Chemotherapy-Induced Peripheral Neuropathy (CIPN) as a Predictor of Decreased Quality of Life in Testicular Germ Cell Tumor Survivors

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) after curative treatment for testicular germ cell tumors (GCTs) has been previously reported. It has been shown that CIPN can contribute to impaired quality of life (QOL) in cancer survivors. Herein, we aimed to evaluate CIPN in association with QOL in GCT survivors.

PATIENTS AND METHODS

European Organization for Research and Treatment of Cancer (EORTC) Quality of Life - Chemotherapy-Induced Peripheral Neuropathy questionnaire (QLQ-CIPN20) and Quality of Life Questionnaire (QLQ-C30) were prospectively completed by GCT survivors (N = 151) at National Cancer Institute in Slovakia during their annual follow-up. The median follow-up was 10 years (range 4-30). Upon obtaining the scores from each questionnaire, each score from QLQ-C30 was correlated with CIPN defined as high or low (above and below median) as obtained from CIPN20.

RESULTS

GCT survivors with high overall CIPN score reported impaired QOL in QLQ-C30. The global health status was lower in survivors with high CIPN versus low CIPN (mean score ± SEM: 67.17 ± 2.00 vs. 86.18 ± 1.76, P < .00001). Survivors with high CIPN reported worse physical, role, emotional, cognitive, and social functioning compared to survivors with low CIPN (all P < .00001). CIPN high survivors perceived more fatigue, nausea, pain, dyspnea, sleeping disorders, and appetite loss compared to CIPN low survivors (all P < .004). Higher burden of CIPN was associated with more financial problems vs CIPN low (mean score ± SEM: 19.70 ± 2.64 vs. 6.67 ± 2.32, P = .00025). Spearman analysis has confirmed negative correlation of overall CIPN20 score with QLQ-C30 global health status (R = -0.53, P < .0001).

CONCLUSION

CIPN is a strong predictor of impairment in QOL among GCT survivors. Molecular mechanisms of neurotoxicity should be intensively studied to find preventive and therapeutic strategies.

Abstract P5-11-04: Differentially expressed genes and their pathways in breast cancer patients with mesenchymal CTC

Background: Circulating tumor cells (CTC) with phenotype of epithelial-mesenchymal transition (CTC_EMT) represent novel subpopulation of CTC associated with inferior outcome in primary breast cancer (PBC). However, molecular characterization of primary tumors associated with this CTC subpopulation is lacking. The aim of this study was to identify signaling pathways associated with presence of CTC_EMT in PBC patients using a comprehensive genomics approach. Methods: This translational study included 17 patients with PBC and 5 donors of normal breast tissue. CTC_EMT were detected before surgery by quantitative RT-PCR assay for expression of epithelial-mesenchymal transition (EMT) genes (TWIST1, SNAIL1, SLUG, ZEB1). Total RNA was extracted, in parallel, from fresh frozen primary tumor and whole-trancriptome profiles were obtained using RNA sequencing and additionally mRNAs profiles by microarray. Genes expressions were further validated by qRT-PCR. Results: Analyzing RNA sequencing and microarray data, we found set of genes differentially expressed in absence or presence of CTC_EMT in PBC. We identified 157 genes differentially expressed in CTC_EMT phenotype compared to patients with non-detectable CTC. Namely, keratin family is represented by genes KRT5, KRT14, KRT17. Gene ontologies related to membrane structure or communication and immunology appears to be involved in CTC-related processes, pathways related to cell junction and various signaling pathways including PI3K and Ras-signaling appear to be significant in processes leading to CTC EMT presence. Conclusions: We suspect multiple genes of having a role in primary tumour processes leading to CTC EMT production in breast cancer patients. Data suggest, that PI3K & Ras-signalling and pathways related to cell junction are the key pathways for changes inside of primary tumour tissue between CTC EMT and CTC- phenotype of breast cancer patients. We propose, additional study with single-cell resolution is needed for better understanding of the processes.

Citation Format: Michal Mego, Dominik Hadzega, Gabriel Minarik, Andrea Soltysova, Petra Nemcova, Katarina Kalavska, Marian Karaba, Juraj Benca, Tatiana Sedlackova, Daniel Pindak, Lubos Klucar. Differentially expressed genes and their pathways in breast cancer patients with mesenchymal CTC [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-11-04.

Association of plasma vitamin D with outcomes in patients with germ cell tumour

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Background: Testicular cancer is the most common malignancy among young men. Vitamin D has pluripotent effects on cancer pathogenesis and plays a role in the metastatic cascade. The aim of this study is to analyze plasma vitamin D in association with clinico-pathological findings and prognosis in patients with testicular germ-cell tumours (GCTs). Methods: This study included 120 newly diagnosed and/or relapsed GCTs patients treated from April 2013 to July 2020. Blood samples were drawn at the time before 1st chemotherapy cycle as well as before the 2nd cycle. Plasma vitamin D was measured using ELISA and matched with disease characteristics and correlated with the patient outcome. For survival analysis the cohort was dichotomized to “low” and “high” based on median vitamin D. Results: Mean ± standard error of mean plasma vitamin D in GCTs patients was 15.87±0.68 mg/ml. Patients with brain metastases had significantly lower D vitamin compared to patients without brain metastases (10.9 ± 3.05 vs 15.99 ± 0.7, p=0.034). Vitamin D was not associated with other patient characteristics. Low vitamin D was associated with an unfavorable response compared to favorable responses (11.26 ± 1.84 vs 16.47± 0.74, p=0.016), with disease recurrence (16.19 vs 13.71, p=0.011) and with inferior progression-free survival but not with overall survival (HR= 3.02, 95%CI (1.36-6.71), p=0.014 for PFS and HR= 2.06, 95%CI (0.84 – 5.06), p=0.135 for OS, respectively). Conclusions: Our study suggests a prognostic value of pretreatment vitamin D concentrations in GCTs patients. Low plasma vitamin D was associated with unfavorable response to therapy and disease recurrence. However, it remains to elucidated whether the biology of the disease confirms a causative role of low vitamin D and if its supplementation affects the outcome.

Peripheral blood immune cell profiling in survivors of testicular germ cell tumors

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Background: Testicular germ cell tumors (GCT) achieve exceptional cure rate with cisplatin-based chemotherapy. Survivors of GCTs represent a unique population to study post-cancer treatment physiology and late toxicities. The impact of cancer treatment on the immune-cell profile in long-term GCT survivors is unknown. In this study, we performed an immune-phenotyping in survivors of GCTs. Methods: Whole peripheral blood was obtained from GCT survivors (N = 202) at National Cancer Institute of Slovakia within the protocol of the ongoing survivorship study on a day of their annual follow-up visit. The median follow-up was 11 years (2-25). GCT survivors were distributed into treatment groups: RT – radiotherapy to the retroperitoneum (N = 18), CT - chemotherapy (N = 143), CTRT - chemotherapy + radiotherapy (N=9); and a control group: AS - active surveillance/orchiectomy only (N=32). Immuno-phenotyping of peripheral blood leukocyte populations was performed with flow-cytometry. Immune cell subpopulations were statistically assessed for associations with received treatment. Results: Survivors treated with RT vs AS had higher no of classical dendritic cells (DCs) (mean ± SEM = 82.0 ± 1.9 vs 76.5 ±1.5, p = 0.03) and non-significantly lower no of plasmacytoid DCs and CD16+ DCs (0.11 ± 0.01 vs 0.15 ± 0.01, p = 0.06 and 54.4 ± 4.1 vs 64.8 ± 3.2, p = 0.07, respectively). Survivors treated with CT vs AS had higher no of CD19+ B cells (11.9 ± 0.3 vs 10.4 ± 0.7, p = 0.04)and lower no of CD8+ T cells (26.0 ± 1.3 vs 23.7 ± 0.6, p = 0.04). Similarly, survivors treated with CTRT vs AS had higher no of CD19+ B cells (13.6 ± 1.4 vs 10.4 ± 0.7, p = 0.04) and lower no of CD8+ T cells (20.7 ± 2.4 vs 26.0 ± 1.3, p = 0.04). Survivors treated with ≥ 400mg/m2 of cisplatin-based chemotherapy vs AS had no of CD19+ B cells (12.2 ± 0.5 vs 10.4 ± 0.7, p = 0.04) and lower no of CD8+ T cells (23.4 ± 0.9 vs 26.3 ±1.3, p = 0.04). The immunoregulatory index CD4/CD8 was higher in CTRT vs AS (2.5 ± 0.3 vs 1.8 ± 0.1, p = 0.04). Conclusions: Certain subpopulations of leukocytes differ according to received treatment in survivors of GCTs. Our results may suggest that chemotherapy and/or radiotherapy may produce long-term immunomodulatory effects. Interplay between B and T cells may be a contributing mechanism of late toxicities. Further research is needed to uncover the causal relationship to the long-term health of GCT survivors.

Prognostic value of circulating cell-free DNA in association with choriocarcinoma syndrome development in patients with germ cell tumors

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Background: Germ cell tumors (GCTs) represent a highly curable malignancy; however, a small portion of patients can develop choriocarcinoma syndrome (CS) connected with acute respiratory distress syndrome (ARDS) with high mortality rate shortly after the chemotherapy start. The aim of this study was to assess the prognostic value of circulating cell-free – extracellular DNA (ecDNA) in patients with GCTs and its association with CS development and outcome. Methods: This study included 23 patients with poor-prognosis GCTs treated from November 2002 to May 2018 at the National Cancer Institute in Slovakia. Pre-treatment total ecDNA, nuclear (ncDNA) and mitochondrial DNA (mtDNA) were quantified in plasma using fluorometry and real-time PCR and analyzed in association with CS development and survival. Results: Four (17%) patients developed CS and all of them died due to ARDS shortly after the chemotherapy start. Total ecDNA, but not ncDNA or mtDNA were associated with CS development. Four out of 11 (37%) patients with high plasma ecDNA developed CS compared to 0 out of 12 (0%) patients with low plasma ecDNA (p = 0.037). In univariate analysis, higher concentration of ecDNA also positively correlated with ECOG PS ≥2, metastatic lung involvement ≥50%, weight loss ≥10%, hemoglobin ≤100 g/l, and neutrophil to lymphocyte ratio ≥ 3.3 at the time of presentation. Patients with low ecDNA had significantly better PFS (HR = 0.35, 95% CI 0.11-1.17, p = 0.043) and OS (HR = 0.26, 95% CI 0.06-1.20, p = 0.032) compared to patients with high pretreatment concentration of ecDNA. Conclusions: In this study we have proved that quantitative analysis of plasma ecDNA has prognostic value for CS development in patients treated due to GCTs. Further research focused on the biology of ecDNA may help us to understand its role as a biomarker, but also a potentially treatable pathogenic factor for choriocarcinoma syndrome development.

Prognostic role of plasma vitamin D and its association with disease characteristics in germ cell tumours

Background

Testicular cancer is the most common malignancy among young men. Vitamin D has pluripotent effects on cancer pathogenesis and plays a role in the metastatic cascade. The aim of this study is to analyze plasma vitamin D in association with clinico-pathological findings and prognosis in patients with germ-cell tumors (GCTs).

Methods

This study included 120 newly diagnosed and/or relapsed GCT patients treated from April 2013 to July 2020, for whom plasma was available in the biobank. Blood samples were drawn the 1st chemotherapy cycle as well as before the 2nd cycle. Plasma vitamin D was measured using ELISA and correlated with disease characteristics and the outcome. For survival analysis, the cohort was dichotomized into "low" and "high" based on median vitamin D.

Results

There was no significant difference in vitamin D plasma levels between healthy donors and GCT patients (p = 0.71). Vitamin D level was not associated with disease characteristics except for brain metastases, where patients with brain metastases had a vitamin D level that was 32% lower compared to patients without brain metastases, p = 0.03. Vitamin D was also associated with response to chemotherapy, with an approximately 32% lower value in patients with an unfavorable response compared to a favorable response, p = 0.02. Moreover, low plasma levels of vitamin D were significantly associated with disease recurrence and inferior progression-free survival (PFS), but not with overall survival (OS) (HR = 3.02, 95% CI 1.36-6.71, p = 0.01 for PFS and HR = 2.06, 95% CI 0.84-5.06, p = 0.14 for OS, respectively).

Conclusion

Our study suggests the prognostic value of pretreatment vitamin D concentrations in GCT patients. Low plasma vitamin D was associated with an unfavorable response to therapy and disease recurrence. However, it remains to be determined whether the biology of the disease confirms a causative role for low vitamin D and whether its supplementation affects the outcome.

Cognitive impairment and biomarkers of gut microbial translocation in testicular germ cell tumor survivors

Background

Survivors of testicular germ cell tumors (GCT) may suffer from late cognitive impairment. We hypothesized that disruption of intestinal barrier during chemotherapy and/or radiotherapy may be a contributing factor of cognitive dysfunction within the gut-blood-brain axis.

Methods

GCT survivors (N = 142) from National Cancer Institute of Slovakia completed the Functional Assessment of Cancer Therapy Cognitive Function questionnaires during their annual follow-up visit at 9-year median (range 4-32). Biomarkers of gut microbial translocation and dysbiosis high mobility group box-1 (HMGB-1), lipopolysaccharide, d-lactate and sCD14 were measured from peripheral blood obtained during the same visit. Each questionnaire score was correlated with biomarkers. Survivors were treated with orchiectomy only (N = 17), cisplatin-based chemotherapy (N = 108), radiotherapy to the retroperitoneum (N = 11) or both (N = 6).

Results

GCT survivors with higher sCD14 (above median) had worse cognitive function perceived by others (CogOth domain) (mean ± SEM; 14.6 ± 0.25 vs 15.4 ± 0.25, p = 0.019), lower perceived cognitive abilities (CogPCA domain) (20.0 ± 0.74 vs 23.4 ± 0.73, p = 0.025) and lower overall cognitive function score (109.2 ± 0.74 vs 116.7 ± 1.90, p = 0.021). There were no significant cognitive declines associated with HMGB-1, d-lactate and lipopolysaccharide. Survivors treated with ≥ 400mg/m2 vs < 400mg/m2 of cisplatin-based chemotherapy had a higher lipopolysaccharide (567.8 μg/L ± 42.7 vs 462.9 μg/L ± 51.9, (p = 0.03).

Conclusions

sCD14 is a marker of monocytic activation by lipopolysaccharide and may also serve as a promising biomarker of cognitive impairment in long-term cancer survivors. While chemotherapy and radiotherapy-induced intestinal injury may be the underlying mechanism, further research using animal models and larger patient cohorts are needed to explore the pathogenesis of cognitive impairment in GCT survivors within the gut-brain axis.

Effect of the PARP inhibitor veliparib on germ cell tumor cell lines

Germ cell tumors (GCTs) usually represent efficiently curable neoplasms due to their chemosensitivity to platinum-based therapeutic regimen. However, some patients develop therapeutic resistance and succumb to their disease. Novel therapeutic approaches are therefore needed for these patients. It has previously been demonstrated that poly (ADP-ribose) polymerase (PARP) expression is upregulated in GCTs compared with normal testis tissue. Therefore, PARP expression was analyzed in GCT cell lines and xenografts and it was examined whether its inhibition by veliparib can reverse cisplatin-resistance. Its expression was analyzed in sensitive and cisplatin-resistant variants (referred to as CisR throughout the manuscript) GCT cell lines and xenografts using quantitative PCR, western blotting and immunohistochemistry. The present study investigated whether the combination of cisplatin with the PARP inhibitor veliparib increased the cytotoxic effect of cisplatin in vitro using a luminescent viability assay and an immunodeficient mouse model in vivo. PARP expression was observed in all tested cell lines, with the highest expression in embryonal carcinoma (EC) cell lines and xenografts. Low or no expression was detected in the JEG-3 choriocarcinoma cell line pairs and xenografts. The combination of veliparib and cisplatin or carboplatin was examined in the cisplatin-resistant NTERA-2 CisR and NCCIT CisR EC cell lines and synergistic effects were observed in NTERA-2 CisR cells. However, in vivo analysis did not confirm this synergy. The present data indicated PARP expression in GCT cell lines and xenografts. However, veliparib failed to increase the cytotoxicity of platinum-based drugs. Therefore, further research is warranted to effectively inhibit PARP using different PARP inhibitors or other drug combinations.

Vitamin D and circulating tumor cells in primary breast cancer

Background

Circulating tumor cells (CTCs) contribute to the metastatic cascade and represent an independent survival predictor in breast cancer (BC) patients. Vitamin D has pleiotropic effects, and its low concentrations are associated with breast cancer and metastasis. The aim of this study was to assess plasma vitamin D in primary BC patients in relation to CTCs.

Methods

This study included 91 non-metastatic BC patients (stage I–III) and 24 healthy donors. Blood samples for the analyses were drawn at the time of surgery. CTCs were assessed using a quantitative RT-PCR assay for expression of epithelial (CK19) or epithelial-to-mesenchymal transition (EMT) genes (TWIST1, SNAIL1, SLUG, and ZEB1). Total 25-OH vitamin D was measured in plasma using ELISA. Plasma cytokines and angiogenic factors were measured by enzyme-linked immunoassay.

Results

CTCs were detected in 30 (33%) patients. Patients with detectable CTCs in peripheral blood had significantly lower vitamin D concentrations in comparison to patients without detectable CTCs ((mean ± SD) 8.50 ± 3.89 µg/L for CTC-positive vs 9.69 ± 3.49 µg/L for CTC-negative patients, p = 0.03). The mean ( ± SD) vitamin D plasma level was 9.3 ± 3.65 µg/L for breast cancer patients compared to 18.6 ± 6.8 for healthy donors (p < 0.000001). There was no association between plasma vitamin D and other patient/tumor characteristics. Plasma vitamin D levels are inversely correlated with plasma TGF-β1, TGF-β2, IL β, IL-5, and eotaxin (all p < 0.05). Patients with vitamin D above the median had a better overall survival (hazard ratio (HR) = 0.36, 95% CI 0.16–0.80, p = 0.017), and combined analysis showed the best survival for CTC-negative patients with vitamin D levels above the median as compared to patients with opposite characteristics (HR = 0.18, 95% CI 0.05–0.63, p = 0.004).

Conclusions

Low vitamin D could be a consequence and hence a biomarker of a more invasive disease. Alternatively, vitamin D could be associated with survival because of its role in tumor dissemination. Whether its supplementation affects the metastatic cascade should be tested in animal experiments and interventional studies.

Effects of primary granulocyte‑colony stimulating factor prophylaxis on the incidence of febrile neutropenia in patients with germ cell tumors

Testicular germ cell tumors (GCTs) are the most common solid malignancy in males aged 15–35 years. Febrile neutropenia (FN) is a serious complication of chemotherapy that frequently occurs in patients with GCTs. The present retrospective study aimed to evaluate the effect of primary granulocyte-colony stimulating factor (G-CSF) prophylaxis on the incidence of FN in patients with GCTs. The present study included a review of the medical records of patients diagnosed with GCTs treated with first-line/adjuvant chemotherapy between January 2000 and December 2017 at the National Cancer Institute (Bratislava, Slovakia). In January 2006, a decision was made to administer G-CSF prophylaxis (filgrastim or pegfilgrastim) to patients after every cycle of chemotherapy. The present study included 385 patients, and out of these, 264 patients received primary G-CSF prophylaxis, while 121 patients did not. A total of 71 patients (18.4%) suffered from FN events. In the subgroup that did not receive primary prophylaxis, 42 patients exhibited FN, while only 29 patients with primary prophylaxis suffered from FN (34.7 vs. 11.0%; P=0.00000003). According to the subgroup analysis, FN incidence was decreased in all groups that received primary prophylaxis, except for patients with stage I GCT receiving adjuvant chemotherapy, without affecting overall survival. Primary G-CSF prophylaxis was associated with markedly reduced FN incidence in patients treated with first-line chemotherapy for metastatic disease. Therefore, the results of the present study suggested that primary G-CSF prophylaxis should be considered in patients with GCT receiving first-line chemotherapy.

Phase II study of Disulfiram and Cisplatin in Refractory Germ Cell Tumors. The GCT-SK-006 phase II trial

BACKGROUND

Multiple relapsed/refractory germ cell tumor (GCT) patients have extremely poor prognosis. Cisplatin resistant testicular GCTs overexpress aldehyde-dehydrogenase (ALDH) isoforms and inhibition of ALDH activity by disulfiram is associated with reconstitution of cisplatin sensitivity in vitro as well as in animal model. This study aimed to determine the efficacy and toxicity of ALDH inhibitor disulfiram in combination with cisplatin in patients with multiple relapsed/refractory GCTs.

METHODS

Disulfiram was administered at a dose of 400 mg daily until progression or unacceptable toxicity, cisplatin was administered at dose 50 mg/m² day 1 and 2, every 3 weeks. Twelve evaluable patients had to be enrolled into the first cohort, and if 0 of 12 patients had treatment response, the study was to be terminated. The results of the first stage of the trial are presented in this report.

RESULTS

Twelve patients with multiple relapsed/refractory GCTs were enrolled in the phase II study from May 2019 to September 2021. Median number of treatment cycles was 2 (range 1-6). None of patients achieved objective response to treatment, therefore the study was terminated in first stage. Median progression-free survival was 1.4 months, 95% CI (0.7-1.5 months), and median overall survival was 2.9 months 95% CI (1.5-4.7 months). Disease stabilization for at least 3 months was observed in 2 (16.7%) patients. Treatment was well tolerated, however, 5 (41.7%) of patients experienced grade 3/4 fatigue, 4 (33.3%) thrombocytopenia, 3 (25.0%) anemia, while 2 (16.7%) experienced neutropenia, nausea and infection.

CONCLUSIONS

This study failed to achieve its primary endpoint and our data suggest limited efficacy of disulfiram in restoring sensitivity to cisplatin in multiple relapsed/refractory GCTs.

Factors Associated With Choriocarcinoma Syndrome Development in Poor-Risk Patients With Germ Cell Tumors

Background

Germ cell tumors (GCTs) represent a highly curable cancer. However, a small proportion of poor-risk patients can develop choriocarcinoma syndrome (CS) connected with acute respiratory distress syndrome (ARDS) with a high mortality rate. Our retrospective study aimed to determine the risk factors of poor-risk GCTs susceptible to CS development.

Patients and Methods

Using a computerized database and a systematic chart review, we identified the records of 532 patients with GCTs treated at the National Cancer Institute from 2000 to 2018. Ninety eligible patients with poor-risk GCTs based on IGCCCG classification were identified. All patients were treated with platinum-based induction chemotherapy. Clinicopathological variables were collected and analyzed in correlation with CS development.

Results

Nine (10%) of 90 patients developed CS in a median of 1 day (1–9 days) after chemotherapy administration. All patients died shortly after the chemotherapy start with a median of 4 days (3–35 days) due to ARDS development. In univariate analysis, metastatic lung involvement ≥50% of lung parenchyma, choriocarcinoma elements in histology specimen, dyspnea, cough, hemoptysis, ECOG PS ≥2, weight loss, hemoglobin ≤100 g/l, and NLR ≥3.3 at the time of presentation were associated with CS development. In multivariate analysis, ECOG PS ≥2 and metastatic lung involvement ≥50% were independently associated with CS. All patients with these two characteristics developed CS, compared to 0% with zero or one of these factors (p < 0.000001).

Conclusions

In our study, we identified factors associated with CS development. These factors might improve the risk stratification of the patients susceptible to CS and improve their outcome.

Phase II study of disulfiram (D) and cisplatin (P) in refractory germ cell tumors (GCTs)

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Background: Multiple relapsed/refractory GCTs patients have extremely poor prognosis, therefore, new treatment strategies are warranted. Previously, we showed, that cisplatin resistant testicular GCTs overexpress aldehyde-dehydrogenase (ALDH) isoforms and inhibition of ALDH activity by disulfiram is associated with reconstitution of cisplatin sensitivity in vitro as well as in animal model. This study aimed to determine the efficacy and toxicity of ALDH inhibitor disulfiram in combination with cisplatin in patients with multiple relapsed/refractory germ cell cancer. Methods: Twelve patients with multiple relapsed/refractory GCTs were enrolled in the phase II study from May 2019 to September 2021. All patients were pretreated with at least 2 cisplatin-based therapies (median 4, range 2 – 7); 6 tumors (50.0%) were absolutely refractory to cisplatin and 9 patients (75.0%) had visceral non-pulmonary metastases. Disulfiram was administered at a dose of 400 mg daily until progression or unacceptable toxicity, cisplatin was administered at dose 50 mg/m2 day 1 and 2, every 3 weeks. Twelve evaluable patients had to be enrolled into the first cohort, and if 0 of 12 patients had treatment response, the study was to be terminated. The results of the first stage of the trial are presented in the this report. Results: Median age was 36 years (range: 29 – 48 years). Median number of treatment cycles was 2 (range 1 – 6). During a median follow-up period of 3.1 months (range: 1.3 – 13.9), all (100%) patients experienced disease progression and died. None of patients achieved objective response to treatment, therefore the study was terminated in first stage. Median progression-free survival (PFS) was 1.4 months, 95% CI (0.7 – 1.5 months), and median overall survival (OS) was 2.9 months 95% CI (1.5 – 4.7 months). Disease stabilization for at least 6 months was observed in 2 (16.7%) patients. Treatment was well tolerated, however, 5 (41.7%) of patients experienced grade 3/4 fatigue, 4 (33.3%) thrombocytopenia, 3 (25.0%) anemia, while 2 (16.7%) experienced neutropenia, nausea and infection. Conclusions: This study failed to achieve its primary end point and our data suggest limited efficacy of disulfiram in restoring sensitivity to cisplatin in multiple relapsed/refractory germ cell tumors. Clinical trial information: NCT03950830.

Circulating tumor cells and vitamin D in primary breast cancer

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Background: Circulating tumor cells (CTCs) contributing to the metastatic cascade and represent an independent survival predictor in breast cancer (BC) patients. Vitamin D has pleiotropic effects and its low concentrations are associated with infections, cancer, but also other pathologic conditions. The aim of this study was to assess plasma vitamin D level in primary BC patients in relation to CTCs. Methods: This study included 91 non-metastatic breast cancer patients (stage I-III) with plasma samples available in the biobank of the National Cancer Institute in Slovakia. Blood samples for the analyses were drawn at the time of surgery. Peripheral blood mononuclear cells (PBMCs) were depleted of hematopoetic cells using RossetteSepTM negative selection kit. RNA extracted from CD45-depleted PBMCs was analyzed for the expression of transcription factors (TWIST1, SNAIL1, SLUG, ZEB1) that induce epithelial-to-mesenchymal transcription (EMT-TF) and epithelial ( CK19) gene transcripts using qRT-PCR. Patient samples with higher epithelial and/or mesenchymal gene transcripts than those of healthy donors (n = 60) were considered CTCs positive. Total 25-OH vitamin D was measured in plasma using ELISA. Results: CTCs were detected in 30 (33%) patients, 14 (15.4%) patients had detectable CTCs with epithelial characteristics, 13 (14.3%) patients had CTCs with an EMT phenotype, while peripheral blood of 3 (3.3%) patients exhibit both CTCs subtypes. Patients with detectable CTCs in peripheral blood had significantly lower vitamin D concentrations in comparison to patients without detectable CTCs (mean ± SD) 8.50 ± 3.89 µg/L for CTCs positive vs. 9.69 ± 3.49 µg/L for CTCs negative patients respectively, P = 0.03). There was no association between plasma vitamin D and other patient/tumor characteristics. At a median follow-up of 96.5 months (range: 8.4 - 109.4 months), 28 patients (30.8%) had experienced a progression and 24 patients (26.4%) had died. Patients with vitamin D above median had better overall survival (HR = 0.36, 95%CI 0.16 – 0.80, P = 0.017) compared to patients below median vitamin D. Conclusions: According to our knowledge, this is the first report of an association between plasma vitamin D concentrations and CTCs in primary breast cancer patients. We suggest that vitamin D could play a direct role in tumor dissemination and its supplementation might affect metastatic cascade. Alternatively, decreased vitamin D could be a consequence and hence a biomarker of a more invasive disease. Animal experiments and interventional studies are needed to prove the causality of the observed association.

Overcoming Chemotherapy Resistance in Germ Cell Tumors

Testicular germ cell tumors (GCTs) are highly curable malignancies. Excellent survival rates in patients with metastatic disease can be attributed to the exceptional sensitivity of GCTs to cisplatin-based chemotherapy. This hypersensitivity is probably related to alterations in the DNA repair of cisplatin-induced DNA damage, and an excessive apoptotic response. However, chemotherapy fails due to the development of cisplatin resistance in a proportion of patients. The molecular basis of this resistance appears to be multifactorial. Tracking the mechanisms of cisplatin resistance in GCTs, multiple molecules have been identified as potential therapeutic targets. A variety of therapeutic agents have been evaluated in preclinical and clinical studies. These include different chemotherapeutics, targeted therapies, such as tyrosine kinase inhibitors, mTOR inhibitors, PARP inhibitors, CDK inhibitors, and anti-CD30 therapy, as well as immune-checkpoint inhibitors, epigenetic therapy, and others. These therapeutics have been used as single agents or in combination with cisplatin. Some of them have shown promising in vitro activity in overcoming cisplatin resistance, but have not been effective in clinical trials in refractory GCT patients. This review provides a summary of current knowledge about the molecular mechanisms of cisplatin sensitivity and resistance in GCTs and outlines possible therapeutic approaches that seek to overcome this chemoresistance.

Chromosome 3p25.3 Gain Is Associated With Cisplatin Resistance and Is an Independent Predictor of Poor Outcome in Male Malignant Germ Cell Tumors

Cisplatin is the main systemic treatment modality for male type II germ cell tumors (GCTs). Although generally very effective, 5%-10% of patients suffer from cisplatin-resistant disease. Identification of the driving mechanisms of resistance will enable improved risk stratification and development of alternative treatments.

Comprehensive Assessment of Selected Immune Cell Subpopulations Changes in Chemotherapy-Naïve Germ Cell Tumor Patients

The pattern of immune cell distribution in testicular germ cell tumors (GCT) significantly differs from the immune environment in normal testicular tissues. The present study aimed to evaluate the role of different leukocyte subpopulation in GCTs. A cohort of 84 chemotherapy-naïve GCT patients was analyzed. Immunophenotyping of peripheral blood leukocyte subpopulations was carried out by flow cytometry. In addition, the data assessing the immunophenotypes and the baseline clinicopathological characteristics of the included subjects were statistically evaluated. Their prognostic value for the assessment of progression-free survival (PFS) and overall survival (OS) was estimated. The percentage of different innate/adaptive immune cell subpopulations was significantly associated with poor risk-related clinical features, including the number of metastatic sites, presence of retroperitoneal, mediastinal, lung, brain and non-pulmonary visceral metastases as well as with the S-stage and International Germ Cell Consensus Classification Group (IGCCCG) risk groups. In univariate analysis, the percentages of neutrophils, eosinophils, dendritic cells type 2, lymphocytes and T cytotoxic cells were significantly associated with PFS, while the neutrophil, non-classical monocyte and lymphocyte percentage were associated with OS. However, all these outcome correlations were not independent of IGCCCG in multivariate analysis. The data indicated a link among different innate/adaptive peripheral immune cell subpopulations in GCT patients. In addition, the association between these subpopulations and tumor characteristics was also investigated. The findings of the present study may contribute to a deeper understanding of the interactions between cancer and innate/adaptive immune response in GCT patients.

Biomarkers of gut microbial transfer and their association with cognitive impairment in long-term survivors of testicular germ cell tumors

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Background: Survivors of testicular germ cell tumors (GCT) may suffer from long-term cognitive impairment. We hypothesized that disruption of intestinal barrier during chemotherapy and/or radiotherapy may be a contributing factor of cognitive dysfunction within the gut-blood-brain axis. Methods: GCT survivors (N = 142) from National Cancer Institute of Slovakia completed the Functional Assessment of Cancer Therapy Cognitive Function questionnaires during their annual follow-up visit at 9-year median (range 4-32). Biomarkers of gut microbial transfer and dysbiosis (GMT) high mobility group box-1 (HMGB-1), lipopolysaccharide (LPS), d-lactate and sCD14 were measured from peripheral blood obtained during the same visit. Each questionnaire score was correlated with biomarkers of GMT. Survivors were treated with orchiectomy only (N = 17), cisplatin-based chemotherapy (N = 108), radiotherapy to the retroperitoneum (N = 11) or both (N = 6). Results: GCT survivors with higher sCD14 had worse cognitive function perceived by others (CogOth domain) (mean ± SEM; 14.6 ± 0.25 vs 15.4 ± 0.25, p = 0.019), lower perceived cognitive abilities (CogPCA domain) (20.0 ± 0.74 vs 23.4 ± 0.73, p = 0.025) and lower overal cognitive function score (109.2 ± 0.74 vs 116.7 ± 1.90, p = 0.021). There were no significant cognitive declines associated with HMGB-1, d-lactate and LPS. Survivors treated with ≥ 400mg/m2 of cisplatin based chemotherapy had higher LPS (567.8 ± 42.7 vs 462.9 ± 51.9, P = 0.03). Survivors treated with chemotherapy + radiotherapy vs orchiectomy only had non-significantly higher sCD14 (7279.9 ± 810.1 vs 5851.0 ± 481.7, P = 0.09). Conclusions: sCD14 may serve as a promising biomarker of cognitive impairment in long-term cancer survivors. While chemotherapy and radiotherapy-induced intestinal injury may be the underlying mechanism, further research using animal models and larger patient cohorts are needed to explore the pathogenesis of cognitive impairment in GCT survivors.

Low-molecular-weight heparin prophylaxis is not associated with decreased incidence of venous thromboembolism in testicular germ cell tumor patients receiving chemotherapy

Venous thromboembolism (VTE), commonly occurring in patients with testicular germ cell tumors (GCT), is associated with increased morbidity and mortality. Prophylactic anticoagulation has been shown to decrease the risk of VTE in patients with malignancies. The objective was to evaluate the effect of low-molecular-weight heparin (LMWH) prophylaxis on the incidence of VTE and outcome in patients with GCT treated with first-line chemotherapy. In this retrospective study, 353 chemotherapy-naive GCT patients were treated with first-line chemotherapy at the National Cancer Institute, Bratislava, Slovakia (2000-2017). Median follow-up was 71 months. VTE was defined as any venous thrombosis or pulmonary embolism, confirmed by imaging, occurring during first-line chemotherapy. Exclusion criteria were LMWH use before starting chemotherapy and VTE on initial staging. We observed 14 (4.0%) VTE events. No visceral thromboses were observed. The difference in VTE incidence between patients with and without prophylaxis was not statistically significant (5.8% vs. 3.2%, p = 0.37). We observed a trend toward longer overall survival in patients without prophylaxis (hazard ratio = 0.61, 95% confidence interval = 0.32-1.13, p = 0.08). Patients with extragonadal GCT receiving VTE prophylaxis had significantly shorter survival (hazard ratio = 0.29, 95% confidence interval = 0.08-1.12, p = 0.04). This effect was most likely driven by a higher incidence of treatment-related deaths in patients with extragonadal GCT receiving LMWH (p = 0.06). LMWH prophylaxis was not associated with decreased VTE incidence. Moreover, there was a higher incidence of treatment-related deaths in patients with extragonadal tumor location. Low-molecular-weight heparin prophylaxis during hospitalization should not be used routinely in patients with testicular germ cell tumors receiving chemotherapy.

Glycan signatures for the identification of cisplatin‐resistant testicular cancer cell lines: Specific glycoprofiling of human chorionic gonadotropin (hCG)

Background

Testicular cancer (TC) is the most frequent type of cancer among young men aged between 15 and 34 years. TC is treated using cisplatin, but 3%–5% of TC patients fail to respond to cisplatin, with a very bad to fatal prognosis. Accordingly, it is most important to quickly and readily identify those TC patients who are resistant to cisplatin treatment.

Methods

This study seeks to investigate changes in the glycosylation associated with cisplatin resistance to TC cell lines.

Results

A specific glycoprofiling of human chorionic gonadotropin (hCG) was analysed in three TC cell lines and one cell line of female origin. A typical calibration curve for hCG glycoprofiling showed a dynamic range up to 50 ng/ml, with a limit of detection of 0.3 ng/ml and assay reproducibility represented by relative standard deviation of 3.0%. Changes in the glycan signatures on hCG were analysed in cisplatin‐sensitive cell lines and in their cisplatin‐resistant sub‐lines using an enzyme‐linked lectin assay (ELLA) protocol. An immobilised antibody was applied to a selective capture of hCG from a cytoplasmic fraction of cell lysates with final incubation using a lectin from a panel of 17 lectins.

Conclusion

The results suggest that one particular lectin Dolichos biflorus agglutinin (DBA) can selectively discriminate sensitive TC cell lines from resistant TC cell lines. Moreover, there are additional lectins which can provide useful information about the strength of cisplatin resistance.

Uncovering Microbial Composition in Human Breast Cancer Primary Tumour Tissue Using Transcriptomic RNA-seq

Recent research studies are showing breast tissues as a place where various species of microorganisms can thrive and cannot be considered sterile, as previously thought. We analysed the microbial composition of primary tumour tissue and normal breast tissue and found differences between them and between multiple breast cancer phenotypes. We sequenced the transcriptome of breast tumours and normal tissues (from cancer-free women) of 23 individuals from Slovakia and used bioinformatics tools to uncover differences in the microbial composition of tissues. To analyse our RNA-seq data (rRNA depleted), we used and tested Kraken2 and Metaphlan3 tools. Kraken2 has shown higher reliability for our data. Additionally, we analysed 91 samples obtained from SRA database, originated in China and submitted by Sichuan University. In breast tissue, the most enriched group were Proteobacteria, then Firmicutes and Actinobacteria for both datasets, in Slovak samples also Bacteroides, while in Chinese samples Cyanobacteria were more frequent. We have observed changes in the microbiome between cancerous and healthy tissues and also different phenotypes of diseases, based on the presence of circulating tumour cells and few other markers.

Burden of chemotherapy-induced peripheral neuropathy and associations with long-term sexual impairment in testicular germ cell tumor survivors

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Background: Chemotherapy-induced peripheral neuropathy (CIPN20) after curative treatment for testicular germ cell tumors (GCTs) has been previously reported. The association of CIPN with long-term sexual function in GCT survivors remains unclear. Methods: European Organization for Research and Treatment of Cancer (EORTC) CIPN20 and PROMIS modified sexual function (SexF) questionnaires were prospectively completed by GCT survivors (N = 128) at National Cancer Institute in Slovakia during their annual follow-up visit. The median follow-up after completion of treatment was 10 years (range 4-25). Upon obtaining the scores from each questionnaire per recommended guidelines, each score from SexF was correlated with CIPN defined as high or low (above and below median) as obtained from CIPN20. Survivors were treated with cisplatin-based chemotherapy, radiotherapy to the retroperitoneum or both. Results: GCT survivors with CIPN reported a self-perceived sexual impairment. The overall perceived sexual impairment was higher in survivors with high vs low CIPN (mean score ± SEM: 7.44 ± 0.24 vs. 6.76 ± 0.21, P = 0.05). However, the overall perceived sexual abilities were not significantly different in CIPN high vs low (16.9 ± 0.68 vs. 16.8 ± 0.59, P = 0.97). The trend towards higher difficulty in maintaining erection was seen in CIPN high vs low survivors (3.94 ± 0.21 vs. 4.12 ± 0.18, P = 0.07). Furthermore, survivors with CIPN high were more disappointed with the quality of their sex life compared to those with CIPN low (1.96 ± 0.12 vs. 1.47 ± 0.11, P = 0.01). Patients with CIPN high had trend towards more anxiety from sexual relationships compared to CIPN low survivors (1.66 ± 0.11 vs. 1.33 ± 0.10, P = 0.06). The level of sexual desire, number of attempts to initiate sexual intercourse, ability to achieve erection, achieve orgasm were not different ( P all > 0.05). Conclusions: GCT survivors with higher burden of CIPN have certain impairment in sexual functioning. We hypothesize there may be a common pathogenetic mechanism of induction in these long-term toxicities of curative treatments.

Predictive factors for choriocarcinoma syndrome development in high-risk patients with germ cell tumors (GCTs)

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Background: Germ cell tumors (GCTs) represent a highly curable cancer. However, a small proportion of patients with super-high-risk characteristics can develop choriocarcinoma syndrome (CS) connected with acute respiratory distress syndrome (ARDS). CS is defined as a syndrome with hemorrhage from metastatic sites in patients with advanced GCTs with high-volume of choriocarcinoma elements, especially those with a choriogonadotropin level over 50,000 IU/l. CS typically develop shortly after the chemotherapy start with high mortality rate. Our retrospective study aimed to determine the risk factors of high-risk GCTs susceptible to CS development. Methods: Using a computerized database and a systematic chart review, we identified the records of 532 patients with GCTs treated in NCI through 2000 to 2018, and 90 eligible patients with high-risk GCTs relying on IGCCCG classification, were identified. All patients were treated with platinum-based induction chemotherapy. Clinicopathological variables were collected and analyzed in correlation to CS development. Results: Nine (10 %) of 90 patients developed CS in a median of 1 day (1- 9 days) after the chemotherapy administration. All patients died shortly after the chemotherapy start with median of 4 days (3-35 days) due to consecutive ARDS development. Predictive factors for CS development were metastatic lung involvement ≥50% of lung parenchyma, choriocarcinoma elements in histology specimen, dyspnea, cough, hemoptysis, ECOG PS ≥2, weight loss and hemoglobin ≤100 g/l at the time of presentation. In multivariate analysis, ECOG PS ≥2 and metastatic lung involvement ≥50% were independently associated with CS. All patients with these two characteristics developed CS compared to 0% with one or zero of these predictive factors (P < 0.000001). Conclusions: In our study we identified predictive factors for CS development. These factors might improve the risk stratification of the patients susceptible to CS development connected with ARDS as well as to find optimal treatment approach for them.

Phase II study of gemcitabine, carboplatin and veliparib in multiple relapsed/refractory germ cell tumors (GCTs)

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Background: GCTs represent a model for the cure of cancer. Nonetheless, a small proportion of patients develop disease recurrence. PARP is overexpressed in GCTs compared to normal testis and PARP overexpression is early event in GCTs development. Gemcitabine and carboplatin showed activity in refractory GCTs. This study aimed to determine the efficacy and toxicity of gemcitabine, carboplatin and PARP inhibitor, veliparib, in patients with multiple relapsed/refractory GCTs. Methods: Fifteen patients with multiple relapsed/refractory GCTs were enrolled in the phase II study from October 2016 to October 2020. All patients were pretreated with at least 2 cisplatin-based therapies (median 2, range 2 – 4); 3 tumors (20.0%) were absolutely refractory to cisplatin and 5 patients (33.3%) had visceral non-pulmonary metastases. Gemcitabine was administered at a dose 800mg/m2 day 1 and 8 every 3 weeks; carboplatin AUC = 4, day 1, every 3 weeks and veliparib 250mg bid day continuously. The primary end point was 12-months progression-free survival (PFS), if < 8 patients experienced 12-months PFS, the treatment will be considered ineffective. Results: Median age was 31 years (range: 22 – 48 months). Median number of treatment cycles was 4 (range 2 – 8). During a median follow-up period of 9.2 months (range: 1.9 – 23.8), all (100%) patients experienced disease progression and 14 patients (93.3%) died. Twelve-months PFS was achieved in 1 (6.7%) patient. Median PFS was 3.1 months, 95%CI (2.2 – 3.9) and median OS was 10.5 months, 95% CI (8.9 – 11.1). Partial remission was observed in 4 (26.7%) and disease stabilization in 5 (33.3%) of patients. Favorable response (complete or partial remission with negative serum tumor markers) experienced 3 (20%) patients. Treatment was well tolerated, however, 12 (80%) of patients experienced grade 3/4 neutropenia, 9 (60%) anemia, 14 (93.3%) thrombocytopenia and 2 (13.3%) febrile neutropenia. Conclusions: This study failed to achieve its primary end point and our data suggest limited efficacy of gemcitabine, carboplatin and veliparib in multiple relapsed/refractory germ cell tumors. Clinical trial information: NCT02860819.

Abstract PS16-26: The prognostic role of MMP 9 in early breast cancer

Background: Matrix metalloproteinase 9 (MMP9) is involved in the extracellular matrix degradation during physiological and pathological conditions including tumorigenesis. This translational study was aimed to evaluate the prognostic role of the intratumoral MMP9 expression and correlate it with presence of CTCs in early breast cancer. Methods: A total of 318 primary breast cancer (PBC) patients were enrolled into this study. Surgical specimens were processed by the tissue microarray method and subjected to immunohistochemistry using the MMP9 monoclonal antibody. The MMP9 expression was evaluated in tumor cell as well as in tumor associated stroma. Quantitative real-time polymerase chain reaction -based assays was applied for identification of CTCs. Results: Significantly increased expression of MMP9 was found in breast cancer cells when compared to tumor associated stroma. A positive correlation was determined between MMP9 expression and hormone positive status as well as low proliferation index of analysed breast cancer tumour cells. Additionally, in tumor associated stroma was confirmed only the association with hormone receptor status. The univariate survival analysis of whole tested population detected no prognostic role of MMP9 expression neither in tumor cells (HR = 0.96, 95% CI 0.58-1.59, P = 0.864) nor in tumor associated stroma (HR = 1.29, 95% CI 0.60-2.78, P = 0.547). However, the subgroup of in hormone receptor negative and triple negative patients with absence of MMP9 expression in tumor cells and stroma had significantly better disease-free survival (DFS) (HR = 0.33, 95% CI 0.12-0.93, P = 0.025, and (HR = 0.14, 95% CI 0.00-4.81, P = 0.002, respectively) and (HR = 0.17, 95% CI 0.05-0.57, P = 0.003); (HR = 0.12, 95% CI 0.00-4.89, P = 0.001) compared with patients with presence of MMP9. Moreover, while tumor MMP9 was prognostic in CTC_EMT positive subgroup (HR = 0.40, 95% CI 0.16-0.95, P = 0.047), absence of stromal MMP9 had protective role in CTC_EP positive patients (HR = 0.18, 95% CI 0.01-2.75, P = 0.053). Conclusions: Our data suggest that the increased expression of MMP9 in PBC was related with favorable tumor characteristics. However, it´s prognostic value was limited only to hormone receptor negative, triple negative, CTC_EMT and CTC_EP positive subgroups. Therefore, we can suppose that evaluating of MMP9 tumor expression could help identify patients with increased risk of disease recurrence in these subgroups of patients.

Citation Format: Michal Mego, Zuzana Cierna, Marian Karaba, Gabriel Minarik, Juraj Benca, Tatiana Sedlackova, Ivana Mrvova, Daniel Pindak, Katarina Rejlekova, Jozef Mardiak, Katarina Kalavska. The prognostic role of MMP 9 in early breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS16-26.

Increased Stromal Infiltrating Lymphocytes Are Associated with the Risk of Disease Progression in Mesenchymal Circulating Tumor Cell-Positive Primary Breast Cancer Patients

Circulating tumor cells (CTCs) and the immune infiltration of tumors are closely related to clinical outcomes. This study aimed to verify the influence of stromal lymphocyte infiltration and the immune context of tumor microenvironment on the hematogenous spread and prognosis of 282 chemotherapy naïve primary BC patients. To detect the presence of mesenchymal CTCs, RNA extracted from CD45-depleted peripheral blood was interrogated for the expression of mesenchymal gene transcripts. Tumor-infiltrating lymphocytes (TILs) were detected in the stromal areas by immunohistochemistry, using CD3, CD8, and CD45RO antibodies. The concentrations of 51 plasma cytokines were measured by multiplex bead arrays. TILs infiltration in mesenchymal CTC-positive patients significantly decreased their progression-free survival (HR = 4.88, 95% CI 2.30–10.37, p < 0.001 for CD3^high; HR = 6.17, 95% CI 2.75–13.80, p < 0.001 for CD8^high; HR = 6.93, 95% CI 2.86–16.81, p < 0.001 for CD45RO^high). Moreover, the combination of elevated plasma concentrations of transforming growth factor beta-3 (cut-off 662 pg/mL), decreased monocyte chemotactic protein-3 (cut-off 52.5 pg/mL) and interleukin-15 (cut-off 17.1 pg/mL) significantly increased the risk of disease recurrence (HR = 4.838, 95% CI 2.048–11.427, p < 0.001). Our results suggest a strong impact of the immune tumor microenvironment on BC progression, especially through influencing the dissemination and survival of more aggressive, mesenchymal CTC subtypes.

Prognostic role of matrix metalloproteinase 9 in early breast cancer

MMP9 is involved in extracellular matrix degradation during various physiological and pathological conditions, including tumorigenesis. The present study aimed to assess the prognostic role of intratumoral MMP9 and to determine its association with circulating tumor cells (CTCs) in patients with early breast cancer. A total of 318 patients with primary breast cancer (PBC) were enrolled into the present study. Specimens were subjected to immunohistochemistry analysis, using the MMP9 monoclonal antibody. MMP9 expression was scored using a weighted histoscore (WH). The results demonstrated that the mean WH ± SEM for MMP9 expression was significantly higher in breast tumor cells compared with tumor associated stromas (132.0±5.2 vs. 50.8±3.7; P<0.00001). Furthermore, a positive association was observed between MMP9 expression, the hormone positive status and proliferation index of analysed breast cancer tumour cells. Notably, the prognostic role of MMP9 was not observed in tumor cells [hazard ratio (HR) =0.96; 95% confidence interval (CI), 0.58-1.59; P=0.864] or tumor associated stroma (HR=1.29; 95% CI, 0.60-2.78; P=0.547). Subgroup analysis demonstrated that patients that were HR negative or triple negative, with low MMP9 expression in tumor cells and stroma had a significantly improved disease-free survival than patients with high MMP9 expression. Taken together, the results of the present study demonstrated that high MMP9 expression in PBC was associated with favorable tumor characteristics. However, the prognostic value of MMP9 was limited to only the HR negative and CTC epithelial-to-mesenchymal transition positive subgroups. Thus, analyzing MMP9 tumor expression may help identify patients with increased risk of disease recurrence in these subgroups.

Plasma thiobarbituric acid reactive substances predicts survival in chemotherapy naïve patients with metastatic urothelial carcinoma

Oxidative stress plays a significant role in development and progression of cancer, including urothelial carcinomas. TBARS (Thiobarbituric acid reactive substances) represents a marker of oxidative stress increased in various diseases. In this prospective study, we tested the hypothesis of plasma TBARS concentration and correlation with survival in chemotherapy naïve MUC (metastatic urothelial carcinoma) patients. Most of subjects (N = 65) were treated with gemcitabine and cisplatin (GC) chemotherapy. Performance status ECOG ≥2 had 11 patients, visceral metastases were present in 43. Based upon the mean of plasma TBARS, subjects were dichotomized into low and high groups. Progression-free survival (PFS), overall survival (OS) and their 95% CI were estimated by Kaplan-Meier method and compared by log-rank test. At median follow-up of 9.6 months, 65 patients experienced progression and 64 died. Subjects with low TBARS had significantly better PFS (HR 0.51) and OS (HR 0.44) opposed to high TBARS. Patients with low TBARS had significantly higher rate of neutropenia G4 and less liver involvement. High TBARS correlated with BMI above 30 kg/m². Performance status and plasma TBARS were proven to be independent predictors of PFS and OS. In this study, high TBARS in MUC patients were associated with poor survival, likely due to more aggressive disease activity as reflected in increased liver involvement. Therefore, this biomarker could be used in clinical practice for early identification of patients with worse prognosis, better patient stratification, and treatment decision making.

Immunotherapy in Testicular Germ Cell Tumors

Testicular germ cell tumors (TGCTs) are malignancies with very high curative potential even in metastatic settings, mainly due to the introduction of cisplatin in the treatment of this disease. However, in a group of patients with cisplatin-refractory disease or with progressive disease despite high-dose salvage chemotherapy treatment, the prognosis is typically dismal. The triple combination of gemcitabine, oxaliplatin, and paclitaxel (GOP) has reasonable efficacy and is considered to be standard care for this group of patients. It remains to be seen, however, whether refractory TGCTs may represent a potential target for immune checkpoint inhibition. This review will focus on the rationale of the use of immunotherapy for platinum-refractory TGCTs and summarize data reporting experiences with immune checkpoint inhibitor treatment for this malignancy.

Plasma Nucleosomes in Primary Breast Cancer

Simple Summary

Nucleosomes composed of DNA and histone proteins enter the extracellular space and end eventually in the circulation when cells die. In blood plasma, they could represent a nonspecific marker of cell death, potentially useful for noninvasive monitoring of cancer. The aim of this study was to analyze circulating nucleosomes in relation to patient/tumor characteristics and prognosis in nonmetastatic breast cancer. This study included 92 patients with breast cancer treated with surgery. Plasma nucleosomes were detected in samples taken in the morning on the day of surgery. Circulating nucleosomes were positively associated with the systemic inflammation but not with other patient/tumor characteristics. Patients with lower nucleosomes had lower risk of disease recurrence compared to patients with higher nucleosomes. Our data suggest that plasma nucleosomes in nonmetastatic breast cancer are associated with systemic inflammation and might have a prognostic value. The underlying mechanisms require further studies.

Abstract

When cells die, nucleosomes composed of DNA and histone proteins enter the extracellular space and end eventually in the circulation. In plasma, they might serve as a nonspecific marker of cell death, potentially useful for noninvasive monitoring of tumor dynamics. The aim of this study was to analyze circulating nucleosomes in relation to patient/tumor characteristics and prognosis in primary breast cancer. This study included 92 patients with breast cancer treated with surgery for whom plasma isolated was available in the biobank. Plasma nucleosomes were detected in samples taken in the morning on the day of surgery using Cell Death Detection ELISA kit with anti-histone and anti-DNA antibodies. Circulating nucleosomes were positively associated with the systemic inflammatory index (SII), but not with other patient/tumor characteristics. Patients with high SII in comparison to low SII had higher circulating nucleosomes (by 59%, p = 0.02). Nucleosomes correlated with plasma plasminogen activator inhibitor-1, IL-15, IL-16, IL-18, and hepatocyte growth factor. Patients with lower nucleosomes had significantly better disease-free survival (HR = 0.46, p = 0.05). In a multivariate analysis, nucleosomes, hormone receptor status, HER2 status, lymph node involvement, and tumor grade were independent predictors of disease-free survival. Our data suggest that plasma nucleosomes in primary breast cancer are associated with systemic inflammation and might have a prognostic value. The underlying mechanisms require further studies.

Long-term sexual functioning in germ-cell tumor survivors

BACKGROUND

Survivors of germ-cell tumors (GCT) may suffer from long-term adverse consequences. Our study was conducted to assess a long-term sexual functioning in GCT survivors.

METHODS

GCT survivors (N = 170) from the National Cancer Institute in Slovakia completed a Sexual Function Questionnaire that was modified from PROMIS Sexual Function and Satisfaction Questionnaire 9-year median follow up (range 5-32) as a primary exploratory aim. Study groups consisted of 17 survivors (10%) who had active surveillance (AS, controls), and 153 (90%) survivors who received treatment beyond orchiectomy (Tx), including cisplatin-based chemotherapy (CT, N = 132; 78%), radiotherapy to the retroperitoneal lymph nodes (RT, N = 12; 7%) or both (CTRT, N = 9; 5%).

RESULTS

In univariate analysis, treatment of any type resulted in difficulty to maintain erection during sexual intercourse compared to patients treated with AS (P = 0.04). Survivors who received CTRT had lower ability to achieve orgasm during sexual activities (P = 0.04) and they reported disappointment with their overall quality of sex life (P = 0.002). The number of attempts to initiate sexual intercourse did not differ. Sexual relationships caused none or mild anxiety and the desire to be sexually active was higher after CTRT (P = 0.05). Multivariable analysis confirmed that orgasmic dysfunction after ≥400 mg/m² of cisplatin and issues in maintaining erection after Tx were independent of retroperitoneal lymph-node dissection (P = 0.03 and P = 0.04, respectively). Survivors were disappointed with the quality of sex life and had stronger desire to be sexually active independent of age, (P = 0.01 and P = 0.05, respectively).

CONCLUSIONS

This study identified an impairment in sexual function may represent an issue for long-term GCT survivors. Treatment with chemotherapy plus radiotherapy were associated with disappointment and stronger sexual desire, while a higher cumulative dose of cisplatin may be responsible for orgasmic dysfunction.

Napabucasin overcomes cisplatin resistance in ovarian germ cell tumor-derived cell line by inhibiting cancer stemness

Background

Cisplatin resistance of ovarian yolk sac tumors (oYST) is a clinical challenge due to dismal patient prognosis, even though the disease is extremely rare. We investigated potential association between cisplatin resistance and cancer stem cell (CSC) markers in chemoresistant oYST cells and targeting strategies to overcome resistance in oYST.

Methods

Chemoresistant cells were derived from chemosensitive human oYST cells by cultivation in cisplatin in vitro. Derivative cells were characterized by chemoresistance, functional assays, flow cytometry, gene expression and protein arrays focused on CSC markers. RNAseq, methylation and microRNA profiling were performed. Quail chorioallantoic membranes (CAM) with implanted oYST cells were used to analyze the micro-tumor extent and interconnection with the CAM. Tumorigenicity in vivo was determined on immunodeficient mouse model. Chemoresistant cells were treated by inhibitors intefering with the CSC properties to examine the chemosensitization to cisplatin.

Results

Long-term cisplatin exposure resulted in seven-fold higher IC₅₀ value in resistant cells, cross-resistance to oxaliplatin and carboplatin, and increased migratory capacity, invasiveness and tumorigenicity, associated with hypomethylation of differentially methylated genes/promotors. Resistant cells exhibited increased expression of prominin-1 (CD133), ATP binding cassette subfamily G member 2 (ABCG2), aldehyde dehydrogenase 3 isoform A1 (ALDH3A1), correlating with reduced gene and promoter methylation, as well as increased expression of ALDH1A3 and higher overall ALDH enzymatic activity, rendering them cross-resistant to DEAB, disulfiram and napabucasin. Salinomycin and tunicamycin were significantly more toxic to resistant cells. Pretreatment with napabucasin resensitized the cells to cisplatin and reduced their tumorigenicity in vivo.

Conclusions

The novel chemoresistant cells represent unique model of refractory oYST. CSC markers are associated with cisplatin resistance being possible targets in chemorefractory oYST.

DNA damage measured in blood cells predicts overall and progression-free survival in germ cell tumour patients

Germ cell tumour (GCT) patients who fail to respond to chemotherapy or who relapse have a poor prognosis. Timely and accurately stratifying such patients could optimise their therapy. We identified endogenous DNA damage levels as a prognostic marker for progression-free (PFS) and overall (OS) survival in chemotherapy-naïve GCT patients. In the present study, we have extended our previous results and reviewed the prognostic power of DNA damage level in GCTs. Endogenous DNA damage levels were measured with the comet assay. Receiver operator characteristic analysis was applied to determine the optimal cut-off value and to evaluate its prognostic accuracy. PFS and OS were estimated by the Kaplan-Meier method and compared using the log-rank test. Hazard ratio (HR) estimates were calculated by Cox regression analysis. A cut-off value of 6.34 provided the highest sensitivity and specificity, with area under curve values of 0.813 and 0.814 for disease progression and mortality, respectively. A % DNA in tail > 6.34 was significantly associated with shorter PFS (HR = 9.54, 95 % confidence interval [CI]: 3.43-26.55, p < 0.001) and OS (HR = 14.62, 95 % CI: 3.14-67.95, p = 0.001) by univariate analysis. The prognostic value of DNA damage measurement was confirmed by multivariate models (HR = 6.45, 95 % CI: 2.22-18.75, p = 0.001 for PFS and HR = 9.40, 95 % CI: 1.70-52.09, p = 0.010 for OS), when HR was adjusted for relevant clinical categories. The added prognostic value of DNA damage in combination with International Germ Cell Cancer Collaborative Group (IGCCCG) risk groups has been revealed. Endogenous DNA damage is an independent prognosticator for PFS and OS in GCT patients and its clinical use, particularly in combination with IGCCCG risk groups, may help in stratifying these patients.

Prognostic value of circulating nucleosomes in primary breast cancer

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Background: Nucleosomes are composed of DNA wound around histone proteins and represent the basic structural unit of chromatin in the nucleus. When cells die, nucleosomes get out of the cell and end eventually in the circulation. Plasma nucleosomes might serve as a non-specific biomarker of cell death, which might be of particular interest for non-invasive tumor monitoring. The aim of this study was to assess the prognostic value of circulating nucleosomes in primary breast cancer. Methods: This study included 92 primary breast cancer patients treated with surgery from March 2012 to February 2015, for whom plasma isolated on the day before surgery was available in the biobank. Plasma nucleosomes were detected using Cell Death Detection ELISA kit with anti-histone and anti-DNA antibodies. Results: Circulating nucleosomes were associated with the systemic inflammatory index (0.17 vs. 0.27, P = 0.02) and with aldehyde-dehydrogenase expression (0.22 vs. 0.15, P = 0.03). Patients with lower than mean nucleosomes had significantly better disease-free survival (HR = 0.46, P = 0.05). The prognostic value was most pronounced in lymph node positive disease with high proliferation rate and in patients with detectable circulating tumor cells with epithelial-to-mesenchymal transition, but negative for epithelial circulating tumor cells. In a multivariate analysis, nucleosomes, hormone receptor status, HER2 status, lymph node involvement and tumor grade were independent predictors of disease-free survival. Conclusions: Our data suggest prognostic value of plasma nucleosomes in primary breast cancer and their association with metastatic ability and stem-cell ness characteristics. Their quantification could be added to the established prognostic markers.

Chemotherapy-induced peripheral neuropathy (CIPN) as a predictor of decreased quality of life and cognitive impairment in testicular germ cell tumor survivors

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Background: Chemotherapy-induced peripheral neuropathy (CIPN20) after curative treatment for testicular germ cell tumors (GCTs) has been previously reported. The impact of CIPN on long-term quality of life (QOL) in GCT survivors remains unclear. Herein, we aimed to evaluate chemotherapy-induced peripheral neuropathy (CIPN20) in association with QOL in GCT survivors. Methods: European Organisation for Research and Treatment of Cancer (EORTC) CIPN20, QLQ-C30 and Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) questionnaires were prospectively completed by GCT survivors (N = 153) at National Cancer Institute in Slovakia during their annual follow-up. The median follow-up was 10 years (range 4-25). Upon obtaining the scores from each questionnaire per recommended guidelines, each score from QLQ-C30 and FACT-Cog was correlated with CIPN defined as high or low (above and below median) as obtained from CIPN20. Results: GCT survivors with CIPN high reported impairment in quality of life in QLQ-C30. The global health status was lower in survivors with high vs low CIPN (mean score ± SEM: 66.5 ± 1.9 vs. 86.2 ± 1.8, P < 0.00001). Survivors with CIPN high reported substantially worse physical, role, emotional, cognitive and social functioning compared to CIPN low (all P < 0.00001). CIPN high survivors perceived more fatigue, nausea, pain, dyspnoea, appetite loss and more sleeping disorders compared to CIPN low (all P < 0.0001). Higher burden of CIPN was associated with more financial problems vs CIPN low (mean score ± SEM: 19.6 ± 2.6 vs. 6.67 ± 2.3, P = 0.0002). Cognitive impairment was higher in all FACT-Cog domains including the overall cognitive function score (all P < 0.001) for CIPN high. Spearman analysis has confirmed negative correlations of CIPN20 overall score with QLQ-C30 global health status (R = -0.54, P < 0.0001) and with FACT-Cog overall cognitive function score (R = -0.52, P < 0.0001). Conclusions: CIPN is a powerful predictor of disturbances in QOL and cognitive functioning among GCT survivors. Physicians should never over-treat patients unnecessarily and novel therapies with lower burden of late toxicity should be researched

The effect of primary granulocyte-colony stimulating factor prophylaxis on incidence of febrile neutropenia in patients with testicular germ cell tumors

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Background: Testicular germ cell tumors (GCTs) represent only one percent of all solid tumors; however, they are the most common solid malignancy in men 15-35 years old. Febrile neutropenia (FN) is a grievous complication of chemotherapy, frequently occurring in GCT patients. The aim of this retrospective study was to assess the effect of primary granulocyte-colony stimulating factor (G-CSF) prophylaxis on the incidence of FN in GCT patients. Methods: This study was conducted using the National Cancer Institute medical records database. Patients diagnosed with germ cell tumors treated with first line/adjuvant chemotherapy at the National Cancer Institute, Bratislava, Slovakia from January 2000 to December 2017 were eligible. Starting in January 2006, patients received G-CSF prophylaxis after every cycle of chemotherapy. Results: Out of 393 patients, 265 patients received primary G-CSF prophylaxis and 128 patients did not receive prophylaxis. The majority of patients (69.97%) were treated with bleomycin, etoposide and cisplatin chemotherapy. There were 61 deaths (15.5%) in our study population. 2- and 5-year OS of the study group was 86.8% and 83.1%, respectively. During the study period, 71 patients (18.1%) suffered FN events. Out of 128 patients who did not receive primary prophylaxis, 42 (32.8%) patients suffered FN, while only 29 (10.9%) patients with primary prophylaxis suffered FN ( P = 0.0000001). On subgroup analysis, FN incidence decreased in all groups with primary prophylaxis, except for patients with stage I GCT receiving adjuvant chemotherapy. Patients receiving G-CSF prophylaxis had significantly longer overall survival when compared to patients without prophylaxis. (HR = 0.44, 95% CI 0.26-0.75; P = 0.0009). Conclusions: Primary G-CSF prophylaxis was associated with significantly decreased FN incidence and longer overall survival in patients treated with first line chemotherapy and should be consider in all patients except stage I disease.

Effect of long-term peripheral neuropathy induced on cisplatin-based chemotherapy or radiation to the retroperitoneum in testicular germ cell tumor survivors

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Background: Treatment for testicular germ cell tumors (GCTs) results in late chemotherapy-induced peripheral neuropathy (CIPN). This study aimed to evaluate impact of curative treatments on different subtypes of self-reported peripheral nerve damage. Methods: GCT survivors (N = 186) followed-up annually at National Cancer Institute in Slovakia have prospectively completed European Organisation for Research and Treatment of Cancer (EORTC) CIPN20 questionnaire at 10 years of median follow-up (range 4-25). EORTC CIPN20 scoring allowed to obtain subscales on sensory function, motor function and autonomy function as well as an overall score. Study groups consisted of survivors treated with chemotherapy (N = 141) and radiotherapy to the retroperitoneum (N = 15). The control group consisted of survivors cured with orchiectomy alone (N = 30) Results: GCT survivors cured with chemotherapy reported higher impairment in overall peripheral neurological function compared to controls (mean score ± SEM: 24.2 ± 0.5 vs. 22.3 ± 1.1, P = 0.03). CIPN20 subscales have shown greater impairment in motor function (P = 0.04), but not in sensory/autonomy functions (both P > 0.05) in chemotherapy group versus controls. Survivors treated with BEPx3 or EPx4 reported similar CIPN in all subscales (all P > 0.05). Motor function was worse in survivors who received ³400mg/m2 of cisplatin compared to ones who received < 400mg/m2 (mean score ± SEM: 9.5 ± 0.2 vs. 8.9 ± 0.3, P = 0.04). Interestingly, patients treated with radiotherapy to the retroperitoneum (but not with chemotherapy) suffered from significantly more peripheral neuropathy in all measured domains compared to the controls (all P < 0.02) Conclusions: Evaluation of long-term perceived peripheral neuropathy after treatment for GCT has shown primarily motor function impairment after chemotherapy. Moreover, significant peripheral neuropathy in all observed CIPN20 subscales after radiotherapy to the retroperitoneum suggests this symptom is not exclusive to cisplatin-based chemotherapy.

Marker of lipid peroxidation TBARS predicts survival in patients with metastaticurothelial carcinoma (MUC)

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Background: Oxidative stress plays a significant role in cancer development and progression. A marker of lipid peroxidation TBARS is upregulated in various diseases. The objective of this prospective study was to explore predictive and prognostic values of TBARS in MUC patients (pts.) before the first-line platinum-based chemotherapy. Methods: Seventy-two consecutive pts. (57 men) with MUC (58 bladder, 14 upper GU tract) were enrolled into this study. Performance status ECOG ≥ 2 had 11 pts., visceral metastases were present in 34 pts. Most common type of treatment regimen was gemcitabine and cisplatin (65 pts.), gemcitabine and carboplatin received 7 pts. Based upon TBARS mean of 6,06 μmol/L, pts. were dichotomized into low and high groups. Progression-free survival (PFS), overall survival (OS) and their 95% CI were estimated by Kaplan-Meier method and compared with log-rank test. Results: At median follow-up of 9.6 months, 65 pts. experienced progression and 64 pts. died. Pts. with low TBARS had significantly better survival opposed to pts. with high TBARS (HR 0.44, 95% CI 0.27-0.74; P = 0,0009 for OS and HR 0.51; 95% CI 0.31-0.84; P = 0,006 for PFS, respectively). Pts. with ECOG ≤ 1 had significantly better both, OS and PFS in comparison to pts. with ECOG > 2. Conclusions: In this study, high plasma TBARS levels in patients with MUC before chemotherapy initiation were associated with poor survival. Therefore, this biomarker could be used for identification of patients with worse prognosis and could lead to better patient stratification and treatment decision making. The study was supported by VEGA 1/0614/12. Key Words: Metastatic Urothelial Carcinoma. Platinum-Based Chemotherapy. Lipid Peroxidation. TBARS. Survival.

Circulating tumor cells and breast cancer-specific mutations in primary breast cancer

Circulating tumor cells (CTCs) play a pivotal role in tumor dissemination and progression, and are considered to be a critical part of the metastatic cascade. The aim of the present research article was to examine breast cancer-specific mutations in primary breast cancer (PBC) using targeted resequencing. A total of 78 patients with PBC were enrolled into this translational study. Reverse transcription-quantitative PCR assay for the expression of epithelial markers (CK19) or epithelial-to-mesenchymal transition (EMT)-related genes (TWIST1, SNAIL1, SLUG and ZEB1) was applied for identification of CTCs prior to surgery. Total DNA was isolated from fresh frozen primary tumors. Sequencing was performed by Agilent SureSelect target enrichment and Illumina paired-end sequencing on the MiSeq platform. The most commonly affected genes were TP53 (mutated in 21 tumors; 26.9%), followed by PIK3CA (mutated in 16 tumors; 20.5%) and BRCA1/2 (mutated in 7 tumors, BRCA1 n=2 and BRCA2 n=5; 9.0%). In our cohort, a significantly higher proportion of patients with epithelial CTCs harbored mutations in the BRCA1/2 genes in the tumor tissue. There were no mutations in specific genes associated with CTCs with the EMT phenotype. To the best of our knowledge, this study is the first to report a correlation between the presence of epithelial CTCs in the peripheral blood and mutations of the BRCA1/2 genes in primary tumor tissue.

Effect of prophylactic anticoagulation on incidence of venous thromboembolism in testicular germ cell tumor patients

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Background: Testicular germ cell tumors (GCTs) are among the most common solid tumors in young males. With the availability of highly effective treatment, improving patients’ quality of life has gained more focus in recent years. Venous thromboembolism (VTE), commonly occurring in GCT patients, is associated with increased morbidity and mortality. Prophylactic anticoagulation has been shown to decrease the risk of VTE in cancer patients. In this retrospective study we evaluated the effect of low molecular weight heparin (LMWH) prophylaxis during hospitalization on incidence of VTE and outcome in GCT patients treated with first-line chemotherapy. Methods: Study population included 394 chemotherapy-naive GCT patients treated with first-line chemotherapy at the National Cancer Institute, Bratislava, Slovakia from January 2000 to December 2017. VTE was defined as any venous thrombosis or pulmonary embolism, confirmed by imaging, occurring during first-line chemotherapy. No visceral thromboses were observed. Results: Forty-one out of 394 patients (10.4%) were diagnosed with VTE on initial staging and were excluded from the analysis. Final cohort included 353 patients. LMWH prophylaxis was administered to 104 patients (29.5%), 249 patients (70.5%) did not receive prophylaxis. We observed 14 (4.0%) VTE events. The difference in VTE incidence between patients with and without prophylaxis was not statistically significant (5.8% vs. 3.2% p = 0.37). We have observed a trend to longer overall survival in patients without prophylaxis (HR = 0.61, 95%CI = 0.32-1.13, p = 0.08). Patients with extragonadal GCT receiving VTE prophylaxis had significantly shorter survival compared to patients without prophylaxis (HR = 0.29, 95%CI = 0.08-1.12, p = 0.04). Conclusions: LMWH prophylaxis was not associated with decreased VTE incidence. Moreover, it was associated with shorter survival in extragonadal GCTs. Taking into account these data, LMWH prophylaxis during hospitalization should not be used in GCT patients receiving chemotherapy.

Biomarkers of lung damage with possible predictiveness of ARDS within CS in super high-risk patients with germ cell tumors

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Background: Germ cell tumors (GCTs) represent a highly curable disease; however, a small proportion of patients with super-high-risk characteristics (choriocarcinoma, massive lung metastases, choriogonadotropin > 50 000 mIU/ml) can develop choriocarcinoma syndrome (CS) and consecutive acute respiratory distress syndrome (ARDS) shortly after the chemotherapy start with high mortality rate. This study aimed to evaluate biomarkers of lung damage as predictive biomarkers for ARDS development within CS in poor-risk GCTs patients. Methods: This study included 23 poor-risk GCTs treated from November 2000 to May 2018 in National Cancer Institute in Slovakia for whom plasma samples before chemotherapy initiation were available. Plasma levels of lung damage biomarkers (surfactant protein (D-SPD), receptor of advanced glycation end-products (sRAGE), and club cell secretory protein – (CC16)) were evaluated by ELISA assays. Results: Five (22%) of 23 patients developed CS, and all of them died shortly after the chemotherapy start. with median of 7 days (4 - 35 days). Four of them developed ARDS within CS, while one patient died due to massive abdominal hemorrhage. Pre-treatment levels of s-RAGE and SPD but not CC-16 were significantly associated with CS development ( P = 0.03 and P = 0.04). Level of sRAGE and SPD correlated significantly with dyspnea, weight loss, extent of metastatic lung involvement and need of mechanical ventilation after chemotherapy start, as well as with PFS and OS, while CC-16 did not correlate with any of these factors. Conclusions: In this study we identified new predictive biomarkers for CS development in poor-risk GCTs. Abovementioned factors might help to improve the risk stratification of these patients with GCTs as well as discover new treatment approaches preventing ARDS development within CS which may result in enhanced treatment outcome.

Abstract P4-01-15: CTC with EMT phenotype are associated with PD-L1 expression in tumor associated stroma in primary breast cancer patients

Background: Circulating tumor cells (CTCs) play role in tumor dissemination and are an independent survival predictor in breast cancer (BC) patients. PD-L1 is prognostic factor in BC and PD-L1 inhibitors prolonged survival in metastatic triple-negative breast cancer. The aim of this study was to assess correlation between CTCs and tumor PD-L1 in BC. Methods: This study included 299 primary BC patients treated by surgery from March 2012 to February 2015. Peripheral blood mononuclear cells (PBMC) were depleted of hematopoietic cells using RossetteSepTM negative selection kit. RNA extracted from CD45-depleted PBMC was interrogated for expression of EMT (TWIST1, SNAIL1, SLUG, ZEB1) and epithelial (CK19) gene transcripts by qRT-PCR. Patient samples with higher epithelial and/or mesenchymal gene transcripts than those of healthy donors (n=60) were considered as CTC positive. Expression of PD-L1 in surgical specimens was evaluated by immunohistochemistry and quantified by multiplicative score (proportion of cells with staining x intensity of staining). Results: CTCs were detected in 75 (25.1%) of patients. CTCs exhibiting only epithelial markers were present in 28 (9.4%) of patients, whereas CTCs with only EMT markers were observed in 53 (17.7%) of patients. In 6 patients, CTCs exhibit both epithelial and EMT markers. Patients with EMT_CTCs had significantly higher mean ± SEM score of PD-L1 expression in tumor associated stroma than those of patients without EMT_CTCs (2.66 ± 0.62 vs. 0.88 ± 0.29, p=0.048). There was no association between CTCs and PD-L1 expression in cancer cells including CTCs subtypes. Tumors without PD-L1 expression had significantly better disease-free survival compared to patients with PD-L1 expression (HR = 0.50, 95%CI 0.29 - 0.86, P = 0.001), however, this prognostic value was restricted to CTC positive subpopulation (HR = 0.24, 95%CI 0.10 - 0.56, P = 0.002), while, in CTC negative patients PD-L1 lack prognostic value (HR = 0.77, 95%CI 0.39 - 1.54, P = 0.45) Conclusion: Our data suggest link between PD-L1 expression in tumor associated stroma and CTCs with EMT phenotype and thus further support connection between immunosuppression and EMT. PD-L1 expression is prognostic only in patients with detectable CTC in peripheral blood suggesting different biology of tumors with detectable CTCs.

Citation Format: Michal Mego, Katarina Kalavska, Marian Karaba, Gabriel Minarik, Juraj Benca, Tatiana Sedlackova, Denisa Manasova, Daniel Pindak, Jozef Mardiak, Zuzana Cierna. CTC with EMT phenotype are associated with PD-L1 expression in tumor associated stroma in primary breast cancer patients [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-01-15.

Increased levels of XPA might be the basis of cisplatin resistance in germ cell tumours

Background

Germ cell tumours (GCTs) represent a highly curable malignity as they respond well to cisplatin (CDDP)-based chemotherapy. Nevertheless, a small proportion of GCT patients relapse or do not respond to therapy. As this might be caused by an increased capacity to repair CDDP-induced DNA damage, identification of DNA repair biomarkers predicting inadequate or aberrant response to CDDP, and thus poor prognosis for GCT patients, poses a challenge. The objective of this study is to examine the expression levels of the key nucleotide excision repair (NER) factors, XPA, ERCC1 and XPF, in GCT patients and cell lines.

Methods

Two hundred seven GCT patients’ specimens with sufficient follow-up clinical-pathological data and pairwise combinations of CDDP-resistant and -sensitive GCT cell lines were included. Immunohistochemistry was used to detect the ERCC1, XPF and XPA protein expression levels in GCT patients’ specimen and Western blot and qRT-PCR examined the protein and mRNA expression levels in GCT cell lines.

Results

GCT patients with low XPA expression had significantly better overall survival than patients with high expression (hazard ratio = 0.38, 95% confidence interval: 0.12–1.23, p = 0.0228). In addition, XPA expression was increased in the non-seminomatous histological subtype, IGCCCG poor prognosis group, increasing S stage, as well as the presence of lung, liver and non-pulmonary visceral metastases. Importantly, a correlation between inadequate or aberrant CDDP response and XPA expression found in GCT patients was also seen in GCT cell lines.

Conclusions

XPA expression is an additional independent prognostic biomarker for stratifying GCT patients, allowing for improvements in decision-making on treatment for those at high risk of refractoriness or relapse. In addition, it could represent a novel therapeutic target in GCTs.

Circulating tumor cells and drug history in primary breast cancer patients

Aim: Different types of chronic medication may affect breast cancer prognosis. Circulating tumor cells (CTCs) play an important role in cancer metastasis formation. There is no evidence of how chronic medication affects CTCs and breast cancer prognosis. The aim of this study was to evaluate association between chronic medication and CTCs in patients with primary breast cancer.

Methods: This study involved 414 patients with stage I-III primary breast cancer. Chronic drug history was collected from patients’ medical records and included all drugs that were prescribed for patients over at least the last 6 months prior to CTCs evaluation. CTCs were detected using a quantitative real-time polymerase chain reaction (qRT-PCR)-based method at the time of breast surgery.

Results: There was no association between CTCs, including their different subpopulations and chronic medication. Chronic medication using angiotensin-converting-enzyme inhibitors (ACEi), metformin, and insulin were associated with inferior disease-free survival (HR = 0.49, 95%CI 0.26-0.94, P = 0.007 for ACEi; HR = 0.27, 95%CI 0.08-0.91, P < 0.001 for metformin; and HR = 0.12, 95%CI 0.01-2.91, P < 0.001 for insulin) and this was most pronounced in patients with epithelial to mesenchymal transition (CTC_EMT) phenotype. In multivariate analysis, chronic administration of metformin and/or insulin was an independent predictor of inferior outcome.

Conclusion: Our findings show that there was no association between chronically used medication and CTCs in primary breast cancer patients. However, administration of ACEi, metformin, and/or insulin could negatively affect prognosis of patients with CTC_EMT.

Liquid biopsy in germ cell tumors: biology and clinical management

Introduction: Liquid biopsy is an increasingly studied approach for optimal and minimally invasive diagnostics of malignant tumors. The aim of this review is to provide evidence and discuss the utility of liquid biopsy in the management of germ cell tumors (GCTs).Areas covered: Herein, we summarize the evidence on liquid biopsy in GCTs including serum tumor markers, circulating tumor cells, microRNA and cell-free DNA. The search of literature was conducted from Pubmed/Medline, ASCO-meeting library searching for terms 'liquid biopsy', 'germ cell tumors', 'circulating tumor cells', 'microRNA', 'cell-free DNA'. Obtained original studies were included. Reference lists of review articles and key original articles were searched for additional original studies. We included articles published between1990 and 2019.Expert opinion: Liquid biopsy is a minimally invasive tool using body fluids for diagnostic purposes in cancer. The established value of serum tumor markers may be already considered a liquid biopsy technique in diagnosis of GCTs. Possible near-future refinements in diagnosis of GCTs are emerging. Further information on diagnosis, prognosis and resistance is added with recently described microRNAs, circulating tumor cells and cell-free DNA. While great promise is shown, further large-scale validation is needed to incorporate these novel liquid biopsies into clinical practice.

Molecular Mechanisms of Resistance in Testicular Germ Cell Tumors - clinical Implications

Testicular germ cell tumors (TGCTs) represent the most common malignancy in men aged 15-35. Due to these tumors' biological and clinical characteristics, they can serve as an appropriate system for studying molecular mechanisms associated with cisplatin-based treatment resistance. This review describes treatment resistance from clinical and molecular viewpoints. Cisplatin resistance is determined by various biological mechanisms, including the modulation of the DNA repair capacity of cancer cells, alterations to apoptotic cell death pathways, deregulation of gene expression pathways, epigenetic alterations and insufficient DNA binding. Moreover, this review describes TGCTs as a model system that enables the study of the cellular features of cancer stem cells in metastatic process and describes experimental models that can be used to study treatment resistance in TGCTs. All of the abovementioned aspects may help to elucidate the molecular mechanisms underlying cisplatin resistance and may help to identify promising new therapeutic targets.

Disulfiram Overcomes Cisplatin Resistance in Human Embryonal Carcinoma Cells

Cisplatin resistance in testicular germ cell tumors (TGCTs) is a clinical challenge. We investigated the underlying mechanisms associated with cancer stem cell (CSC) markers and modalities circumventing the chemoresistance. Chemoresistant models (designated as CisR) of human embryonal carcinoma cell lines NTERA-2 and NCCIT were derived and characterized using flow cytometry, gene expression, functional and protein arrays. Tumorigenicity was determined on immunodeficient mouse model. Disulfiram was used to examine chemosensitization of resistant cells. ALDH1A3 isoform expression was evaluated by immunohistochemistry in 216 patients' tissue samples. Chemoresistant cells were significantly more resistant to cisplatin, carboplatin and oxaliplatin compared to parental cells. NTERA-2 CisR cells exhibited altered morphology and increased tumorigenicity. High ALDH1A3 expression and increased ALDH activity were detected in both refractory cell lines. Disulfiram in combination with cisplatin showed synergy for NTERA-2 CisR and NCCIT CisR cells and inhibited growth of NTERA-2 CisR xenografts. Significantly higher ALDH1A3 expression was detected in TGCTs patients' tissue samples compared to normal testicular tissue. We characterized novel clinically relevant model of chemoresistant TGCTs, for the first time identified the ALDH1A3 as a therapeutic target in TGCTs and more importantly, showed that disulfiram represents a viable treatment option for refractory TGCTs.

Endogenous DNA damage levels in peripheral blood mononuclear cells in patients with muscle-infiltrating urothelial bladder carcinoma

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Background: Cisplatin-based combination chemotherapy is used as a standard neoadjuvant treatment of patients with muscle-infiltrating urothelial bladder carcinoma (MIUBC). DNA damage represents one of the most important factors contributing to its toxicity. The objective of this prospective study is to evaluate the prognostic value of the endogenous DNA damage level in peripheral blood mononuclear cells (PBMCs) from MIUBC patients before treatment with neoadjuvant chemotherapy. Methods: PBMCs isolated from 25 consecutive MIUBC patients (16 men, 64%) were included into this study. Karnofsky index < 80% was present in 1 patient (4%). DNA damage levels in PBMCs were evaluated by the Comet assay and scored as percentage of DNA in tail by the Metafer-MetaCyte analyzing software. Cut-off of 5.25 was used to dichotomize DNA damage level as “high” or “low” based on the previous study. Results: At the median follow-up 12.1 months, 13 patients progressed (52%) and 8 patients (32%) died. The median and IQR (interquartile range) of endogenous DNA damage level was 7.52 (4.07-27.9). Patients with low DNA damage levels had non-significantly better progression free survival (HR = 0.33, 95% CI: 0.09-1.29) and overall survival (HR = 0.64, 95% CI: 0.11-3.87) compared to patients with high DNA damage levels. Conclusions: These data suggest that endogenous DNA damage levels in PBMCs from MIUBC patients may serve as a prognostic marker early identifying patients with poor outcome. This study is supported by VEGA 2/0053/19 and APVV-17-0384.