High-dose chemotherapy for germ cell tumors: do we have a model?

Hematopoietic stem cell mobilization strategies to support high-dose chemotherapy: A focus on relapsed/refractory germ cell tumors

High-dose chemotherapy (HDCT) with autologous hematopoietic stem cell transplantation has been explored and has played an important role in the management of patients with high-risk germ cell tumors (GCTs) who failed to be cured by conventional chemotherapy. Hematopoietic stem cells (HSCs) collected from the peripheral blood, after appropriate pharmacologic mobilization, have largely replaced bone marrow as the principal source of HSCs in transplants. As it is currently common practice to perform tandem or multiple sequential cycles of HDCT, it is anticipated that collection of large numbers of HSCs from the peripheral blood is a prerequisite for the success of the procedure. Moreover, the CD34+ cell dose/kg of body weight infused after HDCT has proven to be a major determinant of hematopoietic engraftment, with patients who receive > 2 × 10⁶ CD34+ cells/kg having consistent, rapid, and sustained hematopoietic recovery. However, many patients with relapsed/refractory GCTs have been exposed to multiple cycles of myelosuppressive chemotherapy, which compromises the efficacy of HSC mobilization with granulocyte colony-stimulating factor with or without chemotherapy. Therefore, alternative strategies that use novel agents in combination with traditional mobilizing regimens are required. Herein, after an overview of the mechanisms of HSCs mobilization, we review the existing literature regarding studies reporting various HSC mobilization approaches in patients with relapsed/refractory GCTs, and finally report newer experimental mobilization strategies employing novel agents that have been applied in other hematologic or solid malignancies.

[Intensification by high dose chemotherapy for germ-cell tumors, still an ongoing subject?]

More than 80 % of patient with metastatic germ cell tumor are cured with first line chemotherapy. Twenty to 30 % of patients will experience relapse or refractory disease with a very poor long-term prognosis. Most of them had metastatic germ cell tumors with a poor prognosis according to the international germ cell classification collaborative group (IGCCCG). The role of treatment intensification by high dose chemotherapy (HDCT) followed by stem cell rescue has not been demonstrated yet in the first line setting compared to standard chemotherapy. The role of HDCT in first or second salvage is also not yet demonstrated, many studies have been published in this situation with a lot of different regimen. Outside clinical trial, HDCT remains an option in salvage therapy, depending on many factors including prognostics factors, previous therapy, general condition and reference center consideration to select eligible patient who could benefit the most of this approach. Results from the international randomized trial TIGER will provide evidence-based information for HDCT strategy.

Indications for haematopoietic stem cell transplantation for haematological diseases, solid tumours and immune disorders: current practice in Europe, 2019

This is the seventh special EBMT report on the indications for haematopoietic stem cell transplantation for haematological diseases, solid tumours and immune disorders. Our aim is to provide general guidance on transplant indications according to prevailing clinical practice in EBMT countries and centres. In order to inform patient decisions, these recommendations must be considered together with the risk of the disease, the risk of the transplant procedure and the results of non-transplant strategies. In over two decades since the first report, the EBMT indications manuscripts have incorporated changes in transplant practice coming from scientific and technical developments in the field. In this same period, the establishment of JACIE accreditation has promoted high quality and led to improved outcomes of patient and donor care and laboratory performance in transplantation and cellular therapy. An updated report with operating definitions, revised indications and an additional set of data with overall survival at 1 year and non-relapse mortality at day 100 after transplant in the commonest standard-of-care indications is presented. Additional efforts are currently underway to enable EBMT member centres to benchmark their risk-adapted outcomes as part of the Registry upgrade Project 2020 against national and/or international outcome data.

First - line, non - cryopreserved autologous stem cell transplant for poor - risk germ - cell tumors: Experience in a developing country

PURPOSE

The current first - line treatment for non - seminomatous germ cell tumor (NSGCT) consists of four cycles of cisplatin, etoposide, and bleomycin (BEP), which results in 5 - year overall survival < 60% in patients with poor - risk features. Autologous hematopoietic stem cell transplantation (auto - HSCT) as a method for overcoming high toxicity after high dose chemotherapy (HDC) has been explored in different solid tumors, but has remained standard practice only for NSGCT. Our objective was to describe outcomes of patients with poor - risk NSGCT who underwent first - line autologous HSCT in a tertiary center in Mexico.

PATIENTS AND METHODS

Twenty nine consecutive patients with NSGCT who received first - line, non - cryopreserved autologous HSCT at the National Institute of Medical Sciences and Nutrition Salvador Zubiran in Mexico City, Mexico, from November 1998 to June 2016, were retrospectively analyzed.

RESULTS

The median age at transplantation was 23 (15 - 39) years. Most patients (n = 18, 62%) had testicular primary tumor, and 23 had metastases (79%). Complete response after auto - HSCT was observed in 45%. Non - relapse mortality was 0. Five - year relapse / progression free and overall survival were 67% and 69%, respectively.

CONCLUSIONS

This small single limited - resource institution study demonstrated that patients with poor - risk NSGCT are curable by first - line HDC plus autologous HSCT and that this procedure is feasible and affordable to perform using non - cryopreserved hematopoietic stem cells.

Secondary malignancies after high-dose chemotherapy in germ cell tumor patients: a 34-year retrospective study of the European Society for Blood and Marrow Transplantation (EBMT)

We aimed to assess the incidence and risk factors of secondary malignancy (SM) in the young adult patients who received high-dose chemotherapy (HDCT) for germ cell tumors (GCT). The EBMT database was interrogated. Criteria for patient selection included adult male GCT and HDCT administered in any line of therapy. Cumulative incidence methods were used to estimate the time-to-SM diagnosis. Univariable Fine and Gray proportional hazard regression evaluated risk factors of SM occurrence. From 1981 to 2015, 9153 autografts were identified. Among 5295 patients, 59 cases of SM, developed after a median follow-up of 3.8 years, were registered. Of these patients, 23 (39%) developed hematologic SM, 34 (57.6%) solid SM (two patients had uncoded SM). Twenty-year cumulative incidence of solid versus hematologic SM was 4.17% (95% CI: 1.78-6.57) versus 1.37% (95% CI: 0.47-2.27). Median overall survival after SM was significantly shorter for patients who developed hematologic SM versus solid SM (8.6 versus 34.4 months, p = 0.003). Age older than 40 years at the time of HDCT was significantly associated with hematologic, but not solid, SM development (p = 0.004 versus p = 0.234). SM occurrence post-HDCT showed different patterns of incidence and mortality in GCT. These data may be important to optimize patient selection, counseling and follow-up after HDCT.

Salvage High-Dose Chemotherapy for Relapsed Pure Seminoma in the Last 10 Years: Results From the European Society for Blood and Marrow Transplantation Series 2002-2012

BACKGROUND

The optimal management of advanced seminoma that relapses after chemotherapy remains unknown. We retrospectively analyzed outcomes with the use of high-dose chemotherapy (HDCT).

PATIENTS AND METHODS

Eligibility included adult male patients with pure seminomatous histology and treatment with salvage HDCT. Data of patients who received HDCT from 13 European Society for Blood and Marrow Transplantation (EBMT) centers were used. Multivariable Cox analyses evaluated the association of prespecified factors (line of treatment, prior radiotherapy, and chemosensitivity according to standard definition), with progression-free (PFS) and overall survival (OS). The prognostic ability of the model was assessed through the concordance statistic.

RESULTS

From December 2002 to December 2012, 46 cases were identified. Median age was 38 years (interquartile range, 35-46 years). HDCT was provided as second-line therapy (n = 14, 30.4%) and in third-line or beyond third-line therapy (n = 20, 43.5%; 12 had missing information). Sixteen patients (34.8%) received paraortic and/or iliac radiotherapy, and 10 (21.7%) had disease that was cisplatin refractory or absolutely refractory. Median follow-up was 22 months (interquartile range, 8-56). On multivariable Cox analysis, refractory disease was a significantly negative prognostic factor for both PFS (hazard ratio, 6.04; 95% confidence interval, 1.86-19.64) and OS (hazard ratio, 3.93; 95% confidence interval, 1.07-14.45), while prior radiotherapy trended to significance for both. The c index was 0.74 and 0.66 for PFS and OS, respectively. The small numbers and the lack of any comparison with conventional-dose chemotherapy are major study limitations.

CONCLUSION

Despite our small sample size, this retrospective analysis suggested that HDCT may represent a valuable therapeutic option for patients with a pure seminoma after standard-dose chemotherapy failure. Our observation requires validation through a prospective study.

Immunotherapy advances in uro-genital malignancies

Immunotherapy for the treatment of cancer has made significant progresses over the last 20 years. Multiple efforts have been attempted to restore immune-mediated tumor elimination, leading to the development of several targeted immunotherapies. Data from recent clinical trials suggest that these agents might improve the prognosis of patients with advanced genito-urinary (GU) malignancies. Nivolumab has been the first immune checkpoint-inhibitor approved for pre-treated patients with metastatic renal cell carcinoma. Pembrolizumab and atezolizumab have shown promising results in both phase I and II trials in urothelial carcinoma. Brentuximab vedotin has demonstrated early signals of clinical activity and immunomodulatory effects in highly pre-treated patients with testicular germ cell tumors. In this review, we have summarized the major clinical achievements of immunotherapy in GU cancers, focusing on immune checkpoint blockade as well as the new immunomodulatory monoclonal antibodies (mAbs) under clinical evaluation for these malignancies.

Leukaemia 'firsts' in cancer research and treatment

Our understanding of cancer biology has been radically transformed over recent years with a more realistic grasp of its multilayered cellular and genetic complexity. These advances are being translated into more selective and effective treatment of cancers and, although there are still considerable challenges, particularly with drug resistance and metastatic disease, many patients with otherwise lethal malignancies now enjoy protracted remissions or cure. One largely unheralded theme of this story is the extent to which new biological insights and novel clinical applications have their origins with leukaemia and related blood cell cancers, including lymphoma. In this Timeline article, I review the remarkable and ground-breaking role that studies in leukaemia have had at the forefront of this progress.

High dose chemotherapy with stem cell support in the treatment of testicular cancer

Testicular germ cell cancer (TGCC) is rare form of malignant disease that occurs mostly in young man between age 15 and 40. The worldwide incidence of TGCC is 1.5 per 100000 man with the highest rates in North Europe. After discovery of cisplatin cure rates of TGCC are very favorable between 90%-95% and unlike most solid tumors, cure rate for metastatic TGCC is around 80%. Metastatic TGCC is usually treated with 3-4 cycles of bleomycin, etoposide, cisplatinum chemotherapy with or without retroperitoneal surgery and cure rates with this approach are between 41% in poor risk group and 92% in good risk group of patients. Cure rates are lower in relapsed and refractory patients and many of them will die from the disease if not cured with first line chemotherapy. High dose chemotherapy (HDCT) approach was used for the first time during the 1980s. Progress in hematology allowed the possibility to keep autologous haematopoietic stem cells alive ex-vivo at very low temperatures and use them to repopulate the bone marrow after sub-lethal dose of intesive myeloablative chemotherapy. Despite the fact that there is no positive randomized study to prove HDCT concept, cure rates in relapsed TGCC are higher after high dose therapy then in historical controls in studies with conventional treatment. Here we review clinical studies in HDCT for TGCC, possibilities of mobilising sufficient number of stem cells and future directions in the treatment of this disease.