Current status of chemotherapy in risk-adapted management for metastatic testicular germ cell cancer

First-line combination chemotherapy with etoposide, ifosfamide and cisplatin for the treatment of disseminated germ cell cancer: Efficacy and feasibility in current clinical practice

OBJECTIVES

To evaluate the efficacy and safety profiles of first-line etoposide, ifosfamide and cisplatin and primary prophylaxis with pegfilgrastim as first-line chemotherapy for disseminated germ cell cancer.

METHODS

This study reviewed 154 consecutive patients with previously untreated disseminated germ cell cancer who received first-line etoposide, ifosfamide and cisplatin between 1995 and 2020. Of these, 54 patients were managed with primary prophylaxis using pegfilgrastim (primary prophylaxis group), and 100 were managed with the therapeutic use of short-acting granulocyte colony-stimulating factor (non-primary prophylaxis group).

RESULTS

The International Germ Cell Cancer Collaborative Group classification identified 90 (58%)/40 (26%)/24 (16%) patients with good/intermediate/poor prognosis, respectively. Overall, 139 patients (90%) were disease free after etoposide, ifosfamide and cisplatin with/without post-chemotherapy surgery. The median relative dose intensity of etoposide, ifosfamide and cisplatin was 96%, and there was a significant difference between the primary prophylaxis and non-primary prophylaxis groups (100% vs 90%, P < 0.01). The 5-year salvage treatment-free and overall survival rates were 83% and 94%, respectively. In total, 138 patients (90%) developed grade 4 hematological toxicities, and there were no treatment-related deaths due to myelosuppression. Grade 4 neutropenia was less commonly observed in the primary prophylaxis group compared with the non-primary prophylaxis group (80% vs 95%, P < 0.01).

CONCLUSIONS

This is the largest study of first-line etoposide, ifosfamide and cisplatin, and its sufficient efficacy and safety profiles are confirmed in current clinical practice. Primary prophylaxis using pegfilgrastim might further improve the feasibility of etoposide, ifosfamide and cisplatin.

Melatonin protects rats testes against bleomycin, etoposide, and cisplatin-induced toxicity via mitigating nitro-oxidative stress and apoptosis

There is growing concern that some cytotoxic regimens for cancer adversely affect spermatogenesis and male fertility. Increasing evidence demonstrated that melatonin has beneficial impacts on reproductive processes; however, whether melatonin can protect against bleomycin, etoposide, and cisplatin (BEP) chemotherapy regimen-induced testicular toxicity, remains obscure. The present study aimed to explore the effect of melatonin on BEP-evoked testicular injury in rats. Adult male Wistar rats (n = 10/group) were intraperitoneally (i.p.) injected with one cycle of 21 days of 0.33 therapeutically relevant dose levels of BEP (.5 mg/kg bleomycin, 5 mg/kg etoposide, and 1 mg/kg cisplatin) with or without melatonin. At the end of the study, sperm parameters, testosterone level, stereology of testes, testicular levels of malondialdehyde (MDA), nitric oxide (NO), and total antioxidant capacity (TAC), the expression of apoptosis-associated genes such as Bcl2, Bax, Caspase-3, p53, and TNF-α (Real-time PCR and Immunohistochemistry) were evaluated. Our findings showed that melatonin restored spermatogenesis by improving sperm count, motility, viability, and morphology. Testosterone level, histopathology, and stereology of testes were significantly improved in melatonin-administrated groups. Furthermore, melatonin recovered the oxidative status of the testes through elevating TAC and ameliorating MDA and NO levels. More importantly, melatonin therapy suppressed BEP-evoked apoptosis by modulating Bcl-2, Bax, Caspase-3, p53, and TNF-α expression in testes. In conclusion, melatonin protects the testes against BEP-induced testicular damage by attenuating nitro-oxidative stress, apoptosis, and inflammation, which provides evidence for melatonin as a possible clinical therapy against BEP-associated gonadotoxicity and male sub/infertility.

Cisplatin, Gemcitabine, and Paclitaxel as a Salvage Second-Line Therapy for Metastatic Germ-Cell Cancer

BACKGROUND

Second-line salvage therapy for patients with metastatic germ-cell cancer (GCC) after the first-line combination of VIP (etoposide, ifosfamide, cisplatin) therapy has not been established. This study evaluated the efficacy and tolerability of the TGP (paclitaxel, gemcitabine, cisplatin) combination chemotherapy as a second-line salvage therapy.

PATIENTS AND METHODS

The medical records of 16 consecutive patients with metastatic GCC who had been treated with first-line VIP therapy followed by second-line TGP therapy between 2005 and 2019 were reviewed and statistically analyzed. Ten patients, excluding the 6 patients treated with TGP without unequivocal progression, were included in the efficacy analysis. All 16 patients were included in the safety analysis.

RESULTS

The median follow-up period from initial TGP administration was 78 months (interquartile range, 46-120 months). The estimated 5-year progression-free and overall survival rates for the 10 patients in the efficacy analysis were 70% and 100%, respectively. Grade 3/4 hematologic toxicity occurred in all 16 patients, but none developed uncontrollable infections or life-threatening bleeding. One patient died of treatment-related secondary leukemia, however.

CONCLUSION

The present study is to our knowledge the first to examine the therapeutic outcomes and safety profile of second-line TGP chemotherapy. VIP followed by TGP might be an alternative first- and second-line conventional regimen for patients with metastatic GCC in this granulocyte colony-stimulating factor era, especially for patients at a high risk of bleomycin-induced pulmonary toxicity.

Prognosis of Patients With Testicular Carcinoma Is Dependent on Metastatic Site

Background: Existing data on the association of metastatic sites and prognosis of patients with metastatic testicular malignancy are limited. In this study, the association of survival outcome and the prognostic value of different metastatic sites in patients with metastatic testicular cancer was investigated.

Methods: A dataset from the Surveillance, Epidemiology and End Results (SEER) survey was selected for a retrospective metastatic testicular cancer cohort study. Patients with different metastatic sites were divided into corresponding groups for further analysis. Kaplan-Meier analysis with log-rank test was implemented for comparison of the survival distribution of cases. Multivariate Cox regression models were then applied to analyze the association of distant metastases with survival for all selected patients and subgroup based on different histological type with a single metastatic site.

Results: A total of 1,661 patients treated for metastatic testicular malignant tumors between 2010 to 2016 were enrolled in this cohort study. Upon initial diagnosis, 61.9, 15.2, 6.7, 6.4, and 36.2% of patients were found to have lung, liver, bone, brain, and distant lymph nodes metastatic sites, respectively. Patients with lung, liver, or bone metastases showed more undesirable prognosis for overall survival (OS) and cancer-specific survival (CSS), in contrast with those with distant lymph node metastases (all P < 0.05). In comparison with patients with more than one metastatic site, those with a single metastasis had extended OS and CSS (both P < 0.001). In patients with a single metastatic site, Kaplan-Meier analysis and multivariate Cox regression demonstrated the association of bone and liver with the worst two groups of OS and CSS. Multivariate Cox models based on histological type showed different prognostic values of metastases in patients with seminoma or non-seminomatous germ cell tumors.

Conclusion: There is much heterogeneity in the oncological outcome of site-specific metastatic patients. Metastatic profiles and the prognostic value of metastases are dependent on the histological type in TC patients. Distant lymph nodes and lung metastases indicate favorable prognostic factors, while bone and liver metastases indicate negative survival outcomes in TC.

Systemic therapy for primary and extragonadal germ cell tumors: prognosis and nuances of treatment

Testicular germ cell tumors are the most common solid tumors in young men. These cancers represent a success story of modern medicine in our ability to cure young patients and offer decades of life, with a 5-year survival rate of approximately 95%. This review outlines the staging and risk classification of testicular cancers, and reviews the current state of knowledge and standard of care for the systemic treatment of testicular germ cell tumors with chemotherapy, focusing on the relevant clinical data supporting each treatment regimen. This review also briefly highlights current areas of active investigation, notably in the relapsed and refractory setting, including ongoing clinical trials.

Possible risk of overestimation of renal function using cystatin C-based eGFR in testicular cancer survivors treated with cisplatin-based chemotherapy

BACKGROUND

Chronic kidney disease (CKD) is a major long-term morbidity of testicular cancer (TC) survivors cured by cisplatin-based chemotherapy. We conducted the present study to elucidate the usefulness of cystatin-based estimated glomerular filtration rates (eGFRcys) for diagnosis of CKD compared to creatinine-based eGFR (eGFRcreat) in those patients.

METHODS

eGFRcys and eGFRcreat were measured in 53 TC survivors. The 24-h creatinine clearance (CrCl) was measured in 12 TC survivors and 17 CKD patients with medical disease; all of them had eGFRcreat <60 m/min/1.73 m². Also, urinary beta2-microglobulin and albumin concentrations in spot urine specimens were measured.

RESULTS

The mean eGFRcreat was significantly lower than eGFRcys, at 67.9 and 95.2 ml/min/1.73 m², respectively (p < 0.05). The prevalence of stage 3-5 CKD differed by GFR estimation methods. It was 47.2% with eGFRcreat and only 7.5% with eGFRcys. There were 21 patients with eGFRcreat <60 ml/min/1.73 m² and eGFRcys ≥60 ml/min/1.73 m². In all 12 TC survivors, the eGFRcys values were higher than both eGFRcreat and GFR (24-h CrCl). In contrast, no difference was observed among eGFR values in the 17 patients with CKD due to medical disease. Ten of 21 patients with eGFRcreat <60 ml/min/1.73 m² and eGFRcys ≥60 ml/min/1.73 m² showed significant beta2-microglobulinuria: a higher prevalence than that in patients with both eGFRs ≥60 ml/min/1.73 m². Also, the incidence of microalbuminuria tended to be high in those patients.

CONCLUSIONS

The present study suggests that eGFRcys may overestimate renal function in TC survivors cured by cisplatin-based chemotherapy.

Increased efficiency of testicular tumor chemotherapy by ultrasound microbubble-mediated targeted transfection of siMDR1

The MDR1 gene encoding P-glycoprotein (P-gp) is an ATP-dependent drug efflux transporter and is related to drug resistance of yolk sac tumors. Drug resistence may be an important factor for the low efficiency of chemotherapy in the treatment of testicular tumors. P-gp, encoded by the MDR1 gene, is an ATP-binding cassette transporter. P-gp exhibits high expression in capillary endothelial cells of the testis and prevents the intracellular accumulation of chemotherapy agents in testicular tumor cells, resulting in drug resistance. In the present study, we aimed to use specific siRNA to silence the expression of the MDR1 gene and P-gp, leading to the reversal of multidrug resistance of testicular tumors and contributing a suitable condition for chemotherapy. Ultrasound microbubble-mediated delivery is a safe and effective tool for gene delivery. In the present study, we demonstrated that ultrasound microbubble-mediated delivery effectively improved the siMDR1 gene transfection in interstitial capillary endothelial cells of the testis, inhibited the expression of P-gp and increased daunorubicin accumulation. The testis tumor model was successfully constructed by injecting 1x10(7) yolk sac tumor cells in 3-week-old Sprague-Dawley rats. Ultrasound microbubble-mediated siMDR1 gene therapy improved the effect of chemotherapy on the testicular tumors. The testicular volume was reduced, the number of tumor cells within the testicular tissues decreased, and pathological changes were mostly recovered. Therefore, the present study indicated that ultrasound microbubble-mediated siMDR1 gene therapy in vivo reversed drug resistance by regulating P-gp expression, providing a promising method for the treatment of testicular tumors.

The E3 ubiquitin protein ligase HERC2 modulates the activity of tumor protein p53 by regulating its oligomerization

The tumor suppressor p53 is a transcription factor that coordinates the cellular response to several kinds of stress. p53 inactivation is an important step in tumor progression. Oligomerization of p53 is critical for its posttranslational modification and its ability to regulate the transcription of target genes necessary to inhibit tumor growth. Here we report that the HECT E3 ubiquitin ligase HERC2 interacts with p53. This interaction involves the CPH domain of HERC2 (a conserved domain within Cul7, PARC, and HERC2 proteins) and the last 43 amino acid residues of p53. Through this interaction, HERC2 regulates p53 activity. RNA interference experiments showed how HERC2 depletion reduces the transcriptional activity of p53 without affecting its stability. This regulation of p53 activity by HERC2 is independent of proteasome or MDM2 activity. Under these conditions, up-regulation of cell growth and increased focus formation were observed, showing the functional relevance of the HERC2-p53 interaction. This interaction was maintained after DNA damage caused by the chemotherapeutic drug bleomycin. In these stressed cells, p53 phosphorylation was not impaired by HERC2 knockdown. Interestingly, p53 mutations that affect its tetramerization domain disrupted the HERC2-p53 interaction, suggesting a role for HERC2 in p53 oligomerization. This regulatory role was shown using cross-linking assays. Thus, the inhibition of p53 activity after HERC2 depletion can be attributed to a reduction in p53 oligomerization. Ectopic expression of HERC2 (residues 2292-2923) confirmed these observations. Together, these results identify HERC2 as a novel regulator of p53 signaling.

Tumor therapy with a urokinase plasminogen activator-activated anthrax lethal toxin alone and in combination with paclitaxel

PA-U2, an engineered anthrax protective antigen that is activated by urokinase was combined with wildtype lethal factor in the treatment of Colo205 colon adenocarcinoma in vitro and B16-BL6 mouse melanoma in vitro and in vivo. This therapy was also tested in combination with the small molecule paclitaxel, based on prior reports suggesting synergy between ERK1/2 inhibition and chemotherapeutics. Colo205 was sensitive to PA-U2/LF while B16-BL6 was not. For the combination treatment of B16-BL6, paclitaxel showed a dose response in vitro, but cells remained resistant to PA-U2/LF even in the presence of paclitaxel. In vivo, each therapy slowed tumor progression, and an additive effect between the two was observed. Since LF targets tumor vasculature while paclitaxel is an antimitotic, it is possible the agents were acting against different cells in the stroma, precluding a synergistic effect. The engineered anthrax toxin PA-U2/LF warrants further development and testing, possibly in combination with an antiangiogenesis therapy such as sunitinib or sorafinib.