Pembrolizumab versus cetuximab concurrent with radiotherapy in patients with locally advanced squamous cell carcinoma of head and neck unfit for cisplatin (GORTEC 2015-01 PembroRad): a multicenter, randomized, phase II trial

Extracellular vesicles as the common denominator among the 7 Rs of radiobiology: From the cellular level to clinical practice

Extracellular vesicles (EVs) are lipid-bound particles released by tumor cells and widely explored in cancer development, progression, and treatment response, being considered as valuable components to be explored as biomarkers or cellular targets to modulate the effect of therapies. The mechanisms underlying the production and profile of EVs during radiotherapy (RT) require addressing radiobiological aspects to determine cellular responses to specific radiation doses and fractionation. In this review, we explore the role of EVs in the 7 Rs of radiobiology, known as the molecular basis of a biological tissue response to radiation, supporting EVs as a shared player in all the seven processes. We also highlight the relevance of EVs in the context of liquid biopsy and resistance to immunotherapy, aiming to establish the connection and utility of EVs as tools in contemporary and precision radiotherapy.

Outcomes following IMRT alone in head and neck squamous cell carcinoma ordinarily managed with concurrent chemo-radiotherapy

PURPOSE/OBJECTIVE(S)

We report outcomes following IMRT-alone in patients with head-and-neck squamous cell carcinoma (HNSCC) ordinarily managed with concurrent chemo-radiotherapy.

MATERIALS/METHODS

HNSCC (excluding T1-2 N0) patients treated with IMRT-alone from 2005 to 2019 were included and restaged according to TNM-8. Overall survival (OS) was stratified by TNM-8 stage subgroups within HPV-positive (HPV + ) and separately within HPV-negative (HPV-) HNSCC. Multivariable analysis (MVA) identified prognostic factors for OS.

RESULTS

A total of 460 patients with HPV + and 623 HPV- HNSCC were identified. Reasons for chemotherapy omission were: age > 70 years and/or frailty (n = 551, 51 %), cisplatin contraindication (n = 241, 22 %), patient' preference (n = 106, 10 %), and clinician's decision (n = 185, 17 %). IMRT was delivered mostly using altered-fractionation: moderately-accelerated (70 Gy/35 fractions [f]/6 weeks [w], 55 %), hypofractionated (60 Gy/25f/5w, 14 %), and hyperfractionated-accelerated (64 Gy/40f/4w, 25 %). Median follow-up was 5.0 years. Five-year OS for HPV + stage-I-single node, stage-I-multiple nodes, stage-II-T1-2 N2, stage-II-T3 N0-N2, and stage-III were 90 %, 79 %%, 80 %, 64 %, and 33 %, and for HPV- stage III, IVA, and IVB were 47 %, 27 %, and 13 %, respectively. MVA confirmed lower OS in HPV + stage-I-multiple nodes (p = 0.03), II-T3 N0-N2 and III (vs stage-I-single node) and HPV- stage IVA/IVB (vs III) (p < 0.01), and marginally lower OS in HPV + stage-II-T3 N0-2 (vs I-single node) (p = 0.07).

CONCLUSION

Altered fractionated IMRT-alone is a valid option for patients with HPV + stage I-single node HNSCC, and an acceptable alternative for elderly/frail or cisplatin ineligible patients with HPV + stage I-multiple nodes and T1-2 N2 HNSCC. Patients with HPV + T3-T4 or N3 and HPV- stage III/IV HNSCC had unsatisfactory OS, requiring further research into alternative options.

Partial versus whole tumor-volume irradiation in combination with immunotherapy: Comparable outcomes in immunosuppressed mouse models of oral squamous cell carcinoma

Radiotherapy is a standard therapy for oral squamous cell carcinoma (OSCC) with immunomodulatory potential. Due to high lymphocyte radiosensitivity, partial tumor-volume irradiation (pIR), targeting only part of the tumor, is being explored for immunomodulation. This study compared the effects of whole tumor-volume irradiation (IR) and pIR, targeting approximately 50 % of the tumor volume, in combination with anti-PD-1 immune checkpoint inhibitors (ICI). The therapeutic efficacy of a single 15 Gy IR or pIR dose combined with anti-PD-1 ICI was evaluated in two immune cold murine OSCC models: human papillomavirus (HPV)-negative MOC1 and HPV-positive MOC1-HPV K1 stably expressing HPV-16 oncogenes E6/E7. Additionally, immune cell populations in the tumor microenvironment (TME) were analyzed using flow cytometry. Both IR and pIR induced transient immune cell infiltration in the TME. However, pIR led to significantly lower tumor growth inhibition than IR. While IR + ICI failed to improve survival compared to IR alone, pIR + ICI significantly prolonged survival compared to pIR alone in the MOC1 model, along with increase in cytotoxic T cell infiltration. In the MOC1-HPV K1 model, responses varied. Responding tumors were enriched with effector memory T cells, whereas non-responders exhibited increased neutrophil (MDSCs) and monocyte-derived dendritic cells infiltration. The study indicates that while pIR has immunomodulatory potential, its effects are comparable to IR in the tested settings. Further research is needed to optimize dosing and scheduling for pIR and anti-PD-1 ICI. Additionally, combination with other immunotherapies could be explored in further studies to enhance treatment efficacy in immune cold OSCC models.

Radiation Dose-Volume Effects on Negative Tumor-Draining Lymph Nodes Affected T-cell Activation and Prognosis in Esophageal Cancer with Chemoradiotherapy

PURPOSE

A preclinical model found that elective nodal irradiation attenuated the efficacy of radiotherapy (RT) and radio-immunotherapy. However, limited clinical studies have explored the correlation between radiation dose-volume parameters of negative tumor-draining lymph nodes (TDLN) and T-cell activation/prognosis for patients with cancer treated with definitive radiochemotherapy.

EXPERIMENTAL DESIGN

Patients with locally advanced esophageal cancer undergoing definitive chemoradiotherapy (CRT) were selected from two prospective trials. Dose-volume parameters of TDLN as well as other lymphocyte-related organs at risk and lymphocyte subsets such as CD3-CD19+ B cells, CD8+CD28+ T cells, and activated T cells (CD3+CD8+HLA-DR+) before and at the end of RT were collected. Logistic analysis was utilized to correlate dose-volume parameters with reductions in lymphocyte subsets. Prognosis of TDLN irradiation was investigated through Kaplan-Meier analysis and Cox hazards models.

RESULTS

Among 512 patients, the median mean dose of TDLN and negative non-TDLN was 25.6 and 15.1 Gy, respectively. Multivariable analyses indicated that TDLN V15 >50% was an independent predictor of poorer local recurrence-free survival (HR, 1.31; P = 0.029) and distant metastasis-free survival (HR, 1.39; P < 0.001), as well as greater reductions in CD3-CD19+ B cells (OR, 1.98; P = 0.002), CD8+CD28+ T cells (OR, 3.42; P < 0.001), and CD3+CD8+HLA-DR+ T cells (OR, 4.67; P = 0.002) after RT.

CONCLUSIONS

A higher radiation dose-volume parameter of TDLNs in patients with esophageal cancer undergoing CRT was significantly associated with suppression of T-cell activation and a worse prognosis. Limiting the percentage of TDLN V15 may be beneficial for improving the prognosis of CRT with or without PD-1 inhibitors.

Neoadjuvant Nivolumab Plus Chemotherapy Followed by Response-Stratified Chemoradiation Therapy in HPV-Negative Head and Neck Cancer: The DEPEND Phase 2 Nonrandomized Clinical Trial

Importance

Neoadjuvant immunotherapy in human papillomavirus (HPV)-negative locoregionally advanced (LA) head and neck squamous cell carcinoma (HNSCC) appears promising, yet its role in nonsurgical treatment for head and neck cancer remains undefined. Neoadjuvant nivolumab plus chemotherapy followed by response-stratified de-escalated chemoradiation therapy (CRT) in HPV-negative LA stage IVa/b HNSCC may improve treatment efficacy while reducing treatment-related toxic effects.

Objective

To determine the deep response rate and tolerability of neoadjuvant nivolumab plus chemotherapy followed by response-stratified CRT in nonvirally mediated stage IVa/b HNSCC.

Design, Setting, and Participants

In this investigator-initiated phase 2 nonrandomized clinical trial conducted at a single academic center, patients with stage IVa/b (American Joint Committee on Cancer Tumor Classification, 8th edition) HPV-negative LA HNSCC were enrolled between 2019 and 2022. Data were analyzed from February 2023 to January 2024.

Interventions

The DEPEND trial evaluated neoadjuvant nivolumab plus carboplatin and paclitaxel, followed by response-stratified CRT. Patients with 50% or greater reduction per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 received de-escalated CRT to 66 Gy with elimination of elective nodal volumes; patients with less than 50% reduction received standard CRT to 70 to 75 Gy. Adjuvant nivolumab was administered for 9 cycles.

Main Outcomes and Measures

The primary end point was deep response rate (DRR; 50% or greater shrinkage per RECIST version 1.1) following neoadjuvant nivolumab plus chemotherapy. Secondary end points included progression-free survival (PFS), overall survival (OS), locoregional control, and distant control. Exploratory end points included acute toxic effects in patients who received response-adapted de-escalated CRT.

Results

Of 36 included patients, 28 (78%) were male, and the median (range) age was 58.9 (27-77) years. All patients started treatment and were available for analysis. The median (range) follow-up was 20 (13-40) months. The primary end point was met, with a DRR following neoadjuvant nivolumab/chemotherapy of 53% (95% CI, 35-70). The objective response rate was 86% (95% CI, 71-95). A total of 19 received de-escalated CRT and 16 received standard CRT. PFS and OS at 2 years were 66% (95% CI, 34-76) and 73% (95% CI, 52-86), respectively. The most common treatment-emergent adverse events for de-escalated and standard CRT were mucositis (14 of 19 [74%] and 15 of 16 [94%], respectively), radiation dermatitis (13 of 19 [68%] and 14 of 16 [88%], respectively), and dry mouth (7 of 19 [37%] and 10 of 16 [63%], respectively).

Conclusions and Relevance

In this phase 2 nonrandomized clinical trial, neoadjuvant nivolumab/chemotherapy led to deep responses in 53% of patients with HPV-negative LA stage IVa/b HNSCC, and response-adapted de-escalated CRT led to favorable survival with lower acute toxic effects among deep responders.

Trial Registration

ClinicalTrials.gov Identifier: NCT03944915.

Efficacy and safety of PD-1/PD-L1 inhibitors combined with standard of care for locally advanced head and neck squamous cell carcinoma: A meta-analysis of randomized controlled trials

OBJECTIVES

Chemoradiotherapy (CRT) or radiotherapy (RT) combined with cetuximab (for cisplatin-ineligible patients) is the standard of care (SoC) for locally advanced head and neck squamous cell carcinoma (LA-HNSCC). This study investigates whether adding programmed cell death-1/programmed cell death-ligand 1 (PD-1/PD-L1) immune checkpoint inhibitors (ICIs) to standard therapy improves survival in patients with LA-HNSCC.

METHODS

A comprehensive search of PubMed, Embase, and the Cochrane Library identified randomized controlled trials (RCTs) evaluating PD-1/PD-L1 inhibitors plus SoC compared with SoC alone for LA-HNSCC. The primary endpoints were progression-free survival (PFS), overall survival (OS), locoregional event-free survival (LEFS), and distant metastasis-free survival (DMFS) at the 1-year and 2-year time points, as well as the incidence of grade 3 or higher adverse events (AEs).

RESULTS

Four RCTs encompassing 1818 patients met the inclusion criteria. Compared with SoC alone, PD-1/PD-L1 inhibitors combined with SoC did not significantly improve 1-year or 2-year PFS, OS, LEFS, or DMFS (all p > 0.05). Subgroup analyses further showed no survival benefit at 2 years in the ICI + CRT, ICI + RT-cetuximab, anti-PD-1, or anti-PD-L1 subgroups. Additionally, there was no statistically significant difference in the incidence of grade 3 or higher AEs between the combined and SoC-only groups (p = 0.69).

CONCLUSIONS

These findings suggest that adding PD-1/PD-L1 inhibitors to standard therapy does not enhance 1-year or 2-year survival for patients with LA-HNSCC, and confers a similar severe safety profile.

Prognostic gene expression signatures for HPV-negative head and neck squamous cell carcinoma

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is a leading cause of cancer-related deaths worldwide, with HPV-negative cases being particularly aggressive. These cases often show poor prognosis and low responsiveness to radiotherapy. Improved prognostic tools and treatment strategies are needed to enhance outcomes.

AIM

To evaluate the prognostic value of various gene expression signatures in predicting survival outcomes in HPV-negative HNSCC patients receiving radiotherapy and to compare their accuracy against the current TNM staging system.

METHODS

This observational cohort study used data from the European BD2Decide project, systematically analyzing gene expression in loco-regionally advanced, non-metastatic HPV-negative HNSCC patients (stage III-IVa/b) treated with curative radiotherapy (post-operative or definitive) between 2008 and 2017. The primary outcome was overall survival (OS), with secondary outcomes including disease-free survival (DFS), distant metastasis-free survival (DMFS), and loco-regional recurrence-free survival (LRRFS). The prognostic performance of selected gene expression signatures was evaluated using receiver operating characteristic (ROC) curves and hazard ratios (HR) from Cox models.

RESULTS

The study included 783 patients, with a median age of 63 years, mostly male (68 %), with significant tobacco (84 %) and alcohol (69 %) exposure. The 172-gene signature (172GS) showed the highest prognostic accuracy, outperforming the TNM system in predicting OS, DFS, DMFS, and LRRFS. Multivariable analysis confirmed its independent prognostic value.

CONCLUSIONS

The 172GS gene signature offers superior prognostic information compared to TNM staging, supporting its potential use for better risk stratification and personalized treatment planning in HPV-negative HNSCC. Future trials should consider tumor biology and gene signatures for better patient selection.

TRIAL REGISTRATION

NCT02832102.

Managing Patients with Head and Neck Cancer and Advanced Age or Comorbidities

The dominant treatment paradigm for locoregionally advanced head and neck squamous cell carcinoma (HNSCC) involves postoperative or definitive radiotherapy with concurrent cisplatin chemotherapy. Despite years of research investigating de-intensified treatment, cisplatin-based chemoradiotherapy remains the standard, yet it is associated with significant acute and chronic toxicity. However, due to shared risk factors, such as advanced age, and tobacco and alcohol use, patients with HNSCC frequently have comorbid illnesses that impact treatment tolerability, adding complexity to treatment-related decision-making. In addition, many patients have medical contraindications to cisplatin, requiring alternative treatment strategies. It is thus important to consider how well patients are likely to tolerate treatment, and how to adapt treatment in response to a patient's condition, when weighing treatment options. In this review, we aim to offer readers guidance in managing the elderly or comorbid patient with HNSCC, with particular attention to (i) approaching comorbidity and fragility assessment to make determinations on intensity of treatment, (ii) considering primary treatment modality (eg, surgery vs radiotherapy, chemo-radiotherapy vs radiotherapy alone) and (iii) choice of concurrent systemic therapy agent.

A strategy for synergistic enhancement of immune circulation in head and neck squamous cell carcinoma by novel nucleic acid drug therapy and immunotherapy

Studies have shown that in the pathogenesis of head and neck squamous cell carcinoma, immune circulation obstruction caused by various factors including metabolic abnormalities, gene mutations, and matrix barrier, is a critical factor for the induction of tumor development and progression. Therefore, the immunotherapy strategy of killing head and neck squamous cell carcinoma cells by an enhanced immune circulation mechanism has attracted much attention. In addition, the rapid development of new nucleic acid drug therapy, such as mRNA, oligonucleotide and small guide RNA (sgRNA), has taken immunotherapy of head and neck squamous cell carcinoma (immune checkpoint inhibitors, tumor vaccines, cellular immunotherapy, cytokines and adjuvants, etc.) to a new level. The combination of nucleic acid therapy with immunotherapy developed for its therapeutic properties has brought a new direction for the diagnosis and treatment of head and neck squamous cell carcinoma, and the combination of the two has had considerable curative effect to patients with refractory/recurrent head and neck squamous cell carcinoma. In this review, we summarized the latest progress of nucleic acid therapy applied to conventional immunotherapy for head and neck squamous cell carcinoma, discussed its mechanism of action and efficacy, and looked into the future development trend.

Multi-omics analysis to uncover the molecular basis of tumor budding in head and neck squamous cell carcinoma

Tumor budding (TB) is a prognostic biomarker in HPV-negative and HPV-positive head and neck squamous cell carcinoma (HNSCC). Analyzing TCGA and CPTAC mutation, RNA, and RPPA data and performing proteomics and IHC in two independent in-house cohorts, we uncovered molecular correlates of TB in an unprecedentedly comprehensive manner. NSD1 mutations were associated with lower TB in HPV-negative HNSCC. Comparing budding and nonbudding tumors, 66 miRNAs, including the miRNA-200 family, were differentially expressed in HPV-negative HNSCC. 3,052 (HPV-negative HNSCC) and 360 (HPV-positive HNSCC) RNAs were differentially expressed. EMT, myogenesis, and other cancer hallmarks were enriched in the overexpressed RNAs. In HPV-negative HNSCC, 88 proteins were differentially expressed, significantly overlapping with the differentially expressed RNAs. CAV1 and MMP14 protein expression investigated by IHC increased gradually from nonbudding tumors to the bulk of budding tumors and tumor buds. The molecular insights gained support new approaches to therapy development and guidance for HNSCC.

Vaccine-Based Immunotherapy for Oropharyngeal and Nasopharyngeal Cancers

Viral infections such as human papillomavirus (HPV) and Epstein-Barr virus (EBV) play a critical role in the onset of oropharyngeal (OPC) and nasopharyngeal cancer (NPC), respectively. Despite advancements in targeted therapies and immunotherapies, in the recurrent/metastatic setting, these tumors remain incurable diseases with poor prognosis. The development of therapeutic tumor vaccines, utilizing either neoantigens or oncoviral antigens, represents a promising addition to the cancer immunotherapy arsenal. Research on vaccine-based immunotherapy for OPC and NPC focuses on targeting viral antigens, particularly HPV E6/E7 and EBV EBNA1/LMP2. The potential for vaccine platforms, including peptide-based, DNA, RNA, and viral vector-based vaccines, to induce durable immune responses against viral antigens is reported. The early-phase clinical trials evaluating vaccine-based therapies for HPV-related OPC and EBV-related NPC revealed safety and preliminary signs of efficacy; however, further clinical trials are crucial for validation. This review provides an overview of the current landscape of vaccine-based strategies for HPV-related OPC and EBV-related NPC, discussing their biological mechanisms and immune processes involved in anti-HPV and anti-EBV vaccine treatments, with a particular focus on the immune factors that influence these therapies.

T cell dynamics with neoadjuvant immunotherapy in head and neck cancer

Immune-checkpoint inhibitors (ICIs) are being tested as neoadjuvant therapies in various solid tumours, including in patients with head and neck squamous cell carcinoma (HNSCC), with promising results. Key findings thus far include that this approach is well-tolerated with favourable clinical outcomes including promising pathological response rates in initial studies. Pathological responses are likely to be increased by combining other agents with anti-PD-(L)1 antibodies. Comparisons of baseline biopsy samples with post-treatment surgical specimens have enabled correlative studies utilizing multiomic and immunogenomic methods. Data from these studies suggest that pretreatment intratumoural tissue-resident memory CD8+ T cells are key drivers of tumour regression and give rise to both local and systemic antitumour immune responses. Analyses of systemic responses have defined a PD-1+KLRG1- circulating CD8+ T cell subpopulation that is highly predictive of response, and revealed the interrelationships between intratumoural clones and circulating CD8+ T cells. Lastly, interrogation of T cell populations within lymph nodes is beginning to delineate the immune crosstalk between the primary tumour and tumour-draining lymph nodes and how this relationship might be disrupted with tumour infiltration of the latter. In this Review, we examine data from trials testing neoadjuvant ICIs in patients with HNSCC, focusing on human papillomavirus-unrelated disease, and highlight correlative immunogenomic findings from these trials.

Prolonged interval hypofractionated radiotherapy facilitates better antitumor immunity

PURPOSE

To evaluate the impact of hypofractionated radiotherapy (Hypo-RT) with different interfraction intervals on tumor growth, immune response, and synergistic effects with anti-PD-1 immunotherapy.

METHODS

The mouse MC38 colon cancer model was utilized. Various radiation regimens were designed to investigate the effects of fraction interval and fraction size on tumor growth, immune mobilization, and combination effects with anti-PD-1 immunotherapy.

RESULTS

For a fixed-dose experiment, the 6 × 5 Gy for every other day (qod) regimen demonstrated an equivalent effect on tumor growth compared to the 6 × 5 Gy once daily (qd) regimen, while the 6 × 5 Gy for twice weekly (biw) regimen failed to inhibit tumor growth. Both qod and biw regimens induced an enhanced immune response, unlike the qd regimen. For a fixed biologically equivalent dose experiment, 6 × 5 Gy qod, 4 × 7 Gy biw, and 2 × 11 Gy once weekly (qw) regimens exhibited similar tumor suppression to the 12 × 3 Gy qd regimen. The long-interval Hypo-RT regimens significantly mobilized host immunity, whereas 12 × 3 Gy qd did not. The peripheral and intratumoral T cells increased as the fraction interval and size increased. All Hypo-RT regimens combined with anti-PD-1 immunotherapy demonstrated higher intratumoral CD8 + T cells and more effective tumor growth delay compared to the 12 × 3 Gy qd regime.

CONCLUSIONS

The current study suggested that a prolonged inter-fraction interval with an increased fraction size in Hypo-RT may be a promising option to balance the therapeutic effect on tumor and immune activation.

Efficacy and safety of immunotherapy for head and neck squamous cell carcinoma: a meta-analysis of randomized clinical trials

Background

Head and neck squamous cell carcinoma (HNSCC) is one of the most common types of cancer worldwide and immune checkpoint inhibitors have shown favorable therapeutic effects in recurrent or metastatic or locally advanced head and neck squamous cell carcinoma (R/M/LA HNSCC). However, the effects of immunotherapy in HNSCC are still inconsistent because of complicating factors. This meta-analysis tries to provide a more precise assessment of the efficacy and safety of this integrated approach in HNSCC.

Methods

We conducted a systematic review and meta-analysis of randomized clinical trials according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. The outcomes were overall survival (OS), progression-free survival (PFS), and treatment-related adverse events (TRAEs). A total of 8 out of 2445 articles were analyzed, including 5067 HNSCC patients, including 823 and 4244 patients with LA HNSCC and R/M HNSCC.

Results

The combined data revealed that immunotherapy has an apparent difference in OS (HR 0.86 95% CI 0.77-0.98) compared with standard of care (Soc, like fluoropyrimidine, methotrexate, docetaxel, or cetuximab) but was equal with the other treatment in PFS (HR 1.08, 95% CI 0.85-1.37). Furthermore, the occurrence of grade 3 or higher adverse events related to the drugs was lower than systematic therapy (OR 0.35, 95% CI 0.17-0.73).

Conclusions

The study has provided compelling evidence that immunotherapy is a significant benefit in OS for HNSCC patients, either R/M HNSCC or LA HNSCC, immunochemotherapy may benefit more for these patients, but double-agent immunotherapy showed no more benefit for R/M HNSCC patients.

Systematic Review Registration

https://www.crd.york.ac.uk/, identifier CRD42023471570.

Recurrent and Metastatic Head and Neck Cancer: Mechanisms of Treatment Failure, Treatment Paradigms, and New Horizons

Background: Head and neck cancer is a deadly disease with over 500,000 cases annually worldwide. Metastatic head and neck cancer accounts for a large proportion of the mortality associated with this disease. Many advances have been made in our understanding of the mechanisms of metastasis. The application of immunotherapy to locally recurrent or metastatic head and neck cancer has not only improved oncologic outcomes but has also provided valuable insights into the mechanisms of immune evasion and ultimately treatment failure. Objectives: This review paper will review our current understanding of biological mechanisms of treatment failure and metastasis. Published and ongoing clinical trials in the management of metastatic head and neck cancer will also be summarized. Methods: A narrative review was conducted to address the current understanding of the mechanisms of treatment failure and current treatment paradigms in recurrent and metastatic head and neck carcinoma. Conclusions: Our understanding of treatment failure in this disease is rapidly evolving. Immunotherapy represents a valuable new tool in the fight against recurrent and metastatic head and neck squamous cell carcinoma. Integrating patient and tumor specific data via artificial intelligence and deep learning will allow for a precision oncology approach, thereby achieving better prognostication and management of patients with this deadly disease.

Concurrent immunotherapy and radiation in cisplatin-ineligible patients with HNSCC: a systematic review & meta-analysis

BACKGROUND

Head and squamous cell carcinoma (HNSCC) in the locally advanced setting is challenging to treat and remains an area of significant morbidity and mortality. For patients who are cisplatin-ineligible and considered unresectable, there is no clear standard of care including the choice of radiosensitizer.

METHODS

OVID Medline, EMBASE, and the Cochrane Central Register of Controlled Trials were systematically searched. Randomized clinical trials (RCTs) of cisplatin-ineligible unresectable HNSCC patients who were randomized to an immune checkpoint inhibitor concurrent with radiation compared to a control arm were included. Data was pooled and assessed using a random-effects model for the meta-analysis.

RESULTS

Three eligible RCTs were identified and analyzed which comprised 594 patients whose median age ranged from 65-72 years. There was no difference in overall survival (pooled HR 1.02, 95% CI 0.76-1.37, p = 0.88) or PFS (pooled HR 0.92, 95% CI 0.68-1.23, p = 0.56). Grade greater than or equal to 3 adverse events were favored to be less in the immunotherapy arm.

CONCLUSIONS AND RELEVANCE

Immune-checkpoint inhibitors are not superior to cetuximab when used with definitive radiation in HNSCC. Further study is warranted, given its potential signal for non-inferior survival with less toxicity profile trends.

Radiotherapy with cetuximab or durvalumab for locoregionally advanced head and neck cancer in patients with a contraindication to cisplatin (NRG-HN004): an open-label, multicentre, parallel-group, randomised, phase 2/3 trial

BACKGROUND

Management of patients with locoregionally advanced head and neck squamous cell carcinoma (HNSCC) when cisplatin is contraindicated is controversial. We aimed to assess whether radiotherapy with concurrent and adjuvant durvalumab would improve outcomes compared with radiotherapy with cetuximab.

METHODS

NRG-HN004 was designed as an open-label, multicentre, parallel-group, randomised, phase 2/3 trial with safety lead-in conducted at 89 academic and community medical centres in North America. Eligible patients were aged 18 years or older with American Joint Committee on Cancer 8th edition stage III-IVB p16-negative HNSCC or unfavourable stage I-III p16-positive oropharyngeal or unknown primary carcinoma, who had a contraindication to cisplatin (Eastern Cooperative Oncology Group [ECOG] performance status 2, renal or hearing impairment, peripheral neuropathy, aged at least 70 years with moderate or severe comorbidity, or aged younger than 70 years with severe comorbidity). Patients were randomly assigned (2:1) by permuted block randomisation (multiples of 6) to intravenous durvalumab 1500 mg starting 2 weeks before radiotherapy then every 4 weeks starting week 2 of radiotherapy (seven cycles) or intravenous cetuximab 400 mg/m2 1 week before radiotherapy then 250 mg/m2 weekly beginning week 1 of radiotherapy (eight cycles), with intensity-modulated radiotherapy (70 Gy in 35 fractions over 7 weeks). Stratification factors were tumour and nodal stage, ECOG performance status and comorbidity, and primary site and p16 status. The phase 2 primary endpoint was progression-free survival in the intention-to-treat population. There was one prespecified interim futility analysis at 50% of progression-free survival information. If the observed hazard ratio was 1·0 or more, favouring cetuximab, early stopping would be considered. Extended follow-up analysis was post hoc. This trial is registered with ClinicalTrials.gov, NCT03258554, and is closed to enrolment.

FINDINGS

Following a ten-patient safety lead-in, the phase 2 trial enrolled 190 patients from March 12, 2019, to July 30, 2021, 186 of whom were randomly assigned (123 to durvalumab and 63 to cetuximab). Median age was 72 years (IQR 64-77), 30 (16%) patients were women and 156 (84%) were men. Phase 2 accrual was suspended in July 30, 2021, following an interim futility analysis, and permanently closed in Sept 1, 2022. The phase 3 part of the trial was not conducted. At a median follow-up of 2·3 years (IQR 1·9-3·1) for the extended follow-up (data cutoff July 31, 2023; post-hoc analysis), 2-year progression-free survival was 50·6% (95% CI 41·5-59·8) in the durvalumab group versus 63·7% (51·3-76·1) in the cetuximab group (hazard ratio 1·33 [95% CI 0·84-2·12]; p=0·89). Adverse events were similar in both groups. The most common grade 3-4 adverse events were dysphagia (26 [22%] of 119 patients in the durvalumab group vs 18 [30%] of 61 patients in the cetuximab group), lymphopenia (33 [28%] vs 20 [33%]), and oral mucositis (13 [11%] vs 11 [18%]). Four (3%) patients in the durvalumab group and one (2%) in the cetuximab group died from treatment-related adverse events (death not otherwise specified, laryngeal oedema, lung infection, and respiratory failure in the durvalumab group and sudden death not otherwise specified in the cetuximab group).

INTERPRETATION

Our findings suggest that durvalumab did not improve outcomes compared with cetuximab in patients with HNSCC with contraindications to cisplatin. Further trials are needed to define the standard of care for this population.

FUNDING

US National Cancer Institute and AstraZeneca.

Myriad factors and pathways influencing tumor radiotherapy resistance

Radiotherapy is a cornerstone in the treatment of various tumors, yet radioresistance often leads to treatment failure and tumor recurrence. Several factors contribute to this resistance, including hypoxia, DNA repair mechanisms, and cancer stem cells. This review explores the diverse elements that drive tumor radiotherapy resistance. Historically, resistance has been attributed to cellular repair and tumor repopulation, but recent research has expanded this understanding. The tumor microenvironment - characterized by hypoxia, immune evasion, and stromal interactions - further complicates treatment. Additionally, molecular mechanisms such as aberrant signaling pathways, epigenetic modifications, and non-B-DNA structures play significant roles in mediating resistance. This review synthesizes current knowledge, highlighting the interplay of these factors and their clinical implications. Understanding these mechanisms is crucial for developing strategies to overcome resistance and improve therapeutic outcomes in cancer patients.

A novel high-risk model identified by epithelial-mesenchymal transition predicts prognosis and radioresistance in rectal cancer

Many studies have shown that tumor cells that survive radiotherapy are more likely to metastasize, but the underlying mechanism remains unclear. Here we aimed to identify epithelial-mesenchymal transition (EMT)-related key genes, which associated with prognosis and radiosensitivity in rectal cancer. First, we obtained differentially expressed genes by analyzing the RNA expression profiles of rectal cancer retrieved from The Cancer Genome Atlas database, EMT-related genes, and radiotherapy-related databases, respectively. Then, Lasso and Cox regression analyses were used to establish an EMT-related prognosis model (EMTPM) based on the identified independent protective factor Fibulin5 (FBLN5) and independent risk gene EHMT2. The high-EMTPM group exhibited significantly poorer prognosis. Then, we evaluated the signature in an external clinical validation cohort. Through in vivo experiments, we further demonstrated that EMTPM effectively distinguishes radioresistant from radiosensitive patients with rectal cancer. Moreover, individuals in the high-EMTPM group showed increased expression of immune checkpoints compared to their counterparts. Finally, pan-cancer analysis of the EMTPM model also indicated its potential for predicting the prognosis of lung squamous cell carcinoma and breast cancer patients undergoing radiotherapy. In summary, we established a novel predictive model for rectal cancer prognosis and radioresistance based on FBLN5 and EHMT2 expressions, and suggested that immune microenvironment may be involved in the process of radioresistance. This predictive model could be used to select management strategies for rectal cancer.

Gold-siRNA supraclusters enhance the anti-tumor immune response of stereotactic ablative radiotherapy at primary and metastatic tumors

Strategies to enhance the anti-tumor immune response of stereotactic ablative radiotherapy (SABR) at primary tumors and abscopal sites are under intensive investigation. Here we report a metabolizable binary supracluster (BSCgal) that combines gold nanoclusters as radiosensitizing adjuvants with small interfering RNA (siRNA) targeting the immunosuppressive mediator galectin-1 (Gal-1). BSCgal comprises reversibly crosslinked cationic gold nanoclusters and siRNA complexes in a polymer matrix that biodegrades over weeks, facilitating clearance (90.3% in vivo clearance at 4 weeks) to reduce toxicity. The particle size well above the renal filtration threshold facilitates passive delivery to tumors. Using mouse models of head and neck cancer, we show that BSCgal augments the radiodynamic and immunotherapeutic effects of SABR at the primary and metastatic tumors by promoting tumor-inhibitory leukocytes, upregulating cytotoxic granzyme B and reducing immunosuppressive cell populations. It outperforms SABR plus Gal-1 antagonists, chemoradiation drug cisplatin or PD-1 inhibitor. This work presents a translatable strategy to converge focal radiosensitization with targeted immune checkpoint silencing for personalized radioimmunotherapy.

Review of Current and Future Medical Treatments in Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a complex cancer requiring a multidisciplinary approach. For patients with locally or regionally advanced disease, surgery and/or radiation are the cornerstones of definitive treatment. Medical therapy plays an important adjunct role in this setting, typically consisting of a platinum-based regimen given as induction, concurrent, or adjuvant treatment. While relapsed/metastatic HNSCC has historically been a difficult-to-treat disease with poor outcomes, options have considerably improved with the incorporation of biologics and immune checkpoint inhibitors. Clinical trials are ongoing to investigate novel approaches, including new and combination immunotherapies, targeted therapies, therapeutic vaccines, antibody-drug conjugates, and cellular therapies. The results thus far have been mixed, highlighting the knowledge gaps that continue to challenge the medical oncologist treating HNSCC. Here, we present the most updated and broad review of the current treatment landscape in both locoregional and metastatic HNSCC and discuss the expansive future medical therapies under investigation.

Adaptive segmentation-to-survival learning for survival prediction from multi-modality medical images

Early survival prediction is vital for the clinical management of cancer patients, as tumors can be better controlled with personalized treatment planning. Traditional survival prediction methods are based on radiomics feature engineering and/or clinical indicators (e.g., cancer staging). Recently, survival prediction models with advances in deep learning techniques have achieved state-of-the-art performance in end-to-end survival prediction by exploiting deep features derived from medical images. However, existing models are heavily reliant on the prognostic information within primary tumors and cannot effectively leverage out-of-tumor prognostic information characterizing local tumor metastasis and adjacent tissue invasion. Also, existing models are sub-optimal in leveraging multi-modality medical images as they rely on empirically designed fusion strategies to integrate multi-modality information, where the fusion strategies are pre-defined based on domain-specific human prior knowledge and inherently limited in adaptability. Here, we present an Adaptive Multi-modality Segmentation-to-Survival model (AdaMSS) for survival prediction from multi-modality medical images. The AdaMSS can self-adapt its fusion strategy based on training data and also can adapt its focus regions to capture the prognostic information outside the primary tumors. Extensive experiments with two large cancer datasets (1380 patients from nine medical centers) show that our AdaMSS surmounts the state-of-the-art survival prediction performance (C-index: 0.804 and 0.757), demonstrating the potential to facilitate personalized treatment planning.

MHC-I and PD-L1 Expression is Associated with Decreased Tumor Outgrowth and is Radiotherapy-inducible in the Murine Head and Neck Squamous Cell Carcinoma Model MOC1

INTRODUCTION

Combined radiotherapy and immune checkpoint inhibition is a potential treatment option for head and neck squamous cell carcinoma (HNSCC). Immunocompetent mouse models can help to successfully develop radio- immunotherapy combinations and to increase our understanding of the effects of radiotherapy on the tumor microenvironment for future clinical translation. Therefore, the aim of this study was to develop a homogeneous, reproducible HNSCC model originating from the Mouse Oral Cancer 1 (MOC1) HNSCC cell line, and to explore the radiotherapy-induced changes in its tumor microenvironment, using flow cytometry and PD-L1 microSPECT/CT imaging.

MATERIALS AND METHODS

In vivo growing tumors originating from the parental MOC1 line were used to generate single cell derived clones. These clones were screened in vitro for their ability to induce programmed cell death ligand 1 (PD-L1) and major histocompatibility complex class I (MHC-I) following IFNγ exposure. Clones with different IFNγ sensitivity were inoculated in C57BL/6 mice and assessed for tumor outgrowth. The composition of the tumor microenvironment of a stably growing (non)irradiated MOC1-derived clone was assessed by immunohistochemistry, flow cytometry and PD-L1 microSPECT/CT.

RESULTS

Low in vitro inducibility of MHC-I and PD-L1 by IFNγ was associated with increased tumor outgrowth of MOC1 clones in vivo. Flow cytometry analysis of cells derived from a stable in vivo growing MOC1 clone MOC1.3D5low showed expression of MHC-I and PD-L1 on several cell populations within the tumor. Upon irradiation, MHC-I and PD-L1 increased on leukocytes (CD45.2+) and cancer associated fibroblasts (CD45.2-/EpCAM-/CD90.1+). Furthermore, PD-L1 microSPECT/CT showed increased tumor uptake of radiolabeled PD-L1 antibodies with a heterogeneous spatial distribution of the radio signal, which co-localized with PD-L1+ and CD45.2+ areas.

DISCUSSION

PD-L1 and MHC-I inducibility by IFNγ in vitro is associated with tumor outgrowth of MOC1 clones in vivo. In tumors originating from a stably growing MOC1-derived clone, expression of these immune-related markers was induced by irradiation shown by flow cytometry on several cell populations within the tumor microenvironment such as immune cells and cancer associated fibroblasts. PD-L1 microSPECT/CT showed increased tumor uptake following radiotherapy, and autoradiography showed correlation of uptake with areas that are heavily infiltrated by immune cells. Knowledge of radiotherapy-induced effects on the tumor microenvironment in this model can help optimize timing and dosage for radio- immunotherapy combination strategies in future research.

Recurrent Versus Metastatic Head and Neck Cancer: An Evolving Landscape and the Role of Immunotherapy

Squamous cell carcinoma of the head and neck (SCCHN) is among the ten most common cancers worldwide, with advanced SCCHN presenting with a 5-year survival of 34% in the case of nodal involvement and 8% in the case of metastatic disease. Disease-free survival at 2 years is 67% for stage II and 33% for stage III tumors, whereas 12-30% of patients undergo distant failures after curative treatment. Previous treatments often hinder the success of salvage surgery and/or reirradiation, while the standard of care for the majority of metastatic SCCHN remains palliative chemo- and immuno-therapy, with few patients eligible for locoregional treatments. The aim of this paper is to review the characteristics of recurrent SCCHN, based on different recurrence sites, and metastatic disease; we will also explore the possibilities not only of salvage surgery and reirradiation but also systemic therapy choices and locoregional treatment for metastatic SCCHN.

Radiation Therapy for HPV-Positive Oropharyngeal Squamous Cell Carcinoma: An ASTRO Clinical Practice Guideline

PURPOSE

Human Papilloma Virus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) is a distinct disease from other head and neck tumors. This guideline provides evidence-based recommendations on the critical decisions in its curative treatment, including both definitive and postoperative radiation therapy (RT) management.

METHODS

ASTRO convened a task force to address 5 key questions on the use of RT for management of HPV-associated OPSCC. These questions included indications for definitive and postoperative RT and chemoradiation; dose-fractionation regimens and treatment volumes; preferred RT techniques and normal tissue considerations; and posttreatment management decisions. The task force did not address indications for primary surgery versus RT. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength.

RESULTS

Concurrent cisplatin is recommended for patients receiving definitive RT with T3-4 disease and/or 1 node >3 cm, or multiple nodes. For similar patients who are ineligible for cisplatin, concurrent cetuximab, carboplatin/5-fluorouracil, or taxane-based systemic therapy are conditionally recommended. In the postoperative setting, RT with concurrent cisplatin (either schedule) is recommended for positive surgical margins or extranodal extension. Postoperative RT alone is recommended for pT3-4 disease, >2 nodes, or a single node >3 cm. Observation is conditionally recommended for pT1-2 disease and a single node ≤3 cm without other risk factors. For patients treated with definitive RT with concurrent systemic therapy, 7000 cGy in 33 to 35 fractions is recommended, and for patients receiving postoperative RT without positive surgical margins and extranodal extension, 5600 to 6000 cGy is recommended. For all patients receiving RT, intensity modulated RT over 3-dimensional techniques with reduction in dose to critical organs at risk (including salivary and swallowing structures) is recommended. Reassessment with positron emission tomography-computed tomography is recommended approximately 3 months after definitive RT/chemoradiation, and neck dissection is recommended for convincing evidence of residual disease; for equivocal positron emission tomography-computed tomography findings, either neck dissection or repeat imaging is recommended.

CONCLUSIONS

The role and practice of RT continues to evolve for HPV-associated OPSCC, and these guidelines inform best clinical practice based on the available evidence.

Targeting EGFR with molecular degraders as a promising strategy to overcome resistance to EGFR inhibitors

Abnormal activation of EGFR is often associated with various malignant tumors, making it an important target for antitumor therapy. However, traditional targeted inhibitors have several limitations, such as drug resistance and side effects. Many studies have focused on the development of EGFR degraders to overcome this resistance and enhance the therapeutic effect on tumors. Proteolysis targeting chimeras (PROTAC) and Lysosome-based degradation techniques have made significant progress in degrading EGFR. This review provides a summary of the structural and function of EGFR, the resistance, particularly the research progress and activity of EGFR degraders via the proteasome and lysosome. Furthermore, this review aims to provide insights for the development of the novel EGFR degraders.

Sculpting the tumour microenvironment by combining radiotherapy and ATR inhibition for curative-intent adjuvant immunotherapy

The combination of radiotherapy/chemoradiotherapy and immune checkpoint blockade can result in poor outcomes in patients with locally advanced head and neck squamous cell carcinoma (HNSCC). Here, we show that combining ATR inhibition (ATRi) with radiotherapy (RT) increases the frequency of activated NKG2A+PD-1+ T cells in animal models of HNSCC. Compared with the ATRi/RT treatment regimen alone, the addition of simultaneous NKG2A and PD-L1 blockade to ATRi/RT, in the adjuvant, post-radiotherapy setting induces a robust antitumour response driven by higher infiltration and activation of cytotoxic T cells in the tumour microenvironment. The efficacy of this combination relies on CD40/CD40L costimulation and infiltration of activated, proliferating memory CD8+ and CD4+ T cells with persistent or new T cell receptor (TCR) signalling, respectively. We also observe increased richness in the TCR repertoire and emergence of numerous and large TCR clonotypes that cluster based on antigen specificity in response to NKG2A/PD-L1/ATRi/RT. Collectively, our data point towards potential combination approaches for the treatment of HNSCC.

Treatment options for cisplatin-ineligible patients with locally advanced head and neck squamous cell carcinoma: a systematic review

PURPOSE

There is no agreed-upon standard option for patients with locally advanced head and neck squamous cell carcinoma (LA HNSCC) unfit for cisplatin-based regimens. Therefore, we performed a systematic review to explore alternative options for this population.

METHODS

We searched PubMed, Cochrane, and Embase databases for observational studies and clinical trials (CTs) assessing treatment options for LA HNSCC cisplatin-ineligible patients. This study was registered in PROSPERO under the number CRD42023483156.

RESULTS

This systematic review included 24 studies (18 observational studies and 6 CTs), comprising 4450 LA HNSCC cisplatin-ineligible patients. Most patients were treated with cetuximab-radiotherapy [RT] (50.3%), followed by carboplatin-RT (31.7%). In seven studies reporting median overall survival (OS) in patients treated with cetuximab-RT, it ranged from 12.8 to 46 months. The median OS was superior to 40 months in two studies assessing carboplatin-RT, and superior to 15 months in two studies assessing RT alone. For other regimens such as nimotuzumab-RT, docetaxel-RT, and carboplatin-RT plus paclitaxel the median OS was 21, 25.5, and 28 months, respectively.

CONCLUSIONS

Our systematic review supports the use of a variety of therapy combinations for LA HNSCC cisplatin-ineligible patients. We highlight the urgent need for clinical studies assessing treatment approaches in this population.

Radiotherapy, immunity, and immune checkpoint inhibitors

Radiotherapy exerts immunostimulatory and immunosuppressive effects, both locally, within the irradiated tumour microenvironment, and systemically, outside the radiation field. Inspired by preclinical data that showed synergy between radiotherapy and immune checkpoint inhibitors, multiple clinical trials were initiated with the hypothesis that combined treatment with radiotherapy and immune checkpoint inhibitors could stimulate a robust systemic immune response and improve clinical outcomes. However, despite early optimism, radioimmunotherapy trials in the curative and metastatic settings have met with little success. In this Review, we summarise the immunostimulatory effects of radiotherapy that provided the theoretical basis for trials of combination radiotherapy and immune checkpoint inhibitors. We also discuss findings from clinical trials incorporating radiotherapy and immune checkpoint inhibitors and examine the success of these trials in the context of the immunosuppressive effects of radiotherapy. We conclude by highlighting targets for relieving radiotherapy-induced immunosuppression with the goal of enhancing the combined effects of radiotherapy and immune checkpoint inhibitors.

Spatially Fractionated Radiotherapy in the Era of Immunotherapy

Spatially fractionated radiotherapy (SFRT) includes historical grid therapy approaches but more recently encompasses the controlled introduction of one or more cold dose regions using intensity modulation delivery techniques. The driving hypothesis behind SFRT is that it may allow for an increased immune response that is otherwise suppressed by radiation effects. With both two- and three-dimensional SFRT approaches, SFRT dose distributions typically include multiple dose cold spots or valleys. Despite its unconventional methods, reported clinical experience shows that SFRT can sometimes induce marked tumor regressions, even in patients with large hypoxic tumors. Preclinical models using extreme dose distributions (i.e., half-sparing) have been shown to nevertheless result in full tumor eradications, a more robust immune response, and systemic anti-tumor immunity. SFRT takes advantage of the complementary immunomodulatory features of low- and high-dose radiotherapy to integrate the delivery of both into a single target. Clinical trials using three-dimensional SFRT (i.e., lattice-like dose distributions) have reported both promising tumor and toxicity results, and ongoing clinical trials are investigating synergy between SFRT and immunotherapies.

Effects of early nutritional intervention on oral mucositis and basic conditions in patients receiving radiotherapy for head and neck cancer: Randomized controlled trial (ChiCTR2000031418)

BACKGROUND & AIMS

This study aims to observe the effects of early nutritional intervention on radiation-induced oral mucositis (OM) and the nutritional status of patients with head and neck cancer (HNC) receiving radiotherapy.

METHODS

Eligible patients receiving radiotherapy for HNC were randomly divided into an early nutritional intervention group (enteral nutritional intervention was administered at the beginning of radiotherapy) and a late nutritional intervention group (enteral nutritional intervention was administered at the beginning of eating restriction) in a 1:1 ratio. The primary endpoint was radiation-induced OM. Secondary endpoints included nutrition-related indicators, immune function, overall survival (OS), progression-free survival (PFS), quality of life, and other radiotherapy-induced adverse effects.

RESULTS

A total of 100 patients were enrolled between 2020 and 2021, including 50 each in the early nutritional intervention group and in the late group. The incidence of Grade-III/IV OM was lower in the early treatment group than in the late treatment group (2% vs 14%, P = 0.059). By week 7 weight loss was significantly lower in the early group than in the late group (1.08 kg, 95% CI: 0.08-2.09, P = 0.035). Regarding the PG-SGA scores after receiving radiotherapy, the early group comprised more well-nourished and fewer malnourished patients than those in the late group (P = 0.002). The scores of the immune function indices of T cell CD3+, CD4+/CD8+, and B cell CD19+ were slightly higher in the early group than in the late group; however, the difference was not statistically significant (all P > 0.05). PFS and OS were better in the early group than in the late group; however, the differences were not statistically significant (P > 0.05).

CONCLUSIONS

Early nutritional intervention can effectively improve the nutritional status and reduce the incidence of high-grade OM in patients with HNC receiving radiotherapy.

TRIAL REGISTRATION

Chinese Clinical Trials Registry (http://www.chictr.org.cn).

CHICTR-ID

ChiCTR2000031418.

Radiotherapy and immunology

The majority of cancer patients receive radiotherapy during the course of treatment, delivered with curative intent for local tumor control or as part of a multimodality regimen aimed at eliminating distant metastasis. A major focus of research has been DNA damage; however, in the past two decades, emphasis has shifted to the important role the immune system plays in radiotherapy-induced anti-tumor effects. Radiotherapy reprograms the tumor microenvironment, triggering DNA and RNA sensing cascades that activate innate immunity and ultimately enhance adaptive immunity. In opposition, radiotherapy also induces suppression of anti-tumor immunity, including recruitment of regulatory T cells, myeloid-derived suppressor cells, and suppressive macrophages. The balance of pro- and anti-tumor immunity is regulated in part by radiotherapy-induced chemokines and cytokines. Microbiota can also influence radiotherapy outcomes and is under clinical investigation. Blockade of the PD-1/PD-L1 axis and CTLA-4 has been extensively investigated in combination with radiotherapy; we include a review of clinical trials involving inhibition of these immune checkpoints and radiotherapy.

Neoadjuvant Nivolumab Plus Chemotherapy Followed By Response-Adaptive Therapy for HPV+ Oropharyngeal Cancer: OPTIMA II Phase 2 Open-Label Nonrandomized Controlled Trial

Importance

Immune checkpoint inhibitors improve survival in recurrent and/or metastatic head and neck cancer, yet their role in curative human papillomavirus-positive oropharyngeal cancer (HPV+ OPC) remains undefined. Neoadjuvant nivolumab and chemotherapy followed by response-adaptive treatment in HPV+ OPC may increase efficacy while reducing toxicity.

Objective

To determine the deep response rate and tolerability of the addition of neoadjuvant nivolumab to chemotherapy followed by response-adapted locoregional therapy (LRT) in patients with HPV+ OPC.

Design, Setting, and Participants

This phase 2 nonrandomized controlled trial conducted at a single academic center enrolled 77 patients with locoregionally advanced HPV+ OPC from 2017 to 2020. Data analyses were performed from February 10, 2021, to January 9, 2023.

Interventions

Addition of nivolumab to neoadjuvant nab-paclitaxel and carboplatin (studied in the first OPTIMA trial) followed by response-adapted LRT in patients with HPV+ OPC stages III to IV.

Main Outcomes and Measures

Primary outcome was deep response rate to neoadjuvant nivolumab plus chemotherapy, defined as the proportion of tumors with 50% or greater shrinkage per the Response Evaluation Criteria in Solid Tumors 1.1. Secondary outcomes were progression-free survival (PFS) and overall survival (OS). Swallowing function, quality of life, and tissue- and blood-based biomarkers, including programmed death-ligand 1 (PD-L1) expression and circulating tumor HPV-DNA (ctHPV-DNA), were also evaluated.

Results

The 73 eligible patients (median [range] age, 61 [37-82] years; 6 [8.2%] female; 67 [91.8%] male) started neoadjuvant nivolumab and chemotherapy. Deep responses were observed in 51 patients (70.8%; 95% CI, 0.59-0.81). Subsequent risk- and response-adaptive therapy was assigned as follows: group A, single-modality radiotherapy alone or transoral robotic surgery (28 patients); group B, intermediate-dose chemoradiotherapy of 45 to 50 Gray (34 patients); and group C, regular-dose chemoradiotherapy of 70 to 75 Gray (10 patients). Two-year PFS and OS were 90.0% (95% CI, 0.80-0.95) and 91.4% (95% CI, 0.82-0.96), respectively. By response-adapted group, 2-year PFS and OS for group A were 96.4% and 96.4%, and group B, 88.0% and 91.0%, respectively. Lower enteral feeding rates and changes in weight, as well as improved swallowing, were observed among patients who received response-adapted LRT. Pathologic complete response rate among patients who underwent transoral robotic surgery was 67.0%. PD-L1 expression was nonsignificantly higher for deeper responses and improved PFS, and ctHPV-DNA clearance was significantly associated with improved PFS.

Conclusions and Relevance

This phase 2 nonrandomized controlled trial found that neoadjuvant nivolumab and chemotherapy followed by response-adapted LRT is feasible and has favorable tolerability, excellent OS, and improved functional outcomes in HPV+ OPC, including among patients with high-risk disease. Moreover, addition of nivolumab may benefit high PD-L1 expressors, and sensitive dynamic biomarkers (eg, ctHPV-DNA) are useful for patient selection.

Trial Registration

ClinicalTrials.gov Identifier: NCT03107182.

Randomized Phase 3 Trial of the Hypoxia Modifier Nimorazole Added to Radiation Therapy With Benefit Assessed in Hypoxic Head and Neck Cancers Determined Using a Gene Signature (NIMRAD)

PURPOSE

Tumor hypoxia is an adverse prognostic factor in head and neck squamous cell carcinoma (HNSCC). We assessed whether patients with hypoxic HNSCC benefited from the addition of nimorazole to definitive intensity modulated radiation therapy (IMRT).

METHODS AND MATERIALS

NIMRAD was a phase 3, multicenter, placebo-controlled, double-anonymized trial of patients with HNSCC unsuitable for concurrent platinum chemotherapy or cetuximab with definitive IMRT (NCT01950689). Patients were randomized 1:1 to receive IMRT (65 Gy in 30 fractions over 6 weeks) plus nimorazole (1.2 g/m2 daily, before IMRT) or placebo. The primary endpoint was freedom from locoregional progression (FFLRP) in patients with hypoxic tumors, defined as greater than or equal to the median tumor hypoxia score of the first 50 patients analyzed (≥0.079), using a validated 26-gene signature. The planned sample size was 340 patients, allowing for signature generation in 85% and an assumed hazard ratio (HR) of 0.50 for nimorazole effectiveness in the hypoxic group and requiring 66 locoregional failures to have 80% power in a 2-tail log-rank test at the 5% significance level.

RESULTS

Three hundred thirty-eight patients were randomized by 19 centers in the United Kingdom from May 2014 to May 2019, with a median follow-up of 3.1 years (95% CI, 2.9-3.4). Hypoxia scores were available for 286 (85%). The median patient age was 73 years (range, 44-88; IQR, 70-76). There were 36 (25.9%) locoregional failures in the hypoxic group, in which nimorazole + IMRT did not improve FFLRP (adjusted HR, 0.72; 95% CI, 0.36-1.44; P = .35) or overall survival (adjusted HR, 0.96; 95% CI, 0.53-1.72; P = .88) compared with placebo + IMRT. Similarly, nimorazole + IMRT did not improve FFLRP or overall survival in the whole population. In total (N = 338), 73% of patients allocated nimorazole adhered to the drug for ≥50% of IMRT fractions. Nimorazole + IMRT caused more acute nausea compared with placebo + IMRT (Common Terminology Criteria for Adverse Events version 4.0 G1+2: 56.6% vs 42.4%, G3: 10.1% vs 5.3%, respectively; P < .05).

CONCLUSIONS

Addition of the hypoxia modifier nimorazole to IMRT for locally advanced HNSCC in older and less fit patients did not improve locoregional control or survival.

Anti‑epidermal growth factor receptor monoclonal antibody therapy in locally advanced head and neck cancer: A systematic review of phase III clinical trials

The present systematic review evaluated the effectiveness of anti-EGFR therapy in combination with radiotherapy (RT) or with chemoradiation compared with the existing standard of care for the treatment of locally advanced head and neck squamous cell carcinoma (LAHNSCC). The PubMed, SCOPUS, EMBASE and COCHRANE databases were searched and 12 phase III randomized controlled trials were included. The effectiveness of the anti-EGFR monoclonal antibody cetuximab was evaluated in nine trials. Nimotuzumab (one trial), zalutumumab (one trial) and panitumumab (one trial) were the monoclonal antibodies evaluated in the remaining three trials. One study tested the effectiveness of adding cetuximab to radical RT and found that patients with LAHNSCC exhibited improvement in locoregional control (LRC), overall survival (OS) and progression-free survival (PFS) compared with those of patients treated with RT alone. A total of three studies tested the effectiveness of adding an anti-EGFR agent to chemoradiation. Of these, a single institution study in which patients received cisplatin at 30 mg/m2 weekly, instead of the standard doses of 100 mg/m2 every 3 weeks or 40 mg/m2 every week, reported significant improvement in PFS with the addition of nimotuzumab to chemoradiotherapy without an improvement in overall survival. However, the other two studies indicated that, when added to standard chemoradiation, the anti-EGFR monoclonal antibodies cetuximab or zalutumumab did not improve survival outcomes. Two phase III trials evaluated RT plus an anti-EGFR agent compared with chemoradiation alone. Of these, one study reported inferior outcomes with cetuximab-RT in terms of OS and LRC, whereas the other study with panitumumab plus RT failed to prove the non-inferiority. Two trials evaluated induction chemotherapy followed by cetuximab-RT compared with chemoradiotherapy and reported no benefits in terms of OS or PFS. Furthermore, one study evaluated induction chemotherapy followed by cetuximab-RT compared with induction chemotherapy followed by chemoradiotherapy and found no improvement in OS or PFS. Finally, three phase III trials tested the effectiveness of cetuximab plus RT in the treatment of human papillomavirus-positive oropharyngeal carcinoma, and found it to be inferior compared with cisplatin-RT in terms of OS, PFS and failure-free survival. Based on the aforementioned findings, it is difficult to conclude that anti-EGFR therapy in any form has an advantage over conventional chemoradiation in the treatment of LAHNSCC.

Camrelizumab-based induction chemoimmunotherapy in locally advanced stage hypopharyngeal carcinoma: phase II clinical trial

This phase II trial aimed to determine the efficacy and safety of induction chemoimmunotherapy of camrelizumab plus modified TPF in locally advanced hypopharyngeal squamous cell carcinoma (LA HSCC) (NCT04156698). The primary endpoint was objective response rate (ORR), and secondary endpoints were 3-year overall survival (OS), progression-free survival (PFS), larynx preservation rate (LPR), and metastasis-free survival (MFS). Patients (cT3-4aN0-2M0), regardless of sex, received induction chemoimmunotherapy for three cycles: camrelizumab 200 mg d1, docetaxel 75 mg/m2 d1, cisplatin 25 mg/m2 d1-3, and capecitabine 800 mg/m2 bid d1-14, q21d. Patients were assigned to radioimmunotherapy if they had a complete or partial response, those with stable or progressive disease underwent surgery and adjuvant (chemo)radiotherapy. Camrelizumab was maintained post-radioimmunotherapy. Fifty-one patients were enrolled with a median follow-up duration of 23.7 months. After induction therapy, the ORR was 82.4% (42/51), meeting the prespecified endpoint. Grade 3/4 adverse events occurred in 26 patients, and no treatment-related death occurred. As three-year outcomes were immature, two-year OS, PFS and LPR were reported. As no distant metastatic event had occurred, MFS was not reported here. The two-year OS, PFS, and LPR rates were 83.0%, 77.1%, and 70.0%, respectively. The induction chemoimmunotherapy of camrelizumab plus TPF showed a high ORR rate with an acceptable safety profile in LA HSCC.

Immune checkpoint inhibitor use in head and neck squamous cell carcinoma: the current landscape and future perspectives

Immune checkpoint inhibitors are licensed for use in patients with unresectable, recurrent or metastatic head and neck squamous cell carcinoma. Multiple published and ongoing trials are assessing efficacy in the curative management of patients in the concomitant, neoadjuvant and/or adjuvant settings, as well as part of multimodality treatment in patients with metastatic disease. This review evaluates the evidence for use of immune checkpoint inhibitors in all stages of head and neck squamous cell carcinoma and considers future approaches.

Global trends and research hotspots of PCSK9 and cardiovascular disease: a bibliometric and visual analysis

Background

Cardiovascular disease (CVD) is a prevalent non-communicable disease globally and holds the position of being the primary cause of mortality worldwide. Consequently, considerable focus has been directed towards the prevention and management of CVD. PCSK9, a frequently targeted element in the treatment and prevention of CVD, can reduce cardiovascular risk by effectively lowering lipid levels even in the context of statin therapy. It also exhibits substantial potential in the diagnosis and treatment of familial hypercholesterolemia from genetic aspects. This bibliometric study aims to analyze and visualize the global trends and emerging hotspots of PCSK9 and CVD researches and provide researchers with new perspectives in further studies.

Methods

The data was obtained from the Web of Science Core Collection database. A total of 2,474 publications related to PCSK9 and CVD published between January 2006 and July 2023 were included. The VOSviewer was used to analyze most-cited references, co-authorship, co-citation, co-occurrence and generate a collaborative network map of authors, countries, and institutions. CiteSpace was used to analyze author and institution centroids, keyword bursts, and timeline graphs.

Result

A total of 2,474 articles related to CVD and PCSK9 were included. The number of articles and citations show an increasing trend from year to year. Publications were mainly from the United States. The most active institution was Amgen Inc. Watts, Gerald F. was the most prolific author. Atherosclerosis was the most published journal. Literature co-citation and keyword co-occurrence revealed that early studies focused on the lipid-lowering effects of PCSK9 inhibitors in the context of statins therapy, long-term efficacy, adverse effects, LDLR, diagnosis and treatment of familial hypercholesterolemia. In recent years, myocardial ischemic protection, CRISPR-based editing, and new therapeutic strategies for arteriosclerotic cardiovascular disease have gotten wide attention. The protein convertase, inflammation, beta-polyacetate, and inclisiran may be the important future research directions.

Conclusion

This study analyses the current status and global trends in the CVD and PCSK9 studies comprehensively, which may provide researchers and policymakers with new and comprehensive perspectives on in this field of research.

Translational Frontiers and Clinical Opportunities of Immunologically Fitted Radiotherapy

Ionizing radiation can have a wide range of impacts on tumor-immune interactions, which are being studied with the greatest interest and at an accelerating pace by the medical community. Despite its undeniable immunostimulatory potential, it clearly appears that radiotherapy as it is prescribed and delivered nowadays often alters the host's immunity toward a suboptimal state. This may impair the full recovery of a sustained and efficient antitumor immunosurveillance posttreatment. An emerging concept is arising from this awareness and consists of reconsidering the way of designing radiation treatment planning, notably by taking into account the individualized risks of deleterious radio-induced immune alteration that can be deciphered from the planned beam trajectory through lymphocyte-rich organs. In this review, we critically appraise key aspects to consider while planning immunologically fitted radiotherapy, including the challenges linked to the identification of new dose constraints to immune-rich structures. We also discuss how pharmacologic immunomodulation could be advantageously used in combination with radiotherapy to compensate for the radio-induced loss, for example, with (i) agonists of interleukin (IL)2, IL4, IL7, IL9, IL15, or IL21, similarly to G-CSF being used for the prophylaxis of severe chemo-induced neutropenia, or with (ii) myeloid-derived suppressive cell blockers.

Pembrolizumab plus concurrent chemoradiotherapy versus placebo plus concurrent chemoradiotherapy in patients with locally advanced squamous cell carcinoma of the head and neck (KEYNOTE-412): a randomised, double-blind, phase 3 trial

BACKGROUND

Despite multimodal therapy, 5-year overall survival for locally advanced head and neck squamous cell carcinoma (HNSCC) is about 50%. We assessed the addition of pembrolizumab to concurrent chemoradiotherapy for locally advanced HNSCC.

METHODS

In the randomised, double-blind, phase 3 KEYNOTE-412 trial, participants with newly diagnosed, high-risk, unresected locally advanced HNSCC from 130 medical centres globally were randomly assigned (1:1) to pembrolizumab (200 mg) plus chemoradiotherapy or placebo plus chemoradiotherapy. Randomisation was done using an interactive response technology system and was stratified by investigator's choice of radiotherapy regimen, tumour site and p16 status, and disease stage, with participants randomly assigned in blocks of four per stratum. Participants, investigators, and sponsor personnel were masked to treatment assignments. Local pharmacists were aware of assignments to support treatment preparation. Pembrolizumab and placebo were administered intravenously once every 3 weeks for up to 17 doses (one before chemoradiotherapy, two during chemoradiotherapy, 14 as maintenance therapy). Chemoradiotherapy included cisplatin (100 mg/m2) administered intravenously once every 3 weeks for two or three doses and accelerated or standard fractionation radiotherapy (70 Gy delivered in 35 fractions). The primary endpoint was event-free survival analysed in all randomly assigned participants. Safety was analysed in all participants who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT03040999, and is active but not recruiting.

FINDINGS

Between April 19, 2017, and May 2, 2019, 804 participants were randomly assigned to the pembrolizumab group (n=402) or the placebo group (n=402). 660 (82%) of 804 participants were male, 144 (18%) were female, and 622 (77%) were White. Median study follow-up was 47·7 months (IQR 42·1-52·3). Median event-free survival was not reached (95% CI 44·7 months-not reached) in the pembrolizumab group and 46·6 months (27·5-not reached) in the placebo group (hazard ratio 0·83 [95% CI 0·68-1·03]; log-rank p=0·043 [significance threshold, p≤0·024]). 367 (92%) of 398 participants treated in the pembrolizumab group and 352 (88%) of 398 participants treated in the placebo group had grade 3 or worse adverse events. The most common grade 3 or worse adverse events were decreased neutrophil count (108 [27%] of 398 participants in the pembrolizumab group vs 100 [25%] of 398 participants in the placebo group), stomatitis (80 [20%] vs 69 [17%]), anaemia (80 [20%] vs 61 [15%]), dysphagia (76 [19%] vs 62 [16%]), and decreased lymphocyte count (76 [19%] vs 81 [20%]). Serious adverse events occurred in 245 (62%) participants in the pembrolizumab group versus 197 (49%) participants in the placebo group, most commonly pneumonia (43 [11%] vs 25 [6%]), acute kidney injury (33 [8%] vs 30 [8%]), and febrile neutropenia (24 [6%] vs seven [2%]). Treatment-related adverse events led to death in four (1%) participants in the pembrolizumab group (one participant each from aspiration pneumonia, end-stage renal disease, pneumonia, and sclerosing cholangitis) and six (2%) participants in the placebo group (three participants from pharyngeal haemorrhage and one participant each from mouth haemorrhage, post-procedural haemorrhage, and sepsis).

INTERPRETATION

Pembrolizumab plus chemoradiotherapy did not significantly improve event-free survival compared with chemoradiotherapy alone in a molecularly unselected, locally advanced HNSCC population. No new safety signals were seen. Locally advanced HNSCC remains a challenging disease that requires better treatment approaches.

FUNDING

Merck Sharp & Dohme, a subsidiary of Merck & Co, Rahway, NJ, USA.

Th2 Cells Are Associated with Tumor Recurrence Following Radiation

The curative treatment of multiple solid tumors, including head and neck squamous cell carcinoma (HNSCC), utilizes radiation. The outcomes for HPV/p16-negative HNSCC are significantly worse than HPV/p16-positive tumors, with increased radiation resistance leading to worse locoregional recurrence (LRR) and ultimately death. This study analyzed the relationship between immune function and outcomes following radiation in HPV/p16-negative tumors to identify mechanisms of radiation resistance and prognostic immune biomarkers. A discovery cohort of 94 patients with HNSCC treated uniformly with surgery and adjuvant radiation and a validation cohort of 97 similarly treated patients were utilized. Tumor immune infiltrates were derived from RNAseq gene expression. The immune cell types significantly associated with outcomes in the discovery cohort were examined in the independent validation cohort. A positive association between high Th2 infiltration and LRR was identified in the discovery cohort and validated in the validation cohort. Tumor mutations in CREBBP/EP300 and CASP8 were significantly associated with Th2 infiltration. A pathway analysis of genes correlated with Th2 cells revealed the potential repression of the antitumor immune response and the activation of BRCA1-associated DNA damage repair in multiple cohorts. The Th2 infiltrates were enriched in the HPV/p16-negative HNSCC tumors and associated with LRR and mutations in CASP8, CREBBP/EP300, and pathways previously shown to impact the response to radiation.

The Next Chapter in Immunotherapy and Radiation Combination Therapy: Cancer-Specific Perspectives

Immunotherapeutic agents have revolutionized cancer treatment over the past decade. However, most patients fail to respond to immunotherapy alone. A growing body of preclinical studies highlights the potential for synergy between radiation therapy and immunotherapy, but the outcomes of clinical studies have been mixed. This review summarizes the current state of immunotherapy and radiation combination therapy across cancers, highlighting existing challenges and promising areas for future investigation.

An open, multicenter, exploratory study of apatinib mesylate maintenance therapy for recurrent/metastatic head and neck squamous cell carcinoma (ChiCTR1800019375)

BACKGROUND

This study evaluated the efficacy of apatinib in maintenance therapy in patients with recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC).

METHODS

Twenty-six patients from three centers were enrolled from November 2018 to September 2021. These patients received 2 weeks apatinib, administered at 250 mg qd. Then apatinib dose may be administered to 500 mg qd continuous in 4 weeks cycle if no patients experienced adverse reaction. Enrolled patients can receive a combination of radiotherapy or chemotherapy. The primary endpoints were progression-free survival (PFS), and secondary endpoints included overall survival (OS), disease control rate (DCR), objective response rate (ORR), quality of life (QOL) score, and adverse drug reactions.

RESULTS

Median PFS of all patients was 3.2 months (95% CI: 2.06-4.33). Median OS of all patients was 7.3 months (95% CI: 2.14-12.46). The DCR was 92.3%. The ORR was 30.8%. In univariate analysis, the results showed that ECOG score 0-1 (HR = 0.31, p = 0.006) and treated with apatinib for more than 60 days (HR = 0.31, p = 0.003) were independent prognostic indicators affecting PFS, and ECOG score 0-1 (HR = 0.40, p = 0.027) and moderately differentiated or highly differentiated (HR = 0.38, p = 0.048) were independent prognostic indicators of OS. The most common adverse events among treated subjects included hypertension (46.1%), fatigue (42.3%), and hand-foot syndrome (23.1%). There were only two cases (7.7%) of Grade III or above adverse reactions.

CONCLUSIONS

Maintenance therapy with apatinib is an effective and well-tolerated regimen in patients with R/M HNSCC.

Kaplan lecture 2023: lymphopenia in particle therapy

PURPOSE

Lymphopenia is now generally recognized as a negative prognostic factor in radiotherapy. Already at the beginning of the century we demonstrated that high-energy carbon ions induce less damage to the lymphocytes of radiotherapy patients than X-rays, even if heavy ions are more effective per unit dose in the induction of chromosomal aberrations in blood cells irradiated ex-vivo. The explanation was based on the volume effect, i.e. the sparing of larger volumes of normal tissue in Bragg peak therapy. Here we will review the current knowledge about the difference in lymphopenia between particle and photon therapy and the consequences.

CONCLUSIONS

There is nowadays an overwhelming evidence that particle therapy reduces significantly the radiotherapy-induced lymphopenia in several tumor sites. Because lymphopenia turns down the immune response to checkpoint inhibitors, it can be predicted that particle therapy may be the ideal partner for combined radiation and immunotherapy treatment and should be selected for patients where severe lymphopenia is expected after X-rays.

Major and durable responses to photon and electron-beam palliative radiotherapies after immune-checkpoint inhibitors in head and neck cancer

BACKGROUND

The immuno-modulatory effects of ionizing radiation are well-known and preclinical studies suggest a synergistic effect of combining radiotherapy (RT) and IO. However, data regarding the clinical activity and safety of this approach are limited.

METHODS

We present the cases of two patients with SCCHN primary progressing to PDL1-based IO within a clinical trial (NCT03383094), that received subsequent but not concurrent palliative RT using two different modalities (electron beam and photon beam therapies).

RESULTS

Both patients achieved major and durable responses at 4 irradiated sites, with excellent tolerance and no grade ≥ 3 toxicities. Complete response occurred in 3 of the disease areas (all locoregional) and partial response in 1 metastatic lesion.

CONCLUSION

Palliative radiotherapy after progression to IO was safe and demonstrated profound and durable responses in the cases presented.

Neoplasia-related and treatment-induced lymphopenia: impact on the outcome of chemoradiotherapy in laryngeal cancer

INTRODUCTION

The role of the immune system in the efficacy of radiotherapy (RT) has been well established. We examined the role of neoplasia-related and treatment-induced lymphopenia in the outcome of RT or chemoradiotherapy (CRT) in squamous cell laryngeal cancer.

MATERIALS AND METHODS

We retrospectively analyzed a series of 135 laryngeal carcinomas treated with radical or postoperative RT/CRT. Six lymphocyte-related variables were defined and examined: i. lymphocyte counts (LCs) before a brief course of induction chemotherapy, ii. pre-RT LCs, iii. post-RT LCs, iv. pre-RT neutrophil/lymphocyte ratio (N/L), v. pre-RT monocyte/lymphocyte ratio (M/L), and vi. pre-RT platelet/lymphocyte ratio (Pt/L).

RESULTS

RT and CRT resulted in a significant decrease of LCs at the end of therapy, and this was significantly more prominent in patients treated with radical intent and neck irradiation (median LC nadir 810/μl vs. 1250/μl; p = .0003). Induction chemotherapy did not intensify the lymphotoxic effect of RT. LCs lower than the 33rd percentile before RT (<1718/μl) and after RT (<720/μl) were significantly linked to poor locoregional progression-free survival (LRFS; p = .02 and p = .08, respectively) and disease-specific overall survival (OS; p = .02 and p = .03, respectively). This was also confirmed multivariate analysis (LRFS: p = .006/HR = 2.41 and p = .08/HR = 1.76, respectively; OS: p = .001/HR = 3.06 and p = .02/HR = 2.07, respectively). High pre-RT N/L, M/L, and Pt/L ratios were also of ominous prognostic relevance.

CONCLUSIONS

Both neoplasia-related and RT-induced lymphopenia define the outcome of RT in terms of locoregional failure, incidence of metastasis, and, finally, disease-specific survival of patients with laryngeal cancer. Restoration of pre-RT lymphopenia and protection of peripheral lymphocytes during RT emerge as critical issues that demand therapeutic interventions to maximize the efficacy of RT/CRT in patients with laryngeal cancer.