Cytoreduction surgery reduces systemic myeloid suppressor cell populations and restores intratumoral immunotherapy effectiveness

Cytoreductive nephrectomy in the era of immune checkpoint inhibitors: a US Food and Drug Administration pooled analysis

BACKGROUND

This pooled analysis of patient-level data from trials evaluated the clinical outcomes of patients with metastatic renal cell carcinoma with or without cytoreductive nephrectomy before a combination of immune checkpoint inhibitor and antiangiogenic therapy.

METHODS

Data from 5 trials of immune checkpoint inhibitors plus antiangiogenic therapy were pooled. Only patients with stage 4 disease at initial diagnosis were included to ensure that nephrectomy was performed for cytoreductive purposes and not to previously treat an earlier stage of disease. The effect of cytoreductive nephrectomy before immune checkpoint inhibitor therapy on outcomes was evaluated using the Kaplan-Meier method and a Cox proportional hazards regression model, adjusted for age, sex, risk group, performance status, and the presence of sarcomatoid differentiation.

RESULTS

A total of 981 patients were included. The estimated median progression-free survival with and without nephrectomy was 15 and 11 months, respectively; the adjusted hazard ratio was 0.71 (95% confidence interval = 0.59 to 0.85). The estimated median overall survival with and without nephrectomy was 46 and 28 months, respectively; the adjusted hazard ratio was 0.63 (95% confidence interval = 0.51 to 0.77). Objective response was 60% of patients with vs 46% of patients without cytoreductive nephrectomy.

CONCLUSIONS

Patients with metastatic renal cell carcinoma who undergo cytoreductive nephrectomy before immune checkpoint inhibitor plus antiangiogenic therapy had improved outcomes compared with patients without cytoreductive nephrectomy. Selection factors for cytoreductive nephrectomy may be prognostic and could not be fully controlled for in this retrospective analysis. Prospective determination of and stratification by prior cytoreductive nephrectomy may be considered when designing clinical trials to assess the impact of this factor on prognosis.

HPV-positive murine oral squamous cell carcinoma: development and characterization of a new mouse tumor model for immunological studies

BACKGROUND

Infection with high-risk human papillomavirus (HPV) strains is one of the risk factors for the development of oral squamous cell carcinoma (OSCC). Some patients with HPV-positive OSCC have a better prognosis and respond better to various treatment modalities, including radiotherapy or immunotherapy. However, since HPV can only infect human cells, there are only a few immunocompetent mouse models available that enable immunological studies. Therefore, the aim of our study was to develop a transplantable immunocompetent mouse model of HPV-positive OSCC and characterize it in vitro and in vivo.

METHODS

Two monoclonal HPV-positive OSCC mouse cell lines were established by inducing the expression of HPV-16 oncogenes E6 and E7 in the MOC1 OSCC cell line using retroviral transduction. After confirming stable expression of HPV-16 E6 and E7 with quantitative real-time PCR and immunofluorescence staining, the cell lines were further characterized in vitro using proliferation assay, wound healing assay, clonogenic assay and RNA sequencing. In addition, tumor models were characterized in vivo in C57Bl/6NCrl mice in terms of their histological properties, tumor growth kinetics, and radiosensitivity. Furthermore, immunofluorescence staining of blood vessels, hypoxic areas, proliferating cells and immune cells was performed to characterize the tumor microenvironment of all three tumor models.

RESULTS

Characterization of the resulting MOC1-HPV cell lines and tumor models confirmed stable expression of HPV-16 oncogenes and differences in cell morphology, in vitro migration capacity, and tumor microenvironment characteristics. Although the cell lines did not differ in their intrinsic radiosensitivity, one of the HPV-positive tumor models, MOC1-HPV K1, showed a significantly longer growth delay after irradiation with a single dose of 15 Gy compared to parental MOC1 tumors. Consistent with this, MOC1-HPV K1 tumors had a lower percentage of hypoxic tumor area and a higher percentage of proliferating cells. Characteristics of the newly developed HPV-positive OSCC tumor models correlate with the transcriptomic profile of MOC1-HPV cell lines.

CONCLUSIONS

In conclusion, we developed and characterized a novel immunocompetent mouse model of HPV-positive OSCC that exhibits increased radiosensitivity and enables studies of immune-based treatment approaches in HPV-positive OSCC.

Robot-Assisted Radical Prostatectomy for Potential Cancer Control in Patients with Metastatic Prostate Cancer

Recently, cytoreductive prostatectomy for metastatic prostate cancer (mPCa) has been associated with improved oncological outcomes. This study was aimed at evaluating whether robot-assisted radical prostatectomy (RARP) as a form of cytoreductive prostatectomy can improve oncological outcomes in patients with mPCa. We conducted a retrospective study of twelve patients with mPCa who had undergone neoadjuvant therapy followed by RARP. The endpoints were biochemical recurrence-free survival, treatment-free survival, and de novo metastasis-free survival. At the end of the follow-up period, none of the enrolled patients had died from PCa. The 1- and 2-year biochemical recurrence-free survival rates were 83.3% and 66.7%, respectively, and treatment-free survival rates were 75.0% and 56.3%, respectively. One patient developed de novo bone metastases 6.4 months postoperatively, and castration-resistant prostate cancer 8.9 months postoperatively. After RARP, the median duration of recovery of urinary continence was 5.2 months. One patient had severe incontinence (>2 pads/day) 24 months postoperatively. RARP may be a treatment option in patients with mPCa who have achieved a serum prostate-specific antigen level < 0.2 ng/mL, and present without new lesions on imaging.

Murine Mammary Carcinoma Induces Chronic Systemic Inflammation and Immunosuppression in BALB/c Mice

Purpose

Methods

Results

Conclusion

Neoadjuvant Gene-Mediated Cytotoxic Immunotherapy for Non-Small-Cell Lung Cancer: Safety and Immunologic Activity

Gene-mediated cytotoxic immunotherapy (GMCI) is an immuno-oncology approach involving local delivery of a replication-deficient adenovirus expressing herpes simplex thymidine kinase (AdV-tk) followed by anti-herpetic prodrug activation that promotes immunogenic tumor cell death, antigen-presenting cell activation, and T cell stimulation. This phase I dose-escalation pilot trial assessed bronchoscopic delivery of AdV-tk in patients with suspected lung cancer who were candidates for surgery. A single intra-tumoral AdV-tk injection in three dose cohorts (maximum 1012 viral particles) was performed during diagnostic staging, followed by a 14-day course of the prodrug valacyclovir, and subsequent surgery 1 week later. Twelve patients participated after appropriate informed consent. Vector-related adverse events were minimal. Immune biomarkers were evaluated in tumor and blood before and after GMCI. Significantly increased infiltration of CD8+ T cells was found in resected tumors. Expression of activation, inhibitory, and proliferation markers, such as human leukocyte antigen (HLA)-DR, CD38, Ki67, PD-1, CD39, and CTLA-4, were significantly increased in both the tumor and peripheral CD8+ T cells. Thus, intratumoral AdV-tk injection into non-small-cell lung cancer (NSCLC) proved safe and feasible, and it effectively induced CD8+ T cell activation. These data provide a foundation for additional clinical trials of GMCI for lung cancer patients with potential benefit if combined with other immune therapies.

CD205+ polymorphonuclear myeloid-derived suppressor cells suppress antitumor immunity by overexpressing GLUT3

Myeloid‐derived suppressor cells (MDSCs) are responsible for antitumor immunodeficiency in tumor‐bearing hosts. Primarily, MDSCs are classified into 2 groups: monocytic (M)‐MDSCs and polymorphonuclear (PMN)‐MDSCs. In most cancers, PMN‐MDSCs (CD11b⁺Ly6C^lowLy6G⁺ cells) represent the most abundant MDSC subpopulation. However, the functional and phenotypic heterogeneities of PMN‐MDSC remain elusive, which delays clinical therapeutic targeting decisions. In the 4T1 murine tumor model, CD11b⁺Ly6G^low PMN‐MDSCs were sensitive to surgical and pharmacological interventions. By comprehensively analyzing 64 myeloid cell‐related surface molecule expression profiles, cell density, nuclear morphology, and immunosuppressive activity, the PMN‐MDSC population was further classified as CD11b⁺Ly6G^lowCD205⁺ and CD11b⁺Ly6G^highTLR2⁺ subpopulations. The dichotomy of PMN‐MDSCs based on CD205 and TLR2 is observed in 4T07 murine tumor models (but not in EMT6). Furthermore, CD11b⁺Ly6G^lowCD205⁺ cells massively accumulated at the spleen and liver of tumor‐bearing mice, and their abundance correlated with in situ tumor burdens (with or without intervention). Moreover, we demonstrated that CD11b⁺Ly6G^lowCD205⁺ cells were sensitive to glucose deficiency and 2‐deoxy‐d‐glucose (2DG) treatment. Glucose transporter 3 (GLUT3) knockdown by siRNA significantly triggered apoptosis and reduced glucose uptake in CD11b⁺Ly6G^lowCD205⁺ cells, demonstrating the dependence of CD205⁺ PMN‐MDSCs survival on both glucose uptake and GLUT3 overexpression. As GLUT3 has been recognized as a target for the rescue of host antitumor immunity, our results further directed the PMN‐MDSC subsets into the CD205⁺GLUT3⁺ subpopulation as future targeting therapy.

Effects of oncolytic viruses and viral vectors on immunity in glioblastoma

Glioblastoma (GBM) is regarded as an incurable disease due to its poor prognosis and limited treatment options. Virotherapies were once utilized on cancers for their oncolytic effects. And they are being revived on GBM treatment, as accumulating evidence presents the immunogenic effects of virotherapies in remodeling immunosuppressive GBM microenvironment. In this review, we focus on the immune responses induced by oncolytic virotherapies and viral vectors in GBM. The current developments of GBM virotherapies are briefly summarized, followed by a detailed depiction of their immune response. Limitations and lessons inferred from earlier experiments and trials are discussed. Moreover, we highlight the importance of engaging the immune responses induced by virotherapies into the multidisciplinary management of GBM.

Phase I study of gene-mediated cytotoxic immunotherapy with AdV-tk as adjuvant to surgery and radiation for pediatric malignant glioma and recurrent ependymoma

BACKGROUND

Gene-mediated cytotoxic immunotherapy (GMCI) is a tumor-specific immune stimulatory strategy implemented through local delivery of aglatimagene besadenovec (AdV-tk) followed by anti-herpetic prodrug. GMCI induces T-cell dependent tumor immunity and synergizes with radiotherapy. Clinical trials in adult malignant gliomas demonstrated safety and potential efficacy. This is the first trial of GMCI in pediatric brain tumors.

METHODS

This phase I dose escalation study was conducted to evaluate GMCI in patients 3 years of age or older with malignant glioma or recurrent ependymoma. AdV-tk at doses of 1 × 1011 and 3 × 1011 vector particles (vp) was injected into the tumor bed at the time of surgery followed by 14 days of valacyclovir. Radiation started within 8 days of surgery, and if indicated, chemotherapy began after completion of valacyclovir.

RESULTS

Eight patients (6 glioblastoma, 1 anaplastic astrocytoma, 1 recurrent ependymoma) were enrolled and completed therapy: 3 on dose level 1 and 5 on dose level 2. Median age was 12.5 years (range 7-17) and Lansky/Karnofsky performance scores were 60-100. Five patients had multifocal/extensive tumors that could not be resected completely and 3 had gross total resection. There were no dose-limiting toxicities. The most common possibly GMCI-related adverse events included Common Terminology Criteria for Adverse Events grade 1-2 fever, fatigue, and nausea/vomiting. Three patients, in dose level 2, lived more than 24 months, with 2 alive without progression 37.3 and 47.7 months after AdV-tk injection.

CONCLUSIONS

GMCI can be safely combined with radiation therapy with or without temozolomide in pediatric patients with brain tumors and the present results strongly support further investigation.

CLINICAL TRIAL REGISTRY

ClinicalTrials.gov NCT00634231.

Efficacy and outcome of holmium laser enucleation of prostate in patients with urinary retention due to advanced prostate cancer

To evaluate the efficacy and safety of holmium laser enucleation of prostate (HoLEP) for treating urinary retention in patients with advanced prostate cancer. Thirty-eight cases of advanced prostate cancer with urinary retention were enrolled in this retrospective study. All the 38 patients were treated with CAB as a basis. Among them, 21 cases chose HoLEP additionally (HoLEP group). Seventeen cases stuck to CAB alone (CAB group). Serum PSA level, International Prostate Symptom Score (IPSS), quality of life score (QoLs), maximal flow rate (Qmax), and post-void residual volume (PVR) at 3, 6, 12, and 18 months after treatment were comparatively analyzed. The perioperative and postoperative parameters of HoLEP were assessed. Both groups demonstrated significant improvement in IPSS, QoLs, Qmax, and PVR during follow-up. But these parameters of HoLEP group improved more rapidly, significantly, and durably than CAB group. No serious complications were observed during and after HoLEP. PSA level of patients in both groups declined dramatically after surgery. But PSA in HoLEP group showed more dramatic and continuous drop. Besides, 1 of 21 patients in HoLEP group transferred into castration-resistant prostate cancer (CRPC) at 18th month of follow-up. While in CAB group, 5 of 17 patients developed into CRPC at 12th month of follow-up (P = 0.02 < 0.05). HoLEP was minimally invasive, safe, and effective, and could serve as a palliative approach to rapidly restore the patients' urine and play a cytoreductive role in advanced PCa to improve the oncological prognosis.

Survival Significance of Patients With Low Prostate-Specific Antigen and High-Grade Prostate Cancer After Radical Prostatectomy, External Beam Radiotherapy, or External Beam Radiotherapy With Brachytherapy

Objective: This study compared survival of prostate cancer patients with low prostate specific antigen level (PSA ≤ 10 ng/ml) and high-grades of Gleason score (GS) of 8–10 with different treatment options (i.e., radical prostatectomy [RP], external beam radiotherapy [EBRT], or external beam radiotherapy with brachytherapy [EBRT+BT]).

Materials and Methods: The Surveillance, Epidemiology and End Results (SEER) database data (2004–2013), and overall survival (OS) and prostate cancer-specific mortality (PCSM), were evaluated using the Cox proportional hazards regression model and Fine and Gray competing risk model.

Results: The SEER data contained 9,114 patients, 4,175 of whom received RP, 4,114 received EBRT, and 825 received EBRT+BT with a median follow-up duration of 47 months. RP patients had significantly better OS than patients with EBRT and EBRT+BT (adjusted HR [AHR]: 3.36, 95% CI: 2.43–4.64, P < 0.001; AHR: 2.15, 95% CI: 1.32–3.48, P = 0.002; respectively). There was no statistical difference in PCSM between RP and EBRT+BT (AHR: 1.31, 95% CI: 0.61–2.80, P = 0.485), while EBRT had worse OS (P < 0.05). The subgroup analysis revealed that there was no statistical difference in prognosis of patients with age of >70 years old, or PSA levels of ≤ 2.5 ng/ml between RP and EBRT+BT (P > 0.05).

Conclusion: RP patients with low PSA levels and high GS had better OS compared to either EBRT or EBRT+BT, while RP and EBRT+BT resulted in significantly lower PCSM, compared to EBRT. Moreover, EBRT+BT and RP were associated with similar survival of patients with age of > 70 years old, or PSA levels of ≤ 2.5 ng/ml.

γ-Secretase inhibitor reduces immunosuppressive cells and enhances tumour immunity in head and neck squamous cell carcinoma

Immune evasion is a hallmark feature of cancer, and it plays an important role in tumour initiation and progression. In addition, tumour immune evasion severely hampers the desired antitumour effect in multiple cancers. In this study, we aimed to investigate the role of the Notch pathway in immune evasion in the head and neck squamous cell carcinoma (HNSCC) microenvironment. We first demonstrated that Notch1 signaling was activated in a Tgfbr1/Pten-knockout HNSCC mouse model. Notch signaling inhibition using a γ-secretase inhibitor (GSI-IX, DAPT) decreased tumour burden in the mouse model after prophylactic treatment. In addition, flow cytometry analysis indicated that Notch signaling inhibition reduced the sub-population of myeloid-derived suppressor cells (MDSCs), tumour-associated macrophages (TAMs) and regulatory T cells (Tregs), as well as immune checkpoint molecules (PD1, CTLA4, TIM3 and LAG3), in the circulation and in the tumour. Immunohistochemistry (IHC) of human HNSCC tissues demonstrated that elevation of the Notch1 downstream target HES1 was correlated with MDSC, TAM and Treg markers and with immune checkpoint molecules. These results suggest that modulating the Notch signaling pathway may decrease MDSCs, TAMs, Tregs and immune checkpoint molecules in HNSCC.

Cytoreductive prostatectomy in metastatic prostate cancer: a systematic review

The impact of cytoreductive radical prostatectomy on oncological outcome in patients with prostate cancer and limited number of bone metastases is unclear. Data from cancer registries, multi-institutional databases and a single institutional case-control study indicate a possible benefit of combined cytoreduction and hormonal therapy compared to hormonal therapy alone. However, the results may be biased by a number of factors. The evidence from studies on cytoreductive prostatectomy is reviewed.

The role of metastasis-directed therapy and local therapy of the primary tumor in the management of oligometastatic prostate cancer

Oligometastasis has been proposed as an intermediate stage of cancer spread between localized disease and widespread metastasis. Oligometastatic malignancy is now being diagnosed more frequently as the result of improvements in diagnostic modalities such as functional imaging. The importance of oligometastasis in managing metastatic prostate cancer is that it is possible to treat with a curative aim by metastasis-directed or local therapy in selected patients. Many studies have shown that these aggressive treatments lead to improved survival in other oligometastatic malignancies. However, few studies have shown definitive benefits of metastasis-directed or local therapy in oligometastatic prostate cancer. Review of the available studies suggests that stereotactic radiotherapy (RT) of metastatic lesions in oligorecurrent disease is a feasible and safe modality for managing oligometastatic prostate cancer. Also, stereotactic RT can delay the start of androgen deprivation therapy. Many retrospective studies of metastatic prostate cancer have shown that patients undergoing local therapy seem to have superior overall and cancer-specific survival compared with patients not receiving local therapy. Ongoing prospective randomized trials would be helpful to evaluate the role of local therapy in oligometastatic prostate cancer.

Outcome predictors of radical cystectomy in patients with cT4 prostate cancer: a multi-institutional study of 62 patients

OBJECTIVES

To identify which patients with macroscopic bladder-infiltrating T4 prostate cancer (PCa) might have favourable outcomes when treated with radical cystectomy (RC).

MATERIALS AND METHODS

We evaluated 62 patients with cT4cN0-1 cM0 PCa treated with RC and pelvic lymph node dissection between 1972 and 2011. In addition to descriptive statistics, the Kaplan-Meier method and log-rank tests were used to depict survival rates. Univariate and multivariate Cox regression analysis tested the association between predictors and progression-free, PCa-specific and overall survival.

RESULTS

Of the 62 patients, 19 (30.6%) did not have clinical progression during follow-up, two (3.2%) had local recurrence, and 32 (51.6%) had haematogenous and nine (14.5%) combined pelvic and distant metastasis. Forty patients (64.5%) died, 34 (54.8%) from PCa and six (9.7%) from other causes. The median (range) survival time of the 19 patients who were metastasis-free at last follow-up was 86 (1-314) months, 8/19 patients had a follow-up of >5 years, and five patients survived metastasis-free for >15 years. Patients without seminal vesicle invasion (SVI) had the best outcomes, with an estimated 10-year PCa-specific survival of 75% compared with 24% for patients with SVI.

CONCLUSION

For cT4 PCa RC can be an appropriate treatment for local control and part of a multimodality-treatment approach. Although recurrences are probable, these do not necessarily translate into cancer-specific death. Men without SVI had a 75% 10-year PCa-specific survival. Although outcomes for patients with SVI are not as favourable, there can be good local control; however, these patients are at higher risk of progression and may need more aggressive systemic treatment.

Oligometastatic prostate cancer: definitions, clinical outcomes, and treatment considerations

The oligometastatic state has been proposed as an intermediate stage of cancer spread between localized disease and widespread metastases. With improvements in diagnostic modalities such as functional imaging, oligometastatic prostate cancer is being diagnosed with greater frequency than ever before. Furthermore, the paradigm for treatment of advanced prostate cancers is shifting toward a more aggressive approach. Many questions surround the understanding of the process and consequences of oligometastasis, meaning that the contemporary literature offers a wide variety of definitions of oligometastatic prostate cancer. Until genomic data exist to provide a biological component to the definition of oligometastatic disease, a clinical diagnosis made on the basis of up to five extrapelvic lesions is reasonable for use. Retrospective studies suggest that interventions such as radical prostatectomy and local or metastasis-directed radiotherapy can be performed in the metastatic setting with minimal risk of toxic effects. These therapies seem to decrease the need for subsequent palliative interventions, but insufficient data are available to draw reliable conclusions regarding their effect on survival. Thus, a protocol for clinicians to manage the patient presenting with oligometastatic prostate cancer would be a useful clinical tool.

Phase II multicenter study of gene-mediated cytotoxic immunotherapy as adjuvant to surgical resection for newly diagnosed malignant glioma

BACKGROUND

Despite aggressive standard of care (SOC) treatment, survival of malignant gliomas remains very poor. This Phase II, prospective, matched controlled, multicenter trial was conducted to assess the safety and efficacy of aglatimagene besadenovec (AdV-tk) plus valacyclovir (gene-mediated cytotoxic immunotherapy [GMCI]) in combination with SOC for newly diagnosed malignant glioma patients.

METHODS

Treatment cohort patients received SOC + GMCI and were enrolled at 4 institutions from 2006 to 2010. The preplanned, matched-control cohort included all concurrent patients meeting protocol criteria and SOC at a fifth institution. AdV-tk was administered at surgery followed by SOC radiation and temozolomide. Subset analyses were preplanned, based on prognostic factors: pathological diagnosis (glioblastoma vs others) and extent of resection.

RESULTS

Forty-eight patients completed SOC + GMCI, and 134 met control cohort criteria. Median overall survival (OS) was 17.1 months for GMCI + SOC versus 13.5 months for SOC alone (P = .0417). Survival at 1, 2, and 3 years was 67%, 35%, and 19% versus 57%, 22%, and 8%, respectively. The greatest benefit was observed in gross total resection patients: median OS of 25 versus 16.9 months (P = .0492); 1, 2, and 3-year survival of 90%, 53%, and 32% versus 64%, 28% and 6%, respectively. There were no dose-limiting toxicities; fever, fatigue, and headache were the most common GMCI-related symptoms.

CONCLUSIONS

GMCI can be safely combined with SOC in newly diagnosed malignant gliomas. Survival outcomes were most notably improved in patients with minimal residual disease after gross total resection. These data should help guide future immunotherapy studies and strongly support further evaluation of GMCI for malignant gliomas.

CLINICAL TRIAL REGISTRY

ClinicalTrials.gov NCT00589875.

[Cytoreductive radical prostatectomy for prostate cancer with minimal osseous metastases: results of a first feasibility and case control study]

BACKGROUND

Androgen deprivation therapy (ADT) represents the standard treatment for patients with prostate cancer (PCA) and osseous metastases. We explored the role of cytoreductive radical prostatectomy in PCA with low volume skeletal metastases in terms of a feasibility study.

MATERIAL AND METHODS

A total of 23 patients with biopsy proven PCA, minimal osseous metastases (≤3 hot spots on bone scan), absence of visceral or extensive lymph node metastases and a decrease in prostate-specific antigen (PSA) to <1.0 ng/ml after neoadjuvant ADT were included in the feasibility study (group A). The control group (group B) consisted of 38 men with metastatic PCA who were treated by ADT alone. Surgery-related complications, time to castration resistance, symptom-free, cancer-specific and overall survival were analyzed using descriptive statistical analyses.

RESULTS

The mean age was 61 years (range 42-69 years) and 64 years (47-83) in groups A and B, respectively, with similar patient characteristics in terms of initial PSA level, biopsy Gleason score, clinical stage and extent of metastatic disease. The median follow-up was 34.5 months (7-75 months) and 47 months (28-96 months) in groups A and B, respectively. Median time to castration resistance was 40 months (9-65 months) and 29 months (16-59 months) in groups A and B, respectively (p=0.04). Patients in group A experienced significantly better clinical symptom-free (38.6 versus 26.5 months, p=0.032) and cancer-specific survival rates (95.6% versus 84.2%, p=0.043) whereas the overall survival was similar. In group A none of the men underwent palliative surgical procedures for locally progressing PCA compared to 29% in group B.

CONCLUSIONS

Cytoreductive radical prostatectomy is feasible in well-selected men with metastatic PCA who responded well to neoadjuvant ADT. These men have a long life expectancy and the risk of locally recurrent PCA and local complications are reduced. Cytoreductive radical prostatectomy might be a treatment option in the multimodal management of PCA with minimal osseous metastases.

[Oncological principles for local control of primary tumor]

OBJECTIVE

Review of the databases of carcinogenesis and the principles of local control of the primary tumor in order to decrease the risk of tumor progression and predict metastatic behavior.

MATERIALS AND METHODS

Review of the literature using Medline databases based on scientific relevance. Research was centered on the characteristics of solid tumor development, the basics of local control of the primary tumor, latest advance in genomics and the oncological principles applied on prostate cancer surgery.

RESULTS

The cornerstone in order to cure a local or locally advanced cancer is to eradicate the primary tumor. This should be done using effective methods that can assure local control, decrease the risk of progression and metastasis. The oncological surgery is the most important step in order to have this tumor control, beside radiotherapy and systemic therapy associated. In localized prostate cancer, surgery remains the gold standard between the multiple therapeutic modalities proposed.

CONCLUSION

The local control of solid malignant tumor is primordial in order to change the natural history of the disease and decrease its risk of progression. This is the goal of oncological surgery, and starting from these principles radical prostatectomy was favored.

Gene-mediated cytotoxic immunotherapy as adjuvant to surgery or chemoradiation for pancreatic adenocarcinoma

BACKGROUND

While surgical resection of pancreatic adenocarcinoma provides the only chance of cure, long-term survival remains poor. Immunotherapy may improve outcomes, especially as adjuvant to local therapies. Gene-mediated cytotoxic immunotherapy (GMCI) generates a systemic anti-tumor response through local delivery of an adenoviral vector expressing the HSV-tk gene (aglatimagene besadenovec, AdV-tk) followed by anti-herpetic prodrug. GMCI has demonstrated synergy with standard of care (SOC) in other tumor types. This is the first application in pancreatic cancer.

METHODS

Four dose levels (3 × 10(10) to 1 × 10(12) vector particles) were evaluated as adjuvant to surgery for resectable disease (Arm A) or to 5-FU chemoradiation for locally advanced disease (Arm B). Each patient received two cycles of AdV-tk + prodrug.

RESULTS

Twenty-four patients completed therapy, 12 per arm, with no dose-limiting toxicities. All Arm A patients were explored, eight were resected, one was locally advanced and three had distant metastases. CD8(+) T cell infiltration increased an average of 22-fold (range sixfold to 75-fold) compared with baseline (p = 0.0021). PD-L1 expression increased in 5/7 samples analyzed. One node-positive resected patient is alive >66 months without recurrence. Arm B RECIST response rate was 25 % with a median OS of 12 months and 1-year survival of 50 %. Patient-reported quality of life showed no evidence of deterioration.

CONCLUSIONS

AdV-tk can be safely combined with pancreatic cancer SOC without added toxicity. Response and survival compare favorably to expected outcomes and immune activity increased. These results support further evaluation of GMCI with more modern chemoradiation and surgery as well as PD-1/PD-L1 inhibitors in pancreatic cancer.

Surgical cytoreduction restores the antitumor efficacy of a Listeria monocytogenes vaccine in malignant pleural mesothelioma

Recent studies suggest that immunotherapy may offer a promising treatment strategy for early-stage malignant pleural mesothelioma (MPM), but advanced tumor burden may limit the efficacy of immunotherapy. Therefore, we hypothesized that surgical cytoreduction could restore the efficacy of vaccine-based immunotherapy for MPM. We developed a murine model of MPM through transduction of a mesothelioma cell line with mesothelin. We used this model to evaluate the efficacy of a Listeria monocytogenes vaccine expressing mesothelin. Tumor growth was significantly inhibited at four weeks in animals vaccinated two weeks prior to tumor cell inoculation as compared to those given an empty vector control (1371 ± 420 mm(3) versus 405 ± 139 mm(3); p < 0.01). Mice vaccinated one week prior to tumor challenge also displayed significant reduction in tumor volume (1227 ± 406 mm(3) versus 309 ± 173 mm(3); p < 0.01). The vaccine had no effect when administered concurrently with tumor challenge, or after tumors were established. Flow cytometry showed reduced mesothelin expression in large tumors, as well as tumor-associated immunosuppression due to increased myeloid derived suppressor cells (MDSCs). These factors may have limited vaccine efficacy for advanced disease. Surgical cytoreduction of established tumors restored the antitumor potency of the therapeutic vaccine, with significantly reduced tumor burden at post-operative day 18 (397 ± 103 mm(3) versus 1047 ± 258 mm(3); p < 0.01). We found that surgery reduced MDSCs to levels comparable to those in tumor-naïve mice. This study demonstrates that cytoreduction surgery restores the efficacy of cancer vaccines for MPM by reducing tumor-related immunosuppression that impairs immunotherapy.

[Radical cancer surgery of renal cell and prostate carcinoma with hematogenous metastasis: benefits]

The therapeutic role of cytoreductive surgery for urogenital malignancies is controversially discussed in the literature. The current article critically reflects the potential impact of cytoreductive surgery in patients with renal cell cancer and prostate cancer with locoregional lymph node or systemic metastases based on a review of the literature and personal experience.Even in the era of molecular targeted therapies in metastatic renal cell cancer, cytoreductive radical nephrectomy seems to exert survival benefit when compared to systemic therapy alone if (1) patients demonstrate a good ECOG performance status, (2) exhibit good or intermediate prognosis according to the Heng criteria, (3) cerebral metastases have been excluded, and (4) >90% of the total cancer volume can be eliminated. Preliminary clinical studies suggest that neoadjuvant systemic treatment might be associated with a significantly reduced 1-year mortality rate.For prostate cancer cytoreductive radical prostatectomy is one of the guideline-recommended treatment options for men with intrapelvic lymph node metastases resulting in survival benefit when compared to androgen deprivation as monotherapy. Cytoreductive radical prostatectomy should be performed (1) in the presence of limited intrapelvic lymph node metastasis without bulky disease, (2) if complete resectability of the primary cancer and its metastasis can be achieved by extended radical prostatectomy and extended pelvic lymphadenectomy, (3) if the patient is included in a multimodality approach, and (4) if the life expectancy is > 10 years.The role of cytoreductive radical prostatectomy in men with osseous metastases remains unclear due to the lack of large clinical trials. Despite the presence of the first promising studies, it is not justified to perform cytoreductive radical prostatectomy outside clinical trials. Preliminary results from small studies indicate that patients with minimal metastatic burden, PSA decrease < 1.0 ng/ml following neoadjuvant ADT for 6 months and complete resectability of the tumor exhibit the best prognosis to benefit from this new surgical approach.

Natural killer T cell activation overcomes immunosuppression to enhance clearance of postsurgical breast cancer metastasis in mice

Metastatic lesions are responsible for over 90% of breast cancer associated deaths. Therefore, strategies that target metastasis are of particular interest. This study examined the efficacy of natural killer T (NKT) cell activation as a post-surgical immunotherapy in a mouse model of metastatic breast cancer. Following surgical resection of orthotopic 4T1 mammary carcinoma tumors, BALB/c mice were treated with NKT cell activating glycolipid antigens (α-GalCer, α-C-GalCer or OCH) or α-GalCer-loaded dendritic cells (DCs). Low doses of glycolipids transiently reduced metastasis but did not increase survival. A high dose of α-GalCer enhanced overall survival, but was associated with increased toxicity and mortality at early time points. Treatment with α-GalCer-loaded DCs limited tumor metastasis, prolonged survival, and provided curative outcomes in ∼45% of mice. However, survival was not increased further by additional DC treatments or co-transfer of expanded NKT cells. NKT cell activation via glycolipid-loaded DCs decreased the frequency and immunosuppressive activity of myeloid derived suppressor cells (MDSCs) in tumor-resected mice. In vitro, NKT cells were resistant to the immunosuppressive effects of MDSCs and were able to reverse the inhibitory effects of MDSCs on T cell proliferation. NKT cell activation enhanced antitumor immunity in tumor-resected mice, increasing 4T1-specific cytotoxic responses and IFNγ production from natural killer (NK) cells and CD8⁺ T cells. Consistent with increased tumor immunity, mice surviving to day 150 were resistant to a second tumor challenge. This work provides a clear rationale for manipulating NKT cells to target metastatic disease.

Myeloid-derived suppressor cells: their role in the pathophysiology of hematologic malignancies and potential as therapeutic targets

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells at various stages of differentiation/maturation that have a role in cancer induction and progression. They function as vasculogenic and immunosuppressive cells, utilizing multiple mechanisms to block both innate and adaptive anti-tumor immunity. Recently, their mechanism of action and clinical importance have been defined, and the cross-talk between myeloid cells and cancer cells has been shown to contribute to tumor induction, progression, metastasis and tolerance. In this review, we focus on the role of MDSCs in hematologic malignancies and the therapeutic approaches targeting MDSCs that are currently in clinical studies.

Cytoreductive radical prostatectomy in patients with prostate cancer and low volume skeletal metastases: results of a feasibility and case-control study

PURPOSE

Androgen deprivation represents the standard treatment for prostate cancer with osseous metastases. We explored the role of cytoreductive radical prostatectomy in prostate cancer with low volume skeletal metastases in terms of a feasibility study.

MATERIALS AND METHODS

A total of 23 patients with biopsy proven prostate cancer, minimal osseous metastases (3 or fewer hot spots on bone scan), absence of visceral or extensive lymph node metastases and prostate specific antigen decrease to less than 1.0 ng/ml after neoadjuvant androgen deprivation therapy were included in the feasibility study (group 1). A total of 38 men with metastatic prostate cancer who were treated with androgen deprivation therapy without local therapy served as the control group (group 2). Surgery related complications, time to castration resistance, and symptom-free, cancer specific and overall survival were analyzed using descriptive statistical analysis.

RESULTS

Mean patient age was 61 (range 42 to 69) and 64 (range 47 to 83) years in groups 1 and 2, respectively, with similar patient characteristics in terms of initial prostate specific antigen, biopsy Gleason score, clinical stage and extent of metastatic disease. Median followup was 34.5 months (range 7 to 75) and 47 months (range 28 to 96) in groups 1 and 2, respectively. Median time to castration resistant prostate cancer was 40 months (range 9 to 65) and 29 months (range 16 to 59) in groups 1 and 2, respectively (p=0.04). Patients in group 1 experienced significantly better clinical progression-free survival (38.6 vs 26.5 months, p=0.032) and cancer specific survival rates (95.6% vs 84.2%, p=0.043), whereas overall survival was similar. Of the men in groups 1 and 2, 20% and 29%, respectively, underwent palliative surgical procedures for locally progressing prostate cancer.

CONCLUSIONS

Cytoreductive radical prostatectomy is feasible in well selected men with metastatic prostate cancer who respond well to neoadjuvant androgen deprivation therapy. These men have a long life expectancy, and cytoreductive radical prostatectomy reduces the risk of locally recurrent prostate cancer and local complications. Cytoreductive radical prostatectomy might be a treatment option in the multimodality management of prostate cancer with minimal osseous metastases.

Intraoperative near-infrared imaging can distinguish cancer from normal tissue but not inflammation

Introduction

Defining tumor from non-tumor tissue is one of the major challenges of cancer surgery. Surgeons depend on visual and tactile clues to select which tissues should be removed from a patient. Recently, we and others have hypothesized near-infrared (NIR) imaging can be used during surgery to differentiate tumors from normal tissue.

Methods

We enrolled 8 canines and 5 humans undergoing cancer surgery for NIR imaging. The patients were injected with indocyanine green (ICG), an FDA approved non-receptor specific NIR dye that accumulates in hyperpermeable tissues, 16–24 hours prior to surgery. During surgery, NIR imaging was used to discriminate the tumor from non-tumor tissue.

Results

NIR imaging identified all tumors with a mean signal-to-background ratio of 6.7. Optical images were useful during surgery in discriminating normal tissue from cancer. In 3 canine cases and 1 human case, the tissue surrounding the tumor was inflamed due to obstruction of the vascular supply due to mass effect. In these instances, NIR imaging could not distinguish tumor tissue from tissue that was congested, edematous and did not contain cancer.

Conclusions

This study shows that NIR imaging can identify tumors from normal tissues, provides excellent tissue contrast, and it facilitates the resection of tumors. However, in situations where there is significant peritumoral inflammation, NIR imaging with ICG is not helpful. This suggests that non-targeted NIR dyes that accumulate in hyperpermeable tissues will have significant limitations in the future, and receptor-specific NIR dyes may be necessary to overcome this problem.

History of myeloid-derived suppressor cells

Tumour-induced granulocytic hyperplasia is associated with tumour vasculogenesis and escape from immunity via T cell suppression. Initially, these myeloid cells were identified as granulocytes or monocytes; however, recent studies have revealed that this hyperplasia is associated with populations of multipotent progenitor cells that have been identified as myeloid-derived suppressor cells (MDSCs). The study of MDSCs has provided a wealth of information regarding tumour pathobiology, has extended our understanding of neoplastic progression and has modified our approaches to immune adjuvant therapy. In this Timeline article, we discuss the history of MDSCs, their influence on tumour progression and metastasis, and the crosstalk between tumour cells, MDSCs and the host macroenvironment.

Intraprostatic distribution and long-term follow-up after AdV-tk immunotherapy as neoadjuvant to surgery in patients with prostate cancer

A phase I-II study to evaluate gene mediated cytotoxic immunotherapy in newly diagnosed prostate cancer before radical prostatectomy was conducted in Monterrey, Mexico.

Vaccine strategies for glioblastoma: progress and future directions

Recent advances in glioblastoma therapy have led to optimism that more effective therapies will improve outcomes. Immunotherapy is a promising approach that has demonstrated the potential to eradicate cancer cells with cellular-level accuracy while minimizing damage to surrounding healthy tissue. Several vaccination strategies have been evaluated for activity against glioblastoma in clinical trials. These include peptide vaccines, polyvalent dendritic cell vaccines, heat shock protein vaccines and adoptive immunotherapy. In this review, we highlight clinical trials representative of each of these approaches and discuss strategies for integrating these therapies into routine patient care.

Changes in the local tumor microenvironment in recurrent cancers may explain the failure of vaccines after surgery

Each year, more than 700,000 people undergo cancer surgery in the United States. However, more than 40% of those patients develop recurrences and have a poor outcome. Traditionally, the medical community has assumed that recurrent tumors arise from selected tumor clones that are refractory to therapy. However, we found that tumor cells have few phenotypical differences after surgery. Thus, we propose an alternative explanation for the resistance of recurrent tumors. Surgery promotes inhibitory factors that allow lingering immunosuppressive cells to repopulate small pockets of residual disease quickly. Recurrent tumors and draining lymph nodes are infiltrated with M2 (CD11b(+)F4/80(hi)CD206(hi) and CD11b(+)F4/80(hi)CD124(hi)) macrophages and CD4(+)Foxp3(+) regulatory T cells. This complex network of immunosuppression in the surrounding tumor microenvironment explains the resistance of tumor recurrences to conventional cancer vaccines despite small tumor size, an intact antitumor immune response, and unaltered cancer cells. Therapeutic strategies coupling antitumor agents with inhibition of immunosuppressive cells potentially could impact the outcomes of more than 250,000 people each year.

Intraoperative near-infrared imaging of surgical wounds after tumor resections can detect residual disease

PURPOSE

Surgical resection remains the most effective therapy for solid tumors worldwide. The most important prognostic indicator for cure following cancer surgery is a complete resection with no residual disease. However, intraoperative detection of retained cancer cells after surgery is challenging, and residual disease continues to be the most common cause of local failure. We hypothesized that visual enhancement of tumors using near-infrared imaging could potentially identify tumor deposits in the wound after resection.

EXPERIMENTAL DESIGN

A small animal model of surgery and retained disease was developed. Residual tumor deposits in the wound were targeted using an U.S. Food and Drug Administration-approved imaging agent, indocyanine green, by the enhanced permeability and retention effect. A novel handheld spectrometer was used to optically visualize retained disease after surgery.

RESULTS

We found residual disease using near-infrared imaging during surgery that was not visible to the naked eye or micro-CT. Furthermore, examination of tumor nodules was remarkably precise in delineating margins from normal surrounding tissues. This approach was most successful for tumors with increased neovasculature.

CONCLUSIONS

The results suggest that near-infrared examination of the surgical wound after curative resection can potentially enable the surgeon to locate residual disease. The data in this study is the basis of an ongoing Phase I/II clinical trial in patients who undergo resection for lung and breast cancer.