Potential Role of the Intratumoral Microbiota in Prognosis of Head and Neck Cancer

The tumor microbiome, a relatively new research field, affects tumor progression through several mechanisms. The Cancer Microbiome Atlas (TCMA) database was recently published. In the present study, we used TCMA and The Cancer Genome Atlas and examined microbiome profiling in head and neck squamous cell carcinoma (HNSCC), the role of the intratumoral microbiota in the prognosis of HNSCC patients, and differentially expressed genes in tumor cells in relation to specific bacterial infections. We investigated 18 microbes at the genus level that differed between solid normal tissue (n = 22) and primary tumors (n = 154). The tissue microbiome profiles of Actinomyces, Fusobacterium, and Rothia at the genus level differed between the solid normal tissue and primary tumors of HNSCC patients. When the prognosis of groups with rates over and under the median for each microbe at the genus level was examined, rates for Leptotrichia which were over the median correlated with significantly higher overall survival rates. We then extracted 35 differentially expressed genes between the over- and under-the-median-for-Leptotrichia groups based on the criteria of >1.5 fold and p < 0.05 in the Mann-Whitney U-test. A pathway analysis showed that these Leptotrichia-related genes were associated with the pathways of Alzheimer disease, neurodegeneration-multiple diseases, prion disease, MAPK signaling, and PI3K-Akt signaling, while protein-protein interaction analysis revealed that these genes formed a dense network. In conclusion, probiotics and specific antimicrobial therapy targeting Leptotrichia may have an impact on the prognosis of HNSCC.

Stem cell-like T cell depletion in the recurrent head and neck cancer immune microenvironment

Human papilloma virus (HPV)-related oncogenesis in head and neck cancer establishes a local microenvironment rich with immune cells, however the composition of the microenvironment in recurrent disease following definitive treatment is poorly understood. Here, we investigate the composition and spatial relationships between tumor and immune cells in recurrent head and neck cancer following curative intent chemoradiotherapy. Multiplexed immunofluorescence with 12 unique markers, through two multiplex immunofluorescent panels, was performed to evaluate 27 tumor samples including 18 pre-treatment primary and 9 paired recurrent tumors. Tumor and immune cell populations were phenotyped and quantified using a previously validated semi-automated digital pathology platform for cell segmentation. Spatial analysis was conducted by evaluating immune cells within the tumor, peri-tumoral stroma, and distant stroma. Initial tumors in patients with subsequent recurrence were found to be enriched in tumor associated macrophages and displayed an immune excluded spatial distribution. Recurrent tumors after chemoradiation were hypo-inflamed, with a statistically significant reduction in the recently identified stem-like TCF1+ CD8 T-cells, which normally function to maintain HPV-specific immune responses in the setting of chronic antigen exposure. Our findings indicate that the tumor microenvironment of recurrent HPV-related head and neck cancers displays a reduction in stem-like T cells, consistent with an immune microenvironment with a reduced ability to mount T-cell-driven anti-tumor immune responses.

Dynamic nomogram for long-term survival in patients with locally advanced oropharyngeal cancer after (chemo)radiotherapy

PURPOSE

This study aimed to establish a nomogram for predicting overall survival (OS) in oropharyngeal cancer patients treated with curative (chemo)radiotherapy.

MATERIALS AND METHODS

The dynamic nomogram was constructed on 273 patients with oropharyngeal squamous cell carcinoma treated in a Tertiary Head and Neck Cancer Unit. The clinical features that were previously reported to be associated with OS were analyzed. The performance of the nomogram was assessed using concordance index (C-index) and calibration curves.

RESULTS

The nomogram incorporated three explanatory variables derived from a decision tree approach including HPV status, N classification according to 8th edition TNM and early response to (chemo)radiotherapy. The nomogram was capable to predict OS with a validation C-index of 0.768. The proposed stratification in risk groups allowed significant distinction between Kaplan-Meier curves for OS outcome (p < 0.0001).

CONCLUSIONS

The nomogram provided an accurate evaluation of OS for oropharyngeal cancer patients treated with curative (chemo)radiotherapy.

The potential of ferroptosis combined with radiotherapy in cancer treatment

Ferroptosis is a new form of regulatory cell death that is closely related to the balance of redox reactions and the occurrence and development of cancer. There is increasing evidence that inducing ferroptosis in cells has great potential in the treatment of cancer. Especially when combined with traditional therapy, it can improve the sensitivity of cancer cells to traditional therapy and overcome the drug resistance of cancer cells. This paper reviews the signaling pathways regulating ferroptosis and the great potential of ferroptosis and radiotherapy (RT) in cancer treatment and emphasizes the unique therapeutic effects of ferroptosis combined with RT on cancer cells, such as synergy, sensitization and reversal of drug resistance, providing a new direction for cancer treatment. Finally, the challenges and research directions for this joint strategy are discussed.

Clinical outcomes in relapsed oropharyngeal cancer after definitive (chemo) radiotherapy

OBJECTIVES

To report clinical outcomes of relapsed oropharyngeal squamous cell carcinoma (OPSCC) after definitive intensity-modulated (chemo)radiotherapy [(C)RT].

MATERIALS AND METHODS

Data for all relapsed patients treated for OPSCC with definitive (C)RT between 2010 and 2016 were collected. Primary end-point was post-failure survival (PFS).

RESULTS

Overall, 273 OPSCC patients completed definitive (C)RT. Of these, 42 cases (n = 26 human papilloma virus (HPV)-negative; n = 16 HPV-positive) had relapsed (n = 23 persistent disease; n = 19 recurrent disease) and were included in the final analysis. Two-year PFS for the entire population was 30.6%; 20.5% for HPV-negative and 43.8% for HPV-positive patients. Salvage curative surgery was associated with a significantly higher 2 years PFS rate (56.2%) compared with palliative treatment (22.9%) and best supportive care (0%) (p < 0.001). A positive trend in 2 years PFS was recorded in the early complete response cases (49.5%) versus patients who did not achieve a complete response within 3 months of the end of (C)RT (23.0%) (p = 0.11).

CONCLUSION

A higher PFS rate is achieved when relapsed OPSCC cases are treated with salvage curative intent. HPV-positive disease and early complete response within 3 months from the end of (C)RT may be related to better PFS.

The microbiota and radiotherapy for head and neck cancer: What should clinical oncologists know?

Radiotherapy is a linchpin in head and neck squamous cell carcinoma (HN-SCC) treatment. Modulating tumour and/or normal tissue biology offers opportunities to further develop HN-SCC radiotherapy. The microbiota, which can exhibit homeostatic properties and be a modulator of immunity, has recently received considerable interest from the Oncology community. Microbiota research in head and neck oncology has also flourished. However, available data are difficult to interpret for clinical and radiation oncologists. In this review, we focus on how microbiota research can contribute to the improvement of radiotherapy for HN-SCC, focusing on how current and future research can be translated back to the clinic. We include in-depth discussions about the microbiota, its multiple habitats and relevance to human physiology, mechanistic interactions with HN-SCC, available evidence on microbiota and HNC oncogenesis, efficacy and toxicity of treatment. We discuss clinically-relevant areas such as the role of the microbiota as a predictive and prognostic biomarker, as well as the potential of leveraging the microbiota and its interactions with immunity to improve treatment results. Importantly, we draw parallels with other cancers where research is more mature. We map out future directions of research and explain clinical implications in detail.

De-escalation studies in HPV-positive oropharyngeal cancer: How should we proceed?

Human papilloma virus (HPV) is a well-established causative factor in a subset of squamous cell carcinomas of the head and neck (HNSCC). Although HPV can be detected in various anatomical subsites, HPV-positive oropharyngeal squamous cell carcinoma (OPSCC) is the most common HPV-related malignancy of the head and neck, and its worldwide incidence is constantly rising. Patients with OPSCC are generally younger, have less co-morbidities and generally have better prognosis due to different biological mechanisms of carcinogenesis. These facts have generated hypotheses on potential treatment modifications, aiming to minimize treatment-related toxicities without compromising therapy efficacy. Numerous randomized clinical trials have been designed to verify this strategy and increasingly real-world evidence data from retrospective, observational studies is becoming available. Until now, the data do not support any modification in contemporary treatment protocols. In this narrative review, we outline recent data provided by both randomized controlled trials and real-world evidence of HPV-positive OPSCC in terms of clinical value. We critically analyze the potential value and drawbacks of the available data and highlight future research directions. This article was written by members and invitees of the International Head and Neck Scientific Group.(www.IHNSG.com).

Optimizing oropharyngeal cancer management by using proton beam therapy: trends of cost-effectiveness

Background

Proton beam therapy (PBT) is a new-emerging cancer treatment in China but its treatment costs are high and not yet covered by Chinese public medical insurance. The advanced form of PBT, intensity-modulated proton radiation therapy (IMPT), has been confirmed to reduce normal tissue complication probability (NTCP) as compared to conventional intensity-modulated photon-radiation therapy (IMRT) in patients with oropharyngeal cancer (OPC). Herein, we evaluated the cost-effectiveness and applicability of IMPT versus IMRT for OPC patients in China, aiming at guiding the proper use of PBT.

Methods

A 7-state Markov model was designed for analysis. Base-case evaluation was performed on a 56-year-old (median age of OPC in China) patient under the assumption that IMPT could provide a 25% NTCP-reduction in long-term symptomatic dysphagia and xerostomia. Model robustness was examined using probabilistic sensitivity analysis, cohort analysis, and tornado diagram. One-way sensitivity analyses were conducted to identify the cost-effective scenarios. IMPT was considered as cost-effective if the incremental cost-effectiveness ratio (ICER) was below the societal willingness-to-pay (WTP) threshold.

Results

Compared with IMRT, IMPT provided an extra 0.205 quality-adjusted life-year (QALY) at an additional cost of 34,926.6 US dollars ($), and had an ICER of $170,082.4/ QALY for the base case. At the current WTP of China ($33,558 / QALY) and a current IMPT treatment costs of $50,000, IMPT should provide a minimum NTCP-reduction of 47.5, 50.8, 55.6, 63.3 and 77.2% to be considered cost-effective for patient age levels of 10, 20, 30, 40 and 50-year-old, respectively. For patients at the median age level, reducing the current IMPT costs ($50,000) to a $30,000 level would make the minimum NTCP-reduction threshold for “cost-effective” decrease from 91.4 to 44.6%, at the current WTP of China (from 69.0 to 33.5%, at a WTP of $50,000 / QALY; and from 39.7 to 19.1%, at a WTP of $100,000 / QALY).

Conclusions

Cost-effective scenarios of PBT exist in Chinese OPC patients at the current WTP of China. Considering a potential upcoming increase in PBT use in China, such cost-effective scenarios may further expand if a decrease of proton treatment costs occurs or an increase of WTP level.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08638-2.

Risk stratified follow up for head and neck cancer patients - An evidence based proposal

Head and neck squamous cell carcinoma (HNSCC) has a significant impact on patients' quality of life and treatment can be associated with severe morbidity. Following completion of treatment, patients are followed up in order to detect potentially salvageable recurrences and to manage long-term toxicities. In recent years, a growing interest has been given to risk stratified follow-up interventions to prevent and detect recurrences and manage treatment toxicities in other tumour sites as well as to transfer some of that care to community services. We review the literature for HNSCC and propose a risk stratified follow up protocol to address these issues and assist clinicians in decision making. A shift in patterns of care is suggested in order to provide a basis to improve care for HNSCC patients after complete response to primary treatment.

Analyzing oropharyngeal cancer survival outcomes: a decision tree approach

OBJECTIVES

To analyze survival outcomes in patients with oropharygeal cancer treated with primary intensity modulated radiotherapy (IMRT) using decision tree algorithms.

METHODS

A total of 273 patients with newly diagnosed oropharyngeal cancer were identified between March 2010 and December 2016. The data set contained nine predictor variables and a dependent variable (overall survival (OS) status). The open-source R software was used. Survival outcomes were estimated by Kaplan-Meier method. Important explanatory variables were selected using the random forest approach. A classification tree that optimally partitioned patients with different OS rates was then built.

RESULTS

The 5 year OS for the entire population was 78.1%. The top three important variables identified were HPV status, N stage and early complete response to treatment. Patients were partitioned in five groups on the basis of these explanatory variables.

CONCLUSION

The proposed classification tree could help to guide future research in oropharyngeal cancer field.

ADVANCES IN KNOWLEDGE

Decision tree method seems to be an appropriate tool to partition oropharyngeal cancer patients.

Role of gene signatures combined with pathology in classification of oropharynx head and neck cancer

Treatment personalisation remains an unmet need in oropharynx cancer (OPC). We aimed to determine whether gene expression signatures improved upon clinico-pathological predictors of outcome in OPC. The clinico-pathological predictors, AJCC version 7 (AJCC 7), AJCC 8, and a clinical algorithm, were assessed in 4 public series of OPC (n = 235). Literature review identified 16 mRNA gene expression signatures of radiosensitivity, HPV status, tumour hypoxia, and microsatellite instability. We quality tested signatures using a novel sigQC methodology, and added signatures to clinico-pathological variables as predictors of survival, in univariate and multivariate analyses. AJCC 7 Stage was not predictive of recurrence-free survival (RFS) or overall survival (OS). AJCC 8 significantly predicted RFS and OS. Gene signature quality was highly variable. Among HPV-positive cases, signatures for radiosensitivity, hypoxia, and microsatellite instability revealed significant underlying inter-tumour biological heterogeneity, but did not show prognostic significance when adjusted for clinical covariates. Surprisingly, among HPV-negative cases, a gene signature for HPV status was predictive of survival, even after adjustment for clinical covariates. Across the whole series, several gene signatures representing HPV and microsatellite instability remained significant in multivariate analysis. However, quality control and independent validation remain to be performed to add prognostic information above recently improved clinico-pathological variables.

Very late xerostomia, dysphagia, and neck fibrosis after head and neck radiotherapy

BACKGROUND

Acute and late toxicity after intensity-modulated radiotherapy (IMRT) for head and neck cancer (HNC) impacts on patient quality of life; yet, very late toxicity data remain scarce. This study assessed dysphagia, xerostomia, and neck fibrosis 3-8 years after IMRT.

METHODS

A retrospective analysis using generalized estimated equations was performed on 60 patients with HNC treated with fractionated IMRT between 2000 and 2015 who had a follow-up ≥8 years. Toxicity was scored using LENT-SOMA scales.

RESULTS

A trend towards a nonlinear global time effect (P = .05) was noted for dysphagia with a decrease during the 5 years post-treatment and an increase thereafter. A significant decrease in xerostomia (P = .001) and an increase in neck fibrosis (P = .04) was observed until 8 years.

CONCLUSIONS

Dysphagia, xerostomia, and neck fibrosis do not appear stable over time and remain highly prevalent in the very late follow-up. Our findings support the need for prospective trials investigating very late toxicity in patients with HNC.

Recent advances in the understanding and management of oropharyngeal cancer

Oropharyngeal squamous cell carcinoma (OPSCC) is an increasing health problem in the developing and developed world. In recent years, there have been major changes in the treatment paradigms for OPSCC. This is because of a number of reasons: the understanding and discovery of a new viral etiology (the human papillomavirus [HPV]), changes in practice patterns owing to advances in radiotherapy, and then an organ preservation strategy with the increased use of chemotherapy. Next came the development of new surgical technologies and the emergence of a new treatment modality, immunotherapy. In this article, we discuss the evolution of OPSCC treatments, starting with the traditional tobacco era. Treatment paradigms then evolved during the organ preservation era, the HPV era, and the minimally invasive surgery era. We are currently in the immunotherapy era, with a number of new drugs becoming available both on trial and by approval for use in the clinical setting for head and neck cancer patients. We discuss a number of trials and the reasons behind attempts at both treatment escalation and treatment de-escalation.

Outcomes after primary intensity-modulated radiation therapy for oropharyngeal squamous cell carcinoma at a New Zealand regional cancer centre: Impact of p16 status

INTRODUCTION

The rising incidence of oropharyngeal squamous cell carcinoma (OPSCC) in New Zealand is due to an increase in the numbers of human papilloma virus (HPV)-associated OPSCC. We evaluated the impact of positive p16 immunohistochemistry, as a surrogate for HPV positivity, on OPSCC outcomes after primary intensity-modulated radiotherapy (IMRT) with or without concurrent chemotherapy.

METHODS

Retrospective review was undertaken of electronic medical records of 90 patients with OPSCC who received primary IMRT with or without chemotherapy between 2008 and mid-2015 at the Regional Cancer Centre, Waikato Hospital, Hamilton, New Zealand.

RESULTS

Median age was 57.5 years. Immunohistochemistry for p16 was positive in 53 (59%) OPSCC while 37 (41%) had negative or unknown p16 status. Median radiotherapy dose was 70 Gy. Chemotherapy was administered to 78 (87%) patients, most receiving high-dose cisplatin. Nine patients had residual disease following treatment completion. Seven patients relapsed, and 26 died during the study period. Five patients with p16-positive OPSCC had persistent or recurrent disease. Actuarial 3-year locoregional control, disease-free survival, and overall survival for all patients were 80.7%, 74.7%, and 77.1%, respectively. Among p16-positive OPSCC patients, 3-year locoregional control, disease-free survival, and overall survival were 89.5%, 80.8%, and 90.9%, respectively.

CONCLUSION

Outcomes after IMRT for OPSCC at Waikato Hospital are in line with the reported literature. Human papilloma virus-related OPSCC has better outcomes compared with patients with unknown or HPV-unrelated OPSCC. Trials are underway evaluating reduced intensity of treatment for HPV-related OPSCC.

Outcomes utilizing intensity-modulated radiotherapy in oropharyngeal cancers: Tonsils versus base of tongue

BACKGROUND

The purpose of this study was to present the outcomes of oropharyngeal cancers treated with intensity-modulated radiotherapy (IMRT) especially the differences between tonsillar and base of tongue (BOT) primaries.

METHODS

Retrospective analysis of 124 patients with biopsy proven squamous cell carcinomas of the oropharynx, treated with IMRT.

RESULTS

Human papillomavirus (HPV) association correlated with improvement in survivals in both tonsillar and BOT primaries. At the 2-year median follow-up, the cumulative incidences of locoregional recurrences were 8% in both the tonsil and BOT groups (P = .76) but the distant metastases were 8% in the tonsil group versus 26% in the BOT group (P = .009). Thirty percent of tonsil primaries has ≥N2c neck disease as compared to 54% of BOT. Incidence of distant metastases increases with advanced nodal classification, especially >N2c.

CONCLUSION

Even though the locoregional controls are excellent with IMRT and chemotherapy, these patients continue to fail distantly, particularly significant for the BOT group and for nodal stage >N2c.

Nodal response after 46 Gy of intensity-modulated radiotherapy is associated with human papillomavirus-related oropharyngeal carcinoma

OBJECTIVES/HYPOTHESIS

This study aimed to analyze the effect of human papillomavirus (HPV)-associated T1-2 node-positive oropharyngeal squamous cell carcinoma (OPSCC) on nodal response, recurrent disease, and survival in patients treated according to the Rotterdam protocol.

STUDY DESIGN

Retrospective cohort study.

METHODS

In total, 77 patients with T1-2 OPSCC with nodal disease, treated between 2000 and 2012, were included in this study. Patients were treated according to the Rotterdam protocol: 46 Gy of IMRT followed by a local boost using cyberknife or brachytherapy (22 Gy) and neck dissection. The presence of HPV was determined by p16^INK4A immunostaining. Outcomes were overall survival, disease-free survival, and the extent of nodal response. Nodal stage was determined following the 7th and 8th American Joint Cancer Committee/Union for International Cancer Control classification.

RESULTS

Overall, 68.4% of patients had p16-positive disease, and 35.4% of all patients achieved complete nodal response (pN0) after 46 Gy of intensity-modulated radiotherapy (IMRT). Based on the 7th TNM classification, nodal response (partial or complete) was significantly associated with HPV status (P = .002). Patients with p16-positive OPSCC had an odds ratio (OR) of 4.6 to achieve complete nodal response. However, smoking interacted with this effect. Applying the 8th TNM classification, complete or partial response was associated with HPV status but was not significant (OR: 1.7, P = .138). Complete nodal response led to 100% overall survival in p16-positive OPSCC patients.

CONCLUSIONS

HPV-related OPSCCs are associated with complete nodal response after 46 Gy of IMRT. Patients with full regional control (pN0) after IMRT and subsequent neck dissection show a significantly better overall survival, but smoking negatively interacts with this effect.

LEVEL OF EVIDENCE

4. Laryngoscope, 128:2333-2340, 2018.

Cancer Radiosensitizers

Radiotherapy (RT) is a mainstay treatment for many types of cancer, although it is still a large challenge to enhance radiation damage to tumor tissue and reduce side effects to healthy tissue. Radiosensitizers are promising agents that enhance injury to tumor tissue by accelerating DNA damage and producing free radicals. Several strategies have been exploited to develop highly effective and low-toxicity radiosensitizers. In this review, we highlight recent progress on radiosensitizers, including small molecules, macromolecules, and nanomaterials. First, small molecules are reviewed based on free radicals, pseudosubstrates, and other mechanisms. Second, nanomaterials, such as nanometallic materials, especially gold-based materials that have flexible surface engineering and favorable kinetic properties, have emerged as promising radiosensitizers. Finally, emerging macromolecules have shown significant advantages in RT because these molecules can be combined with biological therapy as well as drug delivery. Further research on the mechanisms of radioresistance and multidisciplinary approaches will accelerate the development of radiosensitizers.