Single-agent carboplatin AUC10 in metastatic seminoma: A multi-centre UK study of 216 patients

Contemporary Role of Radiation Therapy in Testicular Cancer

Testicular cancer is a rare but curable male malignancy. Seminoma represents the majority of germ cell tumors and is considered radiation sensitive. Radiation treatment plays a role in adjuvant therapy after orchiectomy of stage I, IIA, and IIB seminomas. Radiation dose de-escalation has been effective in preventing tumor recurrences while also limiting acute and long-term toxicities. However, long-term risks, including the prevailing concern of secondary malignancy risk, between adjuvant radiation and chemotherapy play a role in recommendations. Ongoing work continues to be performed to reduce radiation field and dose in combination with chemotherapy while still maintaining excellent outcomes.

Comparative cost-effectiveness of contemporary treatment strategies for stage IIA seminoma

BACKGROUND

The Surgery in Early Metastatic Seminoma (SEMS) trial examined retroperitoneal lymph node dissection as first-line treatment for patients with isolated 1-3 cm retroperitoneal lymphadenopathy. To date, the standard of care for these patients has been either chemotherapy or radiotherapy. Herein, we evaluated the relative cost-effectiveness of these management strategies.

METHODS

A microsimulation model assessed the cost-effectiveness of retroperitoneal lymph node dissection, chemotherapy, and radiotherapy for stage IIA seminoma. Sensitivity analyses were performed to evaluate model robustness. Retroperitoneal lymph node dissection recurrence probabilities were obtained from the SEMS trial. All other probability and utility values were obtained from published literature. Primary outcomes included costs from a commercial insurer's perspective, effectiveness (quality adjusted life-years [QALYs]), and incremental cost-effectiveness ratios using a willingness-to-pay threshold of $100 000/QALY.

RESULTS

At a lifetime horizon, the mean costs per patient for retroperitoneal lymph node dissection, radiotherapy, and chemotherapy were $58 469, $98 783, and $104 096, and the mean QALYs were 40.61, 40.70, and 39.15, respectively. Retroperitoneal lymph node dissection was found to be the most cost-effective approach because of high costs and accrued disutility of chronic toxicities associated with radiotherapy (cost-effectiveness ratios = $433 845/QALY) and chemotherapy (dominated). On 1-way sensitivity analyses, retroperitoneal lymph node dissection was no longer cost-effective if the probabilities of infertility and cardiovascular toxicity after radiotherapy were less than 13% and 16%, respectively, or if the 2-year probability of progression after retroperitoneal lymph node dissection was more than 26%.

CONCLUSIONS

Retroperitoneal lymph node dissection was the most cost-effective treatment approach for stage IIA seminoma. These findings support clinical guideline consideration of including retroperitoneal lymph node dissection as a treatment option for well-selected patients with stage IIA seminoma.

Seminoma and dysgerminoma: evidence for alignment of clinical trials and de-escalation of systemic chemotherapy

Malignant germ cell tumours are a group of rare cancers whose incidence peaks in late adolescence and early adulthood. Dysgerminomas of the ovary and seminomas of the testis are analogous diseases, but seminomas have a 10-fold higher incidence. The two tumours are morphologically identical and are only differentiated by surrounding organ-specific tissue or testicular germ cell neoplasia in situ. They share genetic features including KIT and RAS mutations, amplification of chromosome 12p, and expression of pluripotency markers (NANOG (Nanog homeobox), OCT3/4 (Octamer-binding transcription factor 3/4), and SAL4 (Spalt-like trascription factor 4)). Both histologies are exquisitely sensitive to platinum chemotherapy, and the combination of bleomycin, etoposide, and cisplatin (BEP) yields survival rates greater than 90%. However, BEP causes significant, lifelong toxicity (cardiovascular, renal, respiratory, and neurological) in these young patients with an expectation of cure. Here, we comprehensively review the biological features of dysgerminoma and seminoma to demonstrate that they are biologically analogous diseases. We present available clinical trial data supporting de-escalation of chemotherapy treatment. Finally, we propose that future trials should enrol men, women, and children to benefit all patients regardless of age or sex.

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.

Metastatic seminoma presenting as neck and axillary lymphadenopathy in an elderly man

A man in his 60s presented with a gradual progressive right-sided neck mass. Initial core biopsy was inconclusive and he was treated with a short course of oral prednisone for presumed sarcoidosis. Two months later, the patient developed worsening dysphagia, hoarseness of voice, dyspnea, and weight loss. Physical examination revealed bilateral cervical and right axillary lymphadenopathy. A right axillary lymph node excisional biopsy was performed and immunohistochemistry was diffusely positive for OCT4, SALL4, CD117, PLAP, confirming the diagnosis of metastatic seminoma. He received three cycles of bleomycin, etoposide, and cisplatin; bleomycin was omitted for the fourth cycle due to concern for toxicity. Restaging scans after four cycles of chemotherapy showed a favorable response to therapy. Unfortunately, the patient died from bleomycin pulmonary toxicity. This case illustrates a rare and atypical presentation of metastatic seminoma in an elderly patient.

Proteogenomic Markers of Chemotherapy Resistance and Response in Triple-Negative Breast Cancer

Microscaled proteogenomics was deployed to probe the molecular basis for differential response to neoadjuvant carboplatin and docetaxel combination chemotherapy for triple-negative breast cancer (TNBC). Proteomic analyses of pretreatment patient biopsies uniquely revealed metabolic pathways, including oxidative phosphorylation, adipogenesis, and fatty acid metabolism, that were associated with resistance. Both proteomics and transcriptomics revealed that sensitivity was marked by elevation of DNA repair, E2F targets, G2-M checkpoint, interferon-gamma signaling, and immune-checkpoint components. Proteogenomic analyses of somatic copy-number aberrations identified a resistance-associated 19q13.31-33 deletion where LIG1, POLD1, and XRCC1 are located. In orthogonal datasets, LIG1 (DNA ligase I) gene deletion and/or low mRNA expression levels were associated with lack of pathologic complete response, higher chromosomal instability index (CIN), and poor prognosis in TNBC, as well as carboplatin-selective resistance in TNBC preclinical models. Hemizygous loss of LIG1 was also associated with higher CIN and poor prognosis in other cancer types, demonstrating broader clinical implications.

SIGNIFICANCE

Proteogenomic analysis of triple-negative breast tumors revealed a complex landscape of chemotherapy response associations, including a 19q13.31-33 somatic deletion encoding genes serving lagging-strand DNA synthesis (LIG1, POLD1, and XRCC1), that correlate with lack of pathologic response, carboplatin-selective resistance, and, in pan-cancer studies, poor prognosis and CIN. This article is highlighted in the In This Issue feature, p. 2483.

Single-dose carboplatin followed by involved-node radiotherapy for stage IIA and stage IIB seminoma (SAKK 01/10): a single-arm, multicentre, phase 2 trial

BACKGROUND

Standard treatment options for patients with stage IIA or stage IIB seminoma include either para-aortic and pelvic radiotherapy or three to four cycles of cisplatin-based combination chemotherapy. These options result in 3-year progression free survival rates of at least 90%, but bear risks for acute and late toxic effects, including secondary malignancies. We tested a novel approach combining de-escalated chemotherapy with de-escalated involved node radiotherapy, with the aim of reducing toxicity while preserving efficacy.

METHODS

In the single-arm, multicentre, phase 2 SAKK 01/10 trial, patients with stage IIA or IIB classic seminoma (either at primary diagnosis or at relapse during active surveillance for stage I) were enrolled at ten centres of the Swiss Group for Clinical Cancer Research and ten centres of the German Testicular Cancer Study Group. WHO performance status 0-2, age 18 years or older, and adequate bone marrow and kidney function were required for eligibility. Treatment comprised one cycle of carboplatin (area under the curve 7) followed by involved-node radiotherapy (30 Gy in 15 fractions for stage IIA disease and 36 Gy in 18 fractions for stage IIB disease). The primary endpoint was 3-year progression-free survival. Efficacy analyses were done on the full analysis set, which comprised all patients who signed the informed consent, were registered in the trial, initiated trial treatment, and met all medically relevant inclusion or exclusion criteria. Safety was assessed in all patients who were treated at least once with one of the trial treatments. The study is ongoing but no longer recruiting, and is registered with Clinicaltrials.gov, NCT01593241.

FINDINGS

Between Oct 18, 2012, and June 22, 2018, 120 patients were registered in the study. 116 patients were eligible and started treatment according to the study protocol (46 patients with stage IIA disease and 70 with stage IIB disease). After a median follow-up of 4·5 years (IQR 3·9-6·0), 3-year progression-free survival was 93·7% (90% CI 88·5-96·6). With a target progression-free survival of 95% at 3 years, the primary endpoint was not met. Acute treatment-related adverse events of any grade were noted in 58 (48%) of 116 patients, and grade 3 or 4 treatment-related adverse events occurred in the form of neutropenia in five (4%) patients, thrombocytopenia in three (3%) patients, and vomiting in one (1%) patient. No treatment-related deaths and no late treatment-related adverse events were reported. Serious adverse events were reported in five (4%) of 116 patients (one transient creatinine increase and four second primary tumours).

INTERPRETATION

Despite the fact that the primary endpoint was not met, we observed favourable 3-year progression-free survival with single-dose carboplatin area under the curve 7 and involved-node radiotherapy, with minimal toxic effects. Our findings might warrant discussion with patients about the SAKK 01/10 regimen as an alternative to standard-of-care treatment, but more research on this strategy is needed.

FUNDING

Swiss State Secretariat for Education, Research and Innovation and Rising Tide Foundation for Clinical Cancer Research.

Management of stage II seminoma: a contemporary UK perspective

Background and Aims

Testicular Germ Cell Tumours (TGCTs) are the commonest young adult male cancer, with excellent survival outcomes even with metastatic disease. Chemotherapy, radiotherapy, and surgery are international guideline-dictated standard of care (SOC) treatments for International Germ Cell Cancer Collaborative Group (IGCCCG) “good risk” TGCT, but are associated with significant toxicities. Therapy de-escalation aims to reduce treatment morbidity whilst preserving cure rates, and has been adopted by some centres for stage IIA/B seminoma. Here, we report on the contemporary UK treatment landscape for stage IIA/B seminoma.

Methods

A questionnaire-based survey of NHS England-designated specialist cancer centres hosting supra-regional specialist multi-disciplinary team (sMDT) services (n = 13) as well those within NHS Scotland, NHS Wales and Health and Social Care Northern Ireland. Respondents were asked to order preferences of SOC and therapy de-escalation treatments for stage IIA/B seminoma.

Results

We identified significant geographical heterogeneity in treatment preferences. Whilst up to a third of centres have adopted a treatment de-escalation regimen, the majority deliver combination chemotherapy or radiotherapy.

Conclusion

A wider recognition of UK treatment heterogeneity and consideration of therapy de-escalation strategies at supra-regional sMDTs will increase stage IIA/B seminoma treatment options as part of clinical trials with oncological and quality of life endpoints.

Vinblastine monotherapy induction prior to radiotherapy for patients with intracranial germinoma during the COVID-19 pandemic

BACKGROUND

Patients with localized intracranial germinoma have excellent survival. Reducing treatment burden and long-term sequelae is a priority. Intensive inpatient chemotherapy (e.g., carboPEI = carboplatin/etoposide/ifosfamide) has been effectively employed to reduce radiotherapy treatment volume/dose. Outpatient-based carboplatin monotherapy is associated with excellent outcomes in metastatic testicular seminoma (an identical pathology), and successful vinblastine monotherapy induction (with 77% tumor volume reduction after just two weekly vinblastine doses) has recently been reported in an intracranial germinoma patient.

METHODS

Adapted UK guidelines for germ cell tumor management were distributed during the COVID-19 pandemic, including nonstandard treatment options to reduce hospital visits and/or admissions. This included vinblastine monotherapy for intracranial germinoma (6 mg/m² intravenously, or 4 mg/m² for moderate count suppression, delivered weekly). We describe two such patients treated using this approach.

RESULTS

A 30-year-old male with a localized pineal tumor received 12-week vinblastine induction, with >60% volume reduction, prior to definitive radiotherapy. A 12-year-old female with a metastatic suprasellar tumor and progression at all sites of disease whilst awaiting proton radiotherapy received two vinblastine doses with good early response, including 36% primary tumor volume reduction. The patients tolerated vinblastine well.

CONCLUSION

Patients with intracranial germinoma have excellent outcomes, and reduction of late effects remains a priority. The description of vinblastine monotherapy in these intracranial germinoma patients warrants further exploration.

Gemcitabine, carboplatin and veliparib in multiple relapsed/refractory germ cell tumours: The GCT-SK-004 phase II trial

Background Patients with multiple relapsed/refractory germ cell tumours (GCTs) have an extremely poor prognosis. PARP (poly-ADP-ribose polymerase) is overexpressed in GCTs compared to normal testes, and PARP overexpression is an early event in GCT development. This study aimed to determine the efficacy and toxicity of gemcitabine, carboplatin and the PARP inhibitor veliparib in patients with multiple relapsed/refractory GCTs. Methods Fifteen patients with multiple relapsed/refractory GCTs were enrolled in this phase II study from October 2016 to October 2020. Gemcitabine was administered at a dose of 800 mg/m2 on days 1 and 8 every 3 weeks; carboplatin at a target AUC of 4 on day 1 every 3 weeks; and veliparib at a dose of 250 mg b.i.d. throughout. The primary end point was 12-month progression-free survival (PFS). Results The median number of treatment cycles was 4 (range 2-8). Twelve-month PFS was achieved in 1 (6.7 %) patient. The median PFS was 3.1 months (95 % CI 2.2-3.9), and the median overall survival was 10.5 months (95 % CI 8.9-11.1). Partial remission was achieved in 4 (26.7 %) patients, and disease stabilization was observed in 5 (33.3 %) patients. A favourable response was achieved in 3 (20.0 %) patients. Treatment was well tolerated; however, 11 (73.3 %) patients experienced grade 3/4 neutropenia, 10 (66.7 %) experienced thrombocytopenia, 5 (33.3 %) anaemia and 2 (13.3 %) febrile neutropenia. Conclusions This study failed to achieve its primary endpoint, and our data suggest limited efficacy of gemcitabine, carboplatin and veliparib for multiple relapsed/refractory GCTs. ClinicalTrials.gov Identifier: NCT02860819, registered August 9, 2016.