Retroperitoneal Lymph Node Dissection in Patients with Stage II Seminomatous Germ Cell Tumour.

Treatment de-escalation strategies in patients with seminoma with retroperitoneal metastases are being investigated in ongoing clinical trials. Primary retroperitoneal lymph node dissection conducted by expert surgeons may avoid any cytotoxic treatment and related long-term side effects in ≥70% of patients with clinical stage IIA/B seminoma.

Primary retroperitoneal lymph node dissection for metastatic non-seminomatous germ cell tumours: outcomes and adjuvant chemotherapy.

OBJECTIVES: To compare the outcomes and treatment burden of primary retroperitoneal lymph node dissection (pRPLND) alone versus pRPLND + adjuvant chemotherapy (AC) in patients with pathological stage II (PSII) non-seminomatous germ cell tumours (NSGCT). PATIENTS AND METHODS: Retrospective review of the Princess Margaret Cancer Center eTestes cancer database identified patients with PSII NSGCT after pRPLND between 1995 and 2020. The primary outcome was relapse-free survival (RFS). Secondary outcomes included disease-specific survival (DSS), burden of relapse treatment, and factors associated with relapse. RESULTS: A total of 109 PSII patients were included in the study. There were 96 patients treated with pRPLND alone and 13 treated with pRPLND + AC. The median follow-up was 61 months. The 5-year RFS was 72% for the pRPLND-only group vs 92% for the pRPLND + AC group (hazard ratio [HR] 4.372, 95% confidence interval [CI] 0.59-32.36; P = 0.11). Within the pRPLND-only group the 5-year RFS differed by pN stage (pN1 = 94% vs pN2/N3 = 67%, P = 0.03). Despite a higher relapse rate within the pRPLND-only group, the DSS was similar at 5 years (98% pRPLND only vs 100% pRPLND + AC, P = 0.48). Only 24 (25%) of the patients in the pRPLND-only group required any subsequent chemotherapy. Despite achieving similar survival, the cumulative post-RPLND treatment burden was less for the pRPLND-only group than the pRPLND+AC group overall (average 1.23 vs 2.46 cycles of chemotherapy per patient in group). CONCLUSION: The majority of patients with PSII NSGCT treated with pRPLND alone do not experience a recurrence or require chemotherapy. Despite a lower relapse risk when AC is given, no difference in survival was seen but higher chemotherapy burden was entertained. AC may constitute overtreatment for most patients with PSII NSGCT treated with pRPLND.

Discordance of retroperitoneal and thoracic histologic findings in patients with metastatic germ cell tumors at postchemotherapy residual tumor resection.

INTRODUCTION AND OBJECTIVES: Postchemotherapy residual tumor resection (PC-RTR) is an important part of the multimodal treatment for patients with metastatic germ cell tumors. Simultaneous retroperitoneal and thoracic metastases often require consecutive surgical procedures. This study analyzes the histologic findings after abdominal and thoracic surgery in order to tailor the sequence and intensity of surgery. PATIENTS AND METHODS: From a total of 671 PC-RTRs from 2008 to 2021 we analyzed 50 patients with stage III non-seminomatous germ cell tumor (NSGCT) who had undergone both retroperitoneal and thoracic postchemotherapy residual tumor resection after first-line and salvage chemotherapy. RESULTS: All patients included had stage III NSGCT. 39 and 11 patients received first-line and salvage chemotherapy, respectively. 45 (90%) patients received retroperitoneal resection first, followed by thoracic surgery. Three patients (6%) underwent thoracic surgery before retroperitoneal surgery and two patients (4%) underwent simultaneous surgery. Overall, the histology of retroperitoneal and thoracic specimens was discordant in 23% of cases. After first-line chemotherapy, of fourteen patients with necrosis in retroperitoneal histology, four patients had vital carcinoma in lung histology. In patients with teratoma in the retroperitoneum, the thoracic findings were concordant in most cases (78%). When teratomatous elements were also present in the orchiectomy specimen, concordance was 100%. After salvage chemotherapy, the discordance rate was 55%. CONCLUSION: The data presented in this study underline that retroperitoneal residual masses with necrosis cannot reliably predict histologic findings of thoracic specimens. Patients with teratoma in the retroperitoneum have a high likelihood of teratoma in the thoracic specimen.

Clinical characteristics and survival outcomes of elderly patients with de novo metastatic germ cell tumors.

OBJECTIVES: To determine the outcomes for elderly patients with de novo metastatic germ cell tumors and the influence of patient age on adherence to standard chemotherapy. METHODS: A total of 150 patients who were initially diagnosed with metastatic germ cell tumors and treated at our institution between 2007 and 2021 were included. Patients were classified according to three age groups: aged <40, 40-49, and ≥50 years. Clinicopathological features, adherence to standard first-line chemotherapy, overall survival, and disease-free survival were compared between these groups. We also analyzed the outcomes of patients who received low-intensity induction chemotherapy due to adverse events and/or comorbidities. RESULTS: There was no significant difference in any of the survival outcomes and in the rate of adherence to standard first-line chemotherapy between the three age groups, although elderly patients with intermediate/poor prognosis group tended to receive less-intense chemotherapies. The rate of febrile neutropenia as a chemotherapy-related adverse event was significantly higher in patients aged ≥50 years. No statistical significance in survival outcomes was detected between the group of patients who received relatively low-intensity induction chemotherapy and those who received adequately intensive planned chemotherapy. CONCLUSIONS: The adherence rate of standard fist-line chemotherapy of elderly patients is almost comparable to that of younger patients, although some adverse events should be carefully managed. Even elderly patients with metastatic germ cell tumors can aim for equivalently good survival outcome like younger populations, with effort to adhere to standard chemotherapy.

Metastasis-directed therapy in testicular cancer.

PURPOSE OF REVIEW: This review highlights the importance of addressing testicular cancer metastasizing beyond the retroperitoneum, focusing on multidisciplinary approaches and advances in treatment. RECENT FINDINGS: Recent literature emphasizes on the evolving landscape of metastasis-directed therapy, including surgical interventions, chemotherapy regimens, and radiation therapy. The effectiveness of these treatments varies depending on the site of metastasis, with various approaches improving survival rates and quality of life for patients. We divide our review in an organ-specific manner and focus on chemotherapeutic, surgical, and radiation therapy approaches pertaining to each site of metastasis. SUMMARY: Our review suggests the pressing need for continued research to refine and personalize treatment strategies. These efforts are important for enhancing clinical practice, ultimately leading to better outcomes for patients with metastatic testicular cancer.

Intracranial metastasis of testicular germ cell tumours.

Brain metastasis from testicular germ cell tumour (TGCT) is rare and represents only 2% of metastatic brain tumours. Although TGCTs have a good survival rate, the prognosis of brain metastasis is poor. Due to the rarity of the diagnosis, there are limited studies on the topic and a standardized treatment protocol does not exist. Surgical management has long been considered a positive prognostic factor; however, recent studies have investigated the impact of chemotherapy and radiotherapy in these patients. Current literature suggests multiplicity of brain lesions and treatment with chemotherapy or radiotherapy alone can have a poor impact on the prognosis of the disease. However, studies with larger cohorts are required to understand and develop the optimal treatment protocol for patients with brain metastasis from TGCT.

A comparative study of peri-operative outcomes for 100 consecutive post-chemotherapy and primary robot-assisted and open retroperitoneal lymph node dissections.

PURPOSE: To describe and compare differences in peri-operative outcomes of robot-assisted (RA-RPLND) and open (O-RPLND) retroperitoneal lymph node dissection performed by a single surgeon where chemotherapy is the standard initial treatment for Stage 2 or greater non-seminomatous germ cell tumour. METHODS: Review of a prospective database of all RA-RPLNDs (28 patients) and O-RPLNDs (72 patients) performed by a single surgeon from 2014 to 2020. Peri-operative outcomes were compared for patients having RA-RPLND to all O-RPLNDs and a matched cohort of patients having O-RPLND (20 patients). Further comparison was performed between all patients in the RA-RPLND group (21 patients) and matched O-RPLND group (18 patients) who had previous chemotherapy. RA-RPLND was performed for patients suitable for a unilateral template dissection. O-RPLND was performed prior to the introduction of RA-RPLND and for patients not suitable for RA-RPLND after its introduction. RESULTS: RA-RPLND showed improved peri-operative outcomes compared to the matched cohort of O-RPLND-median blood loss (50 versus 400 ml, p < 0.00001), operative duration (150 versus 195 min, p = 0.023) length-of-stay (1 versus 5 days, p < 0.00001) and anejaculation (0 versus 4, p = 0.0249). There was no statistical difference in complication rates. RA-RPLND had lower median lymph node yields although not significant (9 versus 13, p = 0.070). These improved peri-operative outcomes were also seen in the post-chemotherapy RA-RPLND versus O-RPLND analysis. There were no tumour recurrences seen in either group with median follow-up of 36 months and 60 months, respectively. CONCLUSIONS: Post-chemotherapy RA-RPLND may have decreased blood loss, operative duration, hospital length-of-stay and anejaculation rates in selected cases and should, therefore, be considered in selected patients. Differences in oncological outcomes require longer term follow-up.

The Enigmatic Role of TP53 in Germ Cell Tumours: Are We Missing Something?

The cure rate of germ cell tumours (GCTs) has significantly increased from the late 1970s since the introduction of cisplatin-based therapy, which to date remains the milestone for GCTs treatment. The exquisite cisplatin sensitivity has been mainly explained by the over-expression in GCTs of wild-type TP53 protein and the lack of TP53 somatic mutations; however, several other mechanisms seem to be involved, many of which remain still elusive. The findings about the role of TP53 in platinum-sensitivity and resistance, as well as the reported evidence of second cancers (SCs) in GCT patients treated only with surgery, suggesting a spectrum of cancer predisposing syndromes, highlight the need for a deepened understanding of the role of TP53 in GCTs. In the following report we explore the complex role of TP53 in GCTs cisplatin-sensitivity and resistance mechanisms, passing through several recent genomic studies, as well as its role in GCT patients with SCs, going through our experience of Center of reference for both GCTs and cancer predisposing syndromes.

Expression of programmed death ligand-1 (PD-L1) in metastatic and postchemotherapy viable testicular germ cell tumors.

INTRODUCTION: Chemotherapy for testicular germ cell tumors (GCT) is highly effective, with few patients who do not respond. Clinical studies to evaluated novel treatments are challenging given the rarity of these patients. Therefore, we sought to evaluate PD-L1 staining on metastatic and postchemotherapy viable testicular GCTs as a surrogate for potential benefit for immunotherapy targeting the PD-1/PD-L1 axis. METHODS: Ethics research committee approval for this retrospective study was obtained by four participating institutions (CHU de Québec, St. Joseph's Health Care, Halifax Health Science Centre, Johannes Gutenberg University). Patients with viable metastatic testicular GCTs pathology samples were included. Patients with pure teratoma were excluded. PD-L1 staining with the 22C3 clone was evaluated on samples with >100 viable tumor cells using the combined positive score (CPS). RESULTS: From 51 patients identified at participating institutions, 24 postchemotherapy and 18 chemotherapy-naive metastatic samples were available for PD-L1 staining, with 9 matched prechemotherapy samples and 7 matched orchiectomy pathology samples, respectively. The median CPS score was 55.6 (IQR 16-100) for all metastatic samples, 44.9 (IQR 13-100) for postchemotherapy metastatic samples, and 68.8 (IQR 38-100) for chemotherapy-naïve metastatic samples, with the median number of viable tumor cells at 545, 500, and 550, respectively. Differences were not significant between chemotherapy-naïve and postchemotherapy samples (P = 0.07), though among non-seminoma GCT metastatic samples, CPS scores were significantly lower postchemotherapy (P = 0.02). Significant differences among postchemotherapy metastatic tumors were also seen according to predominant subtype, with lower CPS scores for predominant yolk sac and higher values for predominant seminoma and choriocarcinoma. In 7 patients with matched specimens pre- and postchemotherapy, a significant increase in CPS was observed for seminoma (26.7 vs. 81.7, P = 0.045), but not nonseminoma GCTs. Comparing all chemotherapy naïve-samples, PD-L1 expression was higher in metastatic samples versus testicular samples (mean CPS 68.8 vs. 39.8, P = 0.02). This was also seen in matched chemotherapy-naïve samples (mean CPS 77.9 vs. 33.1, P = 0.01). CONCLUSION: Our results suggest that most patients with refractory GCTs postchemotherapy will not benefit from PD-1/PD-L1 immunotherapy. However, the high PD-L1 expression in patients with predominant or pure seminoma post-chemotherapy suggests this may represent a subgroup for whom further trials may be considered.

Lymph Node Ratio Rather Than Positive Lymph Node Counts Has Better Prognostic Value in Patients With Testicular Germ Cell Tumors.

BACKGROUND: Testicular cancer represents the most common malignancy in young adult men. In the current study, we sought to analyze and compare the prognostic value of lymph node ratio (LNR) as well as positive lymph node counts (LNC) to understand its clinical significance in testicular germ cell tumors. METHODS: We employed eligibility criteria to recruit a total of 931 patients, with testicular cancer, from 2010 to 2015 from The Surveillance, Epidemiology, and End Results (SEER) database. We then used the X-Tile program to calculate LNR and LNC cutoff values and discriminate survival. We then calculated the overall and cancer specific survival rates and analyzed the association between LNR/LNC and clinical pathological characteristics using the χ2 test. Finally, we assessed the relationships between clinical pathological factors and patient survival using univariate Cox proportional hazard analysis. RESULTS: Univariate analysis revealed a significant association between prognosis with age (HR, 5.169; 95% CI, 1.758-15.200; P = 0.003), AJCC stage (III vs I: HR, 9.298; 95% CI, 2.691-32.131; P < 0.001), M stage (HR, 7.897; 95% CI, 3.417-18.251; P < 0.001) and LNR (HR, 3.009; 95% CI, 1.275-7.098; P = 0.012). On the other hand, LNC (HR, 1.743; 95% CI, 0.687-4.420; P = 0.242) was not significantly associated with prognosis. Analysis of the association between LNR/LNC and clinical pathological characteristics showed that high LNR patients tended to have significantly larger tumor sizes (χ2 = 7.877, P = 0.005), as well as advanced T (χ2 = 13.195, P = 0.004), N ( χ2 = 86.775, P < 0.001), M (χ2 = 19.948, P < 0.001) and 7th AJCC (χ2 = 103.074, P < 0.001) stages. In addition, high LNC patients were significantly associated with T (χ2 = 8.799, P = 0.032), N (χ2 = 74.390, P < 0.001) and 7th AJCC (χ2 = 111.759, P < 0.001) stages. CONCLUSION: LNR was a better predictor for long-term prognosis and was closely associated with clinical pathological characteristics than LNC in patients with testicular germ cell tumors.

Pathologic concordance of resected metastatic nonseminomatous germ cell tumors in the chest.

OBJECTIVE: Men with metastatic nonseminomatous germ cell tumors (NSGCTs) often present with residual chest tumors after chemotherapy. We examined the pathologic concordance of intrathoracic disease and outcomes based on the worst pathology of disease resected at first thoracic surgery. METHODS: A retrospective analysis was performed of consecutive patients undergoing thoracic resection for metastatic NSGCT in our institution between 2005 and 2018. RESULTS: Eighty-nine patients (all men) were included. The median age was 29 years (interquartile range [IQR], 23-35 years). Primary sites were testis (n = 84; 94.4%) and retroperitoneum (n = 5; 5.6%). Eighty-seven patients received chemotherapy before undergoing surgery. Nineteen patients (21.3%; group 1) had malignancy resected at first surgery (OR1), and the other 70 patients had benign disease at OR1 (78.7%; group 2). Concordant pathology between lungs was 85.2% in group 1 and 91% in group 2, and between lung and mediastinum was 50% in group 1 and 72.7% in group 2. Despite no teratoma at OR1, 3 patients (15.8%) in group 2 had resection of teratoma (n = 2) or malignancy (n = 1) at future surgery. After a mean follow-up of 65.5 months (IQR, 23.1-89.2 months) for group 1 and 47.7 months (IQR, 13.0-75.1 months) for group 2, overall survival was significantly worse for group 1 (68.4% vs 92.9%; P = .03). CONCLUSIONS: The wide range of pathology resected in patients with intrathoracic NSGCT metastases requires careful decision making regarding treatment. Pathologic concordance between lungs is better than that between lung and mediastinum in patients with intrathoracic NSGCT metastases. Aggressive surgical management should be considered for all residual disease due to the low concordance between sites and the potential for excellent long-term survival even in patients with chemotherapy-refractory disease.

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.

Lymph node density in retroperitoneal lymph node dissection as a novel marker for predicting recurrence in patients with germ cell testicular cancer: A case-control study and long-term clinical experience of a tertiary referral hospital. / La densidad de los ganglios linfáticos en la linfadenectomía retroperitoneal como marcador novel para predecir la recurrencia en pacientes con cáncer testicular de células germinales: estudio de casos y controles y experiencia clínica a largo plazo de un hospital de referencia terciario.

INTRODUCTION AND OBJECTIVES: In this retrospective study, we aimed to evaluate lymph node (LN) density in retroperitoneal lymph node dissection (RPLND) to analyze whether residual mass after chemotherapy might behave as predicting factor for recurrence in patients with germ cell testicular cancer (GCTC). MATERIALS AND METHODS: The data of 185 patients that were operated between 12/2004 and 02/2017 because of GCTC were reviewed retrospectively. LN density was calculated. The patients were compared statistically in terms of demographic features, tumor characteristics, serum tumor marker levels, treatment strategies, and pathological results according to GCTC subtypes. Correlation analysis was performed to determine the parameters related to recurrent disease. RESULTS: The median follow-up was 79 (31-179) months and the median age of the patients was 23 (16-71). The median tumor size was 4 (1-18) cm. Five (2.7%) patients had metastatic disease at initial diagnosis. Seminoma, non-seminomatous-GCT and mix type-GCTC was detected in 62 (33.5%), 60 (32.4%) and 63 (34.1%) patients, respectively. Following inguinal orchiectomy, 48 (25.9%) patients underwent follow-up, 126 (68.1%) patients underwent chemotherapy and 11 (5.9%) patients underwent radiotherapy. A total of 21 (11.4%) patients underwent post-chemotherapy RPLND. Early and late recurrence was seen in 3 (1.6%) and 2 (1.1%) of the patients, respectively. A mild to moderate, negative, but significant correlation was found between the recurrence and the number of LNs containing metastatic deposits and LN density (r= -0.490, P=.024 and r= -0.450, P=.041, respectively). CONCLUSIONS: There was a negative correlation between the number of LNs containing metastatic deposits and LN density and recurrent disease.

Improved outcomes in metastatic germ cell cancer: results from a large cohort study.

PURPOSE: Treatment of metastatic germ cell cancer (GCC) is based on the International Germ Cell Cancer Collaborative Group (IGCCCG) prognostic classification published in 1997. 5-year survival rates were reported to be 91%, 79%, and 48% for patients with good, intermediate and poor prognosis, respectively. However, treatment results may have improved over time due to cumulative experience, improved supportive care and modern-type chemotherapy. METHODS: Patients with metastatic GCC who received cisplatin-based chemotherapy at two institutions in Munich between 2000 and 2013 were retrospectively studied. Clinical characteristics, treatment and outcomes were analyzed with respect to the IGCCG prognostic classification. RESULTS: Of 225 patients (median age 35 years), 72 (32%) had seminoma (S) and 153 (68%) nonseminoma. 175 (78%), 30 (13%) and 20 patients (9%) had good, intermediate and poor prognosis according to the IGCCCG classification. The 2-year-progression free survival of patients with good, intermediate and poor prognosis was 91%, 83% and 37%, and the 5-year-overall survival (OS) was 98%, 96%, and 66%, respectively. There was no significant difference in the OS between patients in the good and intermediate prognosis group. CONCLUSION: Compared to data from the original IGCCCG classification system, the outcome of patients with metastatic GCC has considerably improved over time. While the prognosis of intermediate-risk patients is excellent, treatment in the poor-prognosis group remains to be improved.

Surveillance of postchemotherapy subcentimeter residual retroperitoneal mass in metastatic nonseminomatous germ cell tumor: Does how you measure matter?

BACKGROUND: Approximately 70% to 80% of patients with metastatic nonseminomatous germ cell tumor (NSGCT) treated with cisplatin-based chemotherapy achieve a complete response, defined as normalization of serum tumor markers and either no residual retroperitoneal mass (RRM) or an RRM <1.0 cm. While there is universal agreement that patients with an RRM ≥1.0 cm should undergo retroperitoneal lymph node dissection (RPLND), many institutions including ours recommend surveillance for patients who achieve a complete response. However, studies have not defined which axis of the RRM should be considered when deciding between surveillance and RPLND. PATIENTS AND METHODS: Good-risk metastatic NSGCT patients treated with cisplatin-based chemotherapy who achieved a complete response and underwent surveillance were identified using our institution's electronic medical records. A post-hoc review was performed by a blinded radiologist. The RRM dimensions in the transaxial short axis (TSA), transaxial long axis (TLA), and craniocaudal axis (CCA) were recorded. Differences in the frequency of recurrence between groups with an RRM <1.0 cm and ≥1.0 cm in the TLA and CCA were assessed using the Fisher exact test. RESULTS: Thirty-nine patients who met study criteria were included. At a median follow-up of 63.8 months, 2 patients (5.1%) recurred. Both were successfully treated with salvage chemotherapy and RPLND. Thirteen (33%) and 27 (69%) patients had an RRM ≥1.0 cm in the TLA and CCA, respectively. There were no statistically significant differences in the risk of recurrence between patients with an RRM <1.0 cm and ≥1.0 cm in the TLA (P = 0.54) or CCA (P = 0.53). CONCLUSIONS: Surveillance is an effective strategy in good-risk NSGCT patients with a postchemotherapy RRM <1.0 cm in the TSA. Our study suggests referencing the TSA and not the TLA or CCA may avoid unnecessary postchemotherapy RPLNDs.

A phase 1 study of combined guadecitabine and cisplatin in platinum refractory germ cell cancer.

PURPOSE: Germ cell tumors (GCTs) are cured with therapy based on cisplatin, although a clinically significant number of patients are refractory and die of progressive disease. Based on preclinical studies indicating that refractory testicular GCTs are hypersensitive to hypomethylating agents (HMAs), we conducted a phase I trial combining the next-generation HMA guadecitabine (SGI-110) with cisplatin in recurrent, cisplatin-resistant GCT patients. METHODS: Patients with metastatic GCTs were treated for five consecutive days with guadecitabine followed by cisplatin on day 8, for a 28-day cycle for up to six cycles. The primary endpoint was safety and toxicity including dose-limiting toxicity (DLT) and maximum tolerated dose (MTD). RESULTS: The number of patients enrolled was 14. The majority of patients were heavily pretreated. MTD was determined to be 30 mg/m2 guadecitabine followed by 100 mg/m2 cisplatin. The major DLTs were neutropenia and thrombocytopenia. Three patients had partial responses by RECIST criteria, two of these patients, including one with primary mediastinal disease, completed the study and qualified as complete responses by serum tumor marker criteria with sustained remissions of 5 and 13 months and survival of 16 and 26 months, respectively. The overall response rate was 23%. Three patients also had stable disease indicating a clinical benefit rate of 46%. CONCLUSIONS: The combination of guadecitabine and cisplatin was tolerable and demonstrated activity in patients with platinum refractory germ cell cancer.