations must be made, including assessment of known prognostic factors and choice of the optimal salvage strategy. Evaluation of patients according to their disease biology, response to prior treatment, and the extent of their tumor burden at the time of salvage treatment is crucial for establishing the optimal salvage strategy. Patients with metastatic germ cell cancer in whom adequate cisplatin-based first-line chemotherapy fails should be included in the ongoing randomized TIGER trial comparing conventional-dose chemotherapy with high-dose chemotherapy as first salvage treatment. Outside this trial, patients may be treated with conventional or high-dose chemotherapy depending on the presence or absence of adverse prognostic factors, availability of resources, and patient and physician preferences.

The Role of Salvage High-Dose Chemotherapy in Relapsed Male Germ Cell Tumors

Germ cell tumors (GCT) are a unique tumor entity with excellent cure rates if guideline-endorsed treatment is thoroughly applied. Even patients with widespread metastatic disease can often be cured with cisplatin-based combination chemotherapy as part of a multimodal treatment approach. However, about 30% of patients with metastatic disease at initial presentation, corresponding to about 5-10% of all GCT patients, relapse or progress despite first-line treatment and therefore require salvage chemotherapy. Salvage systemic treatment either consists of conventional-dose cisplatin-based combination chemotherapy or sequential high-dose treatment with carboplatin and etoposide plus subsequent autologous stem cell support. This review is based on a comprehensive literature search of MEDLINE and conference proceedings of ESMO, ASCO, and EAU meetings until 2018 and provides an overview of current treatment options for germ cell cancer patients relapsing after or progressing during first-line cisplatin-based combination chemotherapy.

Therapeutic approaches for refractory germ cell cancer

INTRODUCTION

Most germ cell cancer patients with metastatic disease are cured by cisplatin-based combination chemotherapy. 30% of metastatic patients will develop relapse or progress despite adequate first-line treatment and will require salvage therapy, with about 10% of metastasized patients ultimately developing platinum-resistant and fatal disease. Areas covered: Based on a comprehensive literature search of MEDLINE, EMBASE and conference proceedings of ESMO, ASCO and EAU meetings, this review provides an overview on current and potential future treatment options for platinum-refractory germ cell cancer patients including cytostatics and molecularly targeted therapies. Expert commentary: Treatment of platinum-refractory disease remains challenging and long-term survival is rarely achieved despite multimodal treatment approaches. Targeted treatment approaches do not yet play a role in the treatment of platinum-refractory disease due to lacking efficacy in small, unselected clinical trials. Inclusion of patients into clinical trials is strongly recommended.

[When is surgical resection of metastases in testicular germ cell tumors indicated and is there a scientific basis?]

Surgical resection of metastases represents an integral part of curative management in patients with testicular germ cell tumors (GCT). Primary nerve-sparing retroperitoneal lymph node dissection (nsRPLND) for low volume metastases in clinical stages I-IIB has to be differentiated from the more complex and more extensive postchemotherapeutic procedures. In Europe, primary nerve-sparing retroperitoneal lymph node dissection (nsRPLND) for clinical stage I nonseminomatous GCT (NSGCT) plays a subordinate. In clinical stage IIA/B, nsRPLND is indicated for patients with marker-negative metastases in whom cure rates of about 65% can be achieved with surgery alone. For clinical stage IIA/B seminomas, nsRPLND represents an individual, still experimental procedure with high cure rates. Postchemotherapy residual tumor resection (pRTR) for advanced seminomas is only indicated in the context of a FDG-PET/CT-positive residual mass >3 cm in diameter. For NSGCT, pRTR is indicated in patients with residual masses >1 cm and negative or plateauing tumor markers to resect persisting teratoma or vital cancer. Complete resection of all masses including resection of adjacent vascular, visceral or skeletal metastases is mandatory to achieving the highest cure rate possible. Due to the complexity and the lower rate of significant morbidity and mortality, these procedures should be done at tertiary referral centers.

Consensus Recommendations from the Spanish Germ Cell Cancer Group on the Use of High-dose Chemotherapy in Germ Cell Cancer

BACKGROUND

High-dose chemotherapy (HDCT) has been studied in several clinical scenarios in advanced germ cell cancer (GCC).

OBJECTIVE

To establish a clinical practice guideline for HDCT use in the treatment of GCC patients.

DESIGN, SETTING, AND PARTICIPANTS

An expert panel reviewed information available from the literature. The panel addressed relevant issues concerning and related to HDCT. The guideline was externally reviewed by two international experts.

RESULTS AND LIMITATIONS

The efficacy of HDCT has been demonstrated in selected GCC patients. The most conclusive evidence comes from retrospective analyses that need to be interpreted with caution. HDCT can cure a significant proportion of heavily treated GCC patients. When indicated, sequential HDCT with regimens containing carboplatin and etoposide, as well as peripheral stem-cell support, is recommended. There is no conclusive evidence to recommend HDCT as first-line therapy. According to a multinational retrospective pooled analysis, HDCT might be superior to conventional CT as first salvage treatment in selected patients. There is an urgent need for prospective clinical trials addressing the value of HDCT in GCC patients who experience failure on first-line cisplatin-based CT. In patients who progress on conventional-dose salvage CT, HDCT should be considered. Treatment of these patients at experienced centers is strongly recommended.

CONCLUSIONS

It has been demonstrated that HDCT cures selected GCC patients who experience disease progression on conventional rescue regimens. The panel recommends the inclusion of GCC patients in randomized clinical trials including HDCT.

PATIENT SUMMARY

This consensus establishes clinical practice guidelines for the use and study of high-dose chemotherapy in patients with germ cell cancer.

Platinum-refractory germ cell tumors: an update on current treatment options and developments

PURPOSE

In general, 50 % up to 80 % of metastasized germ cell tumor patients can be cured by platinum-based chemotherapy. However, 3-5 % of patients will still die of platinum-refractory disease and new systemic treatment options are needed to improve treatment success in this difficult setting. This review aims to give an overview on treatment options and current developments in the field of platinum-refractory male germ cell tumors.

METHODS

A comprehensive literature search was conducted searching PubMed, Medline, Cochrane and Embase to identify clinical trials regarding the treatment of platinum-refractory disease. ASCO, EAU and ESMO conference proceedings were searched to identify unpublished results of relevant trials. Comprehensive review papers were hand searched for additional references. Clinicaltrials.gov was checked for ongoing clinical trials in the field of platinum-refractory germ cell tumors.

RESULTS

Outcome of platinum-refractory disease remains poor. Single-agents with reasonable activity are gemcitabine, oxaliplatin and paclitaxel, but complete remissions resulting in long-term survival could not be achieved. The triple-combination of gemcitabine, oxaliplatin and paclitaxel followed by resection of residual masses provides the best outcomes with objective responses in 51 % of patients and long-term survival in approximately 10-15 %. To date, no molecularly targeted agent has shown reasonable activity.

CONCLUSIONS

Treatment options for platinum-refractory disease are limited, but a small subset of patients may achieve long-term disease-free survival by multimodal treatment. The potential of novel targeted agents, i.e. by immune-checkpoint-inhibition remains to be defined.

Outcomes of postchemotherapy retroperitoneal lymph node dissection following high-dose chemotherapy with stem cell transplantation

BACKGROUND

Characterizing the role of postchemotherapy retroperitoneal lymph node dissection (PC-RPLND) after high-dose chemotherapy (HDCT) has been limited by small sample sizes. This study reports on survival after HDCT with stem cell support and PC-RPLND as well as histologic findings in the retroperitoneum.

METHODS

The prospectively maintained testicular cancer database of Indiana University was queried for patients receiving HDCT with stem cell transplantation before PC-RPLND. The cause and date of death were obtained through patient chart review and contact with referring physicians. The Kaplan-Meier method was used to evaluate overall survival (OS). The log-rank test was used for tests of significance. A multivariate, backward, stepwise Cox regression model was built to evaluate predictors of overall mortality.

RESULTS

A total of 92 patients were included in the study. In the entire cohort, the retroperitoneal (RP) histology findings at the time of PC-RPLND were necrosis (26%), teratoma (34%), and cancer (38%). Sixty-six patients (72%) harbored either a teratoma or active cancer in the RP specimen at PC-RPLND. The median follow-up for the entire cohort was 80.6 months. A total of 28 patients (30%) died during follow-up. The 5-year OS rate of the entire cohort was 70%. The most significant predictor of death was PC-RPLND performed in the desperation setting with elevated markers.

CONCLUSIONS

Despite these patients being heavily pretreated with multiple cycles of chemotherapy, including HDCT, approximately three-fourths were found to have a teratoma and/or active cancer in the retroperitoneum. This underscores the importance of PC-RPLND for rendering patients free of disease and providing a potential for cure.

[Surgical therapy of lung metastases]

Surgical treatment of lung metastases from extrathoracic malignancies is an established procedure. Pulmonary metastases are common. Generally, lung metastases are located peripherally and are asymptomatic. Involvement of the bronchial system or infiltration of the chest wall can be symptomatic. The indications for resection are an interdisciplinary decision. Metastasectomy can be with curative or palliative intent. Prerequisitess for pulmonary metastasectomy are primary tumor under control, the absence of extrathoracic metastases, the lack of other promising treatment options, the possibility for complete resection and low perioperative risk. Extra-anatomic resections are common. Perioperative morbidity and mortality is low. A cure is possible in selected patients.

Relationship between primary and metastatic testicular germ cell tumors: a clinicopathologic analysis of 100 cases

Testicular germ cell tumors (GCTs) commonly metastasize to the retroperitoneal lymph nodes (RPLNs). We evaluated 100 cases of RPLN dissection specimens with viable GCTs after chemotherapy and compared them with their corresponding orchiectomy specimens. The mean age of patients was 28 years (range, 15-58 years). The testicular tumors consisted of mixed GCT (n = 72), teratoma (n = 18), seminoma (n = 4), embryonal carcinoma (n = 3), yolk sac tumor (n = 1), and no viable tumor (n = 2). Somatic malignant components were found in 5 cases. The metastatic tumors in the RPLNs consisted of only teratoma (n = 77) and non-teratomatous GCT (n = 23). Twenty-one patients had only teratoma in the RPLNs but not in the testis, and 10 patients had metastatic non-teratomatous GCT components that were not observed in the testis. Six patients had somatic malignant components in the RPLNs, but only one of them had such a component in the testis. Overall, 13 patients died of disease in a mean of 42 months, and the patients with only teratoma in the RPLNs had a lower mortality rate (9%) than those with non-teratomatous components (26%) (P = .044). One patient with somatic components in the primary GCT and 3 patients with somatic components in the metastases died of disease. Our study demonstrates that there is frequent discordance of histologic composition between primary and metastatic testicular GCTs. Teratoma is the most common component in treated GCTs and is usually associated with a more favorable clinical outcome than non-teratomatous GCTs. The presence of somatic components in the RPLNs metastasis indicates a poor prognosis.

Regional deep hyperthermia for salvage treatment of children and adolescents with refractory or recurrent non-testicular malignant germ-cell tumours: an open-label, non-randomised, single-institution, phase 2 study

BACKGROUND

Although the survival of children and adolescents with malignant germ-cell tumours has improved greatly in recent years, the outcome remains poor for those with refractory or recurrent malignant germ-cell tumours. We aimed to determine whether objective tumour response could be achieved in patients with refractory or recurrent malignant germ-cell tumours with PEI-regional deep hyperthermia as salvage treatment.

METHODS

Patients with refractory or recurrent non-testicular malignant germ-cell tumours after standard cisplatin-based chemotherapy were treated prospectively with PEI chemotherapy (cisplatin 40 mg/m(2), delivered intravenously on days 1 and 4; etoposide 100 mg/m(2), intravenously on days 1-4; and ifosfamide 1800 mg/m(2), intravenously on days 1-4) plus simultaneous 1-h regional deep hyperthermia (41-43°C) on days 1 and 4. Patients received three to four treatment courses at 21-day intervals until residual tumour resection was possible; they subsequently received one or two additional courses of PEI-regional deep hyperthermia. Local radiotherapy was given for incompletely resected tumours. Chemotherapy and hyperthermia toxic effects were assessed using WHO grading. The primary endpoint was the proportion of patients who had an objective response as assessed with Response Evaluation Criteria in Solid Tumors version 1.0 guidelines. Secondary endpoints were the event-free survival and overall survival after 5 years. This ongoing PEI-regional deep hyperthermia study (Hyper-PEI protocol) is registered at the German Cancer Society, number 50-2732.

FINDINGS

44 patients aged 7 months to 21 years (median 2 years 7 months) with refractory or recurrent malignant germ-cell tumours (nine patients with poor response, 23 patients with first relapse, 12 patients with multiple relapses) were included in this study. We identified 34 yolk sac tumours, eight embryonal carcinomas, one choriocarcinoma, and one dysgerminoma by histology analysis. Of the 35 patients who had sufficient clinical and radiographical data available for response assessment, 30 (86%) had an objective response to treatment (16 patients had complete remission and 14 had partial remission). 5-year event-free survival was 62% (95% CI 45-75), and 5-year overall survival was 72% (95% CI 55-83). The median follow-up of surviving patients was 82 months (range 9-195). WHO grade 3-4 neutropenia and thrombocytopenia occurred in all 181 chemotherapy cycles. Granulocytopenic fever, which required intercurrent hospital admission, was noted in 29 (66%) of 44 patients after 53 (29%) of 181 courses. Five patients experienced treatment-related grade-3 acute renal toxic effects.

INTERPRETATION

A multimodal strategy integrating PEI-regional deep hyperthermia and tumour resection with or without radiation can successfully treat children and adolescents with refractory or recurrent malignant non-testicular germ-cell tumours. The long-term prognosis of patients with poor response or after first relapse was almost similar to those receiving first-line treatment. This strategy merits further investigation.

FUNDING

Deutsche Krebshilfe eV, Bonn, Elterninitiative Kinderkrebsklinik Düsseldorf eV, the Barbara and Hubertus-Trettnerstiftung, and the Marie Quendt Fund.

Alpha-fetoprotein surge following high-dose chemotherapy in germ cell tumours

In patients with non-seminomatous germ cell tumours (NSGCTs) who receive chemotherapy and have residual disease, a persistently elevated serum marker level after induction chemotherapy indicates active and progressive disease. High-dose chemotherapy (HDCT) is the standard treatment for patients with relapsed NSGCT. We present a case of a patient with residual disease from NSGCT who showed an increase in serum alpha-fetoprotein levels after HDCT, mimicking progression. Resection of the mass did not show viable cells in the tumour specimen, thus suggesting that the elevated level of the marker was expression of hepatic reconstitution after drug-induced liver damage. HDCT is increasingly used in cases of relapsed NSGCT, and the possibility of treatment-induced alpha-fetoprotein elevation must be taken into account in patient management.

Transplantation for refractory germ cell tumors: does it really make a difference?

High-dose chemotherapy (HDC) has been used over the past 25 years for germ-cell tumors in a variety of clinical scenarios. There is consensus at this point that its use as part of first-line treatment does not benefit patients with high-risk tumors. Long-term results of prospective trials in patients with relapsed or with refractory disease indicate that a fraction of them achieve long-term remissions consistent with cures. While HDC constitutes for many oncologists in the US an accepted treatment modality for relapsed or refractory GCT, controversy surrounds its use in those settings. Prognostic models have been developed that allow to prospectively identify poor prognosis patients that might benefit from novel HDC-based approaches.

[Postchemotherapy retroperitoneal lymphadenectomy for testicular cancer. Literature review by the Oncology Committee of the French Association of Urology, External Genitalia Group]

INTRODUCTION

Postchemotherapy retroperitoneal lymphadenectomy (PC RPLDN) leads to an overall survival rate for testicular cancer exceeding 75%. Several questions still persist concerning: preoperative assessment of residual masses, reducing templates of dissection, choosing surgical approaches or including RPLND in high-risk patients' management.

METHOD

The main series in the literature of the past 20 years were analyzed and selected to address these issues and reach a consensual diagnostic and therapeutic approach.

RESULTS

Forty-eight original articles (1992 to 2011) were selected. They confirm that no preoperative tool can predict the histological nature of residual masses. The unilateral modified template is a valid option for selected patients but the full bilateral dissection remains the standard but more morbid. The laparoscopic approach is being evaluated. The LDNRP PC is indicated in "high risk" situations especially after salvage chemotherapy.

CONCLUSION

The bilateral lymphadenectomy by laparotomy of any supracentimeter residual mass, 6 weeks after chemotherapy, for germ cell tumors of the testicle is a standard of care.

Sequential Versus Single High-Dose Chemotherapy in Patients With Relapsed or Refractory Germ Cell Tumors: Long-Term Results of a Prospective Randomized Trial

Purpose

To evaluate the long-term survival rates in patients with relapsed or refractory germ cell tumors (GCTs) after single or sequential high-dose chemotherapy (HDCT).

Patients and Methods

Between November 1999 and November 2004, 211 patients with relapsed or refractory GCT were randomly assigned to treatment with either one cycle of cisplatin 100 mg/m2, etoposide 375 mg/m2, and ifosfamide 6 g/m2 (VIP) plus three cycles of high-dose carboplatin 1,500 mg/m2 and etoposide 1,500 mg/m2 (CE, arm A) or three cycles of VIP plus one cycle of high-dose carboplatin 2,200 mg/m2, etoposide 1,800 mg/m2, and cyclophosphamide 6,400 mg/m2 (CEC, arm B) followed by autologous stem-cell reinfusion. Long-term progression-free survival (PFS) and overall survival (OS) 6 years after random assignment of the last patient were compared by using the log-rank test.

Results

Overall, 108 and 103 patients were randomly assigned to arms A and B, respectivelyl. The study was stopped prematurely because of excess treatment-related mortality in arm B (14%) compared with that in arm A (4%; P = .01). As of December 2010, nine (5%) of 211 patients were lost to follow-up; 94 (45%) of 211 are alive and 88 (94%) of 94 patients are progression free. Five-year PFS is 47% (95% CI, 37% to 56%) in arm A and 45% (95% CI, 35% to 55%) in arm B (hazard ratio [HR], 1.16; 95% CI, 0.79 to 1.70; P = .454). Five-year OS is 49% (95% CI, 40% to 59%) in arm A and 39% (95% CI, 30% to 49%) in arm B (HR, 1.42; 95% CI, 0.99 to 2.05; P = .057).

Conclusion

Patients with relapsed or refractory GCT achieve durable long-term survival after single as well as sequential HDCT. Fewer early deaths related to toxicity translated into superior long-term OS after sequential HDCT.

Treatment strategies and prognostic factors of patients with primary germ cell tumors in the mediastinum

OBJECTIVE

The aim of this study was to evaluate the clinical characteristics and survival outcomes of patients with primary mediastinal germ cell tumor (PMGCT) by identifying the prognostic factors and efficacies of different treatment modalities.

METHODS

Fifty-five patients with PMGCT who were treated consecutively at Cancer Center, Sun Yat-sen University, Guangzhou, from 1988 to 2010 were evaluated retrospectively.

RESULTS

Fifty-two men and 3 women with a median age of 25 years were identified, of whom 17 (30.9%) had pure seminomatous, 38 (69.1%) had nonseminomatous histology, 27 (49.1%) had tumor located at mediastinum, 20 (36.4%) had lung metastases and/or effusions, and 8 (14.5%) had distant metastases. Three treatments surgery, chemotherapy, and radiotherapy were performed in 11 (20%) patients, two treatments chemotherapy plus surgery or radiotherapy were performed in 25 (45.6%), and single treatment surgery or chemotherapy was performed in 17 (30.9%). The other two patients (3.6%) received no treatment. After a median follow-up time of 31.4 months, the 5-year survival rate was 52%. The median overall survival time was 87.9 months. Patients who received two treatments had the longest survival time of 118.3 months, P = 0.000. Those who had pure seminoma histology, whose tumor confined to the mediastinum and who achieved complete or partial remission at initial evaluation, who had complete resection and radiotherapy were considered to have better prognosis according to univariate analysis. On multivariate analysis, extension and response rate at initial evaluation were independently predictive of survival.

CONCLUSIONS

Primary mediastinal germ cell tumor is rare with a dominant frequency in young male patients. Chemotherapy combined with local therapy like surgery or radiotherapy is a reasonable treatment strategy recommended. Extension and initial remission rate are independent prognostic factors.

[High-dose chemotherapy and residual tumor resection in male germ cell tumors]

As a consequence of the unsatisfactory results of conventional dose salvage regimens, in particular for patients with poor prognostic features at the time of relapse or in patients with refractory disease, high-dose chemotherapy (HDCT) was introduced into clinical practice in the late 1980s. The combination of carboplatin and etoposide (CE) still remains the backbone of most high-dose regimens. Multiple modifications with more dose escalations or addition of further drugs have been explored, most often with increased toxicity. With improved expertise in supportive care and the use of peripheral blood stem cells, hematopoetic recovery has been significantly shortened and the initial high treatment-related mortality reduced from more than 10% to about 3%. Since the incorporation of HDCT, even patients with unfavorable prognostic features or patients with second or subsequent relapses can achieve long-term remission. Following HDCT residual tumor resection plays a major role in achieving these long-term results. The proportion of vital residual tumor after HDCT is much higher than in patients after conventional chemotherapy. The role of HDCT remains controversial particularly as a first-line treatment and less so in the first salvage setting. As these patients are rare HDCT and residual tumor resection should only be be provided by high-volume centers with sufficient expertise in performing these complex procedures.

A review of second-line chemotherapy and prognostic models for disseminated germ cell tumors

Despite an excellent prognosis even for patients with disseminated disease, about 20% to 30% of men with advanced germ cell tumors are refractory to first-line chemotherapy or experience disease recurrence after an initial remission with such treatment. Many of these are cured with conventional dose cisplatin/ifosfamide-based regimen or high-dose chemotherapy with stem cell rescue. Controversy exists regarding the optimal choice between these 2 second-line approaches, and available data for each is reviewed here. Clinical factors can help prognosticate patients, and recently an international effort developed a prognostic model for the second-line setting that can be universally applied in future studies.

Histological evidence for the existence of germ cell tumor cells showing embryonal carcinoma morphology but lacking OCT4 expression and cisplatin sensitivity

The biological basis for manifestation of chemotherapy resistance in metastatic testicular germ cell tumors (GCT) remains obscure and is of particular clinical interest. In nonseminomatous GCT (NSGCT) the pluripotent embryonal carcinoma (EC) cells are the precursors of the manifold differentiated structures but also drive the malignant growth. They are known to be hypersensitive towards DNA-damaging agents and to express the embryonal transcription factor OCT4. We recently characterized EC cells that lack OCT4 expression and show cisplatin resistance. In the present, immunohistochemical study we analyzed the composition of NSGCT with the focus on such OCT4-negative EC cells using a NSGCT xenograft model as well as patient-derived NSGCT samples. In the xenograft model, the cisplatin-sensitive cell line H12.1 gives rise to xenografts where EC structures are mainly composed of OCT4-positive cells, whereas xenografts from the resistant cell line 1411HP exclusively comprise OCT4-negative EC areas. We found that post-chemotherapy residual metastatic tumors of patients can be comprised of exclusively OCT4-negative EC, whereas the matched testicular primary tumor harbors OCT4-positive EC. Thorough histological analyses revealed a few examples of such OCT4-negative EC cells also in the testicular primary tumor as well as in xenografts from the cisplatin-sensitive NSGCT-cell line. For these cells we propose an identity as early extraembryonal progenitor cells directly derived from OCT4-expressing EC cells. This challenges the use of the term EC cell. The data also support our hypothesis that malignant growth of resistant NSGCT may be driven by this cell type.

The role of high-dose chemotherapy in the treatment of testicular cancer

Testicular cancer is a highly curable neoplasm, even in the case of extragonadal disease. Nevertheless, patients with adverse prognostic features or relapsing after first-line cisplatin-based chemotherapy have a worse prognosis with a death rate greater than 50%. High-dose chemotherapy (HDC) has long been used in this group of patients. The introduction of stem cells, instead of bone marrow, as the source of hemopoietic cells and the use of leukocyte growth factors have substantially reduced the mortality and morbidity of this procedure although the role of HDC is not well defined. This review summarizes the available data, focusing on published randomized studies. The problems associated with the design of these studies and the interpretation of data are discussed. Currently this HDC approach is mainly used in patients who relapse after first-line chemotherapy. Nevertheless, selection of patients likely to benefit from this treatment remains an issue of intense clinical research.

Retroperitoneal lymph node dissection after chemotherapy

Retroperitoneal lymph node dissection after chemotherapy (PC-RPLND) plays a crucial role in managing patients with advanced germ cell tumours (GCTs). In the last few years improvements in radiographic staging, a better understanding of the role of serum tumour markers, and the introduction of cisplatin-based chemotherapy have all contributed to this surgical therapy. PC-RPLND is necessary when residual radiographic abnormalities are present after chemotherapy. The need for a PC-RPLND in the face of normal findings from computed tomography (CT) is controversial. CT criteria alone are not sufficiently reliable to distinguish viable tumour or teratoma from necrosis. No combination of variables can predict negative retroperitoneal pathology with sufficient accuracy after induction chemotherapy. Unresected teratoma or viable GCT are at least partly chemorefractory and, if untreated, will progress. So completeness of resection is an independent and consistent predictive variable of clinical outcome. In PC-RPLND surgical margins should not be compromised in an attempt to preserve ejaculation, although nerve-sparing dissections are possible in patients with marker normalization after chemotherapy and necrotic tissue in frozen-section histology. In these patients nerve-sparing techniques and the reduction of surgical field to the left- or right-sided template are applicable to preserve antegrade ejaculation and consecutive fertility. The size and location of residual masses coupled with the retroperitoneal desmoplastic reaction make PC-RPLND a technically demanding procedure that should be performed by experienced surgeons in dedicated referral centres.

[Salvage treatment in germ cell tumors : high-dose chemotherapy and the impact of prognostic factors]

The majority of patients with germ cell tumors who fail first-line treatment will still be cured. Patients without first-line chemotherapy who fail surveillance, radiotherapy, or surgery will be managed according to the treatment algorithms of their primary metastatic disease. These patients usually receive three to four cycles of cisplatin, etoposide, and bleomycin.Salvage treatment of patients who relapse after first-line chemotherapy is more complex and requires an experienced and highly specialized team. Two distinct treatment strategies can be pursued: four cycles of conventional-dose chemotherapy with cisplatin, ifosfamide, and either etoposide, paclitaxel, or vinblastine; or early intensification of first-salvage treatment using sequential high-dose chemotherapy. Salvage surgery is frequently required after completion of salvage chemotherapy to completely resect all radiologic residual manifestations. Patients with brain metastases should receive upfront whole brain radiation concurrent with salvage chemotherapy. Patients with late relapses more than 2 years after first-line treatment should receive immediate salvage surgery whenever this is technically feasible.

Salvage chemotherapy after failure of first-line chemotherapy in patients with metastatic testicular cancer

PURPOSE OF REVIEW

Because of the small number of relapsed patients, their prognostic variability and the complexity of second-line therapy, randomized studies are largely lacking and treatment recommendations for patients with relapse after first-line chemotherapy are derived from retrospective series or phase II studies. This review summarizes the existing evidence including several recently published larger studies on the use of high-dose chemotherapy in these patients.

RECENT FINDINGS

Patients with unfavorable features such as incomplete response to first-line therapy, cisplatin refractoriness, multiple relapses or advanced stage at initial diagnosis have been shown to benefit from salvage high-dose chemotherapy with autologous stem cell support. Long-term survival rates of up to 60% have been reported after salvage high-dose chemotherapy for these patients. The treatment for patients relapsing after complete remission to first-line therapy, cisplatin-sensitive disease and gonadal primary remains controversial. Excellent long-term event-free survival rates of up to 80% have been reported after both conventional and high-dose chemotherapy. Surgery remains an important part of any salvage strategy.

SUMMARY

The prognosis of patients relapsing after first-line cisplatin-based chemotherapy has improved with multimodality therapy including conventional and high-dose chemotherapy, surgery and radiation. The treatment of these patients requires a close cooperation of experienced medical oncologists, urologists and radiation oncologists.

Postchemotherapy residual masses in germ cell tumor patients: our experience

BACKGROUND

The nature of post-chemotherapy tumor residuals can be determined only by excision and histological examination, but at present no consensus has been reached as to whether all patients with residual masses should undergo adjunctive surgery.

PATIENTS AND METHODS

Between August 1991 and September 2004, 120 patients with metastatic germ cell tumors were diagnosed at our hospital and 35 of these patients (30%) underwent adjunctive surgery after cisplatin-based chemotherapy. If serum tumor markers were still raised salvage chemotherapy was administered.

RESULTS

At the time of surgical intervention 30 patients (86%) had a partial remission with normal markers. Necrosis, differentiated teratoma and undifferentiated tumor were found in nine (30%), 19 (63%) and two (7%) of all patients. Five patients (14%) underwent postchemotherapy resections after second-line cisplatin-based combination chemotherapy. Four of the 35 patients died as a result of their malignant germ cell tumor. The median observation time after the initial diagnosis was 99 months (range 15-172 months).

CONCLUSIONS

Secondary resection of residual masses after first or second-line chemotherapy is still an essential part of the treatment of metastatic testicular cancer. Resection of mature teratoma or viable cancer adds to long-term event-free and overall survival in these patients.

[The approach to tumors of the retrocrural mediastinum]

Retrocrural tumors of the lower posterior mediastinum are rare. Most tumors in this region involve lymphatic metastasis of germ cell tumors. Formerly these tumors were resected through a combined thoracoabdominal approach, with division of the diaphragm and effecting an at least partial phrenic paresis. The ventral approach via bilateral subcostal incision with cranial extension avoids this problem and allows a bilateral access to the retrocrural space. From November 1999 to December 2005, using this approach we operated on 12 patients with residual germ cell tumors after chemotherapy. In all cases radical resection was obtained. Intra- or postoperative complications did not occur. All patients are still alive and free of disease.

Topoisomerase II Alpha Expression in Testicular Germ Cell Tumors

OBJECTIVES

Inhibitors of topoisomerase II alpha (TopoIIalpha), an enzyme with a crucial role in DNA maintenance, are included in the chemotherapy protocols for testicular germ cell tumors (GCTs). Despite the success of current chemotherapy regimens, a significant number of patients experience relapse. We analyzed TopoIIalpha expression in primary and metastatic testicular GCTs because this enzyme is a target for some antineoplastic agents.

METHODS

Primary GCT specimens from 109 patients, including 57 seminomas and 52 mixed GCTs (41 embryonal carcinomas, 23 yolk sac tumors, 19 seminomas, 8 choriocarcinomas, 17 teratomas with immature elements, and 16 teratomas with mature elements), were obtained from our archives. The metastatic lesions from 11 of the patients with mixed GCTs included seven teratomas with mature components, five embryonal carcinomas, one yolk sac tumor, one choriocarcinoma, and one teratoma with immature components. Representative sections were subjected to immunohistochemistry with monoclonal antibody against TopoIIalpha, and the nuclear staining findings were evaluated.

RESULTS

Most embryonal carcinoma (100%), yolk sac tumor (95%), seminoma (88%), and choriocarcinoma (62%) components of the GCTs were TopoIIalpha immunoreactive. None of the teratoma specimens with mature elements expressed TopoIIalpha.

CONCLUSIONS

The results of our study have shown that TopoIIalpha is expressed in most seminomas, embryonal carcinomas, yolk sac tumors, and choriocarcinomas, suggesting a possible mechanism of sensitivity of these components to TopoIIalpha inhibitors. Teratomas with mature and immature elements expressed low levels of TopoIIalpha, which might contribute to their chemoresistance. These findings imply that the variable chemoresponsiveness of testicular GCTs could have an underlying molecular basis.