A systematic review of neoadjuvant and definitive immunotherapy in locally advanced head and neck squamous cell carcinoma

BACKGROUND

Patients with locally advanced head and neck squamous cell carcinoma (HNSCC) require multi-modality treatment. Immune checkpoint inhibitors (ICIs) are now standard of care in management of recurrent/metastatic HNSCC. However, its role in the definitive and neoadjuvant setting remains unclear.

METHODS

A literature search was conducted that included all articles investigating ICI in untreated locally advanced (LA) HNSCC. Data was extracted and summarised and rated for quality using the Cochrane risk of bias tool.

RESULTS

Of 1086 records, 29 met the final inclusion criteria. In both concurrent and neoadjuvant settings, the addition of ICI was safe and did not delay surgery or reduce chemoradiotherapy completion. In the concurrent setting, although ICI use demonstrates objective responses in all published trials, there has not yet been published data to with PFS or OS benefit. In the neoadjuvant setting, combination ICI resulted in superior major pathological response rates compared to ICI monotherapy without a significant increase adverse event profiles, but its value in improving survival is not clear. ICI efficacy appears to be affected by tumour characteristics, in particular PD-L1 combined positive score, HPV status and the tumour microenvironment.

CONCLUSIONS

There is significant heterogeneity of ICI use in untreated LA HNSCC with multiple definitive concurrent and neoadjuvant protocols used. Resultantly, conclusions regarding the survival benefits of adding ICI to standard-of-care regimens cannot be made. Further trials and translational studies are required to elucidate optimal ICI sequencing in the definitive setting as well as better define populations more suited for neoadjuvant protocols.

Response to Neoadjuvant Targeted Therapy in Operable Head and Neck Cancer Confers Survival Benefit

PURPOSE

Neoadjuvant targeted therapy provides a brief, preoperative window of opportunity that can be exploited to individualize cancer care based on treatment response. We investigated whether response to neoadjuvant therapy during the preoperative window confers survival benefit in patients with operable head and neck squamous cell carcinoma (HNSCC).

PATIENTS AND METHODS

A pooled analysis of treatment-naïve patients with operable HNSCC enrolled in one of three clinical trials from 2009 to 2020 (NCT00779389, NCT01218048, NCT02473731). Neoadjuvant regimens consisted of EGFR inhibitors (n = 83) or anti-ErbB3 antibody therapy (n = 9) within 28 days of surgery. Clinical to pathologic stage migration was compared with disease-free survival (DFS) and overall survival (OS) while adjusting for confounding factors using multivariable Cox regression. Circulating tumor markers validated in other solid tumor models were analyzed.

RESULTS

92 of 118 patients were analyzed; all patients underwent surgery following neoadjuvant therapy. Clinical to pathologic downstaging was more frequent in patients undergoing neoadjuvant targeted therapy compared with control cohort (P = 0.048). Patients with pathologic downstage migration had the highest OS [89.5%; 95% confidence interval (CI), 75.7-100] compared with those with no stage change (58%; 95% CI, 46.2-69.8) or upstage (40%; 95% CI, 9.6-70.4; P = 0.003). Downstage migration remained a positive prognostic factor for OS (HR, 0.22; 95% CI, 0.05-0.90) while adjusting for measured confounders. Downstage migration correlated with decreased circulating tumor markers, SOX17 and TAC1 (P = 0.0078).

CONCLUSIONS

Brief neoadjuvant therapy achieved pathologic downstaging in a subset of patients and was associated with significantly better DFS and OS as well as decreased circulating methylated SOX17 and TAC1.

Case report: Patient specific combination of surgery and immunotherapy in advanced squamous cell carcinoma of the head and neck - a case series and review of literature

BACKGROUND

Prognosis of patients with recurrent or metastatic head and neck cancer is generally poor. Adjuvant immunotherapy (IT) featuring immune checkpoint inhibition (ICI) is standard of care in advanced stage head and neck squamous cell carcinoma (HNSCC) and cutaneous squamous cell carcinoma (CSCC). ICI response rates in CSCC are described as higher than in HNSCC. IT is constantly shifting into earlier disease stages which confronts the surgeon with immunotherapeutically pre-treated patients. It is therefore becoming increasingly difficult to assess which patients with symptomatic tumor disease and a lack of curative surgical option might benefit from salvage surgery.

CASE PRESENTATIONS

The following 6 cases describe therapeutic decision-making regarding ICI and (salvage) surgery in patients with advanced stage HNSCC or CSCC. Cases A and B focus on neoadjuvant ICI followed by salvage surgery. In Cases C and D salvage surgery was performed after short-term stabilization with partial response to ICI. The last two cases (Cases E and F) address the surgical approach after failure of ICI. All cases are discussed in the context of the current study landscape and with focus on individual decision-making. For better understanding, a timetable of the clinical course is given for each case.

CONCLUSIONS

ICI is rapidly expanding its frontiers into the neoadjuvant setting, frequently confronting the surgeon with heavily pretreated patients. Salvage surgery is a viable therapeutic concept despite the rise of systemic treatment options. Decision-making on surgical intervention in case of a salvage surgery remains an individual choice. For neoadjuvant ICI monitoring regarding pathological tumor response or tumor necrosis rate, we suggest correlation between the initial biopsy and the definite tumor resectate in order to increase its significance as a surrogate marker. Scheduling of neoadjuvant ICI should be further investigated, as recent studies indicate better outcomes with shorter time frames.

Prognostic impact of the number of metastatic lymph nodes after surgery in locally advanced hypopharyngeal cancer

Background

Postoperative chemoradiotherapy (CRT) is a standard therapy for patients with high-risk factors for head and neck squamous cell carcinoma, including positive margin and extra-nodal extension (ENE). However, the prognostic impact of the number of pathological metastatic lymph nodes (pLNs) in hypopharyngeal carcinoma (HPC) is unclear. Thus, this study aimed to investigate postoperative prognostic factors for locally advanced hypopharyngeal squamous cell carcinoma (LA-HPSCC) with a focus on the number of pLNs.

Methods

We retrospectively analyzed medical records of 99 consecutive patients with LA-HPSCC who underwent total pharyngo-laryngo-esophagectomy (TPLE) and bilateral neck dissection (ND) between December 2002 and May 2019.

Results

The median follow-up time for all censored patients was 63.2 months. The median overall survival (OS) was 101.0 months (95% confidence interval [CI] 48.1–134.9). patients had pLNs ≥ 3. Forty-six (45.5%) patients were diagnosed with ENE. Twenty (20.2%) patients received postoperative CRT. The multivariate analysis revealed that pLNs ≥ 3 (median OS: 163.2 vs. 31.8 months, hazard ratio [HR] 2.39, 95% CI 1.16–4.94, p < 0.01) and ENE (median OS: 161.0 vs. 26.3 months, HR 4.60, 95% CI 2.26–9.36, p < 0.01) were significantly associated with poor prognosis and that postoperative CRT (HR 0.34, 95% CI 0.16–0.72, p < 0.01) was significantly associated with better prognosis. The cumulative incidence of distant metastasis was higher in patients with pLNs ≥ 3 than in those with pLNs < 3 (p < 0.01).

Conclusion

pLNs ≥ 3 and ENE were significant poor prognostic factors for patients with LA-HPSCC who underwent TPLE and bilateral ND.

Phase II Trial of Adjuvant Nivolumab Following Salvage Resection in Patients with Recurrent Squamous Cell Carcinoma of the Head and Neck

PURPOSE

Locoregional relapse in patients with head and neck squamous cell carcinoma (HNSCC) is common, approaching 50% for some subsites despite multimodality therapy. Salvage surgery is the standard of care, but able to achieve durable control in only a minority of patients. While adjuvant radiotherapy or chemo-radiotherapy is offered to select patients, this approach can be prohibitively toxic. Given the activity and tolerability of programmed death-1 inhibitors in metastatic HNSCC, we investigated the safety and efficacy of adjuvant nivolumab after salvage surgical resection.

PATIENTS AND METHODS

This was an open-label, multi-institutional phase II clinical trial (NCT03355560). Patients with recurrent, resectable HNSCC were enrolled within 6 weeks of salvage surgery. Six 28-day cycles of adjuvant nivolumab were planned. The primary endpoint was 2-year disease-free survival (DFS) more than 58%, based on an institutional historical control group of 71 patients with recurrent HNSCC who underwent salvage surgery.

RESULTS

Between February 2018 and February 2020, 39 patients were enrolled. At a median follow-up of 22.1 months, 2-year DFS was 71.4% [95% confidence interval (CI), 57.8-88.1] and the 2-year overall survival (OS) was 73% (95% CI, 58-91.8). Three of 39 (8%) patients experienced grade 3 treatment-related adverse events and 3 of 39 (8%) discontinued treatment due to side effects. Ten of 39 had locoregional recurrence, while 2 of 10 also had synchronous metastatic disease. There was no difference in DFS between PD ligand-1 (PD-L1)-positive and PD-L1-negative patients. There was a nonsignificant trend toward improved DFS in patients with high tumor mutational burden (P = 0.083).

CONCLUSIONS

Adjuvant nivolumab after salvage surgery in locally recurrent HNSCC is well tolerated and showed improved DFS compared with historical controls.

Programmed cell death protein 1 axis blockade in locally advanced squamous cell carcinoma of the head and neck: Neoadjuvant and adjuvant approaches

Immunotherapy and in particular programmed cell death protein 1 (PD-1) inhibitors have been applied not only in the management of recurrent or metastatic disease but also as component of potentially curative treatment for many solid tumors. The incorporation of immunotherapy as neoadjuvant and /or adjuvant therapy in the treatment paradigm of locally advanced squamous cell carcinoma of the head and neck (SCCHN) is appealing with the goals of enhancing antitumor efficacy and, at the same time, reduce toxicity. This review analyzes the rationale for employing immunotherapy in the neoadjuvant and adjuvant settings, reviews the results of relevant clinical trials, and examines the potential benefits and caveats of neoadjuvant and/or adjuvant approaches in patients with SCCHN.

Tadalafil Enhances Immune Signatures in Response to Neoadjuvant Nivolumab in Resectable Head and Neck Squamous Cell Carcinoma

PURPOSE

We hypothesize that the addition of the phosphodiesterase-5 inhibitor tadalafil to the PD-1 inhibitor nivolumab, is safe and will augment immune-mediated antitumor responses in previously untreated squamous cell carcinoma of the head and neck (HNSCC).

PATIENTS AND METHODS

We conducted a two-arm multi-institutional neoadjuvant randomized trial in any-stage resectable HNSCC (NCT03238365). Patients were stratified at randomization by human papillomavirus (HPV) status. Patients in both arms received nivolumab 240 mg intravenously on days 1 and 15 followed by surgery on day 28. Those in the combination therapy arm also received tadalafil 10 mg orally once daily for 4 weeks. Imaging, blood, and tumor were obtained pretreatment and posttreatment for correlative analysis.

RESULTS

Neoadjuvant therapy was well-tolerated with no grade 3 to 5 adverse events and no surgical delays. Twenty-five of 46 (54%) evaluable patients had a pathologic treatment response of ≥20%, including three (7%) patients with a complete pathologic response. Regardless of HPV status, tumor proliferation rate was a negative predictor of response. A strong pretreatment T-cell signature in the HPV-negative cohort was a predictor of response. Tadalafil altered the immune microenvironment, as evidenced by transcriptome data identifying enriched B- and natural killer cell gene sets in the tumor and augmented effector T cells in the periphery.

CONCLUSIONS

Preoperative nivolumab ± tadalafil is safe in HNSCC and results in more than 50% of the patients having a pathologic treatment response of at least 20% after 4 weeks of treatment. Pretreatment specimens identified HPV status-dependent signatures that predicted response to immunotherapy while posttreatment specimens showed augmentation of the immune microenvironment with the addition of tadalafil.

Neoadjuvant Immunotherapy Strategies in HPV-Related Head-and-Neck Cancer

Purpose of review

Herein, we review current evidence and future directions of neoadjuvant immunotherapy in HPV-related head and neck squamous cell carcinoma (HNSCC) by describing published data and ongoing clinical trials.

Recent findings

Although HNSCCs have shown response to immune checkpoint inhibitors in recurrent/metastatic disease, a limited number of patients benefit from this treatment. There is an expanding interest in clarifying the clinical benefit of immunotherapy in earlier stage disease setting including at initial presentation. Neoadjuvant immunotherapy for HPV-related HNSCCs represents a rational approach, as these cancers bear strong viral antigens.

Summary

The majority of patients with HPV-related HNSCC have good prognosis and treatment de-intensification strategies are under evaluation to decrease toxicity and maintain efficacy. On the other hand, a subset of patients with HPV-related HNSCC have a poorer prognosis and additional treatment options are need to improve outcome. Multiple clinical trials are ongoing to evaluate whether neoadjuvant immunotherapy will achieve these goals.

[Immunotherapy of head and neck cancer : Highlights of the ASCO and ESMO annual meetings 2021]

BACKGROUND

This year's American Society of Clinical Oncology (ASCO) meeting included interesting data on first-line therapy of nasopharyngeal carcinomas with PD‑1 inhibitors and on checkpoint inhibition in various clinical constellations. At the European Society of Medical Oncology (ESMO) meeting, the results of the CheckMate-651 study were presented.

MATERIALS AND METHODS

All abstracts and presentations from the ASCO and ESMO meetings 2021 on immunotherapy in head and neck cancer (HNSCC) were evaluated for their relevance. The most interesting studies are elaborated upon herein.

RESULTS

Studies on locally advanced HNSCC showed an improved response after neoadjuvant pembrolizumab administration. A second cycle did not improve the response rate, but the proportion of patients with a good response was almost doubled. The CheckRad CD8 study showed an improvement in progression-free survival by induction chemoimmunotherapy with tremelimumab and durvalumab followed by stratification according to the CD8 immune cell infiltrate. Two studies were presented on first-line treatment of recurrent/metastatic nasopharyngeal carcinomas. Chemoimmunotherapy showed a higher response rate and prolonged progression-free survival with a similar adverse event profile. In recurrent/metastatic HNSCC, the CheckMate 651 study showed an increased duration of response with nivolumab and ipilimumab and higher response rates than pembrolizumab alone. The primary endpoints for overall survival were not achieved.

CONCLUSION

PD‑1 inhibition has great potential to change the therapeutic landscape for nasopharyngeal carcinomas in the future. In HNSCC, CD8 tumor infiltrate presents a promising predictive marker for selecting patients who can benefit from radioimmunotherapy. The combination of nivolumab and ipilimumab did not improve overall survival in palliative first-line therapy; thus, no change in the current standard is expected.

Induction Chemotherapy in Low-Risk HPV+ Oropharyngeal Cancer

OPINION STATEMENT

Human papillomavirus (HPV) associated oropharyngeal squamous cell carcinoma (OPSCC) is rapidly increasing in incidence, and has now become the most common head and neck cancer (HNC). Studies have demonstrated that HPV associated OPSCC is associated with a favorable prognosis compared with its HPV-negative counterparts, yet standard multimodality therapy is often associated with substantial acute and late treatment-related toxicity. While locoregional control is improved in HPV+ OPSCC, distant metastasis rate has gained recognition as a major cause of death in this population, with some studies suggesting similar rates as non-HPV-related cancers. Induction chemotherapy has been of long-standing interest in locoregionally advanced HNC, yet its use in combination with concomitant chemoradiation remains an area of controversy as a survival benefit remains unproven following randomized trials. Nevertheless, response to induction chemotherapy remains an important dynamic and prognostic biomarker, with response-adaptive de-intensified therapy in HPV+ OPSCC gaining traction in single-arm phase II studies demonstrating promising results. The emergence of immunotherapy in the recurrent/metastatic setting for HNC has led to enthusiasm to incorporate in the curative setting, yet its role remains undefined. Our institutional paradigm for HPV+ OPSCC incorporates induction therapy followed by risk and response adaptive locoregional treatment. Ultimately, the role of induction therapy in HPV+ OPSCC will need to be investigated in a randomized setting to be incorporated routinely into clinical practice.

Neoadjuvant immunotherapy in head and neck cancer: Rationale, current evidence and future perspective

Immune-checkpoint inhibitors (ICIs) have shown to improve survival in the first- and second-line settings of recurrent/metastatic squamous cell carcinoma of the head and neck (SCCHN). In the past two years more than a dozen neoadjuvant IO studies have been reported in SCCHN, demonstrating the feasibility of one or a few doses of single agent or combination ICIs. This approach seems safe with no surgical delays due to toxicity in most of the studies with no new safety signals. Efficacy in terms of pathologic response appears promising both with single-agent ICIs and especially with chemo-IO combinations. The scientific rationale and current clinical evidence of neoadjuvant IO trials in SCCHN will be reviewed, including currently debated aspects such as the methodology for radiological and pathological evaluation as well as types and criteria for biomarker use in this setting. Finally, the future perspective of neoadjuvant IO in SCCHN will be approached.

Neoadjuvant presurgical PD-1 inhibition in oral cavity squamous cell carcinoma

Oral cavity squamous cell carcinoma (OCSCC) is a prevalent surgically treated subset of head and neck cancer with frequent recurrence and poor survival. Immunotherapy has demonstrated efficacy in recurrent/metastatic head and neck cancer. However, whether antitumor responses could be fostered by neoadjuvant presurgical immunotherapy remains unclear. Using a Simon's two-stage design, we present results of a single-arm phase-II trial where 12 patients with stage II-IVA OCSCC received 3 to 4 biweekly doses of 3 mg/kg nivolumab followed by definitive surgical resection with curative intent. Presurgical nivolumab therapy in this cohort shows an overall response rate of 33% (n = 4 patients; 95% CI: 12%-53%). With a median follow up of 2.23 years, 10 out of 12 treated patients remain alive. Neoadjuvant nivolumab is safe, well-tolerated, and is not associated with delays in definitive surgical treatment in this study. This work demonstrates feasibility and safety for incorporation of nivolumab in the neoadjuvant setting for OCSCC (ClinicalTrials.gov: NCT03021993).

Neoadjuvant PD-1/PD-L1 Inhibitors for Resectable Head and Neck Cancer: A Systematic Review and Meta-analysis

Importance

The emerging approach of neoadjuvant immunotherapy for solid cancers has set the ground for the integration of programmed cell death 1 (PD-1)/PD-1 ligand 1 (PD-L1) inhibitors into the neoadjuvant setting of head and neck squamous cell carcinoma (HNSCC) treatment.

Objective

To assess the reported efficacy and safety of neoadjuvant immunotherapy for resectable HNSCC.

Data Sources and Study Selection

Electronic databases, including PubMed (MEDLINE), Embase, the Cochrane Library, and ClinicalTrials.gov were systematically searched for published and ongoing cohort studies and randomized clinical trials that evaluate neoadjuvant immunotherapy for resectable HNSCC. The search results generated studies from 2015 to July 2021.

Data Extraction and Synthesis

Two investigators (R.M. and L.K.) independently identified and extracted articles for potential inclusion. Random and fixed models were used to achieve pooled odds ratios. All results are presented with 95% CIs. Data quality was assessed by means of the Cochrane Collaboration's risk of bias tool.

Main Outcomes and Measures

The primary outcomes were reported efficacy, evaluated by major pathological response and pathological complete response in the primary tumors and lymph nodes separately, and safety, assessed by preoperative grade 3 to 4 treatment-related adverse events and surgical delay rate.

Results

A total of 344 patients from 10 studies were included. In 8 studies, neoadjuvant immunotherapy only was administered, and the other 2 studies combined immunotherapy with neoadjuvant chemotherapy and/or radiotherapy. The overall major pathological response rate in the primary tumor sites from studies reporting on neoadjuvant immunotherapy only was 9.7% (95% CI, 3.1%-18.9%) and the pathological complete response rate was 2.9% (95% CI, 0%-9.5%). Preoperative grade 3 to 4 treatment-related adverse events were reported at a rate of 8.4% (95% CI, 0.2%-23.2%) and surgical delay at a rate of 0% (95% CI, 0%-0.9%). There was a favorable association of neoadjuvant immunotherapy with all outcome measures. The subgroup analyses did not find one specific anti-PD-1/PD-L1 agent to be superior to another, and the favorable association was demonstrated by either immunotherapy alone or in combination with anti-CTLA-4.

Conclusions and Relevance

In this systematic review and meta-analysis, neoadjuvant anti-PD-1/PD-L1 immunotherapy for resectable HNSCC was well tolerated and may confer therapeutic advantages implied by histopathological response. Long-term outcomes are awaited.

Immunotherapy for Head and Neck Cancer: A Paradigm Shift From Induction Chemotherapy to Neoadjuvant Immunotherapy

Neoadjuvant immunotherapy has the potential to enhance clinical outcomes by increasing anti-tumor immune responses in the presence of abundant tumor-derived antigen in an immune microenvironment that has not been exposed to previous therapy. The current mainstay of advanced head and neck squamous cell carcinoma (HNSCC) treatment remains surgery and radiotherapy with/without conventional chemotherapy. Despite this multi-modality treatment, advanced human papillomavirus (HPV)-negative HNSCC shows poor prognosis. Treatment intensification with neoadjuvant (induction) chemotherapies with platinum drugs are insufficient to significantly prolong overall survival. Although only 15-20% of patients benefit, immunotherapies have been approved and widely used for recurrent and metastatic HNSCC. These successes have led to checkpoint blockade therapies being testing in earlier treatment settings. Recent clinical trials of neoadjuvant immunotherapy show promising results and this methodology has the potential to change the treatment algorithm of HNSCC. This overview examines the treatment history of neoadjuvant approaches for HNSCC, and especially focuses on the recent topics of neoadjuvant immunotherapy for HNSCC.

[Trials in head and neck cancer - Highlights of the ASCO Annual Meeting 2021]

The therapeutic options in head and neck oncology are rapidly developing, especially through the use of checkpoint inhibitors. Currently, numerous therapeutic studies with new molecular targets or new drug combinations are underway in patients with head and neck cancer. The most important results of the studies presented at the ASCO Annual Meeting 2021 on head and neck cancer will be presented in this paper.