Effects of combined radiotherapy with immune checkpoint blockade on immunological memory in luminal-like subtype murine bladder cancer model.

MIBC is a highly lethal disease, and the patient survival rate has not improved significantly over the last decades. UPPL is a cell line that can be used to recapitulate the luminal-like molecular subtype of bladder cancer and to discover effective treatments to be translated in patients. Here, we investigate the effects of combinational treatments of radiotherapy and immunotherapy in this recently characterized UPPL tumor-bearing mice. We first characterized the baseline tumor microenvironment and the effect of radiation, anti-PD-L1, and combinatorial treatments. Then, the mice were re-challenged with a second tumor (rechallenged tumor) in the contralateral flank of the first tumor to assess the immunological memory. Radiation slowed down the tumor growth. All treatments also decreased the neutrophil population and increased the T cell population. Anti-PD-L1 therapy was not able to synergize with radiation to further delay tumor growth. Furthermore, none of the treatments were able to generate immune memory. The treatments were not sufficient to induce a significant and lasting pool of memory cells. We show here that anti-PD-L1 treatment added to radiotherapy was not enough to achieve T cell-mediated memory in UPPL tumors. Stronger T cell activation signals may be required to enhance radiation efficacy in luminal-like bladder cancer.

Integrating novel immunotherapeutic approaches in organ-preserving therapies for bladder cancer.

Bladder cancer (BC) is a prevalent malignancy with significant morbidity and mortality. Over the years, the landscape of bladder cancer treatment has witnessed notable advancements, particularly in the realm of immunotherapy. Immunotherapy has emerged as a promising adjunct to organ-preserving approaches, harnessing the immune system's potential to target and eliminate cancer cells. Organ preservation strategies offer viable alternatives to radical cystectomy to avoid the morbidities associated with radical surgery, as well as to respond to the needs of patients unfit for or who have refused surgery. However, the challenge lies in achieving durable disease control while minimizing treatment-related toxicities. This review highlights the significance of immune checkpoint inhibitors, such as anti-programmed cell death 1 (PD-1)/programmed cell death 1 ligand 1 (PD-L1) antibodies, in the treatment of localized bladder cancer. The clinical efficacy of immune checkpoint inhibitors, as both neoadjuvant and adjuvant therapies in combination with radiation or chemotherapy, is discussed. Moreover, the potential of immunotherapies beyond immune checkpoint inhibition, including combinations with bacillus Calmette-Guérin (BCG) instillations and/or investigational gene therapies, is explored. Furthermore, the predictive value of the tumour immune microenvironment for the success of these strategies is examined. Understanding the complex interplay between tumour immunity and therapeutic interventions can aid in identifying predictive biomarkers and tailoring personalized treatment strategies. Further research and clinical trials are warranted to optimize the use of immunotherapy in conjunction with organ-preserving therapies, potentially leading to enhanced patient outcomes and quality of life.

Feasibility and Impact of Immunohistochemistry-based Molecular Subtyping for Muscle-invasive Bladder Cancer in Patients Treated with Radiation-based Therapy.

Background: Distinct molecular subtypes of muscle-invasive bladder cancer (MIBC) have been identified via gene expression profiling. Objective: We investigated the feasibility of a simple immunohistochemistry (IHC)-based Lund subtyping method and the association of MIBC subtypes with oncological outcomes for patients after bladder-preserving radiation-based therapy. Design setting and participants: Transurethral resected tumor tissues from 104 patients treated with radiation-based therapy were sampled on tissue microarray blocks. Outcome measurements and statistical analysis: The expression of KRT5, GATA3, and p16 proteins was scored via digital image analysis. Hierarchical clustering was used to classify tumors as the basal subtype or one of two luminal subtypes: genomically unstable (GU) or urothelial-like (URO). Subtypes were evaluated for association with complete response (CR), recurrence-free survival (RFS), and overall survival (OS). Results and limitations: The median OS was 43 mo (95% confidence interval 19-77) and median follow-up was 55 mo (interquartile range 39-75). Age and clinical stage had a significant impact on OS (p < 0.05). IHC-based subtype classification was feasible in most patients (89%). The subtype was basal in 23.6%, GU in 14.0%, URO in 31.2%, and unclassified in 31.2% of patients. No significant differences in CR, RFS, or OS were observed between the molecular subtypes. Limitations include the retrospective design and relatively small sample size. Conclusions: IHC-based molecular MIBC subtyping using a three-antibody algorithm is feasible in most patients treated with radiation-based therapy. MIBC subtype was not associated with response or survival. Further prospective studies are warranted to confirm the lack of association between molecular subtype and survival in patients treated with trimodal therapy. Patient summary: For patients with invasive bladder cancer treated with radiation-based therapy, we classified tumors into different subtypes using just three molecular stains. This method is cheaper and more widely available than the usual approach. However, we did not find an association between different cancer subtypes and survival.

Impact of Programmed Death-ligand 1 Expression on Oncological Outcomes in Patients with Muscle-invasive Bladder Cancer Treated with Radiation-based Therapy.

Background: No biomarkers are recommended for patients undergoing radiation-based therapy (RT) for muscle-invasive bladder cancer (MIBC). Objective: We aim to evaluate the predictive role of programmed death-ligand 1 (PD-L1) expression on the oncological outcomes of patients treated with RT for MIBC. Design setting and participants: A single-center retrospective analysis of tumor specimens collected through transurethral resection (TURBT) from 104 MIBC patients, implemented in a tissue microarray and stained with the SP263 PD-L1 clone (Ventana Medical Systems, Tucson, AZ, USA), was conducted. Two reviewers measured the PD-L1 H-score for tumor and immune cells. Intervention: RT (maximal TURBT followed by radiation and concurrent chemotherapy when eligible). Outcome measurements and statistical analysis: Logistic and Cox regression models were used to predict 3-mo complete response (CR) and overall survival (OS) after RT, respectively. Results and limitations: A total of 88 (85%) patients had cT2 disease and 39 (37.5%) had high immune cell PD-L1 expression. A CR was achieved in 68 (65%) patients. On the multivariable analysis (MVA), a higher clinical stage (p = 0.02) and a low immune cell PD-L1 H-score (p = 0.02) were associated with a decreased CR after RT. The median time to death was 43 mo (95% confidence interval 20-66). On Cox MVA, a high immune cell PD-L1 H-score (p = 0.0017) was associated with better OS, independently of performance status (p = 0.0005) or tumor stage (p = 0.0013). A high tumor cell PD-L1 H-score was not an independent predictor of CR or OS. Limitations of the study include the retrospective design. Conclusions: MIBC patients with high PD-L1 expression on immune cells appear to have better oncological outcomes following RT. Our results may aid in patient stratification for future clinical trial design. Patient summary: In this report, we evaluated the role of programmed death-ligand 1 (PD-L1) expressed on tumor and immune cells in the tumor microenvironment for patients treated with a bladder-sparing regimen. We found that PD-L1 overexpression on immune cells is able to predict a better response to radiation-based therapy.

Role of Serum Lymphocyte-derived Biomarkers in Nonmetastatic Muscle-invasive Bladder Cancer Patients Treated with Trimodal Therapy.

BACKGROUND: The role of serum lymphocyte-based biomarkers, such as the neutrophil-to-lymphocyte (NLR), lymphocyte-to-monocyte (LMR), and platelet-to-lymphocyte (PLR) ratios, was previously studied in patients with muscle-invasive bladder cancer (MIBC) treated with radical cystectomy but remains underexplored in patients treated with trimodal therapy (TMT). OBJECTIVE: To analyze the impact of serum lymphocyte-based biomarkers on main oncological outcomes after TMT for MIBC. DESIGN SETTING AND PARTICIPANTS: A retrospective study, including 176 patients treated with TMT for nonmetastatic MIBC (cT2-4/cN0-2) between 2001 and 2017 at a tertiary academic center, was conducted. INTERVENTION: TMT, consisting of initial maximal transurethral resection of the bladder tumor, followed by radiotherapy with concurrent chemotherapy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Clinicopathological characteristics, serum laboratory tests, and imaging reports were collected. NLR, LMR, and PLR were calculated before and at the end of TMT. Dynamic patterns of NLR, LMR, and PLR during TMT were studied. Multivariable regression models were performed to estimate the effect of these biomarkers on complete response (CR) to TMT and survival. RESULTS AND LIMITATIONS: The median age was 75 yr (interquartile range 66-82). Staging was cT2 in 156 (89%) and cN0 in 159 (90%) patients. A pretreatment NLR (pre-NLR) of ≥4.0 was independently associated with lower CR rates (odds ratio 0.32; p = 0.013). In addition, a pre-NLR of ≥4.0 was associated with worse cancer-specific survival (hazard ratio [HR] 1.88; p = 0.032) and overall survival (OS; HR 1.61; p = 0.033) together with other factors such as hydronephrosis, Eastern Cooperative Oncology Group performance status, and cT stage 3-4a. When both pre- and post-treatment variables were considered, an increase in NLR beyond 75% during TMT (HR 1.63; p = 0.035) was associated with worse OS. This study was limited by its retrospective design. CONCLUSIONS: A high pre-NLR value was independently associated with lower rates of CR and worse survival in MIBC patients undergoing TMT. Prospective validation is needed to implement NLR into clinical practice. PATIENT SUMMARY: In this study, we reported the oncological outcomes of patients with muscle-invasive bladder cancer treated with trimodal therapy. We found that the neutrophil-to-lymphocyte ratio, a cheap and available blood-derived biomarker, was associated with response to trimodal therapy and survival outcomes.

Role of neutrophil extracellular traps in radiation resistance of invasive bladder cancer.

Radiation therapy (RT) is used in the management of several cancers; however, tumor radioresistance remains a challenge. Polymorphonuclear neutrophils (PMNs) are recruited to the tumor immune microenvironment (TIME) post-RT and can facilitate tumor progression by forming neutrophil extracellular traps (NETs). Here, we demonstrate a role for NETs as players in tumor radioresistance. Using a syngeneic bladder cancer model, increased NET deposition is observed in the TIME of mice treated with RT and inhibition of NETs improves overall radiation response. In vitro, the protein HMGB1 promotes NET formation through a TLR4-dependent manner and in vivo, inhibition of both HMGB1 and NETs significantly delays tumor growth. Finally, NETs are observed in bladder tumors of patients who did not respond to RT and had persistent disease post-RT, wherein a high tumoral PMN-to-CD8 ratio is associated with worse overall survival. Together, these findings identify NETs as a potential therapeutic target to increase radiation efficacy.

Phase 1 Trial of Atezolizumab Plus Trimodal Therapy in Patients With Localized Muscle-Invasive Bladder Cancer.

PURPOSE: Immune checkpoint programmed death-ligand 1 inhibitor therapy has shown response in metastatic muscle invasive bladder cancer (MIBC). We evaluated the safety and tolerability of atezolizumab (anti-programmed death-ligand 1) in combination with trimodal therapy in patients with localized MIBC. METHODS AND MATERIALS: A prospective nonrandomized phase 1 study using a 3 + 3 design was conducted in patients with localized MIBC (T2-T4a N0M0) treated on a bladder preservation program. After transurethral resection of bladder tumor, patients received concurrent radiation therapy at a fixed dose of 50 Gy in 20 fractions, gemcitabine (100 mg/m2, intravenously once weekly for 4 weeks) and atezolizumab (1200 mg intravenously every 3 weeks for 16 cycles). The primary endpoint was safety/toxicity profile. RESULTS: Between May 2018 and March 2019, 8 patients (6 male and 2 female) were enrolled. The first 5 patients received atezolizumab at 1200 mg, 3 of whom developed grade 3 side effects (2 of them dose-limiting toxicity). Atezolizumab dose was reduced to 840 mg for 3 additional patients. The study was terminated due to the presence of 3 grade 3 adverse events (2 of which were dose-limiting toxicity) despite the reduced atezolizumab dose. Gastrointestinal events were the main toxicity. No grade 4 to 5 adverse effects were observed. CONCLUSIONS: Concurrent administration of atezolizumab with concomitant hypofractionated radiation therapy and gemcitabine appears to be associated with unacceptable gastrointestinal toxicity. Although the numbers studied are small, our results suggest considerable caution with its concurrent use with trimodal therapy for MIBC.

Refining assessment of response to radiation-based therapy for muscle-invasive bladder cancer: Is post-treatment tumor bed biopsy always necessary?

INTRODUCTION: Radiation-based therapy (RT) has emerged as a suitable alternative to radical cystectomy (RC) and pelvic lymph node dissection for muscle-invasive bladder cancer (MIBC) patients. Routine biopsy after RT to rule out residual disease remains inconsistent across guidelines. Our objective was to review the significance of a bladder biopsy in terms of assessment of response post-RT and its potential impact on survival. PATIENTS AND METHODS: This was a single-center retrospective study on patients with MIBC (cT2-4aN0-2M0) treated with curative intent RT. A total of 169 patients with primary urothelial carcinoma were analyzed. Patients' demographic, clinical and pathological variables, imaging, cystoscopy, urine cytology, and biopsy reports after RT were collected and compiled. Whenever urine cytology was positive or cystoscopy showed any malignant-appearing lesion, the first assessment post-RT was considered suspicious for residual disease. A descriptive population analysis was reported. Cox regression multivariable analysis was performed to identify independent variables associated with survival outcomes. RESULTS: Median age was 75 years (interquartile range 66-82) and clinical staging was cT2 in 152 (90%) patients. Cytology and cystoscopy were normal in 140 (83%) after RT. Of patients with a control biopsy, residual MIBC was present in 3 (5%) and non-MIBC in another 6 (11%). On the contrary, a for-cause biopsy due to a suspicious assessment post-RT did not yield residual cancer in 45% of patients. Multivariable analysis showed that age (hazard ratio [HR] 1.04, P< 0.001), lymphovascular invasion (HR 1.68, P = 0.03) and a suspicious assessment after RT (HR 3.21; P< 0.001) were significantly associated with worse OS. This study was limited by its retrospective design. CONCLUSIONS: A routine biopsy after RT may be warranted to assess treatment response. This might be particularly important for patients who may benefit from early surgical intervention for residual MIBC. Further prospective studies are needed to confirm our findings.

PD-1/PD-L1 Immune Checkpoint Inhibition with Radiation in Bladder Cancer: In Situ and Abscopal Effects.

The combination of radiation with immune checkpoint inhibitors was reported in some cancers to have synergic effects both locally and distally. Our aim was to assess this combined therapy on both radiated and nonradiated bladder tumors and to characterize the immune landscape within the tumor microenvironment. Murine bladder cancer cells (MB49) were injected subcutaneously in both flanks of C57BL/6 mice. Mice were randomly assigned to the following treatments: placebo, anti-PD-L1 (four intraperitoneal injections over 2 weeks), radiation to right flank (10 Gy in two fractions), or radiation+anti-PD-L1. Tumor digestion, flow cytometry, and qPCR were performed. Log-rank analysis was used for statistical significance. Radiation+anti-PD-L1 group demonstrated statistically significant slower tumor growth rate both in the radiated and nonirradiated tumors (P < 0.001). Survival curves demonstrated superior survival in the combination group compared with each treatment alone (P = 0.02). Flow cytometry showed increased infiltration of immunosuppressive cells as well as CTL in the radiation and combination groups (P = 0.04). Ratio of immunosuppressive cells to CTL shifted in favor of cytotoxic activity in the combination arm (P < 0.001). The qPCR analysis revealed downregulation of immunosuppressive genes (CCL22, IL22, and IL13), as well as upregulation of markers of CTL activation (CXCL9, GZMA, and GZMB) within both the radiated and distant tumors within the combination group. Combining radiation with immune checkpoint inhibitor provided better response in the radiated tumors and also the distant tumors along with a shift within the tumor microenvironment favoring cytotoxic activity. These findings demonstrate a possible abscopal effect in urothelial carcinoma with combination therapy.

The immune mediated role of extracellular HMGB1 in a heterotopic model of bladder cancer radioresistance.

Radical cystectomy (RC) together with bilateral pelvic lymph node dissection remains the standard treatment for muscle invasive bladder cancer (MIBC). However, radiation-based treatments such as tri-modal therapy (TMT) involving maximally performed transurethral resection of bladder tumor (TURBT), radiotherapy (XRT), and a chemosensitizer represent an attractive, less invasive alternative. Nevertheless, 25-30% of MIBC patients will experience local recurrence after TMT and half will develop metastasis. Radioresistance of tumor cells could potentially be one of the causes for local recurrence post treatment. High mobility group box-1 (HMGB1) was shown to play a role in bladder cancer radioresistance through its intracellular functions in promoting DNA damage repair and autophagy. Recently, HMGB1 was found to be passively released from irradiated tumor cells. However, less is known about the involvement of extracellular HMGB1 in impairing radiation response and its exact role in modulating the tumor immune microenvironment after XRT. We identified a novel mechanism of bladder cancer radioresistance mediated by the immunological functions of HMGB1. The combination of radiation plus extracellular HMGB1 inhibition markedly improved the radiation response of tumors and resulted in marked changes in the immune landscape. Moreover, combining radiation and HMGB1 inhibition significantly impaired tumor infiltrating MDSCs and TAMs -but not Tregs- and shifted the overall tumor immune balance towards anti-tumoral response. We conclude that extracellular HMGB1 is involved in bladder cancer radioresistance through promoting pro-tumor immune mechanisms.

Adjuvant therapy in stage III endometrial cancer confined to the pelvis.

OBJECTIVE: To review outcomes of patients with stage III endometrial cancer confined to the pelvis treated with adjuvant pelvic radiotherapy (RT) or sequential chemoradiotherapy (CRT). METHODS: Between 1990 and 2012, 144 patients diagnosed with stage IIIA, B or C1 endometrial cancer were treated in our institution. All were treated with total hysterectomy, bilateral salpingo-oophorectomy ±â€¯lymph node dissection. Post-operatively, 67 patients received adjuvant RT alone, 37 CRT, 21 chemotherapy alone and 19 had no adjuvant therapy. This analysis focuses on the 104 patients treated with RT or CRT. RESULTS: The median follow-up was 61 months. Forty-six patients (44%) were stage IIIA, 6 (6%) were stage IIIB and 52 (50%) stage IIIC1. The 5-year overall survival (OS), disease-free survival (DFS) and disease-specific survival (DSS) for patients treated by RT alone vs. CRT were, respectively, 67% vs. 61% (p = 0.55); 67% vs. 51% (p = 0.35); and 76% vs. 65% (p = 0.21). Grade 3 disease was an independent predictor for worse OS (HR = 6.01, p = 0.001), DFS (HR = 3.16, p = 0.03), and DSS (HR = 3.77, p = 0.02). In patients with grade 3 disease (n = 49), the 5-year OS was superior for the CRT (42% vs. 56%, p = 0.007). CONCLUSIONS: In patients with stage III endometrial cancer confined to the pelvis, the addition of adjuvant chemotherapy with RT significantly improved OS in grade 3 disease. Grade 3 histology is a strong predictor for poor outcome. Further randomized studies aiming specifically at stage III disease are warranted.

Presence of lymphocytic infiltrate cytotoxic T lymphocyte CD3+, CD8+, and immunoscore as prognostic marker in patients after radical cystectomy.

Tumor-Infiltrating Lymphocytes (TILs) has been shown to be essential to predict disease outcome in several types of cancers. Moreover, the distribution of cytotoxic T lymphocytes (CD8+) and T cells in general (CD3+) have been used to establish an Immunoscore, as a new cancer prognosticator for survival in colon and lung cancer. In bladder cancer, immune activation has been shown to be associated with genomic subtypes of muscle invasive bladder cancer (MIBC). We sought to evaluate the prognostic impact of these immune cell types in MIBC patients treated with radical cystectomy. For this purpose, cystectomy sections (n = 67) with identifiable invasive margin were selected and stained for CD8+ and CD3+ tumour infiltrating lymphocytes (TILs); both tumor core (CT) and invasive margin (IM) were assessed. Immunoscore was calculated based on previously defined criteria and used to illustrate differences in survival. High density of CD8IM TILs was associated with better disease-free (DFS) (P = 0.01) and overall survival (OS) (P = 0.02) whereas CD3IM TILs were associated with better OS (P = 0.05). Immunoscore was associated with improved DFS (P = 0.02) and OS (P = 0.05). The expression of cytotoxic T cells (CD8+ T cells) in TCGA bladder cancer was also investigated from RNA-Seq profiles of 344 cases. T cell cytotoxicity associated genes (n = 113) were derived from MSig GSEA database. Luminal (n = 121) and basal (n = 68) samples were used to evaluate expression differences. Differential expression (P<0.05) of cytotoxic T cell genes was noted across different molecular subsets of bladder cancer within TCGA analysis. Our data suggests host immune system appears to play a valuable prognostic role in MIBC.

Programmed cell death ligand-1 expression in tumor and immune cells is associated with better patient outcome and decreased tumor-infiltrating lymphocytes in uveal melanoma.

Programmed cell death-1/ligand (PD-1/PD-L1) interaction negatively regulates T cell activity. PD-L1 expression in tumor cells, antigen-presenting cells, and lymphocytes of the tumor microenvironment is associated with response to treatment with PD-1/PD-L1 inhibitors, but there is still debate on the cutoff value that correlates with responders. In uveal melanoma (UM), 40% of patients will develop liver metastases and, amongst them, 90% will succumb to their disease. The aim of this study was to analyze PD-L1 expression as a prognostic marker and as a possible therapeutic target for UM. Sixty-seven enucleated eyes from UM patients with relevant clinical information were analyzed. Univariate and multivariate analysis were used to evaluate association of PD-L1 with survival. PD-L1 expression was positive relatively to tumor cells, immune cells, and the tumor and tumor-infiltrating immune cell group scoring in 46, 34 and 55% of the cases, respectively. On univariate analysis, tumor cells and the tumor and tumor-infiltrating immune cell group PD-L1 expression was associated with a longer metastasis-free survival (P = 0.04 and P = 0.007). However, on multivariate analysis, only the tumor and tumor-infiltrating immune cell group positivity was associated with longer metastasis-free survival (P = 0.01). Furthermore, tumor cells and the tumor and tumor-infiltrating immune cell group PD-L1 expression was associated with decreased tumor-infiltrating lymphocytes (P = 0.02). PD-L1, when expressed in uveal melanoma, is associated with better patient outcome and decreased tumor-infiltrating lymphocytes. These results support the consideration of anti-PD-1/PD-L1 therapy in uveal melanoma. To determine the best cutoff value, further studies from patients enrolled in clinical trials treated with PD-1/PD-L1 inhibitors are necessary.

Prognostic factors for progression in atypical meningioma.

In patients with postoperative residual atypical meningiomas, by using volumetric instead of linear measurements in follow-up imaging studies, the authors detected disease progression earlier. By using this approach, treatment for recurrent disease can be instituted promptly with potentially better tumor control and less toxicity due to smaller volume of residual disease.

Phase I Clinical Trial of Everolimus Combined with Trimodality Therapy in Patients with Muscle-Invasive Bladder Cancer.

Background: Local control following trimodality therapy (TMT) for muscle-invasive bladder cancer (MIBC) requires further optimization. Objective: Evaluating the biologic endpoint, feasibility, and toxicity of integrating everolimus to TMT in patients with MIBC. Methods: This was a phase I trial in patients with MIBC who were not surgical candidates or who refused cystectomy. Following maximal transurethral tumor resection, patients were treated by radiotherapy (50 Gy/20 fractions), gemcitabine (100 mg/m2/weekly) and escalating doses of everolimus (2.5-5.0 mg/day). Everolimus was given daily for one month prior to radiation, during treatment, and one month post-radiation. Toxicity assessment followed the Radiation Therapy Oncology Group Acute Radiation Morbidity Scoring Criteria. Biologic endpoint with downregulation of phospho-S6 (pS6) was assessed using immunohistochemistry. Local response was evaluated with imaging and bladder biopsy post-therapy. Results: 10 patients were recruited; 8 males, 2 females. Median age was 78 years (range: 63-85). Four patients entered everolimus 2.5 mg cohort. Six other patients entered everolimus 5.0 mg cohort. Toxicities were encountered in 2 patients (Grade I), 6 patients (Grade II), 9 patients (Grade III) and 1 patient (Grade IV), with some experiencing more than one toxicity. Most Grade III and IV toxicities were encountered from everolimus alone prior to combination testing. Trial was terminated early due to toxicity. Interestingly, 6/10 patients (60%) achieved a complete response with negative post-treatment biopsies. Significant decrease of pS6 was demonstrated post-therapy (p = 0.03). Conclusions: Although combining everolimus with TMT achieved a biological endpoint and complete response in a significant number of patients with MIBC and negative prognostic factors, it was associated with unacceptable increased toxicity.

The Role of HMGB1 in Radioresistance of Bladder Cancer.

Although radical cystectomy surgery is the standard-of-care for muscle-invasive bladder cancer, it entails complete removal of the bladder and surrounding organs which leads to substantial loss in the quality-of-life of patients. Radiotherapy, which spares the bladder, would be a more appropriate treatment modality if we can utilize molecular markers to select patients with better response to radiation. In this study, we investigate a protein called high mobility group box protein 1 (HMGB1) as a predictive marker for radiotherapy response in bladder cancer. Our in vitro results indicate a positive correlation between higher levels of HMGB1 protein and resistance to radiation in various cell lines. Upon HMGB1 protein knockdown, highly significant (>1.5-fold) sensitization to radiotherapy was achieved. We saw that loss of HMGB1 was associated with at least two times higher (P < 0.001) DNA damage in cell lines postradiation. Our results also depicted that autophagy was inhibited more than 3-fold (P < 0.001) upon HMGB1 knockdown, implicating its role in autophagy as another cause of bladder cancer radioresistance. Further validation was done in vivo by conducting mouse tumor xenograft experiments, where HMGB1 knockdown tumors showed a significantly better (P < 0.001) response to radiotherapy and decreased autophagy (shown by P62 staining) as compared with controls. The cumulative findings of our in vitro and in vivo studies highlight the significance of HMGB1 as a radiation response marker as well as its utility in radiosensitization of bladder cancer.

Prostate-specific antigen bounce after high-dose-rate prostate brachytherapy and hypofractionated external beam radiotherapy.

PURPOSE: To report the frequency, timing, and magnitude of prostate-specific antigen (PSA) bounce (PB) in patients who received high-dose-rate (HDR) brachytherapy (HDRB) plus hypofractionated external beam radiation therapy (HypoRT) and to assess a possible correlation between PB and biochemical failure (BF). METHODS AND MATERIALS: Patients with intermediate-risk prostate cancer received 10Gy single-fraction (192)Ir HDRB followed by 50Gy in 20 daily fractions of HypoRT without androgen deprivation therapy. All patients had a minimum 2-year followup. The PB was defined as PSA elevation higher than 0.2ng/mL from previous measurement with subsequent drop to pre-bounce level. The BF was defined as PSA nadir+2ng/mL. RESULTS: A total of 114 patients treated between 2001 and 2009 were eligible for analysis. At a median followup of 66 months, the PB was found in 45 (39%) patients with a median time to bounce of 16 months (range, 3-76 months). The median time to PSA normalization after a PB was 9 months (range, 2-40 months). The median magnitude of PB was 0.45ng/mL (range, 0.2-6.62). The BF occurred in 12 (10.5%) patients of whom three had a PB. Median time to BF was 52.5 months. Four patients (3.5%) in the PB group fit the criteria for BF. CONCLUSIONS: The PB is common after HDRB and HypoRT and can occur up to 76 months after treatment. It can rarely fit the criteria for BF. The time to PB is shorter than the time to BF. There is a lower incidence of BF in patients with a PB. An acknowledgment of this phenomenon should be made when interpreting PSA results during followup to prevent unnecessary interventions.

Enhancer of zeste homolog 2 expression is associated with metastasis and adverse clinical outcome in clear cell renal cell carcinoma: a comparative study and review of the literature.

CONTEXT: Enhancer of zeste homolog 2 (EZH2), a histone methyltransferase mediating chromatin condensation and epigenetic modulation, is overexpressed in various human carcinomas and is associated with adverse clinicopathologic characteristics and biologic behavior. The expression of EZH2 in renal cell carcinomas (RCCs) has not been fully characterized yet. OBJECTIVE: To evaluate the prognostic role of EZH2 in RCC by analyzing the immunohistochemical staining pattern of the marker in relation to pathologic features and clinical outcome. DESIGN: We correlated the immunolabeling of EZH2 with multiple clinicopathologic features, including Fuhrman nuclear grade, pathologic stage, metastatic status, and clinical outcome in 223 clear cell RCCs (CRCCs) and 21 papillary RCCs, by using tissue microarrays of primary and metastatic cases. RESULTS: Most CRCCs (75%) showed positive EZH2 staining, with most primary tumors showing focal staining in comparison to nonfocal staining in metastatic cases. In primary tumors, EZH2 expression was associated with higher nuclear grade and lower pathologic stage. Metastatic tumors showed a higher number of positive cases (81% versus 67%) and a more diffuse and more intense pattern of staining than primary CRCCs. For the 22 locally advanced primary tumors (T3/4) and 43 metastatic RCCs, patients who experienced RCC-related deaths significantly overexpressed the marker in comparison to patients who did not experience RCC-related mortality. CONCLUSIONS: By showing that EZH2 expression is associated with increased metastatic potential and a worse clinical outcome, this study suggests that EZH2 can serve as a prognostic biomarker for RCC, thus confirming it as a key molecule driving oncogenesis and metastasis.

Combining mTOR inhibition with radiation improves antitumor activity in bladder cancer cells in vitro and in vivo: a novel strategy for treatment.

PURPOSE: Radiation therapy for invasive bladder cancer allows for organ preservation but toxicity and local control remain problematic. As such, improving efficacy of treatment requires radiosensitization of tumor cells. The aim of study is to investigate if the mammalian Target of Rapamycin (mTOR), a downstream kinase of the phosphatidylinositol 3-kinase (PI3K)/AKT survival pathway, may be a target for radiation sensitization. EXPERIMENTAL DESIGN: Clonogenic assays were performed using 6 bladder cancer cell lines (UM-UC3, UM-UC5, UM-UC6, KU7, 253J-BV, and 253-JP) in order to examine the effects of ionizing radiation (IR) alone and in combination with RAD001, an mTOR inhibitor. Cell cycle analysis was performed using flow cytometry. In vivo, athymic mice were subcutaneously injected with 2 bladder cancer cell lines. Treatment response with RAD001 (1.5 mg/kg, daily), fractionated IR (total 9Gy = 3Gy×3), and combination of RAD001 and IR was followed over 4 weeks. Tumor weight was measured at experimental endpoint. RESULTS: Clonogenic assays revealed that in all bladder cell lines tested, an additive effect was observed in the combined treatment when compared to either treatment alone. Our data indicates that this effect is due to arrest in both G1 and G2 phases of cell cycle when treatments are combined. Furthermore, our data show that this arrest is primarily regulated by changes in levels of cyclin D1, p27 and p21 following treatments. In vivo, a significant decrease in tumor weight was observed in the combined treatment compared to either treatment alone or control. CONCLUSIONS: Altering cell cycle by inhibiting the mTOR signaling pathway in combination with radiation have favorable outcomes and is a promising therapeutic modality for bladder cancer.

Relevance of the mammalian target of rapamycin pathway in the prognosis of patients with high-risk non-muscle invasive bladder cancer.

High-risk non-muscle invasive bladder cancer (NMIBC) is associated with higher rates of recurrence and progression. Molecular markers within aberrant signaling pathways in cancer need further evaluation of their role as prognostic indicators and potential future targets for prevention of recurrence. Our objective was to investigate the role of the mammalian target of rapamycin (mTOR) signaling pathway on the stage and outcome of patients with high-risk NMIBC. Tissue microarrays were built from archival bladder tumor specimens (n = 142). Various clinicopathologic variables were collected retrospectively from patients treated with transurethral resection. Immunohistochemical staining was performed for phosphatase and tensin homolog, phosphorylated Akt, phosphorylated mTOR, phosphorylated S6 (p-S6), eukaryotic translation initiation factor 4E-binding protein-1, and p27. Multivariate analysis using Cox regression models addressed recurrence-free survival (RFS), progression-free survival, and worsening-free survival. In multivariate analysis, p-S6 was an independent predictor of shorter RFS (hazard ratio, 3.55; 95% CI, 1.31-9.64). Expression of p27 was inversely correlated with RFS (hazard ratio, 0.27; 95% CI, 0.10-0.74). Low levels of phosphatase and tensin homolog expression were associated with worsening-free survival (P < .03). None of the markers showed correlation with progression-free survival. Our results demonstrate that activation of the mTOR pathway, as assessed by p-S6 and expression of p27, might be used to provide prognostic information, particularly as a predictor of recurrence among patients with high-risk NMIBC.