Predictive biomarkers of bacillus calmette-guérin immunotherapy response in bladder cancer: where are we now?

The impact of single-nucleotide polymorphisms on intravesical recurrence after bacillus Calmette-Guérin therapy for non-muscle invasive bladder cancer in a genome-wide association study

OBJECTIVE

Bacillus Calmette-Guérin (BCG) instillation therapy is widely used to reduce intravesical recurrence in non-muscle invasive bladder cancer (NMIBC). In this study, we aimed to reveal the genetic variations associated with intravesical recurrence after BCG therapy for NMIBC in a genome-wide association study (GWAS).

MATERIALS AND METHODS

This study included Japanese patients with NMIBC, in whom genomic DNA was obtained from whole blood samples. The association between genetic variation and treatment failure was analyzed by GWAS in 44 patients treated with BCG instillation as a discovery cohort. Candidate single-nucleotide polymorphisms (SNPs) were examined separately in 47 patients treated with BCG instillation and in 62 patients treated with chemotherapeutic agent instillation as validation studies.

RESULTS

Among the 44 patients in the discovery cohort, 14 cases experienced intravesical recurrent diseases. GWAS identified 12 candidate SNPs (rs9374832, rs35176001, rs363765, rs2127120, rs4277759, rs73664140, rs1607282, rs12141654, rs4541358, rs6986852, rs12373386, and rs17637903). In the validation study, a genetic risk stratification model using the number of risk alleles in rs363765 and rs6986852 discriminated the risk of intravesical recurrence after BCG therapy, but not after non-BCG therapy.

CONCLUSION

This study suggested that several SNPs were associated with intravesical recurrence after BCG therapy for NMIBC. A genetic risk model may be useful to predict intravesical recurrence after BCG therapy, warranting further research and development for clinical application.

The therapeutic and prognostic implications of molecular biomarkers in urothelial carcinoma

Urothelial cell carcinoma (UCC) of the bladder and upper urinary tract is a heterogeneous disease with distinct biologic features resulting in different clinical behaviors. Bladder cancer (BC) is classified into non-muscle invasive BC (NMIBC) and muscle invasive BC (MIBC). NMIBC is associated with high recurrence rates and risk of progression to invasive disease, whereas MIBC is complicated by systemic recurrence after radical cystectomy because of the limited efficacy of available therapies. UCC of the upper urinary tract (UUT-UCC) is a rare but aggressive urologic cancer characterized by multifocality, local recurrence, and metastasis. Conventional histopathologic evaluation of UCC, including tumor stage and grade, cannot accurately predict the behavior of BC and UUT-UCC. Recent clinical and preclinical studies aimed at understanding the molecular landscape of UCC have provided insight into molecular subtyping, inter- or intratumoral heterogeneity, and potential therapeutic targets. Combined analysis of molecular markers and standard pathological features may improve risk stratification and help monitor tumor progression and treatment response, ultimately improving patient outcomes. This review discusses prognostic and therapeutic biomarkers for BC and UUT-UCC, and describes recent advances in molecular stratification that may guide prognosis, patient stratification, and treatment selection.

The role of cancer stem cells in immunotherapy for bladder cancer: An in vitro study

OBJECTIVE

Bladder cancer is characterized by frequent recurrence and progression. CD44+ cancer stem cells (CSCs) might be one of the main reasons for recurrence. Although Bacillus Calmette Guerin (BCG) has become a gold standard immunotherapy, after treatment recurrence frequently occur. Based on this knowledge, the aim of this study was to evaluate the changes in cytokine and chemokine expressions in bladder cancer and CSCs cultures in vitro with BCG only and in combination with IL2 and lymphocyte (MNCs) applications.

MATERIAL AND METHODS

In this study, 3 cell lines of human bladder cancer cells with different characteristics (T24, 5637, and JMSU-1) and CD44+ bladder CSCs isolated by magnetic bead isolation (Miltenyl Magtech) were used. Bladder cancer cell lines and bladder CSCs in complete medium were cultured under humidified conditions of 37°C temperature in 5% CO₂. BCG only and its combination with IL2 and MNCs were applied to bladder cancer cell lines and bladder CSCs for 24, 48, and 72 hours. Annexin V-PI was used to detect the percentages of apoptotic and necrotic cells in treatment groups and control groups. After treatments, total RNAs were isolated and converted to cDNA for each group and controls. Quantitative fold changes in terms of gene expression were measured by RT2-PCR array and fold changes for expression levels of genes were compared among groups. Eighty-four genes were analyzed in standard array of chemokines and cytokines (Biorad).

RESULTS

BCG treatment with 7.32 µg/ml dose alone and in combination with IL2 (1000 IU/ml) and MNCs (1000 cells/ml) were found to be most effective on bladder cancer cells. When BCG and its combinations were applied to CSCs of the 3 cell lines, BCG treatment showed cytotoxic effect on CSCs as well as cancer cells. CSCs of 3 cell lines over expressed CXCL5, CCL8, CNTF, and CSF2 compared with cancer cells. Cancer cells over expressed IL6, TNSFF11, FASLG, and CXCL9 compared with CSCs. In all 3 cell lines, BCG application increased expression of CXCL5 and LTB and also decreased CCL20 and IL6. When BCG was combined with IL2 and MNCs, CXCL10, CXCL5, and IFNG were increased and CXCL12, IL6, and TNSF11 were decreased. BCG treatment of CSCs caused increases in ADIPOQ, CXCL10, and XCL1 and a decrease in CCL8. When IL2 and MNCs were combined with BCG, the expression of many cytokines and chemokines decreased.

CONCLUSION

BCG treatment changes the expression of many cytokines and chemokines in bladder cancer. The expression differs in 3 different cell lines and their CSCs. Immune modulation of each case differs from each other. The effectivity of BCG-based immunotherapy in bladder cancer on CSCs might decrease in combination with IL2. Our results indicate that recurrence after BCG treatment for bladder cancer may not occur mainly based on the CSCs hypothesis considering bladder cancer occurs at different loci of surface epithelium.

Genome-wide association study of genetic variations associated with treatment failure after intravesical bacillus Calmette-Guérin therapy for non-muscle invasive bladder cancer

Bacillus Calmette-Guérin (BCG) instillation is a key therapy to manage non-muscle invasive bladder cancer (NMIBC). However, intravesical BCG therapy fails in approximately half of the patients, leading to recurrence and progression. We aimed to reveal the genetic variations associated with treatment failure after intravesical BCG therapy for NMIBC. This study included 91 Japanese patients treated with BCG instillation for NMIBC. Genomic DNA was obtained from patient whole-blood samples, and a genome-wide association study and genotyping for target regions were performed. The association between genetic variation and treatment failure was analyzed by genome-wide association in 44 patients as the discovery cohort. As a validation study, candidate single nucleotide polymorphisms (SNPs) were examined among 47 patients in another cohort. The genome-wide association study indicated 19 candidate SNPs (rs1607282, rs7825442, rs1319325, rs3738088, rs4250, rs11894207, rs161448, rs2764326, rs2814707, rs3787194, rs58081719, rs3095966, rs73520681, rs16877113, rs16887173, rs10269584, rs11772249, rs118137814, and rs61094339) associated with BCG failure. Following the cumulative analysis of candidate SNPs, 2-gene (rs73520681 and rs61094339) and 4-gene (rs4250, rs11894207, rs73520681, and rs61094339) models successfully predicted treatment failure after intravesical BCG therapy. This study showed that several SNPs were possibly associated with outcome after intravesical BCG therapy in a Japanese population with NMIBC. The cumulative models of these SNPs may have value in clinical applications, although this should be confirmed in future studies.

Polymorphisms of genes encoding cytokines predict the risk of high-grade bladder cancer and outcomes of BCG immunotherapy

Introduction

The present study investigated the association of cytokines genes polymorphisms (IL-2, IL-8 and IL-18) and polymorphisms in genes encoding molecules related to the differentiation of Th17 subpopulation (IL-17 and IL-23R) with the risk of bladder cancer (BC) and response to BCG immunotherapy.

Material and methods

Altogether, 175 BC patients treated with BCG due to high-grade non-muscle invasive tumors and 207 healthy individuals were genotyped for the following polymorphisms: IL-17A-197G>A (rs2275913); IL-17F+7488T>C (rs763780); IL-23Rc.309C>A (rs10889677);IL-23Rc.1142G>A (rs11209026); IL-2-330T>G (rs2069762), IL-8-251A>T (rs4073), and IL-18-137G>C (rs187238) using the TaqMan SNP genotyping assays.

Results

The IL-23Rc.-309C>A[A] allele was associated with the risk of BC (OR: 1.42, p = 0.03). Moreover, heterozygocities for IL-17A-197G>A[GA] and IL-18-137G>C[GC] increased the risk of BC, as compared to both homozygotes (OR: 1.67, p = 0.01 and OR: 1.84, p = 0.008, respectively). The IL-18-137G>C[GC] heterozygous patients had the highest risk of tumor recurrence and progression, and the worst recurrence-free and progression-free survival. Homozygous IL-17A-197G>A[GG] patients presented the best recurrence-free survival, while IL-17A-197G>A[AA] patients had 1.8-fold higher risk of recurrence.

Conclusions

The present study highlighted the importance of IL-17, IL-18, and IL-23R gene polymorphisms for BC susceptibility and BCG immunotherapy outcomes. It may help to identify appropriate candidates for early radical treatment.

Immune phenotype of peripheral blood mononuclear cells in patients with high-risk non-muscle invasive bladder cancer

PURPOSE

To explore the immune phenotype of peripheral blood mononuclear cells (PBMC) in patients with high-risk non-muscle invasive bladder cancer (NMIBC).

METHODS

We prospectively collected blood samples from patients with high-risk NMIBC treated at our institution. PBMC were analyzed by flow cytometry to determine the frequency of T cells and NK cells and the expression of immunoregulatory molecules (Tim-3, TIGIT and PD-1). PBMC from healthy donors (HD) were included for comparison, and associations with response to BCG were investigated.

RESULTS

A total of 38 patients were included, 19 BCG responders and 19 BCG refractory. Compared to 16 PBMC from HD, the frequency of total NK cells was significantly higher in patients with NMIBC [15.2% (IQR: 11.4, 22.2) vs. 5.72% (IQR: 4.84, 9.79); p = 0.05], whereas the frequency of T cells was not statistically different. Both Tim-3 and TIGIT expressions were significantly higher in NMIBC compared to HD, particularly in NK cells [13.8% (11.0; 22.4) vs. 5.56% (4.20; 10.2) and 34.9% (18.9; 53.5) vs. 1.82% (0.63; 5.16), respectively; p < 0.001]. Overall, the expression of PD-1 in all cell types was low in both NMIBC patients and HD. The immune phenotype was not significantly different before and after initiation of BCG. However, the proportion of CD8+ T cells before BCG was significantly higher in responders.

CONCLUSION

The immune phenotype of PBMC from patients with high-risk NMIBC was significantly different from HD, regardless of the presence of disease or the initiation of BCG. Peripheral CD8+ T cells could play a role in response to BCG.

Waiting in the wings: the emerging role of molecular biomarkers in bladder cancer

INTRODUCTION

Bladder cancer (BCa) is the fifth most frequently diagnosed cancer worldwide and is, in fact, the most expensive cancer on a per-patient to treat basis. There is a critical need to implement new tests into clinical practice to improve the quality of clinical care, decrease unnecessary invasive therapies and ultimately save costs. Currently, no molecular or genetic biomarker has been widely integrated into daily clinical practice. However, major milestones have been achieved in our understanding of the molecular alterations in BCa that will provide the basis for integrating molecular and genetic biomarkers into clinical decision making to guide management. Clinical implementation of such novel molecular and genetic concepts is the cornerstone in an effort to usher the age of precision medicine into patient care. Areas covered: In this review, the authors discuss the emerging role of molecular biomarkers in patients receiving BCG immunotherapy as well as neoadjuvant and adjuvant chemotherapy in BCa. Expert commentary: Molecular predictive and prognostic biomarkers in BCa are promising diagnostic options that will pave the way for molecular-based personalized medicine.

Tertiary Lymphoid Structures Associate with Tumour Stage in Urothelial Bladder Cancer

BACKGROUND

Urothelial bladder cancer (UBC) is a highly prevalent disease in North America, however its optimal management remains elusive. The contribution of B cell associated responses is poorly understood in bladder cancer. Lymphoid neogenesis is a hallmark of an active immune response at tumor sites that sometimes leads to formation of tertiary lymphoid structures (TLS) that resemble germinal centers formed in secondary lymphoid organs.

OBJECTIVE

This study was conducted with an aim to investigate the presence and characteristics of TLS in UBC with a focus to compare and contrast the TLS formation in treatment naive low grade non-muscle invasive (NMIBC) and muscle invasive bladder cancers (MIBC).

METHODS

The study cohort consisted of transurethral bladder resection tumour (TURBT) specimens from 28 patients. Sections showing lymphoid aggregates in hematoxylin and eosin (H&E) stained TURBT specimens were further subjected to multi-color immunohistochemistry using immune cell markers specific to CD20+ B cells, CD3+ and CD8+ T cells, PNAd+ high endothelial venules, CD208+ mature dendritic cells, CD21+ follicular dendritic cells to confirm the hallmarks of classical germinal centers.

RESULTS

Our pilot study investigating the presence of TLS in bladder cancer patients is the first to demonstrate that well-formed TLS are more common in aggressive high grade MIBC tumors compared to low grade NIMBC.

CONCLUSIONS

These novel findings suggest B cell mediated anti-tumour humoral immune responses in bladder cancer progression.

Clinical Behavior of Bladder Urothelial Carcinoma in Young Patients: A Single Center Experience

Background. There is not enough evidence about clinical behavior of bladder cancer in younger patients. Objective. We aimed to evaluate the clinical characteristics and prognosis of bladder urothelial carcinoma patients under the age of 40 years. Methods. Medical records of patients listed in our cancer database were retrospectively reviewed. A total of 40 patients who were initially diagnosed with bladder urothelial carcinoma at the age less than 40 years were included in the study. Patients' records were reviewed for recurrence and progression rates, demographic data, medical history, and treatment modalities. Results. Pathological results revealed 33 (82.5%) Ta low-grade, 6 (15%) T1 high-grade, and 1 (2.5%) T2 high-grade urothelial carcinomas. Recurrence was detected in 14/39 (35.9%) patients but progression was not observed in any patients. The mean age of recurrent patients was significantly higher than nonrecurrent patients (34.8 versus 28.5 years; p < 0.05). Besides, recurrence was detected in only 1 patient with the age under 30 years (6.2%) and 13 patients (54.1%) between 30 and 40 years old, respectively (p < 0.05). Conclusion. Bladder urothelial carcinoma diagnosed at young age tends to be a low pathologic stage, with relatively low rate of recurrence and progression.

Tumor-Associated Macrophages Provide Significant Prognostic Information in Urothelial Bladder Cancer

Inflammation is an important feature of carcinogenesis. Tumor-associated macrophages (TAMs) can be associated with either poor or improved prognosis, depending on their properties and polarization. Current knowledge of the prognostic significance of TAMs in bladder cancer is limited and was investigated in this study. We analyzed 184 urothelial bladder cancer patients undergoing transurethral resection of a bladder tumor or radical cystectomy. CD68 (pan-macrophage marker), MAC387 (polarized towards type 1 macrophages), and CLEVER-1/Stabilin-1 (type 2 macrophages and lymphatic/blood vessels) were detected immunohistochemically. The median follow-up time was 6.0 years. High macrophage counts associated with a higher pT category and grade. Among patients undergoing transurethral resection, all studied markers apart from CLEVER-1/Stabilin-1 were associated with increased risk of progression and poorer disease-specific and overall survival in univariate analyses. High levels of two macrophage markers (CD68/MAC387^+/+ or CD68/CLEVER-1^+/+ groups) had an independent prognostic role after transurethral resection in multivariate analyses. In the cystectomy cohort, MAC387, alone and in combination with CD68, was associated with poorer survival in univariate analyses, but none of the markers were independent predictors of outcome in multivariate analyses. In conclusion, this study demonstrates that macrophage phenotypes provide significant independent prognostic information, particularly in bladder cancers undergoing transurethral resection.

Pyuria predicts poor prognosis in patients with non-muscle-invasive bladder cancer treated with bacillus Calmette-Guérin

This study was conducted to evaluate the utility of pyuria as a predictive marker of bacillus Calmette-Guérin (BCG) treatment for non-muscle-invasive bladder cancer (NMIBC). A cohort of 243 NMIBC patients treated with BCG through intravesical instillation between 1994 and 2007 at the Tokyo Metropolitan Tama Medical Center were enrolled in this retrospective study. Pyuria was defined as urine containing ≥10 white blood cells per high-power field. A total of 30 of the patients with pyuria (30/37, 81%) and 87 patients of those without pyuria (87/206, 42%) exhibited recurrence following BCG treatment. The 3-year recurrence-free survival rate of patients with and without pyuria following BCG treatment was 20 and 62%, respectively. The multivariate Cox proportional hazards regression model indicated that pyuria was an independent predictor of disease recurrence following BCG treatment. Patients with inflammatory NMIBC exhibited resistance to therapy with intravesical instillation of BCG.

Immunotherapy for urothelial cancer: from BCG to checkpoint inhibitors and beyond

Since its introduction almost 40 years ago, intravesical BCG for non-muscle invasive bladder cancer remains one of the most successful cancer immunotherapies. However, up to 40% of patients will progress after BCG therapy and develop invasive bladder cancer. Despite its extensive clinical use, we are only beginning to understand how BCG works. Here we review preclinical and clinical data that implicate BCG-induced Th1 and cytotoxic cellular immune responses in cancer regression. We propose that future immunotherapies should aim to augment Th1 and/or cellular responses in those that fail BCG therapy. We review clinical trials of immunotherapy in bladder cancer with a focus on the promising role of checkpoint blockade inhibitors that target the programmed cell death 1/programmed death-ligand 1 (PD-L1) axis and/or cytotoxic T lymphocyte antigen 4.

Immunogenicity of murine solid tumor models as a defining feature of in vivo behavior and response to immunotherapy

Immune profiling has been widely used to probe mechanisms of immune escape in cancer and identify novel targets for therapy. Two emerging uses of immune signatures are to identify likely responders to immunotherapy regimens among individuals with cancer and to understand the variable responses seen among subjects with cancer in immunotherapy trials. Here, the immune profiles of 6 murine solid tumor models (CT26, 4T1, MAD109, RENCA, LLC, and B16) were correlated to tumor regression and survival in response to 2 immunotherapy regimens. Comprehensive profiles for each model were generated using quantitative reverse transcriptase polymerase chain reaction, immunohistochemistry, and flow cytometry techniques, as well as functional studies of suppressor cell populations (regulatory T cells and myeloid-derived suppressor cells), to analyze intratumoral and draining lymphoid tissues. Tumors were stratified as highly or poorly immunogenic, with highly immunogenic tumors showing a significantly greater presence of T-cell costimulatory molecules and immune suppression in the tumor microenvironment. An absence of tumor-infiltrating cytotoxic T lymphocytes and mature dendritic cells was seen across all models. Delayed tumor growth and increased survival with suppressor cell inhibition and tumor-targeted chemokine+/-dendritic cells vaccine immunotherapy were associated with high tumor immunogenicity in these models. Tumor MHC class I expression correlated with the overall tumor immunogenicity level and was a singular marker to predict immunotherapy response with these regimens. By using experimental tumor models as surrogates for human cancers, these studies demonstrate how select features of an immune profile may be utilized to identify patients most likely to respond to immunotherapy regimens.

Response of high-risk of recurrence/progression bladder tumours expressing sialyl-Tn and sialyl-6-T to BCG immunotherapy

Background:

High risk of recurrence/progression bladder tumours is treated with Bacillus Calmette-Guérin (BCG) immunotherapy after complete resection of the tumour. Approximately 75% of these tumours express the uncommon carbohydrate antigen sialyl-Tn (Tn), a surrogate biomarker of tumour aggressiveness. Such changes in the glycosylation of cell-surface proteins influence tumour microenvironment and immune responses that may modulate treatment outcome and the course of disease. The aim of this work is to determine the efficiency of BCG immunotherapy against tumours expressing sTn and sTn-related antigen sialyl-6-T (s6T).

Methods:

In a retrospective design, 94 tumours from patients treated with BCG were screened for sTn and s6T expression. In vitro studies were conducted to determine the interaction of BCG with high-grade bladder cancer cell line overexpressing sTn.

Results:

From the 94 cases evaluated, 36 had recurrence after BCG treatment (38.3%). Treatment outcome was influenced by age over 65 years (HR=2.668; (1.344–5.254); P=0.005), maintenance schedule (HR=0.480; (0.246–0.936); P=0.031) and multifocallity (HR=2.065; (1.033–4.126); P=0.040). sTn or s6T expression was associated with BCG response (P=0.024; P<0.0001) and with increased recurrence-free survival (P=0.001). Multivariate analyses showed that sTn and/or s6T were independent predictive markers of recurrence after BCG immunotherapy (HR=0.296; (0.148–0.594); P=0.001). In vitro studies demonstrated higher adhesion and internalisation of the bacillus to cells expressing sTn, promoting cell death.

Conclusion:

s6T is described for the first time in bladder tumours. Our data strongly suggest that BCG immunotherapy is efficient against sTn- and s6T-positive tumours. Furthermore, sTn and s6T expression are independent predictive markers of BCG treatment response and may be useful in the identification of patients who could benefit more from this immunotherapy.

Predicting response to bacillus Calmette-Guérin (BCG) in patients with carcinoma in situ of the bladder

PURPOSE

Currently, there is no reliable tool to predict response to intravesical bacillus Calmette-Guérin (BCG). Based on the fact that BCG is a Th1-polarizing immunotherapy, we attempt to correlate the pretreatment immunologic tumor microenvironment (Th1 or Th2) with response to therapy.

MATERIALS AND METHODS

Bladder cancer patients with initial diagnosis of carcinoma in situ (Tis) were stratified based on their response to BCG treatment. A total of 38 patients met inclusion criteria (20 patients who responded and 18 patients who did not respond). Immunohistochemical (IHC) methods known to assess the type of immunologic microenvironment (Th1 vs. Th2) were performed on tumor tissue obtained at initial biopsy/resection: the level of tumor eosinophil infiltration and degranulation (Th2 response); the number of tumor-infiltrating GATA-3(+) (Th2-polarized) lymphocytes; and the number of tumor-infiltrating T-bet(+) (Th1-polarized) lymphocytes. Results obtained from these metrics were correlated with response to treatment with BCG immunotherapy.

RESULTS

The IHC metrics of the tumor immune microenvironment prior to BCG treatment were each statistically significant predictors of responders (R) vs. nonresponders (NR). Eosinophil infiltration and degranulation was higher for R vs. NR: 1.02 ± 0.17 vs. 0.5 ± 0.12 (P = 0.01) and 1.1 ± 0.15 vs. 0.56 ± 0.15 (P = 0.04), respectively. Ratio of GATA-3(+) (Th2-polarized) lymphocytes to T-bet(+) (Th1-polarized) lymphocytes was higher for R vs. NR: 4.85 ± 0.94 vs. 0.98 ± 0.19 (P<0.001). The 3 markers were combined to create a Th2 signature biomarker, which was a statistically significant (P<0.0001) predictor of R vs. NR. All IHC markers demonstrated that a preexisting Th1 immunologic environment within the tumor was predictive of BCG failure.

CONCLUSION

The Th1 vs. Th2 polarization of bladder tumor immune microenvironment prior to treatment with BCG represents a prognostic metric of response to therapy. If a patient has a preexisting Th1 immunologic response within the tumor, there is no value in using a therapy intended to create a Th1 immunologic response. An algorithm integrating 3 IHC methods provided a sensitive and specific technique that may become a useful tool for pathologists and urologists to predict response to BCG in patients with carcinoma in situ of the bladder.

BCG immunotherapy for bladder cancer--the effects of substrain differences

Genetic mutations have been progressively introduced to BCG by repeated serial passage over many decades of its culture and global dissemination. Thus, marked differences exist in the phenotype, antigenicity, reactogenicity, and clinical characteristics of the numerous substrains of BCG currently in use for bladder cancer immunotherapy. These differences influence proposed mycobacterial antitumour mechanisms and toxicity, potentially resulting in variations in clinical efficacy and adverse effects. However, although there is evidence of substrain-related differences in the clinical efficacy of BCG as a tuberculosis vaccine, evidence of an effect on bladder cancer immunotherapy remains elusive, owing to the lack of appropriately powered head-to-head comparative clinical trials, the nonstandardization of BCG manufacture, and variation in treatment protocols--possibly itself a response to underlying substrain differences. Advances in our understanding of mycobacterial genetics, structure and function, and host-pathogen interactions might explain differences in clinical practice and outcomes. These advances are guiding the identification of biomarkers for reactogenicity and efficacy, and the rational design of immunotherapeutic strategies to eliminate the use of live bacilli for bladder cancer therapy.

FASL polymorphism is associated with response to bacillus Calmette-Guérin immunotherapy in bladder cancer

OBJECTIVE

Deregulation of FAS/FASL system may lead to immune escape and influence bacillus Calmette-Guérin (BCG) immunotherapy outcome, which is currently the gold standard adjuvant treatment for high-risk non-muscle invasive bladder tumors. Among other events, functional promoter polymorphisms of FAS and FASL genes may alter their transcriptional activity. Therefore, we aim to evaluate the role of FAS and FASL polymorphisms in the context of BCG therapy, envisaging the validation of these biomarkers to predict response.

PATIENTS AND METHODS

DNA extracted from peripheral blood from 125 patients with bladder cancer treated with BCG therapy was analyzed by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism for FAS-670 A/G and FASL-844 T/C polymorphisms. FASL mRNA expression was analyzed by real-time Polymerase Chain Reaction.

RESULTS

Carriers of FASL-844 CC genotype present a decreased recurrence-free survival after BCG treatment when compared with FASL-844 T allele carriers (mean 71.5 vs. 97.8 months, P = 0.030) and have an increased risk of BCG treatment failure (Hazard Ratio = 1.922; 95% Confidence Interval: [1.064-3.471]; P = 0.030). Multivariate analysis shows that FASL-844 T/C and therapeutics scheme are independent predictive markers of recurrence after treatment. The evaluation of FASL gene mRNA levels demonstrated that patients carrying FASL-844 CC genotype had higher FASL expression in bladder tumors (P = 0.0027). Higher FASL levels were also associated with an increased risk of recurrence after BCG treatment (Hazard Ratio = 2.833; 95% Confidence Interval: [1.012-7.929]; P = 0.047). FAS-670 A/G polymorphism analysis did not reveal any association with BCG therapy outcome.

CONCLUSIONS

Our results suggest that analysis of FASL-844 T/C, but not FAS-670 A/G polymorphisms, may be used as a predictive marker of response to BCG immunotherapy.

Newly Developed Synbiotics and the Chemotherapy-Damaged Gut

Mucositis is a common side-effect of cancer chemotherapy and radiotherapy. Features of mucositis include erythema, ulceration, and inflammation of the gastrointestinal tract accompanied by clinical symptoms of abdominal pain and digestive disturbances. New treatment strategies are required. Experimental evidence is accumulating showing therapeutic promise for new nutraceutical agents including probiotic bacteria, probiotic-derived factors, prebiotics, and plant extracts. However, the targeted development of new combinations of these agents (synbiotics) to combat mucositis remains largely unexplored. The current review addresses the potential for these nutraceutical agents to reduce the severity of chemotherapy-damaged mucositis by strategically aligning their underlying mechanism of action with features of mucositis pathogenesis. The potential for certain plant extracts to act as prebiotics, in combination with probiotics or their derived factors, is further investigated. These unique synbiotic formulations could form the basis of a new naturally sourced adjunctive approach to cancer chemotherapy.