Clinical Outcome of Nivolumab Plus Ipilimumab in Patients with Locally Advanced Non-Small-Cell Lung Cancer with Relapse after Concurrent Chemoradiotherapy followed by Durvalumab

Nivolumab plus ipilimumab showed promising efficacy in patients with metastatic non-small-cell lung cancer (NSCLC). The efficacy of the nivolumab plus ipilimumab combination regimen in NSCLC patients who relapse after durvalumab consolidation following concurrent chemoradiotherapy (CCRT) has not been determined. Between January 2021 and June 2022, clinical data were retrospectively extracted from the medical records of patients with NSCLC who received nivolumab plus ipilimumab after CCRT and durvalumab consolidation. A total of 30 patients were included in this analysis. The median number of durvalumab treatment cycles was 11. Median PFS and OS with nivolumab plus ipilimumab were 4.2 months (95% confidence interval [CI]: 0.7-7.7) and 18.5 months (95% CI: 3.5-33.5), respectively. The 6-month and 12-month PFS rates were 46.7% (95% CI: 28.8-64.5) and 36.4% (95% CI: 19.0-53.7). In multivariate analysis, a significant correlation was observed between a durvalumab treatment duration of 6 months or more and PFS (p = 0.04) as well as OS (p = 0.001). Grade 3 adverse events, including pneumonitis, dermatitis, and colitis, occurred in 10% of the patients. This study suggests that nivolumab plus ipilimumab is effective, especially in patients who have received durvalumab for 6 months or more, and tolerable for patients who relapsed after durvalumab following CCRT.

Evofosfamide and Gemcitabine Act Synergistically in Pancreatic Cancer Xenografts by Dual Action on Tumor Vasculature and Inhibition of Homologous Recombination DNA Repair

Aims: Pancreatic ductal adenocarcinomas (PDACs) form hypovascular and hypoxic tumors, which are difficult to treat with current chemotherapy regimens. Gemcitabine (GEM) is often used as a first-line treatment for PDACs but has issues with chemoresistance and penetration in the interior of the tumor. Evofosfamide, a hypoxia-activated prodrug, has been shown to be effective in combination with GEM, although the mechanism of each drug on the other has not been established. We used mouse xenografts from two cell lines (MIA Paca-2 and SU.86.86) with different tumor microenvironmental characteristics to probe the action of each drug on the other. Results: GEM treatment enhanced survival times in mice with SU.86.86 leg xenografts (hazard ratio [HR] = 0.35, p = 0.03) but had no effect on MIA Paca-2 mice (HR = 0.91, 95% confidence interval = 0.37-2.25, p = 0.84). Conversely, evofosfamide did not improve survival times in SU.86.86 mice to a statistically significant degree (HR = 0.57, p = 0.22). Electron paramagnetic resonance imaging showed that oxygenation worsened in MIA Paca-2 tumors when treated with GEM, providing a direct mechanism for the activation of the hypoxia-activated prodrug evofosfamide by GEM. Sublethal amounts of either treatment enhanced the toxicity of other treatment in vitro in SU.86.86 but not in MIA Paca-2. By the biomarker γH2AX, combination treatment increased the number of double-stranded DNA lesions in vitro for SU.86.86 but not MIA Paca-2. Innovation and Conclusion: The synergy between GEM and evofosfamide appears to stem from the dual action of GEMs effect on tumor vasculature and inhibition by GEM of the homologous recombination DNA repair process. Antioxid. Redox Signal. 39, 432-444.

Extensive-Stage Small-Cell Lung Cancer: Current Landscape and Future Prospects

Small-cell lung cancer (SCLC) is characterized by aggressive disease progression and tendency to metastasize. Although chemotherapy for extensive-stage SCLC (ES-SCLC) has remained unchanged for decades, immune checkpoint inhibitors have become the primary therapy for ES-SCLC. However, the number of patients benefiting from immunotherapy is limited, and the treatment outcomes remain unsatisfactory. In addition, predictive biomarkers for immunotherapy have not yet been identified. Recent reports have shed light on the genomics of SCLC and defined four distinct molecular subtypes based on transcription factor expression. This may increase our understanding of the biology of SCLC and identify novel therapeutic targets and drugs. In this article, we review the current standard management of ES-SCLC and present the most recent reports to further our understanding of molecular classification, predictive biomarkers, and prospective therapies, including immunotherapy, chemotherapy, and targeted therapy.

Efficacy and safety of amrubicin therapy after chemoimmunotherapy in small cell lung cancer patients

Background

Although the addition of immune checkpoint inhibitors (ICIs) to platinum-doublet chemotherapy has improved the efficacy of first-line therapy in extensive-disease small cell lung cancer (SCLC) patients, the best treatment option for patients with recurrent SCLC has not yet been determined. We conducted a retrospective study to evaluate the efficacy and safety of amrubicin (AMR) therapy after treatment with ICIs.

Methods

We retrospectively assessed patients with recurrent SCLC who received AMR after chemoimmunotherapy at the Niigata Lung Cancer Treatment Group from August 2019 to February 2021.

Results

This analysis included 30 patients. The median progression-free survival (PFS) and overall survival (OS) were 3.8 (95% CI: 2.7–4.2) and 10 (95% CI: 7.4–14.8) months, respectively. The median PFS and OS did not significantly differ between the sensitive and refractory groups [PFS; 3.1 (95% CI: 1.1–4.0) vs. 4.2 (95% CI: 2.3–4.8) months, P=0.1142, OS; 10.0 (95% CI: 5.2–14.8) vs. 10.4 (95% CI: 3.8–NE) months, P=0.5525]. The most common adverse event was grade ≥3 neutropenia, which occurred in 22 of 30 patients (73%), and 2 patients (7%) discontinued AMR due to adverse events.

Conclusions

AMR after chemoimmunotherapy shows good clinical efficacy and safety in patients with recurrent SCLC.

PEGPH20, a PEGylated human hyaluronidase, induces radiosensitization by reoxygenation in pancreatic cancer xenografts. A molecular imaging study

PURPOSE

PEGylated human hyaluronidase (PEGPH20) enzymatically depletes hyaluronan, an important component of the extracellular matrix, increasing the delivery of therapeutic molecules. Combinations of chemotherapy and PEGPH20, however, have been unsuccessful in Phase III clinical trials. We hypothesize that by increasing tumor oxygenation by improving vascular patency and perfusion, PEGPH20 will also act as a radiosensitization agent.

EXPERIMENTAL DESIGN

The effect of PEGPH20 on radiation treatment was analyzed with respect to tumor growth, survival time, p02, local blood volume, and the perfusion/permeability of blood vessels in a human pancreatic adenocarcinoma BxPC3 mouse model overexpressing hyaluronan synthase 3 (HAS3).

RESULTS

Mice overexpressing HAS3 developed fast growing, radiation resistant tumors that became rapidly more hypoxic as time progressed. Treatment with PEGPH20 increased survival times when used in combination with radiation therapy, significantly more than either radiation therapy or PEGPH20 alone. In mice that overexpressed HAS3, EPR imaging showed an increase in local pO2 that could be linked to increases in perfusion/permeability and local blood volume immediately after PEGPH20 treatment. Hyperpolarized [1-13C] pyruvate suggested PEGPH20 caused a metabolic shift towards decreased glycolytic flux. These effects were confined to the mice overexpressing HAS3 - no effect of PEGPH20 on survival, radiation treatment, or pO2 was seen in wild type BxPC3 tumors.

CONCLUSIONS

PEGPH20 may be useful for radiosensitization of pancreatic cancer but only in the subset of tumors with substantial hyaluronan accumulation. The response of the treatment may potentially be monitored by non-invasive imaging of the hemodynamic and metabolic changes in the tumor microenvironment.

Phase II study of nanoparticle albumin-bound paclitaxel monotherapy for relapsed non-small cell lung cancer with patient-reported outcomes (NLCTG1302)

Background

This multicenter, open-label, single-arm phase II study [Niigata Lung Cancer Treatment Group (NLCTG) 1302] was conducted to evaluate the efficacy and safety of nanoparticle albumin-bound paclitaxel (nab-paclitaxel) monotherapy for previously treated patients with advanced non-small cell lung cancer (NSCLC). We also investigated chemotherapy-induced peripheral neuropathy (CIPN) to evaluate the quality of life (QOL).

Methods

Sixty-five patients with advanced NSCLC from 14 participating institutions who had previously undergone one or two cytotoxic chemotherapy regimens were enrolled in this study. The patients received 100 mg/m² nab-paclitaxel intravenously on days 1, 8, and 15, every 4 weeks. The primary endpoint was overall objective response rate. CIPN symptoms were prospectively assessed using the Patient Neurotoxicity Questionnaire (PNQ) and Common Terminology Criteria for Adverse Events (CTCAE).

Results

The overall response rate (ORR) was 18.5% [95% confidence interval (CI): 10.9–29.6%], and the median progression-free survival (PFS) was 3.4 (95% CI: 2.5–4.3) months. Median overall survival (OS) was 8.6 (95% CI: 7.1–10.2) months. The most common non-hematologic grade ≥3 adverse events were infection (7.7%) and hyponatremia (4.6%). Neutropenia was the most common grade 3 or 4 adverse event (30.8%), and febrile neutropenia developed in 6.2% patients. The PNQ and CTCAE scores for motor peripheral neuropathy were low (kappa =0.10).

Conclusions

The primary endpoint was achieved. Nab-paclitaxel was well tolerated and showed anti-tumor activity in patients with previously treated NSCLC. This study demonstrates a low degree of concordance in CIPN grading between physicians and patients.

Trial Registration

University hospital Medical Information Network Clinical Trial Registry (ID: UMIN000012343).

Abstract 5974: Multimodal molecular imaging detects early reoxygenation induced by hyaluronan depletion in pancreatic cancer model mouse

[Purpose] In pancreatic ductal adenocarcinoma (PDAC) which is characterized by an intense desmoplastic feature, the extracellular matrix (ECM) can significantly influence the tumor microenvironment (TME). Hyaluronan (HA), a major component of ECM, is associated with elevated tumor pressure, vascular collapse, and poor perfusion in TME, conferring hypoxia. HA expression is also correlated with poor prognosis in the patients with PDAC. PEGylated human hyaluronidase (PEGPH20) enzymatically depletes hyaluronan in tumors. The resultant improvement in vascular patency and blood perfusion is expected to increase the delivery of therapeutic molecules. The aim of this study was to investigate the change in physiologic and metabolic profile of the tumor in response to treatment with PEGPH20 using multi-modal imaging techniques. We also investigated the capability of PEGPH20 to enhance treatment effect of radiation. [Methods] Athymic nude mice were inoculated with BxPC3 (human pancreatic adenocarcinoma) tumor cells transduced with hyaluronan synthase 3 (HAS3) to the right tibial periosteum. BxPC3-HAS3 tumor treated with PEGPH20 or control buffer were scanned with Electron paramagnetic Resonance imaging (EPRI), dynamic contrast enhanced (DCE) MRI, ultra-small superparamagnetic iron oxide (USPIO) MRI, Photoacoustic imaging (PAI), and Hyperpolarized 13C-MRI using [1-13C] pyruvate to evaluate intratumor pO2, intratumor perfusion, blood volume, O2 saturation, and glycolysis, respectively. [Results] EPRI showed significantly increased pO2 in PEGPH20 treated group. DCE-MRI and USPIO-MRI showed improved perfusion/permeability and local blood volume, respectively after PEGPH20 treatment, accounting for the increase in tumor oxygenation. PAI provided the evidence of immediate changes in tumor oxygenation after treatment. Hyperpolarized 13C-MRI using [1-13C] pyruvate suggested the decreased glycolytic flux evaluated by lactate/pyruvate ratio after PEGPH20 treatment. Combination of radiotherapy and PEGPH20 synergistically delayed tumor progression and prolonged the survival. [Conclusions] This study examined the effect of PEGPH20 on TME in PDAC xenograft model by using non-invasive multimodal imaging techniques. In summary, the non-invasive imaging modalities were useful in evaluating the changes in hemodynamics and metabolism in TME induced by modulation of ECM such as PEGPH20 treatment. PEGPH20 enhanced treatment effect of radiation therapy. The results validated the utility of the imaging methods to non-invasively monitor the changes in TME and predicted the radiosensitizing effect of hyaluronan depletion.

Citation Format: Yu Saida, Tomohiro Seki, Shun Kishimoto, Jeffrey R. Brender, Gadisetti VR. Chandramouli, Yasunori Otowa, Kota Yamashita, Kazutoshi Yamamoto, Nallathamby Devasahayam, Murali C. Krishna. Multimodal molecular imaging detects early reoxygenation induced by hyaluronan depletion in pancreatic cancer model mouse [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5974.

Hypoxia Imaging As a Guide for Hypoxia-Modulated and Hypoxia-Activated Therapy

Significance: Oxygen imaging techniques, which can probe the spatiotemporal heterogeneity of tumor oxygenation, could be of significant clinical utility in radiation treatment planning and in evaluating the effectiveness of hypoxia-activated prodrugs. To fulfill these goals, oxygen imaging techniques should be noninvasive, quantitative, and capable of serial imaging, as well as having sufficient temporal resolution to detect the dynamics of tumor oxygenation to distinguish regions of chronic and acute hypoxia. Recent Advances: No current technique meets all these requirements, although all have strengths in certain areas. The current status of positron emission tomography (PET)-based hypoxia imaging, oxygen-enhanced magnetic resonance imaging (MRI), ¹⁹F MRI, and electron paramagnetic resonance (EPR) oximetry are reviewed along with their strengths and weaknesses for planning hypoxia-guided, intensity-modulated radiation therapy and detecting treatment response for hypoxia-targeted prodrugs. Critical Issues: Spatial and temporal resolution emerges as a major concern for these areas along with specificity and quantitative response. Although multiple oxygen imaging techniques have reached the investigative stage, clinical trials to test the therapeutic effectiveness of hypoxia imaging have been limited. Future Directions: Imaging elements of the redox environment besides oxygen by EPR and hyperpolarized MRI may have a significant impact on our understanding of the basic biology of the reactive oxygen species response and may extend treatment possibilities.

Prognostic significance of procalcitonin in small cell lung cancer

Background

Procalcitonin (PCT) is a serological marker whose utility has been established in infectious disease areas. Although serum calcitonin is a prognostic predictor in patients with medullary thyroid carcinoma, the clinical usefulness of PCT remains unclear in lung cancer patients.

Methods

As a discovery cohort, we retrospectively analyzed consecutive patients with non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) who received first-line chemotherapy at our institution, and PCT blood levels were measured. As the validation cohort, PCT blood levels were prospectively evaluated in SCLC patients before first-line chemotherapy. The correlation between a PCT increase and prognosis was examined in the discovery and validation cohorts.

Results

Twenty-three SCLC patients and 26 NSCLC patients were enrolled as the discovery cohort, and 30 SCLC patients were enrolled as the validation cohort. The PCT level in SCLC patients was significantly higher than that in NSCLC patients. The PCT level was not associated with WBC count and weakly associated with the CRP level. In both the discovery and validation cohorts, the median survival time was significantly shorter in SCLC patients with PCT-high than in SCLC patients with PCT-normal (discovery; 11.7 vs. 89.7 months, P<0.005, validation; 9.6 vs. 22.6 months, P<0.005).

Conclusions

It may be difficult to differentiate bacterial infections in SCLC patients by PCT, as PCT is elevated even in SCLC patients without infectious diseases. This is the first study to prospectively verify that pretreatment PCT levels have a significant negative correlation with prognosis in SCLC patients.

PD-1 blockade therapy augments the antitumor effects of lymphodepletion and adoptive T cell transfer

Lymphodepleting cytotoxic regimens enhance the antitumor effects of adoptively transferred effector and naïve T cells. Although the mechanisms of antitumor immunity augmentation by lymphodepletion have been intensively investigated, the effects of lymphodepletion followed by T cell transfer on immune checkpoints in the tumor microenvironment remain unclear. The current study demonstrated that the expression of immune checkpoint molecules on transferred donor CD4⁺ and CD8⁺ T cells was significantly decreased in lymphodepleted tumor-bearing mice. In contrast, lymphodepletion did not reduce immune checkpoint molecule levels on recipient CD4⁺ and CD8⁺ T cells. Administration of anti-PD-1 antibodies after lymphodepletion and adoptive transfer of T cells significantly inhibited tumor progression. Further analysis revealed that transfer of both donor CD4⁺ and CD8⁺ T cells was responsible for the antitumor effects of a combination therapy consisting of lymphodepletion, T cell transfer and anti-PD-1 treatment. Our findings indicate that a possible mechanism underlying the antitumor effects of lymphodepletion followed by T cell transfer is the prevention of donor T cell exhaustion and dysfunction. PD-1 blockade may reinvigorate exhausted recipient T cells and augment the antitumor effects of lymphodepletion and adoptive T cell transfer.

Hypoxia-Activated Prodrug Evofosfamide Treatment in Pancreatic Ductal Adenocarcinoma Xenografts Alters the Tumor Redox Status to Potentiate Radiotherapy

Aims: In hypoxic tumor microenvironments, the strongly reducing redox environment reduces evofosfamide (TH-302) to release a cytotoxic bromo-isophosphoramide (Br-IPM) moiety. This drug therefore preferentially attacks hypoxic regions in tumors where other standard anticancer treatments such as chemotherapy and radiation therapy are often ineffective. Various combination therapies with evofosfamide have been proposed and tested in preclinical and clinical settings. However, the treatment effect of evofosfamide monotherapy on tumor hypoxia has not been fully understood, partly due to the lack of quantitative methods to assess tumor pO₂in vivo. Here, we use quantitative pO₂ imaging by electron paramagnetic resonance (EPR) to evaluate the change in tumor hypoxia in response to evofosfamide treatment using two pancreatic ductal adenocarcinoma xenograft models: MIA Paca-2 tumors responding to evofosfamide and Su.86.86 tumors that do not respond. Results: EPR imaging showed that oxygenation improved globally after evofosfamide treatment in hypoxic MIA Paca-2 tumors, in agreement with the ex vivo results obtained from hypoxia staining by pimonidazole and in apparent contrast to the decrease in K^trans observed in dynamic contrast-enhanced magnetic resonance imaging (DCE MRI). Innovations: The observation that evofosfamide not only kills the hypoxic region of the tumor but also improves oxygenation in the residual tumor regions provides a rationale for combination therapies using radiation and antiproliferatives post evofosfamide for improved outcomes. Conclusion: This study suggests that reoxygenation after evofosfamide treatment is due to decreased oxygen demand rather than improved perfusion. Following the change in pO₂ after treatment may therefore yield a way of monitoring treatment response. Antioxid. Redox Signal. 35, 904-915.

Multimodal Molecular Imaging Detects Early Responses to Immune Checkpoint Blockade

Immune checkpoint blockade (ICB) has become a standard therapy for several cancers, however, the response to ICB is inconsistent and a method for noninvasive assessment has not been established to date. To investigate the capability of multimodal imaging to evaluate treatment response to ICB therapy, hyperpolarized ¹³C MRI using [1-¹³C] pyruvate and [1,4-¹³C2] fumarate and dynamic contrast enhanced (DCE) MRI was evaluated to detect early changes in tumor glycolysis, necrosis, and intratumor perfusion/permeability, respectively. Mouse tumor models served as platforms for high (MC38 colon adenocarcinoma) and low (B16-F10 melanoma) sensitivity to dual ICB of PD-L1 and CTLA4. Glycolytic flux significantly decreased following treatment only in the less sensitive B16-F10 tumors. Imaging [1,4-¹³C2] fumarate conversion to [1,4-¹³C2] malate showed a significant increase in necrotic cell death following treatment in the ICB-sensitive MC38 tumors, with essentially no change in B16-F10 tumors. DCE-MRI showed significantly increased perfusion/permeability in MC38-treated tumors, whereas a similar, but statistically nonsignificant, trend was observed in B16-F10 tumors. When tumor volume was also taken into consideration, each imaging biomarker was linearly correlated with future survival in both models. These results suggest that hyperpolarized ¹³C MRI and DCE MRI may serve as useful noninvasive imaging markers to detect early response to ICB therapy. SIGNIFICANCE: Hyperpolarized ¹³C MRI and dynamic contrast enhanced MRI in murine tumor models provide useful insight into evaluating early response to immune checkpoint blockade therapy.See related commentary by Cullen and Keshari, p. 3444.

Comparison of survival and perioperative outcome of the colonic stent and the transanal decompression tube placement and emergency surgery for left-sided obstructive colorectal cancer: a retrospective multi-center observational study "The CODOMO study"

PURPOSE

Advances in endoscopic technology have led to the reevaluation of self-expandable metallic stent (SEMS) placement as a bridge-to-surgery (BTS) in patients with obstructive colorectal cancer. In Japan, after inclusion of SEMS placement as a BTS in the medical insurance coverage in 2012, this procedure has been increasingly performed. However, a transanal decompression tube (TADT) placement has been used as a BTS. We aimed to retrospectively evaluate the optimal strategy for obstructive left-sided colorectal cancer (OLCRC) by comparing SEMS and TADT placement with emergency surgery.

METHODS

We included 301 patients with stage II and III OLCRC from 27 institutions. The study patients were divided into Surgery group (emergency surgery, n = 103), SEMS group (BTS by SEMS, n = 113), and TADT group (BTS by TADT, n = 85). We compared the survival and perioperative outcomes of patients in the Surgery group as a standard treatment with those in the SEMS and TADT groups.

RESULTS

The 3-year relapse-free survival rate in patients in the Surgery group was 74.8%, while that in patients in the SEMS group and TADT group were 69.0% (p = 0.39) and 55.3% (p = 0.006), respectively. The technical success rate was not statistically different, but the clinical success rate was significantly higher in the SEMS group than in the TADT group (p = 0.0040). With regard to postoperative complications after curative surgery, the SEMS group had significantly lower of complications (≥ grade 2) than the Surgery group (p = 0.022).

CONCLUSION

Patients who underwent SEMS placement for OLCRC had similar oncological outcomes to patients who underwent emergency surgery.

Trehalose as an alternative to glycerol as a glassing agent for in vivo DNP MRI

PURPOSE

In dynamic nuclear polarization (DNP), the solution needs to form a glass to attain significant levels of polarization in reasonable time periods. Molecules that do not form glasses by themselves are often mixed with glass forming excipients. Although glassing agents are often essential in DNP studies, they have the potential to perturb the metabolic measurements that are being studied. Glycerol, the glassing agent of choice for in vivo DNP studies, is effective in reducing ice crystal formation during freezing, but is rapidly metabolized, potentially altering the redox and adenosine triphosphate balance of the system.

METHODS

DNP buildup curves of ¹³ C urea and alanine with OX063 in the presence of trehalose, glycerol, and other polyol excipients were measured as a function of concentration. T₁ and T_m relaxation times for OX063 in the presence of trehalose were measured by EPR.

RESULTS

Approximately 15-20 wt% trehalose gives a glass that polarizes samples more rapidly than the commonly used 60%-wt formulation of glycerol and yields similar polarization levels within clinically relevant timeframes.

CONCLUSIONS

Trehalose may be an attractive biologically inert alternative to glycerol for situations where there may be concerns about glycerol's glucogenic potential and possible alteration of the adenosine triphosphate/adenosine diphosphate and redox balance.

Long-term follow-up of the randomized trial of mesorectal excision with or without lateral lymph node dissection in rectal cancer (JCOG0212)

BACKGROUND

Japan Clinical Oncology Group (JCOG) 0212 (ClinicalTrials.gov NCT00190541) was a non-inferiority phase III trial of patients with clinical stage II-III rectal cancer without lateral pelvic lymph node enlargement. The trial compared mesorectal excision (ME) with ME and lateral lymph node dissection (LLND), with a primary endpoint of recurrence-free survival (RFS). The planned primary analysis at 5 years failed to confirm the non-inferiority of ME alone compared with ME and LLND. The present study aimed to compare ME alone and ME with LLND using long-term follow-up data from JCOG0212.

METHODS

Patients with clinical stage II-III rectal cancer below the peritoneal reflection and no lateral pelvic lymph node enlargement were included in this study. After surgeons confirmed R0 resection by ME, patients were randomized to receive ME alone or ME with LLND. The primary endpoint was RFS.

RESULTS

A total of 701 patients from 33 institutions were assigned to ME with LLND (351) or ME alone (350) between June 2003 and August 2010. The 7-year RFS rate was 71.1 per cent for ME with LLND and 70·7 per cent for ME alone (hazard ratio (HR) 1·09, 95 per cent c.i. 0·84 to 1·42; non-inferiority P = 0·064). Subgroup analysis showed improved RFS among patients with clinical stage III disease who underwent ME with LLND compared with ME alone (HR 1·49, 1·02 to 2·17).

CONCLUSION

Long-term follow-up data did not support the non-inferiority of ME alone compared with ME and LLND. ME with LLND is recommended for patients with clinical stage III disease, whereas LLND could be omitted in those with clinical stage II tumours.

Efficacy of EGFR-TKIs with or without upfront brain radiotherapy for EGFR-mutant NSCLC patients with central nervous system metastases

Background

Although the clinical efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR‐TKIs) in EGFR‐mutant non‐small cell lung cancer (NSCLC) patients has been demonstrated, their efficacy in EGFR‐mutant NSCLCs with central nervous system (CNS) metastases and the role of radiotherapy remain unclear. This study aimed to determine if it is preferable to add upfront cranial radiotherapy to EGFR‐TKIs in patients with EGFR‐mutant NSCLC with newly diagnosed brain metastases.

Methods

We retrospectively analyzed the data of EGFR‐mutant NSCLC patients with CNS metastases who received EGFR‐TKIs as a first‐line therapy.

Results

A total of 104 patients were enrolled and 39 patients received upfront brain radiotherapy, while 65 patients received first and second generation EGFR‐TKIs first. The median time to treatment failure (TTF) was 7.8 months (95% confidence interval [CI]: 6.3–9.4). The median survival time (MST) was 24.0 months (95% CI: 20.1–30.1). The overall response rate of the CNS was 37%. The median CNS progression‐free survival (PFS) was 13.2 months (95% CI: 10.0–16.2). Brain radiotherapy prior to EGFR‐TKI prolonged TTF (11.2 vs. 6.8 months, P = 0.038) and tended to prolong CNS‐PFS (15.6 vs. 11.1 months, P = 0.096) but was not significantly associated with overall survival (MST 26.1 vs. 24.0 months, P = 0.525). Univariate and multivariate analyses indicated that poor performance status and the presence of extracranial metastases were poor prognostic factors related to overall survival.

Conclusion

EGFR‐TKI showed a favorable effect for EGFR‐mutant NSCLC patients with CNS metastases. Prolonged TTF and CNS‐PFS were observed with upfront brain radiotherapy.

Effect of Lymphodepletion on Donor T Cells and the Role of Recipient Cells Persisting after Cytotoxic Treatments in Cancer Immunotherapies

The effectiveness of lymphodepletion in antitumor immunity has been well established. Although recent studies have elucidated some of the broad mechanisms underlying the augmentation of antitumor immunity by lymphodepletion, such as increased availability of cytokines due to the elimination of cellular elements and improvement in tumor antigen presentation, the precise mechanisms remain unclear. Previous studies have focused on the enhancement of the functions of transferred antitumor CD8+ T cells after lymphodepletion. In this review, we discuss the important role of other immune cells in the effectiveness of lymphodepletion. Recent studies have demonstrated that lymphodepletion enhances not only transferred tumor-specific CD8+ T cells but also tumor-specific CD4+ T cells and polyclonal naïve T cells. Moreover, recipient immune cells, including CD8+ T cells, regulatory T cells, dendritic cells, and macrophages, are involved in the augmentation of antitumor effects by lymphodepletion. These host cells can survive lymphodepletive therapies and play a role in the development of antitumor immunity after lymphodepletion. Improvements in the understanding of lymphodepletion allow us to design effective cancer immunotherapy.

Transfer of in vitro-expanded naïve T cells after lymphodepletion enhances antitumor immunity through the induction of polyclonal antitumor effector T cells

The adoptive transfer of effector T cells combined with lymphodepletion has demonstrated promising antitumor effects in mice and humans, although the availability of tumor-specific T cells is limited. We and others have also demonstrated that the transfer of polyclonal naïve T cells induces tumor-specific effector T cells and enhances antitumor immunity after lymphodepletion. Because tumors have been demonstrated to induce immunosuppressive networks and regulate the function of T cells, obtaining a sufficient number of fully functional naïve T cells that are able to differentiate into tumor-specific effector T cells remains difficult. To establish culture methods to obtain a large number of polyclonal T cells that are capable of differentiating into tumor-specific effector T cells, naïve T cells were activated with anti-CD3 mAbs in vitro. These cells were stimulated with IL-2 and IL-7 for the CD8 subset or with IL-7 and IL-23 for the CD4 subset. Transfer of these hyperexpanded T cells after lymphodepletion showed significant antitumor efficacy, and tumor-specific effector T cells were primed from these expanded T cells in tumor-bearing hosts. Moreover, these ex vivo-expanded T cells maintained T cell receptor diversity and showed long-term persistence of memory against specific tumors. Further analyses revealed that combination therapy consisting of vaccination with dendritic cells that were co-cultured with irradiated whole tumor cells and the transfer of ex vivo-expanded T cells significantly enhanced antitumor immunity. These results indicate that the transfer of ex vivo-expanded polyclonal T cells can be combined with other immunotherapies and augment antitumor effects.

Focal Fatty Masses of the Pancreas

Five patients with solitary fatty mass of the pancreas examined with CT and ultrasound (US) were evaluated. The areas of fat replacement were located in the pancreatic neck, body or tail. The size ranged from 4 to 30 mm in the longest diameter. The shape varied from roundish, to ovoid to semicircular, and the contour was universally well defined. The internal structure was homogeneous in 3 patients, but in one case there were thin septa and, in another, a slightly hyperdense part in the peripheral portion. All the masses except the smallest one were in part contact with pancreatic fat. CT showed fat with the same density as the peripancreatic fat and low HU units. The mass was hypoechoic in 2 cases and hyperechoic in one. The masses in the tail of the pancreas were not detected by US.

Abstract 3153: Critical roles of chemo-resistant effector and regulatory T cells in cancer immunotherapy during hemostatic proliferation

Antitumor immunity has been well established to be augmented by cytotoxic lymphodepletion therapies. Adoptively transferred naïve and effector T cells proliferate extensively and show enhanced antitumor effects during homeostatic proliferation when they were adoptively transferred into tumor-bearing hosts that were lymphodepleted with cytotoxic agents or by whole body irradiation. Although the impact of lymphodepletion on transferred donor T cells has been well evaluated, its influence on recipient T cells is largely unknown. The current study demonstrates that both regulatory T cells (Tregs) and effector CD8+ T cells from lymphopenic recipients play critical roles in the development of antitumor immunity after lymphodepletion. Cyclophosphamide (CPA) treatment depleted lymphocytes more efficiently than other cytotoxic agents, such as fludarabine, cisplatin, etoposide, paclitaxel or gemcitabine; however, the percentage of CD4+CD25+Foxp3+ Tregs was significantly increased in CPA-treated lymphopenic mice. Depletion of these chemo-resistant Tregs following CPA treatment and transfer of naïve CD4+ T cells augmented the antitumor immunity and significantly suppressed tumor progression. Further analyses revealed that recipient CD8+ T cells were responsible for this augmentation. Using Rag2−/− mice or depletion of recipient CD8+ T cells after CPA treatment abrogated the augmentation of antitumor effects in CPA-treated reconstituted mice. The transfer of donor CD4+ T cells enhanced the proliferation of CD8+ T cells and the priming of tumor-specific CD8+ T cells originating from the lymphopenic recipients. These results highlight the importance of the recipient cells surviving cytotoxic regimens in cancer immunotherapies.

Citation Format: Ko Sato, Satoshi Watanabe, Yu Saida, Tomohiro Tanaka, Junko Baba, Aya Ohtsubo, Satoshi Shoji, Daisuke Ishikawa, Rie Kondo, Masaaki Okajima, Satoru Miura, Junta Tanaka, Hiroshi Kagamu, Hirohisa Yoshizawa, Ichiei Narita. Critical roles of chemo-resistant effector and regulatory T cells in cancer immunotherapy during hemostatic proliferation. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3153. doi:10.1158/1538-7445.AM2015-3153

Randomized clinical trial of skin closure by subcuticular suture or skin stapling after elective colorectal cancer surgery

Background

The best suture method to prevent incisional surgical-site infection (SSI) after clean-contaminated surgery has not been clarified.

Methods

Patients undergoing elective colorectal cancer surgery at one of 16 centres were randomized to receive either subcuticular sutures or skin stapling for skin closure. The primary endpoint was the rate of incisional SSI. Secondary endpoints of interest included time required for wound closure, incidence of wound problems, postoperative length of stay, wound aesthetics and patient satisfaction.

Results

A total of 1264 patients were enrolled. The cumulative incidence of incisional SSI by day 30 after surgery was similar after subcuticular sutures and stapled closure (8·7 versus 9·8 per cent respectively; P = 0·576). Comparison of cumulative incidence curves revealed that SSI occurred later in the subcuticular suture group (P = 0·019) (hazard ratio 0·66, 95 per cent c.i. 0·45 to 0·97). Wound problems (P = 0·484), wound aesthetics (P = 0·182) and postoperative duration of hospital stay (P = 0·510) did not differ between the groups; subcuticular sutures took 5 min longer than staples (P &lt; 0·001). Patients in the subcuticular suture group were significantly more satisfied with their wound (52·4 per cent versus 42·7 per cent in the staple group; P = 0·002).

Conclusion

Compared with skin stapling, subcuticular sutures did not reduce the risk of incisional SSI after colorectal surgery. Registration number: UMIN000004001 (http://www.umin.ac.jp/ctr).

Abstract 2818: Dendritic cell vaccination and regulatory T-cell depletion augment antitumor immunity after cytotoxic therapy

The ability of lymphodepleting cytotoxic regimens to augment antitumor immune responses has been well established. We and others have previously reported that naïve T cells, as well as effector T cells, transferred into lymphopenic tumor-bearing mice acquire memory-like phenotypes and show antitumor effects. The transfer of naïve T cells into irradiated lymphopenic mice inhibited tumor progression. Further analyses revealed that the transfer of CD4+ naïve T cells was essential for this augmentation of antitumor immunity after lymphodepletion.

To enhance the antitumor efficacy of lymphodepletion and transfer of naïve T cells, we have tested anti-CTLA-4 mAbs and anti-CD25 mAbs for depletion of regulatory T cells. Mice were irradiated with 500 cGy to deplete lymphocytes and were transferred i.v. with T cells (2 x 107). On the same day, mice were inoculated with MCA205 tumor cells (1 x 105) followed by the injection of anti-CTLA-4 mAbs (UC10) or the injection of anti-CD25 mAbs (PC61). Although the injection of anti-CTLA-4 mAbs showed minimal augmentation of the antitumor effects of the combination of lymphodepletion and naïve T cell transfer, anti-CD25 mAbs significantly enhanced antitumor immune responses. Next, we evaluated whether dendritic cell vaccination augments this combination therapy. Different from previous experiments, 3-day tumor-bearing mice were irradiated and reconstituted with T cells. Dendritic cells were generated from bone marrow of naïve mice and were co-cultured with irradiated MCA205 tumor cells followed by stimulation with agonistic anti-CD40 mAbs. We found that dendritic cell vaccination significantly inhibited tumor growth in irradiated reconstituted mice.

Previously, we reported that a significant increase of CD4+CD25+Foxp3+ regulatory T cells in irradiated mice. We demonstrated that these radio-resistant regulatory T cells from irradiated recipient mice suppressed the development of antitumor immunity. To clarify the roles of other recipient cells in antitumor immunity during recovery from lymphopenia, Rag-2 knockout mice were irradiated and reconstituted with T cells. These mice were then inoculated MCA205 tumor cells. In Rag-2 knockout mice, antitumor effects were not observed after lymphodepletion and reconstitution. These findings indicate that recipient T cells or B cells were required to augment antitumor immunity in lymphopenic mice in our model.

Citation Format: Tomohiro Tanaka, Satoshi Watanabe, Ko Sato, Yu Saida, Junko Baba, Koichiro Nozaki, Daisuke Ishikawa, Natsue Igarashi, Satoshi Shoji, Masaaki Okajima, Satoru Miura, Junta Tanaka, Hiroshi Tanaka, Hiroshi Kagamu, Hirohisa Yoshizawa, Ichiei Narita. Dendritic cell vaccination and regulatory T-cell depletion augment antitumor immunity after cytotoxic therapy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2818. doi:10.1158/1538-7445.AM2014-2818

DEAD/H (Asp-Glu-Ala-Asp/His) box polypeptide 3, X-linked is an immunogenic target of cancer stem cells

Accumulating evidence suggests that most solid malignancies consist of heterogeneous tumor cells and that a relatively small subpopulation, which shares biological features with stem cells, survives through potentially lethal stresses such as chemotherapy and radiation treatment. Since the survival of this subpopulation of cancer stem cells (CSC) plays a critical role in recurrence, it must be eradicated in order to cure cancer. We previously reported that vaccination with CD133(+) murine melanoma cells exhibiting biological CSC features induced CSC-specific effector T cells. These were capable of eradicating CD133(+) tumor cells in vivo, thereby curing the parental tumor. In the current study, we indicated that DEAD/H (Asp-Glu-Ala-Asp/His) box polypeptide 3, X-linked (DDX3X) is an immunogenic protein preferentially expressed in CD133(+) tumor cells. Vaccination with DDX3X primed specific T cells, resulting in protective and therapeutic antitumor immunity. The DDX3X-primed CD4(+) T cells produced CD133(+) tumor-specific IFNγ and IL-17 and mediated potent antitumor therapeutic efficacy. DDX3X is expressed in various human cancer cells, including lung, colon, and breast cancer cells. These results suggest that anti-DDX3X immunotherapy is a promising treatment option in efforts to eradicate CSC in the clinical setting.

Abstract 3963: Chemo-resistantregulatory T cells suppress the development of antitumor immunity aftercytotoxic regimens

Previous studies demonstrated that naïve T cells transferred into lymphopenic hosts develop into memory like T cells and acquire some effector functions. We and others have shown that sublethal whole body irradiation and transfer of naïve T cells augment antitumor immunity and inhibited tumor progression. Further, we found a significant increase of CD4+CD25+Foxp3+ regulatory T cells (Treg) in irradiated mice. Depletion of those radio-resistant Treg after irradiation and transfer of naïve T cells enhanced generation of antitumor effector T cells and suppressed tumor progression (Baba J, et al. 2012, Blood). The combination of lymphodepletion and transfer of naïve T cells seems to be a promising strategy. However, whole body irradiation has not been routinely used in clinical settings. Previously, we demonstrated that the sublethal doses of cyclophosphamide (CPA) efficiently depleted lymphocytes in mice, and enhanced antitumor effects of transferred naïve T cells. In this study, we examined the effect of lymphodepleting doses of CPA on immune suppressor cells. Similar to the irradiated lymphopenic hosts, a significant increase of Treg was observed in mice treated with CPA. The combination of CPA, transfer of naïve T cells and Treg depletion with anti-CD25 monoclonal antibodies succeeded to cure advanced skin tumors.To evaluate the proliferation and apoptosis of Treg increasing in CPA-treated mice, we performed BrdU incorporation, Ki-67 expression and Annexin V apoptosis assay. The results indicated that the increased percentage of Treg during recovery from lymphopenia is due to the rapid proliferation of Treg that survive CPA treatment.

Next, we investigated which subsets of donor T cells are necessary in this combination therapy. CD4+ or CD8+ T cells were depleted from donor T cells before transfer into lymphopenic skin tumor bearing mice. Depletion of CD4+ T cells, but not CD8+ T cells eliminated the antitumor effects. Intracellular cytokine FACS revealed that transfer of CD4+ T cells following CPA treatment induced tumor specific effector CD4+ T cells in lymphopenic hosts. Interestingly, transfer of CD4+ T cells also induced CD8+ effector T cells from CPA treated recipient cells. Depletion of CD8+ recipient cells with anti-CD8 monoclonal antibodies abrogated the antitumor effects of lymphodepletion and CD4+ T cells transfer. Furthermore, Transfer of CD4+ T cells into Rag-2 knockout mice showed no antitumor effects. These results suggested that donor CD4+ T cells induce effector CD8+ T cells originate from recipients after CPA treatment and suppress tumor progression. Our results showed that the combination of CPA treatment, naïve CD4+ T cell transfer, and Treg depletion had potent antitumor efficacy. Both of donor CD4+ T cells and recipient CD8+ T cells were necessary for this augmentation of antitumor immunity.

Citation Format: Yu Saida, Satoshi Watanabe, Tomohiro Tanaka, Junko Baba, Koh Satoh, Satoshi Shoji, Natsue Igarashi, Koichirou Nozaki, Masaaki Okajima, Satoru Miura, Junta Tanaka, Hiroshi Kagamu, Hirohisa Yoshizawa, Ichiei Narita. Chemo-resistantregulatory T cells suppress the development of antitumor immunity aftercytotoxic regimens. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3963. doi:10.1158/1538-7445.AM2013-3963

Esophageal submucosal dissection under steady pressure automatically controlled endoscopy (SPACE): a randomized preclinical trial

BACKGROUND AND STUDY AIMS

A new overtube system has been developed for steady pressure automatically controlled endoscopy (SPACE) in the gastrointestinal tract. The objectives of this study were to validate the feasibility and safety of SPACE in the esophagus, and to evaluate its potential advantages over conventional (manually insufflating) endoscopy in endoscopic submucosal dissection (ESD).

METHODS

This was a multicenter preclinical trial using acute porcine models (n = 20). In Experiment 1 (feasibility/safety study), SPACE was attempted in the esophagus with continuous monitoring of cardiopulmonary parameters and intraluminal pressures in the downstream bowel. Different insufflation pressures were tested to optimize the insufflation condition. Each session was video-recorded and scored by blinded reviewers. In Experiment 2 (randomized trial), esophageal ESD was attempted using either SPACE or conventional endoscopy, and results were compared.

RESULTS

In Experiment 1, SPACE was performed safely without intraluminal pressure elevation in the downstream bowel. According to video review, SPACE provided more stable, reproducible, and rapid visualization than conventional endoscopy. The insufflation pressure was optimized at 14 mmHg for esophageal SPACE. In Experiment 2, ESD was completed in all animals. The ESD time was significantly shorter with SPACE compared with conventional endoscopy (1326 vs. 1616 seconds; P = 0.009). Responses to questionnaires showed that 94 % - 100 % of participants considered SPACE to provide improved exposure and more uniform tissue tension than conventional endoscopy. Other data were comparable.

CONCLUSIONS

SPACE is feasible, safe, and potentially effective for complicated endoscopic procedures, such as ESD. SPACE improves and standardizes endoscopic exposure and tissue tension. A clinical study is required to further confirm its safety and clinical effectiveness.

Abstract 1550: Successful treatment of advanced tumors with chemo-immunotherapy: a combination of cyclophosphamide and inhibition of chemo-resistant immune suppressor cells

It is well known that naïve T cells transferred into lymphopenic hosts develop into memory like T cells and acquire some effector functions. We and others have been shown that transfer of naïve T cells following sublethal whole body irradiation augmented antitumor immunity and inhibited tumor progression. Further analyses showed that antitumor effector T cells were primed from transferred naïve T cells. Although the exact mechanism underlying this enhancement of antitumor immune responses remains unclear, possible explanations have been proposed; depletion of suppressor cells, improvement of tumor-antigen presentation, and elimination of lymphocytes competing activation cytokines. Combination of lymphodepletion by cytotoxic regimens, such as chemotherapy or radiotherapy, and transfer of naïve T cells seems to be a promising strategy. Although whole body irradiation induces lymphopenia to tumor-bearing animals and enhances antitumor immunity, it has not been routinely used in clinical settings. To test whether cytotoxic agents deplete lymphocytes and enhance antitumor immune responses, we infused cyclophosphamide (CPA), fludarabine, cisplatin and etoposide at the sublethal doses to mice. CPA treatment depleted 95% of lymphocytes in mice, and enhanced antitumor effects of transferred naïve T cells. Other cytotoxic drugs failed to augment antitumor immunity in combination with transfer of T cells. Previously, we have demonstrated that CD4+CD25+Foxp3+ regulatory T cells (Treg) and CD11b+Gr-1+ myeloid-derived suppressor cells (MDSC) inhibited priming of antitumor effector T cells. Depletion of these suppressor cells increased the number of tumor-specific T cells and augmented antitumor immune responses. To examine the effect of sublethal doses of cyclophosphamide on immune suppressor cells, we injected cyclophosphamide into mice and harvested lymph-nodes and spleens for FACS analyses. Unexpectedly, we found a significant increase in the frequency of Treg and MDSC after CPA treatment. Magnetically isolated Treg and MDSC from cyclophosphamide treated mice suppressed tumor-specific responses of effector T cells in vitro. Depletion of Treg with anti-CD25 monoclonal antibodies following CPA administration and transfer of naïve T cells increased the number of antitumor effector T cells. Further, the combination of Treg depletion, CPA treatment and transfer of naïve T cells succeeded to cure 20-day established skin tumors in mice. We have also been testing whether inhibition of MDSC after CPA treatment augments antitumor immunity. Our results showed that CPA treatment efficiently depletes lymphocytes and enhanced antitumor immune responses despite an increase of immune suppressor cells. Further inhibition of suppressor cells after CPA administration successfully treated advanced tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1550. doi:1538-7445.AM2012-1550

Abstract 2685: Irradiation and reconstitution with in vitro-expanded polyclonal T cells from naïve mice augments antitumor response

Transfer of naïve T cells into lymphopenic tumor-bearing hosts induces antitumor effector T cells effectively and inhibits tumor progression. Although the exact mechanism underlying this augmentation of antitumor immune responses remains unclear, possible explanations have been proposed; depletion of suppressor cells, improvement of tumor-antigen presentation, and elimination of lymphocytes competing activation cytokines. Thus, the combination of lymphodepletion by cytotoxic regimens, such as chemotherapy or radiotherapy, and transfer of naïve T cells seems to be an attractive approach. Because of difficulty to acquire enough number of naïve T cells from cancer patients, it is necessary to establish a method for obtaining the large number of naïve T cells.

The current study seeks to determine whether lymphodepletion and transfer of in vitro expanded T cells enhances antitumor immunity. We stimulated CD4+ and CD8+ T cells from naïve C57/BL6 mice with homeostatic cytokines. At day9 of culture, their number increased 4 to 10-fold. FACS analysis demonstrated TCR diversity of stimulated T cells. Resulted cells were injected into mice harboring MCA205 fibrosarcoma after sublethal irradiation (500 rad). As well as transfer of fresh naïve T cells, transfer of stimulated T cells strongly inhibited tumor-progression. To confirm whether in vitro stimulated T cells become antitumor effector T cells and retarded tumor growth, GFP+ T cells were expanded in vitro and transferred into irradiated wild mice. On the same day, mice were inoculated s.c. with tumor cells. Twelve days later, tumor-draining LNs were harvested and cells were stimulated with the anti-CD3/IL-2 method. Activated tumor-draining LN cells were analyzed for secretion of IFN-γ after specific tumor stimulation. Intracellular IFN-γ staining revealed that the majority of effector T cells were GFP+ donor cells. We next examined whether dendritic cell vaccination enhances antitumor immune responses of in vitro stimulated T cells. Bone marrow dendritic cells were co-cultured with irradiated tumor cells and were injected into mice reconstituted with in vitro stimulated T cells. Compared with transfer of T cells alone, the combination of vaccination and transfer of T cells significantly delayed tumor progression.

We report in this study that even after nonspecific stimulation, naïve T cells retain their ability to respond to tumor-antigens when they are transferred into lymphopenic hosts. Irradiation and reconstitution with in vitro stimulated T cells can be useful conditioning for cancer immunotherapy, especially for vaccination with tumor antigens.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2685. doi:10.1158/1538-7445.AM2011-2685

Abstract 2694: DEAD/H (Asp-Glu-Ala-Asp/His) box polypeptide 3, X-linked is a CD133+ tumor-specific protein and induces antitumor immunity

Cancer cells that exclusively maintain the ability of self-renewal and differentiation are termed cancer stem cells (CSCs). It is still controversial if the classical CSC hierarchy exists in all of solid tumors, however, accumulating evidence suggests that heterogeneity within cancer cells exists and that cancer survives as the cells with CSC features during potentially lethal stresses, including chemotherapy, radiation treatment, and molecular targeting therapy. Although it is necessary to eradicate CSCs to obtain cure of cancer, effective treatment has not been elucidated. Interestingly, most of the identified immunogenic tumor antigens are cancer/testis (CT) antigens. One of the reasons why CT antigens are immunogenic is that they are unlikely to maintain peripheral tolerance, owing to restricted expression in the testis and in immortal malignant cells, because Tregs are maintained with antigen stimulation by dendritic cells (DCs) that acquire dying cells in the steady state. Since CSCs are highly immortal, it is possible that they possess immunogenic antigens that are not expressed in differentiated cancer cells or normal epithelial cells, and that these antigens may be ideal therapeutic targets for cancer treatment. Recently it was reported that CT antigens are mainly expressed in CSCs.

We isolated CD133+ tumor cells, which possessed CSC properties, from B16 melanoma cells. We found that CSC-specific LN T cells primed by the CD133+ tumor vaccine mediated potent antitumor therapeutic efficacy by eradicating CSCs in tumor, thereby curing parental melanomas that comprised &lt;1% CSCs. Interestingly, CD133+ tumor antigens tended to prime type 17 helper T (Th17) cells and Th1 cells, but not Th2 cells. Our proteome analyses revealed that DEAD/H (Asp-Glu-Ala-Asp/His) box polypeptide 3, X-linked (DDX3X) is one of CD133+ melanoma-specific proteins. B16 tumor cells didn't lose CD133 expression by DDX3X knock down but lost the ability to proliferate in an anchoring independent manner. We examined DDX3X expression in 6 human cancer cell lines. HCT116 (colon cancer), and 87.5 (small cell lung cancer), were CD133+ and S2 (small cell lung cancer), A549 (lung cancer), PC9 (lung cancer), and WM115 (melanoma) were CD133-. HCT116 and 87.5 expressed DDX3X but all of other CD133- cancer cells didn't. The LN T cells draining DDX3X vaccines exhibited specific IFNγ and IL-17 release upon CD133+ tumor stimulation. A DDX3X vaccination induced antitumor protective immunity against parental melanoma. These results indicate that anti-CSC, especially anti-DDX3X, immunotherapy is a promising treatment option in the clinical setting.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2694. doi:10.1158/1538-7445.AM2011-2694

[Case of IgG4-related tubulointerstitial nephritis showing the progression of renal dysfunction after a cure for autoimmune pancreatitis]

A 78-year-old-man was admitted to our hospital because of renal insufficiency 20 months after the onset of autoimmune pancreatitis. He had cerebral infarction and prostatic hypertrophy as complications. He had been previously diagnosed with autoimmune pancreatitis (AIP). The initial therapy was started with oral prednisolone at the dose of 0.8 mg/kg (40 mg/day). Prednisolone had been tapered off gradually through a one-year period. Four months later from terminating prednisolone, a follow-up CT showed multiple low-density areas in both kidneys without swelling of the pancreas. Furthermore, 4 months later, laboratory findings showed progressive renal insufficiency. On admission, BP was 167/77 mmHg, and the bilateral submaxillary glands were swollen. He did not have pretibial edema. Laboratory findings were as follows. BUN 55.9 mg/dL, Cre 6.17 mg/dL, Amy 65 mg/dL, TP/Alb 9.5/4 g/dL, gamma-gl 43.7%, IgG/IgA/IgM 3,395/112/74 mg/dL, IgG4 1,460 mg/dL, urinary protein 1.38 g/day, and 24 hr-Ccr 11.8 mL/min/1.73 m2. Percutaneous renal needle biopsy was conducted. Light microscopic findings demonstrated tubulointerstitial nephritis (TIN) and membranous change. Immunofluorescent microscopic findings indicated diffuse deposition of IgG2 and IgG4 in the renal interstitium. On the basis of these findings, the condition was diagnosed as IgG4-related tubulointerstitial nephritis. As renal insufficiency was progressing, hemodialysis was started soon after admission and oral prednisolone was also started at the dose of 0.4 mg/kg (20 mg/day). However, improvement of renal function has not been obtained and hemodialysis and prednisolone tapering are still being conducted. This case showed severe tubulointerstitial nephritis requiring hemodialysis after a cure for autoimmune pancreatitis. IgG4-related renal disease rarely needs hemodialysis. This case indicates that the prognosis of IgG4-related systemic disease is not necessarily good and further accumulation of cases is required.

Pedicle involvement on MR imaging is common in osteoporotic compression fractures

BACKGROUND AND PURPOSE

Pedicle involvement on MR imaging has been considered specific for malignancy. However, we also noted the findings in many patients with osteoporosis and hypothesized that it is not specific for malignant lesions. The aim of this study was to evaluate the prevalence of pedicle involvement in painful osteoporotic compression fractures and to determine whether the sign is specific for malignancy.

MATERIALS AND METHODS

We retrospectively reviewed MR images and CT scans of 152 patients who underwent PV for painful compression fractures. There were 140 patients (225 vertebrae) with osteoporotic fractures and 12 patients (19 vertebrae) with malignant fractures. Three radiologists evaluated the degree and extent of signal-intensity changes of the pedicle on MR imaging by consensus. The CT findings were also evaluated. The chi(2) test was used for statistical analyses.

RESULTS

Of the 225 vertebrae of osteoporotic fractures and 19 vertebrae of malignant fractures, pedicle involvement on MR imaging was seen in 144 (64%) and 16 (84.2%) vertebrae, respectively, and there was no statistically significant difference (P = .065). Positive pedicle involvement in osteoporotic fractures was seen in 84 (77%) of 109 vertebrae with early-phase fractures (< or =3 months) and 60 (51.7%) of 116 vertebrae with chronic-phase fractures (>3 months), and this was statistically significant (P < .001). Among 144 osteoporotic vertebrae that showed positive pedicle involvement on MR imaging, 45 (31%) showed pedicle fractures and 55 (38.2%) showed sclerotic change on CT.

CONCLUSIONS

Pedicle involvement was seen frequently in patients with osteoporotic compression fractures and was not specific for malignancy in our study group.