Survival outcomes of patients with germ cell tumors treated with high-dose chemotherapy for refractory or relapsing disease

The Use of Salvage Chemotherapy for Patients with Relapsed Testicular Germ Cell Tumor (GCT) in Canada: A National Survey

BACKGROUND

Although metastatic germ cell tumor (GCT) is highly curable with initial cisplatin-based chemotherapy (CT), 20-30% of patients relapse. Salvage CT options include conventional (CDCT) and high dose chemotherapy (HDCT), however definitive comparative data remain lacking. We aimed to characterize the contemporary practice patterns of salvage CT across Canada.

METHODS

We conducted a 30-question online survey for Canadian medical and hematological oncologists with experience in treating GCT, assessing treatment availability, patient selection, and management strategies used for relapsed GCT patients.

RESULTS

There were 30 respondents from 18 cancer centers across eight provinces. The most common CDCT regimens used were TIP (64%) and VIP (25%). HDCT was available in 13 centers (70%). The HDCT regimen used included carboplatin and etoposide for two cycles (76% in 7 centers), three cycles (6% in 2 centers), and the TICE protocol (11%, in 2 centers). "Bridging" CDCT was used by 65% of respondents. Post-HDCT treatments considered include surgical resection for residual disease (87.5%), maintenance etoposide (6.3%), and surveillance only (6.3%).

CONCLUSIONS

HDCT is the most commonly used GCT salvage strategy in Canada. Significant differences exist in the treatment availability, selection, and delivery of HDCT, highlighting the need for standardization of care for patients with relapsed testicular GCT.

High-dose chemotherapy for relapsed germ cell tumours: outcomes in low-volume specialized centres

OBJECTIVE

To report treatment patterns and survival outcomes of patients with relapsed and refractory metastatic germ cell tumours (GCTs) treated with high-dose chemotherapy (HDCT) and autologous stem-cell transplantation in low-volume specialized centres within the widely dispersed populations of Australia and New Zealand between 1999 and 2019.

PATIENTS AND METHODS

We conducted a retrospective analysis of 111 patients across 13 institutions. Patients were identified from the Australasian Bone Marrow Transplant Recipient Registry. We reviewed treatment regimens, survival outcomes, deliverability and toxicities. Primary endpoints included overall (OS) and progression-free survival (PFS). Cox proportional hazards models were used to test the association of survival outcomes with patient and treatment factors.

RESULTS

The median (range) age was 30 (14-68) years and GCT histology was non-seminomatous in 84% of patients. International Prognostic Factors Study Group (IPFSG) prognostic risk category was very low/low, intermediate, high and very high in 18%, 36%, 25% and 21% of patients, respectively. Salvage conventional-dose chemotherapy (CDCT) was administered prior to HDCT in 59% of patients. Regimens included paclitaxel, ifosfamide, carboplatin and etoposide (50%), carboplatin and etoposide (CE; 28%), carboplatin, etoposide and ifosfamide (CEI; 6%), carboplatin, etoposide and cyclophosphamide (CEC; 5%), CEC-paclitaxel (6%) and other (5%). With a median follow-up of 4.4 years, the 1-, 2- and 5-year PFS rates were 62%, 57% and 52%, respectively, and OS rates were 73%, 65% and 61%, respectively. There were five treatment-related deaths. Progression on treatment occurred in 17%. In a univariable analysis, worse International Germ Cell Cancer Collaborative Group (IGCCCG) and IPFSG prognostic groups were associated with inferior survival outcomes. An association of inferior survival was not found with the number of high-dose cycles received nor when HDCT was delivered after salvage CDCT.

CONCLUSION

This large dual-national registry-based study reinforces the efficacy and deliverability of HDCT for relapsed and refractory metastatic GCT in low-volume specialized centres in Australia and New Zealand, with survival outcomes comparable to those found in international practice.

Mediastinal germ cell tumours: where we are and where we are going-a narrative review

OBJECTIVE

In this review, we summarize the current state of the art of primary mediastinal germ cell tumours (PMGCTs) and we highlight challenges and future research directions for this disease.

BACKGROUND

PMGCTs account for 1-3% of all germ cell malignancies and for 15% of adult anterior mediastinal cancers. In 60-70% of cases PMGCTs are represented by nonseminomatous germ cell tumours (GCTs), and in 30-40% of cases by seminomas. Even if PMGCTs share histological and biochemical characteristics with gonadal GCTs, they have peculiar clinical and biological features. Nonseminomatous PMGCTs have a poor prognosis, with a 5-year overall survival (OS) rate of 40-50% after platinum-based chemotherapy and surgery, and a long-term OS of only 10% after salvage treatment. Due to the rarity of this disease, no level 1 evidence is available from randomised trials for PMGCTs. The combination of bleomycin, etoposide, and cisplatin (BEP) or etoposide, ifosfamide and cisplatin (VIP) for 4 cycles are recommended as first line treatment options for nonseminomatous PMGCTs. Surgery of the residual disease after chemotherapy is fundamental in the treatment of nonseminomatous PMGCTs. PMGCTs have high TP53 pathway gene alterations, while targetable gene alterations are rarely identified, thus challenging the advance of precision medicine in this field.

METHODS

We performed a narrative review of international literature published in English on PMGCTs, focusing the attention on clinical trials, international guidelines and translational studies.

CONCLUSIONS

Treatment of patients with PMGCTs is challenging and should be performed in experienced centers. International collaborations should become a priority to ensure optimal patient management. Clinical investigation of new therapeutic options remains an important unmet clinical need, and inclusion of patients in clinical trials should be encouraged. Liquid biopsy is a new promising strategy in PMGCTs.

Salvage treatment for children with relapsed/refractory germ cell tumors: The Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP) experience

BACKGROUND

Malignant germ cell tumors (GCTs) are a heterogeneous group of rare neoplasms in children. Optimal outcome is achieved with multimodal therapies for patients with both localized and advanced disease, especially after the introduction of platinum-based chemotherapy regimens. In this respect, data on salvage treatment for children with relapsed or platinum-refractory disease are still limited.

METHODS

Retrospective analysis of data regarding patients affected by malignant GCTs with platinum-refractory or relapsed disease after first-line treatment according to AIEOP TCGM 2004 protocol was conducted.

RESULTS

Twenty-one patients, 15 females and 6 males, were considered for the analysis. All 21 patients received second-line conventional chemotherapy (SLCT), two of these immediately after surgery for local relapse removal. Two patients showed a progression of disease during SLCT and died of disease shortly thereafter, whereas 19 patients were in partial remission (PR) or complete remission (CR) after SLCT. Treatment after SLCT consisted in surgery on residual tumor mass (9/19) followed by high dose of chemotherapy (HDCT) with autologous hematopoietic stem cell support (16/19). The overall survival (OS) and event-free survival of the whole populations are 71% and 66.6%, respectively. Platinum-refractory patients OS is 54.5% compared with 91.5% of the relapsed group. There were no treatment-related deaths.

CONCLUSION

SLCT followed or not by HDCT is an effective salvage treatment for children with relapsed/refractory GCTs. However, the role of HDCT following SLCT needs to be further investigated, especially regarding the identification of specific patient subgroups, which can benefit from this more intensive treatment.