Germ Cell Cancer Collaborative Group Research Articles

PE078 Robotic assisted retroperitoneal lymph node dissection: Defining selection parameters: A B-SAFE approach from the Anglican germ cell cancer collaborative group

PE078 Robotic assisted retroperitoneal lymph node dissection: Defining selection parameters: A B-SAFE approach from the Anglican germ cell cancer collaborative group

704P Characteristics and palliative management of patients with cisplatin-refractory germ cell tumours: A Global Germ Cell Cancer Collaborative Group (G3) retrospective registry study

704P Characteristics and palliative management of patients with cisplatin-refractory germ cell tumours: A Global Germ Cell Cancer Collaborative Group (G3) retrospective registry study

Association between glutathione S-transferases M1 expression and treatment outcome in germ cell tumor patients.

Cisplatin-based chemotherapy is the mainstay in the treatment of germ cell tumors (GCTs). Glutathione S-transferases (GSTs) are polymorphic enzymes that catalyze the glutathione conjugation of alkylating agents, platinum compounds, and free radicals formed by chemotherapy and are thus implicated in developing treatment resistance. This study aimed to assess the expression level of GST mu 1 (GSTM1) and its association with treatment outcomes in patients with GCT. This translational study included tumor specimens from 207 patients with newly diagnosed GCTs, as well as cisplatin-sensitive GCT cell line xenografts and their resistant variants for all histological variants of GCTs. GSTM1 expression was detected by reverse transcription-quantitative PCR and immunohistochemistry using monoclonal antibodies, scored by the multiplicative quickscore (QS) method. GSTM1 expression was correlated with patient/tumor characteristics and treatment outcomes. The highest GSTM1 expression was observed in seminoma, followed by choriocarcinoma, embryonal carcinoma, and yolk sac tumor, while the lowest was observed in teratoma (p<0.0001). There was no association between GSTM1 expression in tumor tissue and patient/tumor characteristics. The low GSTM1 expression was associated with significantly better relapse-free survival compared with high GSTM1 (HR=0.50, 95% CI 0.23-1.09, p=0.03) but not overall survival (HR=0.61, 95% CI 0.24-1.54, p=0.22). Multivariate analysis showed that the prognostic value of GSTM1 was independent of the International Germ Cell Cancer Collaborative Group (IGCCCG) score. These data revealed the prognostic value of GSTM1 in GCTs, with a high GSTM1 expression associated with worse outcomes, suggesting that GSTM1 could be responsible, in part, for treatment resistance in GCTs.

Predicting outcomes in malignant ovarian germ cell tumors using the modified International Germ Cell Cancer Collaborative Group classification system

ObjectivesThe aim of our study was to evaluate the feasibility of the modified International Germ Cell Cancer Collaborative Group risk classification system in Chinese female patients with malignant ovarian germ...

Regional Differences in Stage III Nonseminoma Germ Cell Tumor Patients Across SEER Registries

PurposeWe investigated regional differences in patients with stage III nonseminoma germ cell tumor (NSGCT). Specifically, we investigated differences in baseline patient, tumor characteristics and treatment characteristics, as well as cancer-specific mortality (CSM) across different regions of the United States. MethodsUsing the Surveillance, Epidemiology, and End Results (SEER) database (2004-2018), patient (age, race/ethnicity), tumor (International Germ Cell Cancer Collaborative Group [IGCCCG] prognostic groups) and treatment (systemic therapy and retroperitoneal lymph dissection [RPLND] status) characteristics were tabulated for stage III NSGCT patients, according to 12 SEER registries representing different geographic regions. Multinomial regression models and multivariable Cox regression models testing for cancer-specific mortality (CSM) were used. ResultsIn 3,174 stage III NSGCT patients, registry-specific patient counts ranged from 51 (1.5%) to 1630 (51.3%). Differences across registries existed for age (12%-31% for age 40+), race/ethnicity (5%-73% for others than non-Hispanic whites), IGCCCG prognostic groups (24%-43% vs. 14-24% vs. 3%-20%, in respectively poor vs. intermediate vs. good prognosis), systemic therapy (87%-96%) and RPLND status (12%-35%). After adjustment, clinically meaningful inter-registry differences remained for systemic therapy (84%-97%) and RPLND (11%-32%). Unadjusted 5-year CSM rates ranged from 7.1% to 23.3%. Finally in multivariable analyses addressing CSM, 2 registries exhibited more favorable outcomes than SEER registry of reference (SEER Registry 12): SEER Registry 4 (Hazard Ratio (HR): 0.36) and SEER Registry 9 (HR: 0.64; both P = .004). ConclusionWe identified important regional differences in patient, tumor and treatment characteristics, as well as CSM which may be indicative of regional differences in quality of care or expertise in stage III NGSCT management.

Brain metastases in testicular cancer: A single-institution experience in Guatemala.

e17019 Background: Brain metastases secondary to germ cell tumors develop in 2 to 3% of patients, in addition to implying a poor prognosis, its incidence in advanced stages increases to 10-15%. The European Urology Association guidelines recommend performing imaging studies using MRI or brain contrasted tomography to rule out metastases in patients with multiple lung metastases, or high beta subunit of human Chorionic Gonadotropin (β-HCG) values, or those in the poor-prognosis International Germ Cell Cancer Collaborative Group (IGCCCG) risk group. Methods: Retrospective descriptive study in patients with brain metastasis for testicular cancer at the Liga Nacional Contra el Cáncer – INCAN Guatemala, from 2018 to 2022. From medical records, we obtained: demographic, clinico-pathological and treatment data. Median was calculated for age, while frequencies and percentages were computed for the categorical variables. Results: Of the 238 patients diagnosed with testicular cancer, 22% (52) presented a β-HCG above 5,000 IU/L, of which 27% (14) developed brain metastases with a mean age of 28 years. Corresponding to 6% of the total cases studied. Among histological subtypes the most common was choriocarcinoma (43%), follow by mixed germ cell cancer (36%), embrionary carcinoma (14%) and classic seminoma (7%). All of the patients belonged to prognostic group S2. Most patients reported first symptom was headache (42%), followed by seizures (21%), cognitive dysfunction (15%), motor dysfunction (10%) and others (12%). Management of these patients included: orchidectomy in all of them, 57% (8) of patients died, of them 50% (4) of patients died before any other therapy. The rest of them, received chemotherapy and none received radiotherapy or surgery for the brain metastases. Conclusions: The presence of brain metastases in testicular cancer increases the mortality produced by the disease as previously reported in other regions of the world, reason why the early suspicion of it, should prompt the evaluation with a brain MRI or computed tomography.

Prognostic factors and survival in men with testicular germ cell tumors (GCT).

e17018 Background: The International Germ Cell Cancer Collaborative Group (IGCCCG) has recently discovered new factors for GCT in 2021. We have estimated previously known and new prognostic factors in patients with nonseminomatous germ cell tumors (NSGCT) and seminoma treated at N.N. Petrov NMRC of Oncology. Methods: From 2011 to 2021, the study included 273 adult patients receiving standard cisplatin-based chemotherapy. Primary endpoints were progression-free survival (PFS) and overall survival (OS). Survival was estimated using the Kaplan-Meier and Cox methods. Results: 5-year OS rates were 94%, 85% and 70% in the good, intermediate, and poor prognosis groups, respectively for NSGCT and 95% and 86% in good and intermediate prognosis groups for seminoma (p&lt;0.05). 5-year PFS rates were 74%, 51%, and 41% for NSGCT and 76% and 62% for seminoma of the above-mentioned prognostic groups, respectively (p&lt;0,05). Presence of pulmonary metastases (mts) (HR 0.177; 95% CI: 0.051-0.612; p=0.006), non-pulmonary visceral mts (HR 4.636; 95% CI: 1.710-12.570; p= 0.003), elevated LDH of ≥ 2.5 limit of normal (≥ 2.5 × ULN) (HR 4.107; 95% CI: 1.614-10.451; p= 0.003), treatment in high-experienced clinic (HR 0.37; 95% CI: 0.147-0.919; p=0.0032), and non-compliance with guidelines (HR 3.731; 95% CI: 1.456-9.564; p= 0.006) was significantly associated with OS in NSGCT. The presence of pulmonary mts (HR 0.15; 95% CI: 0.024-0.877; p=0.035) and elevated LDH ≥ 2.5 × ULN (HR 0.109; 95% CI: 0.015-0.775; p=0.027) were the only factors associated with poor OS in seminoma. The presence of pulmonary mts (HR 0.446; 95% CI: 0.247-0,804; p=0.007), non-pulmonary visceral mts (HR 2.668; 95% CI: 1.390-5,120; p=0.003) and treatment in high-experienced clinic (HR 1.852; 95% CI: 1.059-3.238; p=0.031), were significantly associated with inferior PFS in NSGCT. Pulmonary mts were the only significant (HR 0.301; 95% CI: 0.100-0.910; p=0.033) factor in the multivariate OS analysis for all testicular GCT. The absence of non-pulmonary visceral mts (HR 0.522: 95% CI: 0.265-0.963; p=0.019) and compliance with guidelines (HR 0.565; 95% CI: 0.309-0.910; p=0.038) were significant factors in the multivariate PFS model for all patients with testicular GCT. Conclusions: The original IGCCCG classification remains the reference for treatment decisions for testicular GCT in daily practice. Non-compliance with guidelines and treatment in high-experienced clinic could become additional poor prognostic factors.

High-Dose Chemotherapy and Autologous Stem Cell Transplantation for Salvage Therapy of Relapsed/Refractory Germ Cell Tumors: A Single-Center Experience

Introduction: The optimal management of relapsed/refractory germ cell tumors remains unsettled. In this study, we aimed to evaluate the efficacy of high-dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT) as salvage therapy in patients who progressed after at least one line of cisplatin-based chemotherapy. Methods: We retrospectively reported the results of 133 patients who underwent HDCT and ASCT as salvage therapy from 2016 to 2021. Patients received 3 cycles of paclitaxel, ifosfomide and cisplatin (TIP) regimen as induction and 1 cycle of carboplatin 700 mg/m2 on days 1–3 plus etoposide 750 mg/m2 on days 1–3, followed by ASCT. Demographic and clinicopathological features of patients, the International Germ Cell Cancer Collaborative Group (IGCCCG) risk group at diagnosis, serum alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (HCG) levels before HDCT, treatment-related complications and survival outcomes were recorded. Results: The median age of the patients was 31 (range 18–62). The median follow-up was 31.1 months (95% CI, 28.9–33.3 months). During the median follow-up period, 74 of the 133 patients were still alive, and 63 of these were in complete remission. The median progression-free survival (PFS) was 25.8 months (95% CI, 8.1–43.4 months). The 2-year PFS rate was 50.3% and the 2-year overall survival (OS) rate was 60.8%. Variables that remained statistically significant in multivariable analysis and were associated with poor prognosis were mediastinal primary tumor location, presence of brain metastases, and higher AFP and HCG levels at baseline. Conclusion: One course of HDCT and ASCT after induction with TIP is an effective and feasible treatment option for salvage treatment of relapsed/refractory germ cell tumors, with cure rates of up to 60%.

Survival outcomes of postchemotherapy retroperitoneal lymph node dissection for nonseminomatous germ cell tumors: A retrospective cohort study from a single tertiary center in South India.

Chemotherapy, postchemotherapy retroperitoneal lymph node dissection (pcRPLND), and metastasectomy remain the standard of care for the management of advanced nonseminomatous germ cell tumor (NSGCT). We retrospectively studied 73 patients who had pcRPLND at a single tertiary-care center (2003-2022). Surgical and clinicopathological features and oncological outcomes are presented. The mean age was 28.27 years (15-48). Three-fourths had Stage III disease at diagnosis. International Germ Cell Cancer Collaborative Group risk stratification was 54.54% and 21.21% in intermediate risk, and poor risk, respectively. Sixty-two patients had Standard, 7 had Salvage and 4 underwent Desperation pcRPLND. Eleven patients (15.06%) required adjunctive procedures. Thirteen patients (17.8%) had ≥ class 3 Clavien-Dindo complications and postoperative mortality occurred in 5 (6.8%) patients. The histopathologies (HPE) of the pcRPLNDs were necrosis, teratoma, and viable tumor in 39.7%, 45.2%, and 15.1%, respectively. Seven patients underwent metastasectomy. An 85% size reduction in the size of RPLN predicted necrosis. There was 71.4% concordance between pcRPLND and metastasectomy HPEs. The median follow-up was 26.72 months (inter-quartile range - 13.25-47.84). The 2-year recurrence-free survival (RFS) rate was 93% (95% confidence interval [CI]-83%-97%) and the overall survival (OS) rate was 90% (95% CI-80%-95%). This is the largest series of pcRPLND for NSGCT in India to our knowledge. Although most of the cohort belonged to stage III, an RFS and OS rate of >90% at 2 years was achieved. We believe that successful management of postchemotherapy residual masses in NSGCT is contingent on the availability of multidisciplinary expertise and is therefore best done at tertiary-care referral centers.

Impact of teratoma on survival probabilities of patients with metastatic non-seminomatous germ cell cancer: Results from the IGCCCG Update Consortium

AimsTo resolve the ongoing controversy surrounding the impact of teratoma (TER) in the primary among patients with metastatic testicular non-seminomatous germ-cell tumours (NSGCT). Patients and methodsUsing the International Germ Cell Cancer Collaborative Group (IGCCCG) Update Consortium database, we compared the survival probabilities of patients with metastatic testicular GCT with TER (TER) or without TER (NTER) in their primaries corrected for known prognostic factors. Progression-free survival (5y-PFS) and overall survival at 5 years (5y-OS) were estimated by the Kaplan-Meier method. ResultsAmong 6792 patients with metastatic testicular NSGCT, 3224 (47%) had TER in their primary, and 3568 (53%) did not. In the IGCCCG good prognosis group, the 5y-PFS was 87.8% in TER versus 92.0% in NTER patients (p = 0.0001), the respective 5y-OS were 94.5% versus 96.5% (p = 0.0032). The corresponding figures in the intermediate prognosis group were 5y-PFS 76.9% versus 81.6% (p = 0.0432) in TER and NTER and 5y-OS 90.4% versus 90.9% (p = 0.8514), respectively. In the poor prognosis group, there was no difference, neither in 5y-PFS [54.3% in TER patients versus 55.4% (p = 0.7472) in NTER], nor in 5y-OS [69.4% versus 67.7% (p = 0.3841)]. NSGCT patients with TER had more residual masses (65.3% versus 51.7%, p < 0.0001), and therefore received post-chemotherapy surgery more frequently than NTER patients (46.8% versus 32.0%, p < 0.0001). ConclusionTeratoma in the primary tumour of patients with metastatic NSGCT negatively impacts on survival in the good and intermediate, but not in the poor IGCCCG prognostic groups.

A population-based validation of the IGCCCG Update Consortium for survival in metastatic non-seminoma testis cancer.

In 2021, the International Germ Cell Cancer Collaborative Group (IGCCCG) Update Consortium reported improved overall survival (OS) rates in a modern cohort of metastatic non-seminoma testis cancer patients within each of the IGCCCG prognosis groups (96% in good vs. 89% in intermediate vs. 67% in poor), compared to the previous IGCCCG publication (92% in good vs. 80% in intermediate vs. 48% in poor). We hypothesized that a similar survival improvement may apply to a contemporary North-American population-based cohort of non-seminoma testis cancer patients. The Surveillance, Epidemiology, and End Results (SEER) database (2010-2018) was used. Kaplan-Meier plots and multivariable Cox regression models tested the effect of IGCCCG prognosis groups on overall mortality (OM). Of 1672 surgically treated metastatic non-seminoma patients, 778 (47%) exhibited good vs. 251 (15%) intermediate vs. 643 (38%) poor prognosis. In the overall cohort, five-year OS rate was 94% for good prognosis vs. 87% for intermediate prognosis vs. 65% for poor prognosis. In multivariable Cox regression models predicting OM, intermediate (Hazard ratio [HR] 2.4, 95% confidence interval [CI] 1.4-3.9, P<0.001) and poor prognosis group (HR 6.6, 95% CI 1.0-1.0, P<0.001) were independent predictors of higher OM, relative to good prognosis group. The survival improvement reported by the IGCCCG Update Consortium is also operational in non-seminoma testis cancer patients within the most contemporary SEER database. This observation indicates that the survival improvement is not only applicable to centres of excellence, but also applies to other institutions at large.

Current outstanding challenges in germ cell tumors.

Despite the remarkable advances in the treatment of germ cell tumors (GCT), several challenges remain. This review aims to highlight some of these challenges and provide guidance on how to navigate through them. Patients with International Germ Cell Cancer Collaborative Group poor risk disease have worse prognosis and investigating novel therapeutic interventions are warranted in this population. Patients with brain metastases require a multidisciplinary approach by a group of clinicians experienced in the management of germ cell tumors. Patients with platinum refractory disease have poor prognosis and development of novel treatment options is urgently needed. Conventional tumor markers including alpha fetoprotein and human chorionic gonadotropin remain standard. Development of novel biomarkers to detect minimal residual disease or teratoma is needed. Management of patients with GCT requires a multidisciplinary approach. Patients should preferably be evaluated at tertiary care centers with expertise in the management of this disease.

Treatment efficacy implications of incorrect utilization of tumor marker levels and risk group assignment according to the International Germ Cell Consensus Classification (IGCCCG).

505 Background: Patients withmetastatic germ cell tumors of the testis (GCTs) are risk-stratified according to the International Germ Cell Cancer Collaborative Group (IGCCCG) classification system for further therapy decision. This risk classification is based on metastatic load as well as tumor marker levels of AFP, HCG and LDH assessed pre-chemotherapy after orchiectomy treatment. An incorrect classification is possible when pre-orchiectomy marker levels are used, possibly resulting in over- or undertreatment of patients. Therefore, the aim was to investigate the potential frequency and clinical relevance of incorrect risk stratification using pre-orchiectomy tumor marker levels. Methods: Patients with metastasized nonseminomatous GCT (NSGCT)were included in a multicenter registry analysis which was conducted by investigators of the German Testicular Cancer Study Group (GTCSG). Based on the marker levels at different timepoints, IGCCCG risk groups were calculated. The agreement was tested using Cohen’s kappa. Results: A total of698 of 1983 (35%) patients were diagnosed with metastatic NSGCTs, and 546 (78%) had sufficient data for 232 follow-up data points. By using pre-orchiectomy tumor marker levels, 111 patients (20%) would have been incorrectly classified. Seventy-five patients (14%) were classified into a higher risk category, and 36 patients (6%) were classified into a lower risk category. Cohen’s kappa was 0.69 (p &lt; 0.001), showing a strong agreement between the use of both marker timepoints. The treatment of misclassified patients would have resulted in an overtreatment of 75 patients or undertreatment of 36 patients. Conclusions: The use of pre-orchiectomy tumor marker levels may lead to an incorrect risk classification and might subsequently lead to under- or overtreatment of patients. Part of these data were published in: Majewski et al. Cancer Med. 2023.

Clinico-epidemiological Profile and Outcome of Testicular Germ Cell Tumors: A Retrospective Study from a Tertiary Cancer Centre of North-East India

Introduction: Testicular Germ Cell Tumor (GCT) is a disease of young adults and is also highly curable. But in India, most of the patients present in an advanced stage and succumb to the disease as compared to the Western nations where patients present at an earlier stage and are mostly cured. Also, there is a scarcity of literature on testicular GCT from the Indian subcontinent. We present our experience from the Tata Memorial Centre of North-east India. Methods: This retrospective study was conducted at Tata Memorial Centre - BBCI, Guwahati for the period of 5 years from January 2018 to December 2022. The study focused on epidemiology, clinical presentation, and treatment outcomes. Results: Seventy-two cases of testicular GCTs were studied (28 cases were seminoma, and 44 were non-seminoma). Most common presenting stage was stage I in seminoma (53.6%), and stage III (77.2%) in non-seminoma. As per the International Germ Cell Cancer Collaborative Group (IGCCCG) classification, 25%, 35%, and 40% of patients were good-risk, intermediate-risk, and poor-risk in non-seminoma. In patients with seminoma, 54% and 46% were in good and intermediate-risk, respectively. Seventy-two percent and 21% had achieved a radiologic complete response (CR) and partial response (PR) with conventional chemotherapy in patients with seminoma. Radiologic CR and PR rates were 20% and 61% among non-seminoma patients. The median recurrence-free survival (RFS) was 43 months. RFS was better in seminoma versus non-seminoma, stage I versus stage III, and good-risk versus high-risk group. Conclusion: Most of our patients presented with an advanced stage of the disease and a high nodal burden. In patients with non-seminoma GCT, the best response to conventional chemotherapy was a partial response. The use of an alternative chemotherapy regimen to improve outcomes for such patients can be further explored.

Testicular cancer: new developments, molecular pathology, and current research keynote.

Germ cell tumors (GCTs) are now considered acurable cancer, with a> 95% cure rate in all patients and about 90% cure rate in patients with metastatic disease. The success of physicians in curing the disease is underpinned by multidisciplinary advances. Of relevance in this regard are the nowadays-applied homogeneous terminology based on pathologically better characterized testicular neoplasms and the development of awidely used risk stratification model for metastatic disease introduced by the International Germ Cell Cancer Collaborative Group in 1997 and updated in 2021. Non-pulmonary visceral metastases, high levels of the serum tumor markers alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG), and primary mediastinal non-seminoma are currently identified as determinants of poor prognosis. In addition, the presence of distinct microRNA profiles between seminomas and non-seminoma GCTs has opened up important perspectives in terms of noninvasive biomarkers that can be used in diagnosis and treatment monitoring.

Prechemotherapy Not Preorchiectomy Serum Tumor Markers Accurately Identify International Germ Cell Cancer Collaborative Group Prognostic Groups in Nonseminoma.

For men with testicular cancer, levels of tumor markers in their blood are used when making decisions on chemotherapy intensity. Use of test results for samples taken before removal of the cancer-bearing testicle instead of immediately before chemotherapy can lead to inadequate treatment recommendations.

Risk analysis of subsequent therapies after first-line chemotherapy in advanced testicular cancer patients.

Testicular cancer is the most common solid cancer diagnosed among young men. Despite good response to chemotherapy and a high survival rate, subsequent salvage therapies may still be required for some patients in advanced stages. The predictive and prognostic markers are crucial unmet needs. We retrospectively analyzed advanced testicular cancer patients who had received first-line chemotherapy between January 2002 and December 2020. The associations between baseline characteristics and clinical outcomes were evaluated. Of the 68 included patients, the median age was 29 years. Among them, 40 patients received only first-line chemotherapy while the remaining 28 received subsequent chemotherapy or surgeries. Data reveal that 82.5% (33/40) of the patients in the chemotherapy-only group were recorded as a good prognostic risk using the International Germ Cell Cancer Collaborative Group classification when compared with 35.7% (10/28) in the second-line therapy group. In the chemotherapy-only group, 53.8% of patients were presented with lymph node metastasis compared with 78.6% in the second-line therapy group ( p = 0.068). Fifteen percent of patients (6/40) were recorded as S stage 2-3 in the chemotherapy-only group, whereas 85.2% (23/28) were recorded as such in the second-line therapy group ( p < 0.001). The 5-year overall survival estimation was 92.9% in the chemotherapy-only group and 77.3% in the second-line therapy group. Univariate analysis for overall survival revealed that those patients at the S 2-3 stage and those receiving second-line therapies showed a trend of having an increased death risk (hazard ratio [HR] = 8.26, 95% confidence interval (CI), 0.99-68.67, p = 0.051; HR = 7.76, 95% CI, 0.93-64.99, p = 0.059, respectively). The S 2-3 stage was also independently associated with the risk of subsequent therapy (HR = 33.13; 95% CI, 2.55-430.64, p = 0.007). Our real-world data show the predictive role of serum tumor marker stage 2-3 to be associated with any subsequent therapies after first-line chemotherapy. This can facilitate clinical decision making during the testicular cancer treatment process.

Patterns of Relapse in Australian Patients With Clinical Stage 1 Testicular Cancer: Utility of the Australian and New Zealand Urogenital and Prostate Cancer Trials Group Surveillance Recommendations.

International guidelines advocate for active surveillance as the preferred treatment strategy for patients with stage 1 testicular cancer after orchidectomy although a personalized discussion is required. We conducted an analysis of individuals registered in iTestis, Australia's testicular cancer registry, to describe the patterns of relapse and outcomes of patients treated in Australia where the Australian and New Zealand Urogenital and Prostate Cancer Trials Group Surveillance Recommendations are widely adopted. A total of 650 individuals diagnosed between 2000 and 2020 were included, 63% (411 of 650) seminoma and 37% (239 of 650) nonseminoma. The median age was 34 years (range 14-74). 26% (106 of 411) with seminoma and 15% (36 of 239) nonseminoma received adjuvant chemotherapy. After a median follow-up of 43 months (range 0-267) postorchidectomy, relapse occurred in 10% (43 of 411) of seminoma and 18% (43 of 239) of nonseminoma. The two-year relapse-free survival was 92% (95% CI, 89 to 95) and 82% (95% CI, 78 to 87) in seminoma and nonseminoma, respectively. All relapses (86 of 86) were detected at a routine surveillance visit; 98% (85 of 86) were asymptomatic and detected solely through imaging (62 of 86, 72%), tumor markers (6 of 86, 7%), or a combination (17 of 86, 20%). The most common relapse site was isolated retroperitoneal lymphadenopathy (53 of 86, 62%). No nonpulmonary visceral metastases occurred. At relapse, 98% (84 of 86) had International Germ Cell Cancer Collaborative Group (IGCCCG) good prognosis; 2 of 86 intermediate prognosis (both nonseminoma). No deaths occurred. In our cohort of stage 1 testicular cancer, where national surveillance recommendations have been widely adopted, recurrences were detected at routine surveillance visits and, almost exclusively, asymptomatic with IGCCCG good-prognosis disease. This provides reassurance that active surveillance is safe.

MP50-06 SURVIVAL OF TESTICULAR PURE TERATOMA VS. MIXED GERM CELL TUMOR PATIENTS ACROSS ALL STAGES

MP50-06 SURVIVAL OF TESTICULAR PURE TERATOMA VS. MIXED GERM CELL TUMOR PATIENTS ACROSS ALL STAGES

Treatment de-escalation for stage II seminoma.

International Germ Cell Cancer Collaborative Group good-risk metastatic seminoma has cure rates of >95%. Within this risk group, patients with stage II disease exhibit the best oncological outcomes with the standard-of-care treatment strategies of radiotherapy or combination chemotherapy. However, these treatments can be associated with substantial early and late toxic effects. Therapy de-escalation aims to reduce treatment morbidity whilst preserving oncological outcomes. The evidence supporting such approaches is largely from non-randomized institutional data, and therefore this strategy is not recognized as standard of care. Current de-escalation approaches for stage II seminoma include single-agent chemotherapy, radiotherapy and surgery based on early data from clinical studies. Increased recognition of emerging data on treatment modification to reduce morbidity whilst maintaining cure rates and consideration of therapy de-escalation could improve patient survivorship outcomes.