Tumour mismatch repair protein loss is associated with advanced stage in oral cavity squamous cell carcinoma

Influence of Immunoexpression of Mismatch Repair Complex Proteins on Disease-Free Survival in Non-Surgically Treated Oropharyngeal Squamous Cell Carcinomas

OBJECTIVE

To evaluate the influence of MMR complex protein immunoexpression on disease-free survival in oropharyngeal SCC treated non-surgically.

MATERIALS AND METHODS

85 cases of oropharyngeal SCC diagnosed and treated at the Ceará Cancer Institute were surveyed, from which clinical-pathological data and paraffin blocks of incisional biopsies were retrieved for immunohistochemical reaction for MSH2, MSH6, PMS2, MLH1 and p16. Disease-free survival was calculated and Kruskal-Wallis and Friedman/Dunn tests, chi-square and Fisher's exact, Log-Rank Mantel Cox and Cox regression were performed.

RESULTS

In p16- tumors, loss of MSH2 expression was associated with shorter disease-free survival (p = 0.035) and mean MSH6 expression was significantly higher than MSH2 (p = 0.001). Loss of MSH2 expression in p16 + tumors was associated with longer disease-free survival compared to p16- tumors. Imbalance in the MSH6/MSH2 ratio in p16 + tumors was associated with longer survival compared to p16- tumors. MLH1/PMS2 imbalance was significantly higher in p16 + with recurrence (p = 0.003). Low MSH2 immunoexpression increased the risk of relapse by 9.10 times (CI95% 1.99 to 83.06).

CONCLUSION

Microsatellite instability in oropharyngeal SCC is demonstrated by the association between loss of protein expression and its heterodimer imbalance with disease-free survival. It was demonstrated that the imbalance of the MMR complex can consequently lead to resistance to treatment and a decrease in disease-free survival in p16 + oropharyngeal SCC tumors.

Fusobacterium nucleatum impairs DNA mismatch repair and stability in patients with squamous cell carcinoma of the head and neck

BACKGROUND

Dysbiosis of the laryngeal microbiota has been demonstrated to the development of head and neck squamous cell carcinoma (HNSCC), but the association of Fusobacterium and Fusobacterium nucleatum (F. nucleatum) with DNA mismatch repair (MMR) and microsatellite instability (MSI) has not been investigated.

METHODS

The abundance of Fusobacterium and F. nucleatum, the status of deficient MMR (dMMR) and MSI, and MMR-related gene expression were analyzed in 171 HNSCC tissues, 61 paired para-tumor tissues, and 60 vocal cord polyp tissues. The molecular mechanism of F. nucleatum and MMR-related gene expression were investigated in two human HNSCC cell lines (Tu 686 and FD-LSC-1).

RESULTS

Our results demonstrated that a high Fusobacterium abundance was detected in the HNSCC tissues and was exaggerated in the recurrent patients. We further found that a high Fusobacterium abundance was detected in the HNSCC tissues with dMMR and MSI. The Fusobacterium abundance was negatively correlated with the expression of MLH1, MSH2, and MSH6 in the HNSCC tissues. The Fusobacterium abundance was closely associated with the F. nucleatum abundance in the HNSCC tissues. F. nucleatum increased miR-205-5p expression to suppress MLH1, MSH2, and MSH6 expression via the TLR4- and MYD88-dependent innate immune signaling pathway, resulting in dMMR, DNA damage, and cell proliferation in HNSCC.

CONCLUSIONS

F. nucleatum impacts HNSCC epigenetic changes in tissues with dMMR to promote DNA damage and cell proliferation by suppressing MMR-related gene expression via the TLR4/MYD88/miR-205-5p signaling pathway, which is valuable in the development of efficient strategies for HNSCC prevention and treatment.

LAY SUMMARY

This study clearly indicates that Fusobacterium induced head and neck squamous cell carcinoma (HNSCC) aggressiveness to affect poor prognosis in HNSCC patients by epigenetic alteration of DNA mismatch repair (MMR) and microsatellite instability. Moreover, the research has shown that Fusobacterium nucleatum ( F. nucleatum ) impacts HNSCC epigenetic changes in tissues with deficient MMR to promote DNA damage and cell proliferation by suppressing MMRrelated gene expression via the TLR4/MYD88/miR-205-5p signaling pathway.

Cross-comparison of microbiota in the oropharynx, hypopharyngeal squamous cell carcinoma and their adjacent tissues through quantitative microbiome profiling

Aims

To clarify the absolute abundance of microbial communities on hypopharyngeal squamous cell carcinoma and their correlation to those in the oropharynx.

Methods

Clinical data, swabs, and tissue samples from 27 HPSCC patients were collected in this study and divided into three sampling groups: 19 oropharyngeal mucosa (OPM), 27 hypopharyngeal carcinomas tissues (HC), and 26 corresponding adjacent tissues (AT). Relative microbiome profiling (RMP), and quantitative microbiome profiling (QMP) of 16S rRNA amplicon sequencing were used for analysis.

Results

Beta-diversity showed that abundance and phylogenetic tree in OPM group were less when compared to either HC and AT. Although HC and AT were found to have similar microbiota, Bray-Curtis based beta-diversity still highlighted differences. Fusobacterium, Porphyromonas, Haemophilus, and Peptostreptococcus at the genus level in OPM were positively correlated with HC. After categorizing HC through TNM staging, the abundance of genera Fusobacterium, Parvimonas, and Dialister were found to be enhanced in higher T classifications (T3-4) and advanced stages (Ⅳ).

Conclusions

QMP yielded more comprehensive results than RMP. Dysbiosis was found in OPM groups and could be used to narrow down differential microbiome for the HC group. Genera of Parvimonas, Fusobacterium, and Dialister were deemed asrisk factors of advanced HPSCC.

PMS2: a potential prognostic protein marker in oral squamous cell carcinoma

Background

An increase in oral squamous cell carcinoma (OSCC) cases was observed despite the reduction in exposure to classic risk factors. Although the exact cause of this trend remains unknown, epigenetic factors could be contributing to an increased occurrence of these tumors. This study aims to assess the influence of PMS2 protein immunoexpression on the prognosis of patients with OSCC.

Material and Methods

This study comprised 76 cases of OSCC treated between 2011 and 2016. Immunohistochemical staining for PMS2 was performed. For evaluation, 10 fields per histological section were photographed at a 400x magnification and positively-stained cells were counted with Image J. Mann-Whitney and Kruskal-Wallis tests were used to compare the immunolabeling pattern with the clinical-pathological and prognostic characteristics. Survival analysis was performed with Chi-square, Long-Rank Mantel-Cox and Cox regression tests (p<0.05).

Results

An overexpression of PMS2 was observed in N0/1 tumors and in oral cancers found in unusual locations. In patients ≤60 years of age, high levels of PMS2 ( >60%; p=0.041) were associated with low survival (p=0.029). In multivariate analysis, surgery combined with chemotherapy (p=0.030) and high PMS2 immunoexpression (p=0.042) significantly increased the risk of death for ≤60 years old patients.

Conclusions

The findings of this study indicate that PMS2 can be a potential prognostic protein marker in OSCC patients 60 years of age and younger.

Key words:Squamous cell carcinoma, mouth neoplasms, mismatch repair endonuclease PMS2, survival.

Application of the Interaction between Tissue Immunohistochemistry Staining and Clinicopathological Factors for Evaluating the Risk of Oral Cancer Progression by Hierarchical Clustering Analysis: A Case-Control Study in a Taiwanese Population

The aim of this single-center case-control study is to investigate the feasibility and accuracy of oral cancer protein risk stratification (OCPRS) to analyze the risk of cancer progression. All patients diagnosed with oral cancer in Taiwan, between 2012 and 2014, and who underwent surgical intervention were selected for the study. The tissue was further processed for immunohistochemistry (IHC) for 21 target proteins. Analyses were performed using the results of IHC staining, clinicopathological characteristics, and survival outcomes. Novel stratifications with a hierarchical clustering approach and combinations were applied using the Cox proportional hazard regression model. Of the 163 participants recruited, 102 patients were analyzed, and OCPRS successfully identified patients with different progression-free survival (PFS) profiles in high-risk (53 subjects) versus low-risk (49 subjects) groups (p = 0.012). OCPRS was composed of cytoplasmic PLK1, phosphoMet, and SGK2 IHC staining. After controlling for the influence of clinicopathological features, high-risk patients were 2.33 times more likely to experience cancer progression than low-risk patients (p = 0.020). In the multivariate model, patients with extranodal extension (HR = 2.66, p = 0.045) demonstrated a significantly increased risk for disease progression. Risk stratification with OCPRS provided distinct PFS groups for patients with oral cancer after surgical intervention. OCPRS appears suitable for routine clinical use for progression and prognosis estimation.

Predictive factors in the treatment of oral squamous cell carcinoma using PD-1/PD-L1 inhibitors

Due to immune impairment and lymphocyte enrichment of oral squamous cell carcinoma (OSCC), anti-PD-1/PD-L1 therapy is regarded as a potential treatment option. However, tumor heterogeneity, differences in the immune conditions of patients, and the interrelation between tumor cells and stromal cells within the tumor microenvironment (TME) could affect the therapeutic efficacy of immune checkpoint blockades. Therefore, to maximize the benefit of blockade PD-1/PD-L1 axis, to find an efficient predictor (the possible clinical parameters or biological factors) before treatment are of great importance. In this review, we discuss the advantages of anti-PD-1/PD-L1 therapy for OSCC patients and find three respects that are currently available in predicting curative effect. Firstly, OSCC with high PD-L1 expression evaluating by immunohistochemistry (high tumor proportion score (TPS) and combined positive score (CPS)) are considered to be suitable for anti-PD-1/PD-L1 therapy. Secondly, gene-level predictive biomarkers including high metastatic mismatch repair deficiency (dMMR) signature or enrichment of interferon-γ and PD1 signaling pathway is expected to be favorable factors. Besides, PET/CT parameters (SUV_max, MTV, TLG) are proved to be correlated with PD-L1 expression, and some newly developed immunoPET probes are enlarging the application of PET/CT in predicting therapeutic efficacy of PD-1/PD-L1 inhibitors.

Mismatch Repair Proteins in Oropharyngeal Squamous Cell Carcinoma: A Retrospective Observational Study

Cases of oropharyngeal squamous cell carcinoma are on the rise and the disease now ranks as the most common human papillomavirus-related cancer. Although risk factors have been extensively discussed in the literature, the role of the DNA mismatch repair system remains unanswered. To evaluate the impact of the DNA mismatch repair (MMR) protein immunostaining on the tumor progression and prognosis of oropharyngeal squamous cell carcinoma (OPSCC). This retrospective observational study comprised 50 cases of OPSCC. Immunohistochemistry for MSH2, MSH6, PMS2, MLH1, Ki67, p16 and caspase-3 was performed. The expression of these proteins was assessed in surgical resection margins, primary tumor (PT), and lymph node metastasis (LNM) of p16+ and p16- OPSCC. Clinical-pathological involvement in immunostaining was evaluated with Kruskal-Wallis/Dunn or Mann-Whitney test, Wilcoxon test and Spearman's correlation. Overall survival (OS) was analyzed with Log-Rank Mantel-Cox and Cox regression. MSH6 and caspase-3 showed high expression in PT (p16+ and p16 -) and in LNM (p16+ and p16-), and high levels of MSH2 were found in LNM (p16+ and p16 -). An imbalance in MutSα also was observed. PMS2 and caspase-3 expression was associated with poor survival in p16- OPSCC and, in multivariate analysis, MSH2, MSH6 and MLH1 had the poorest prognostic impact in p16+ OPSCC. MMR protein immunostaining is involved in OPSCC progression, dissemination and prognosis. The overexpression of MMR proteins as a response to increased DNA mismatch caused by cell proliferation and MSH2, MSH6 and MLH1 proteins might constitute a prognostic marker in p16+ OPSCC.

The Mismatch Repair System (MMR) in Head and Neck Carcinogenesis and Its Role in Modulating the Response to Immunotherapy: A Critical Review

Simple Summary

The dysfunction of the mismatch repair system, an important mechanism for the detection and correction of DNA replication mistakes, may often lead to instability in the length of specific genetic sequences, known as microsatellites, and to the accumulation of mutations. Microsatellite instability is a well-known risk factor for the development of colorectal cancers and other types of tumors but is also considered a positive predictor of the immunotherapy response. Malignancies harboring such a specific genomic instability are very immunogenic because of the great number of aberrant antigens they produce. Therapies based on the blockade of specific immune checkpoints have shown to induce an effective immune response against microsatellite-unstable cancer. Many studies proved that microsatellite instability has a decisive role in the carcinogenesis and the malignant progression of head and neck cancer and, in the near future, it may become a useful tool in tailoring immunotherapy also in this field of precision oncology.

Abstract

The mismatch repair (MMR) system has a major role in the detection and correction of DNA replication errors, resulting from DNA polymerase slippage or nucleotides misincorporation. Specific inherited/acquired alterations or epigenetic inactivation of MMR genes are associated with microsatellite instability (MSI): the loss of crucial function in repairing DNA alterations can promote carcinogenesis by favoring the accumulation of thousands of mutations in a broad spectrum of different anatomic sites such as colon, stomach, prostate, esophagus, endometrium, lung and head and neck. Recent extensive data suggest that tumor mutational burden strongly correlates with a clinical response to immunotherapy using checkpoint inhibitors and this response is influenced by MMR deficiency in a wide range of human solid cancers. In this context, few data about this crucial point are available for head and neck cancer (HNC). In this review, we discuss the role of MMR alterations and the resulting MSI in HNC pathogenesis. Furthermore, by summarizing the clinical available data on how they influence the progression of precancerous lesions and the risk of recurrence or second primary tumors, we want to define the current role of MSI in the management of HNC. Finally, we analyze the complex interaction between cancer cells and the immune system addressing the data now available about a potential correlation between microsatellite instability and immunotherapy response in HNC.

Mismatch repair protein loss in cutaneous head and neck squamous cell carcinoma

BACKGROUND

The treatment of advanced cutaneous head and neck cutaneous squamous cell carcinomas (HNcSCC) results in significant morbidity. Recently, immune checkpoint inhibitor treatment has been approved for DNA mismatch repair (MMR) deficient patients in a histology-agnostic manner. This study aims to evaluate the incidence of MMR deficiency in advanced HNcSCC and its association with clinicopathologic factors.

METHODS

The cohort included 176 consecutive HNcSCC cases treated with curative intent. Immunohistochemistry for MMR proteins (hMLH1, hMSH2, hMSH6, and hPMS2) was performed. Clinicopathological and survival data was collected prospectively.

RESULTS

The incidence of MMR protein deficiency was 9.1%. There was no association between age, incidence of metachronous malignancies, clinicopathological factors, or survival outcomes.

CONCLUSION

A higher incidence of MMR deficiency was observed in this cohort of advanced HNcSCC. The lack of association with young age at onset or increased incidence of metachronous malignancies suggests that MMR deficiency is likely to be sporadic in HNcSCC.

Expression of DNA repair genes in oral squamous cell carcinoma using reverse transcription-quantitative polymerase chain reaction

OBJECTIVE

The aim of this study was to evaluate the expression of DNA repair genes in cases of oral squamous cell carcinoma (OSCC).

STUDY DESIGN

Expression of the MLH1, MSH2, MLH3, ATM, MRE11A, XRCC1, and PMS2 genes was evaluated by reverse transcription-quantitative polymerase chain reaction in the OSCC group (32 patients) and the control group (15 patients). The groups were compared by using the Mann-Whitney test, with Bonferroni correction. Associations between gene expression levels and clinical data were explored by using Pearson's and Spearman's correlation coefficients, with P value less than .05 indicating a significant difference.

RESULTS

The MLH1, MSH2, MLH3, ATM, MRE11A, XRCC1, and PMS2 genes were downregulated in the OSCC group compared with the control group, with significant values for MLH1 (P < .0001); MSH2 (P = .038); MLH3 (P < .0001); ATM (P < .0001); MRE11A (P < .0001); XRCC1 (P = .0004); and PMS2 (P = .008). Analysis of the correlation between gene expression and clinical data only revealed a significant negative correlation between age and expression of the PMS2 gene.

CONCLUSIONS

Expression of the DNA repair genes MLH1, MSH2, MLH3, ATM, MRE11 AMRE11A, XRCC1, and PMS2 was reduced in OSCC.

Prognostic significance of smoking and alcohol history in young age oral cavity cancer

OBJECTIVE

To assess prognostic factors of patients with operable oral cavity squamous cell carcinoma (OSCC), focusing on the associations with smoking/alcohol exposure and age.

MATERIALS AND METHODS

A total of 247 patients with OSCC who received curative surgery ± adjuvant radiotherapy were analyzed. The patient subgroups were divided according to pretreatment smoking/alcohol exposure. Individuals aged 45 years or less were classified as younger patients.

RESULTS

The median follow-up was 52.2 months. The 5-year locoregional progression-free survival (LRFFS), distant metastasis-free survival (DMFS), overall survival (OS), and cancer-specific survival (CSS) rates were 85.2%, 88.3%, 78.1%, and 83.5%, respectively. An advanced stage, differentiation, and lympho-vascular space invasion were significantly associated with lower OS and CSS. In a subgroup analysis of younger patients (n = 49), more smoking/alcohol exposure was significantly associated with better OS (hazard ratio [HR]: 0.21, 95% confidence interval [CI]: 0.05-0.95, p = .043). With increasing age, the HR for smoking/alcohol exposure with respect to OS increased up to 11.59 (95% CI: 1.49-89.84, p = .019) in older patients.

CONCLUSION

Younger OSCC patients with non- or less smoking/alcohol exposure showed unfavorable outcomes. The prognostic significance of pretreatment smoking/alcohol exposure changed from favorable to detrimental with increasing age in operable OSCC.

Immunohistochemical evaluation of mismatch repair proteins and p53 expression in extrauterine carcinosarcoma/sarcomatoid carcinoma

Introduction

Carcinosarcoma (CS) is a tumor with components: epithelial (carcinomatous) and mesenchymal (sarcomatous), developing in the mechanism of epithelial-mesenchymal transition. It is known that the p53 defect is a frequent finding in a carcinosarcoma in different anatomical locations, additionally, in a subgroup of uterine CS MMR defect plays a role in the pathogenesis. The aim of this paper was to investigate the frequency of MMR and p53 aberrations in extrauterine CS.

Material and methods

Twenty eight extrauterine CS from the lung (n = 8), breast (n = 6), head and neck (n = 5), ovary (n = 3), urinary bladder (n = 3), adrenal gland (n = 1), skin (n = 1), and stomach (n = 1) were stained for hMLH1, PMS2, hMSH2, hMSH6 and p53. The pattern of expression was evaluated separately in carcinomatous and sarcomatous component.

Results

Immunostainings for hMLH1, PMS2, hMSH2 and hMSH6 were positive in all tumors. p53 defect was observed in 19 out of 28 samples (67.85%). In all cases except one (96.42%) there was a concordance between sarcomatoid and carcinomatous components.

Conclusions

MMR deficiency does not seem to play a role in the pathogenesis of extrauterine CS. p53 aberrant expression is frequent and almost always consistent in carcinomatous and sarcomatous component.