Clinical outcome of stereotactic body radiotherapy for lung-only oligometastatic head and neck squamous cell carcinoma: Is the deferral of systemic therapy a potential goal?

Long-term efficacy analysis of radiotherapy and local management of metastases in patients with newly diagnosed oligometastatic nasopharyngeal carcinoma: A prospective, single-arm, single-center clinical study

PURPOSE

We conducted a single-center, single-arm study (NCT03129412) to prospectively analyze the long-term outcomes of newly diagnosed patients with oligometastatic nasopharyngeal carcinoma (NPC) who received radical radiotherapy and local treatment of metastases.

PATIENTS AND METHODS

Patients who reached disease controll after platinum-based palliative chemotherapy continued to receive radical radiotherapy for the nasopharyngeal region and neck. Appropriate local treatments were selected to treat the metastatic lesions. The primary endpoint of this study was overall survival (OS) and the secondary endpoint was progression-free survival (PFS).

RESULTS

Fifty-one patients were included in the final analysis. During a median follow-up of 60 months, the median OS and PFS were 53.87 and 24.23 months, respectively. The 1-year, 3-year, and 5-year PFS and OS rates were 76.5 %, 38.1 %, and 31.8 % and 98 %, 75.4 %, 45.6 %, respectively. Both single and multivariate analysis indicated that maintenance therapy after radiotherapy could significantly increase PFS (36.43 vs. 16.1 months, P = 0.005). The OS of patients with single organ metastasis was significantly better than that of patients with double organ metastasis (P = 0.001). In addition, the number of metastatic organs also significantly affected PFS in the multifactor analysis.

CONCLUSION

Patients with newly diagnosed oligometastatic NPC can achieve long-term survival after receiving radical radiotherapy to the primary site and local treatment for metastases.

Stereotactic Body Radiotherapy in Recurrent and Oligometastatic Head and Neck Tumours

The treatment of head and neck cancers (HNCs) encompasses a complex paradigm involving a combination of surgery, radiotherapy, and systemic treatment. Locoregional recurrence is a common cause of treatment failure, and few patients are suitable for salvage surgery. Reirradiation with conventional radiation techniques is challenging due to normal tissue tolerance limits and the risk of significant toxicities. Stereotactic body radiotherapy (SBRT) has emerged as a highly conformal modality that offers the potential for cure while limiting the dose to surrounding tissue. There is also growing research that shows that those with oligometastatic disease can benefit from curative intent local ablative therapies such as SBRT. This review will look at published evidence regarding the use of SBRT in locoregional recurrent and oligometastatic HNCs.

Stereotactic radiotherapy in the management of oligometastatic and recurrent head and neck cancer: a single-center experience

INTRODUCTION

Oligometastatic disease (OMD) is a metastatic stage that could benefit maximally from local therapies. Patients in this state have a better prognosis relative to those with disseminated metastases. Stereotactic radiotherapy provides a non-invasive ablative tool for primary malignant tumors and metastases.

MATERIALS AND METHODS

We searched our register for patients with oligometastatic or recurrent head and neck cancer (OMD/R-HNC) who received stereotactic radiotherapy to manage their OMD/R. We evaluated the survival outcomes and prognostic factors that affected the survival of those patients.

RESULTS

In all, 31 patients with 48 lesions met the inclusion criteria for the analysis. The lesions comprised various metastatic sites, with the majority being pulmonary (37 lesions). Squamous cell cancer was the most common histology (26 patients). The median overall survival (mOS) was 33 months, with a progression-free survival (PFS) of 9.6 months. Eight patients received subsequent stereotactic radiotherapy after disease progression. The local control (LC) rates were 91.3, 87.7, and 83% at 6, 12, and 36 months. Patients with the de novo OMD who received stereotactic radiotherapy as their initial treatment had a median systemic treatment-free survival of 23.9 months. In univariate analysis, a trend for better OS was observed in patients with p16-positive squamous cell tumors; patients who progressed within 150 days after diagnosis had a significantly lower OS. De novo OMD showed significantly better PFS compared to induced OMD. Multivariate analyses identified p16-positive squamous cell cancer, metachronous OMD and a longer time to progression as positive predictors of OS, while de novo OMD was the only positive predictor for PFS. Treatment-related toxicities were generally mild, with two cases of grade 3 dysphagia reported.

CONCLUSION

Stereotactic radiotherapy demonstrated favorable outcomes in patients with OMD/R-HNC with limited toxicities. Further studies are warranted to validate these findings and optimize treatment strategies for this patient population.

Treatment Outcome in Head and Neck Cancer With Distant Metastasis at Initial Diagnosis

OBJECTIVE

Recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) treatment has changed dramatically with the introduction of immune checkpoint inhibitors (ICIs). However, there are few reports of treatment outcomes on HNSCC with distant metastasis (M1) at initial diagnosis, and its treatment strategy has not been standardized. We aimed to analyze the treatment outcome and prognostic factors of patients with HNSCC with initial M1 disease.

METHODS

In this multi-institutional retrospective study, 98 patients with HNSCC were initially diagnosed with M1 disease between 2007 and 2021. The patients were divided into the non-palliative (received any systemic chemotherapy, n = 60) and palliative (did not receive systemic chemotherapy, n = 38) groups. Overall survival (OS) was compared between the groups. In the non-palliative group, predictors of OS were explored based on patient characteristics and treatment details.

RESULTS

The median OS in the non-palliative group was 15 months (95% confidence interval [CI], 10-20), which was significantly longer than that in the palliative group (3 months, 95% CI, 2-5) (p < 0.001). Multivariate analysis revealed that administration of locoregional radiation therapy (RT) (hazard ratio [HR] 0.407 [95% CI 0.197-0.844]; p = 0.016), ICIs (HR 0.216 [95% CI 0.088-0.532]; p < 0.001) and RT/surgery for distant metastasis (HR 0.373 [95% CI 0.150-0.932]; p = 0.034) were the independent prognostic factors of OS.

CONCLUSION

An intensive treatment strategy combining systemic therapy using ICIs with RT/surgery for locoregional or distant metastasis may yield a survival benefit for patients with HNSCC with M1 disease.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:1679-1686, 2024.

Stereotactic Body Radiotherapy for Extracranial Oligometastatic Disease from Head and Neck Primary Cancers: A Systematic Review and Meta-Analysis

INTRODUCTION

Stereotactic body radiotherapy (SBRT) is increasingly used to treat disease in the oligometastatic (OM) setting due to mounting evidence demonstrating its efficacy and safety. Given the low population representation in prospective studies, we performed a systematic review and meta-analysis of outcomes of HNC patients with extracranial OM disease treated with SBRT.

METHODS

A systematic review was conducted with Cochrane, Medline, and Embase databases queried from inception to August 2022 for studies with extracranial OM HNC treated with stereotactic radiotherapy. Polymetastatic patients (>five lesions), mixed-primary cohorts failing to report HNC separately, lack of treatment to all lesions, nonquantitative endpoints, and other definitive treatments (surgery, conventional radiotherapy, and radioablation) were excluded. The meta-analysis examined the pooled effects of 12- and 24-month local control (LC) per lesion, progression-free survival (PFS), and overall survival (OS). Weighted random-effects were assessed using the DerSimonian and Laird method, with heterogeneity evaluated using the I2 statistic and Cochran Qtest. Forest plots were generated for each endpoint.

RESULTS

Fifteen studies met the inclusion criteria (639 patients, 831 lesions), with twelve eligible for quantitative synthesis with common endpoints and sufficient reporting. Fourteen studies were retrospective, with a single prospective trial. Studies were small, with a median of 32 patients (range: 6-81) and 63 lesions (range: 6-126). The OM definition varied, with a maximum of two to five metastases, mixed synchronous and metachronous lesions, and a few studies including oligoprogressive lesions. The most common site of metastasis was the lung. Radiation was delivered in 1-10 fractions (20-70 Gy). The one-year LC (LC1), reported in 12 studies, was 86.9% (95% confidence interval [CI]: 79.3-91.9%). LC2 was 77.9% (95% CI: 66.4-86.3%), with heterogeneity across studies. PFS was reported in five studies, with a PFS1 of 43.0% (95% CI: 35.0-51.4%) and PFS2 of 23.9% (95% CI: 17.8-31.2%), with homogeneity across studies. OS was analyzed in nine studies, demonstrating an OS1 of 80.1% (95% CI: 74.2-85.0%) and OS2 of 60.7% (95% CI: 51.3-69.4%). Treatment was well tolerated with no reported grade 4 or 5 toxicities. Grade 3 toxicity rates were uniformly below 5% when reported.

CONCLUSIONS

SBRT offers excellent LC and promising OS, with acceptable toxicities in OM HNC. Durable PFS remains rare, highlighting the need for effective local or systemic therapies in this population. Further investigations on concurrent and adjuvant therapies are warranted.

Management of head and neck carcinomas with synchronous or metachronous oligometastatic disease: Role of locoregional radiotherapy and metastasis-directed radiotherapy

Head and neck carcinomas are initially metastatic in about 15% of cases. Radiotherapy is a cornerstone in the multimodal strategy at the locoregional phase. In patients with head and neck cancer, often heavily pretreated and with comorbidities, who relapse locoregionally or at distant sites, radiotherapy has also become increasingly important at the metastatic phase. Data on the optimal sequence of systemic treatments and metastasis-directed treatments including stereotactic irradiation are still lacking. Several randomized head and neck trials have been initiated that should provide important answers, including one recent GORTEC trial.

Pathological nodal status as a main predictive factor of survival and treatment outcomes of submandibular salivary gland cancers: A 25-year single center experience

INTRODUCTION

Aim of this study was to explore the survival predictive factors and treatment outcomes in a cohort of SGC patients treated at a single center over a period of 25 years.

MATERIALS AND METHODS

Patients who had received primary treatment for SGC were enroled. Outcomes evaluated were: overall survival (OS), disease specific survival (DSS), recurrence free survival (RFS), locoregional recurrence free survival (LRFS) and distant metastasis free survival (DFS).

RESULTS

A total of 40 patients with SGC were enroled in the study. The most common tumor was the adenoid cystic carcinoma (60% of cases). Cumulative OS for 5-and 10-year follow up period was 81% and 60%, respectively. Thirteen patients (32.5%) developed distant metastases during follow-up. Nodal status, high-grade histology, tumor stage and adjuvant radiation-therapy (RT) were significant variables on multivariate analysis for survival and treatment outcomes.

CONCLUSIONS

Submandibular gland carcinomas represent rare and heterogenous tumor group regarding histological appearance and locoregional and distant metastatic potential. Tumor histological grade, AJCC tumor stage and nodal status were the strongest predictive factors for survival and treatment outcomes. RT improved OS and locoregional treatment outcome, but not DFS. Elective neck dissection (END) could be beneficial for selected cases of SGC. Superselective neck dissection of levels I-IIa may be the level of dissection for END. Distant metastases were the main cause of death and treatment failure. Prognostic factors for poor DMFS were AJCC stage III and IV, high tumor grade and nodal status.

Survival, Treatment Outcome, and Safety of Multiple and Repeated Courses of Stereotactic Body Radiotherapy for Pulmonary Oligometastases of Head and Neck Squamous Cell Carcinoma

Current literature regarding survival and treatment outcome of SBRT in patients with pulmonary oligometastatic head and neck squamous cell carcinoma (HNSCC) is limited. Additionally, most of the published studies include metastatic lesions deriving also from primaries with histologies other than SCC when investigating the outcome of SBRT. The aim of the present retrospective study is to explore local control (LC) of treated metastases, progression-free survival (PFS), and overall survival (OS) of exclusively pulmonary oligometastatic HNSCC-patients treated with SBRT. Between 2006 and 2021, a total of 46 patients were treated with SBRT for a maximum of four pulmonary oligometastases (PM) concurrently (mean PM per patient = 2.0; range 1 to 6 PM, total of 92). Of these, 17 patients (37.0%) developed new pulmonary metastases after their first SBRT. Repeated courses of SBRT were required once in 15 patients (88.2%) and twice in 2 patients (11.8%). Median follow-up was 17 months (range, 0-109 months). One year after completion of SBRT, LC rate, PFS, and OS were 98.7%, 37.9%, and 79.5%, respectively. After two years, LC rate, PFS, and OS were 98.7%, 28.7%, and 54.9%; as well as 98.7%, 16.7%, and 31.0% after five years. Radiochemotherapy (HR 2.72, p < 0.001) or radiotherapy as primary treatment (HR 8.60; p = 0.003), as well as reduced patient performance status (HR 48.30, p = 0.002), were associated with lower PFS. Inferior OS correlated with poor performance status (HR 198.51, p < 0.001) and surgery followed by radiochemotherapy (HR 4.18, p = 0.032) as primary treatment, as well as radiotherapy alone (HR 7.11, p = 0.020). Treatment of more than one PM is an independent predictor of impaired OS (HR 3.30, p = 0.016). SBRT of HNSCC-derived PMs results in excellent LC rates and encouraging OS rates of 54.9% at two years along with good tolerability (no more than grade 2 toxicities). Favourable outcome and low toxicity also apply to repeated courses of SBRT of newly emerging PMs.

Outcomes for oligometastatic head and neck cancer treated with stereotactic body radiotherapy: Results from an international multi-institutional consortium

BACKGROUND

We report the results of an international multi-institutional cohort of oligometastatic (OMD) head and neck cancer (HNC) patients treated with SBRT.

METHODS

Patients with OMD HNC (≤5 metastases) treated with SBRT between 2008 and 2016 at six institutions were included. Treated metastasis control (TMC), progression-free survival (PFS), and overall survival (OS) were analyzed by multivariable analysis (MVA).

RESULTS

Forty-two patients with 84 HNC oligometastases were analyzed. The TMC rate at 1 and 2 years were 80% and 66%, with a median time to recurrence of 10.1 months. The median PFS and OS were 4.7 and 23.3 months. MVA identified a PTV point maximum (BED)10 > 100 Gy as a predictor of improved TMC (HR = 0.31, p = 0.034), and a cumulative PTV > 48 cc as having worse PFS (HR = 2.99, p < 0.001).

CONCLUSION

Favorable TMC and OS was observed in OMD HNCs treated with SBRT.

Combining Radiotherapy and Immunotherapy in Head and Neck Cancer

Head and neck squamous cell carcinoma (HNSCC) is a leading cause of morbidity and mortality globally. Despite significant advances in well-established treatment techniques, prognosis for advanced-stage HNSCC remains poor. Recent, accumulating evidence supports a role for immunotherapy in HNSCC treatment. Radiation therapy (RT), a standard treatment option for HNSCC, has immunomodulatory and immunostimulatory effects that may enhance the efficacy of immunotherapy. In several cancer types, combining RT and immunotherapy has been shown to improve tumor response rates, increase survival, and reduce toxicity compared to traditional chemotherapy and radiation therapy. This review provides a timely overview of the current knowledge on the use of RT and immunotherapy for treating HNSCC. It highlights the potential advantages of combining these therapies, such as improved tumor response rates, increased survival, and reduced toxicity. The review also discusses the challenges that need to be addressed when redefining the standard of care in HNSCC, and proposes further research to optimize treatment combinations, minimize radiation-induced toxicity, and identify suitable patient populations for treatment.

Durable complete remission with local therapies after neoadjuvant and adjuvant nivolumab in recurrent/metastatic head and neck cancer

Up to 10-15% of patients with first-line recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) present with platinum-refractory disease. The anti-PD1 nivolumab is the first therapeutic option in this setting achieving a 19.2% objective response rate and a 7.7-month median overall survival (OS). Given the poor prognosis of platinum-refractory patients, those showing slow progressive disease with no functional status deterioration should maintain nivolumab beyond progression in the absence of severe or unmanageable toxicities. Another strategy is to use local therapies such as radiotherapy and surgical tumor resection in cases of oligometastatic or oligoprogressive disease. Both strategies may significantly improve disease control and OS in these populations. We present the case of a patient with platinum-refractory disease treated with first-line nivolumab beyond progression who achieved a durable complete response after palliative radiation and surgical resection of five tumor lesions. To our knowledge, this is the first reported case of an R/M HNSCC treated with such a strategy outside a clinical trial and contributes to the evidence for combining anti-PD1 agents and local therapies in selected patients with R/M HNSCC.

The oligometastatic setting in HNSCC: A critical review by the Rete Oncologica Piemonte e Valle d'Aosta multidisciplinary team

INTRODUCTION

The oligometastatic disease is a low burden metastatic disease that might still benefit from curable treatment. Squamous cell carcinoma of the head and neck (HNSCC) is a complex group of malignancies, with high rates of loco-regional recurrences. Distant metastases are less frequent, and a single or few deposits are often observed (oligometastatic disease). The optimal management of oligometastatic HNSCC remains to be defined.

MATERIALS AND METHODS

Key references were derived from a PubMed query. Hand searching and clinicaltrials.gov were also used.

RESULTS

This paper contains a narrative report and a critical discussion of the available evidence on the management of oligometastatic HNSCC patients, with a focus on metastasis-directed therapy (MDT), particularly stereotactic ablative radiotherapy (SABR).

CONCLUSIONS

in line with literature data, the multidisciplinary evaluation emerged as the key element in the management of oligometastatic HNSCC patients.

Current perspectives on recurrent HPV-mediated oropharyngeal cancer

In the recent years, the prevalence of HPV-positive oropharyngeal squamous cell carcinoma (OPSCC) has increased significantly. Currently, nearly 80-90% of all oropharynx tumors are HPV-positive. In addition, it is now recognized that HPV-positive tumor status is associated with good prognosis and improved response to chemoradiation. However, within this setting, there are still patients with HPV-positive OPSCC who will experience recurrence. With the increasing incidence of HPV-mediated OPSCC, recurrent HPV disease is also becoming more prevalent and there is an increasing need to understand the unique presentation and treatment of recurrent HPV-mediated disease. In this review, we will discuss epidemiology of recurrent HPV-positive OPSCC, role of surgical salvage, re-irradiation, and the role of upcoming novel treatments and immunotherapy. Historically, recurrent oropharyngeal disease has been associated with poor prognosis and high morbidity. However, recent advances have transformed the landscape for salvage treatment of HPV-mediated OPSCC. Liquid biomarkers offer potential for early detection of recurrence, robotic techniques may reduce morbidity of surgical salvage, improvements in re-irradiation approaches reduce toxicities, and novel immune based therapies on the horizon are offering promising results. These advances combined with the improved prognosis of HPV-positive disease offer to transform our approach to recurrent disease of the oropharynx.

Oligometastatic Head and Neck Cancer: Challenges and Perspectives

Simple Summary

Oligometastasis represents a disease state and an opportunity for cure when metastases emerge. Emerging evidence supports that most head and neck cancer patients with oligometastatic disease are likely to benefit from curative intent local ablative therapy if appropriate selection criteria are applied. Biomarkers to predict development of oligometastasis, as well as to identify which patients could benefit from a radical intent approach, are under investigation. This review summarizes recent knowledge about the characteristics, investigational efforts, and evidence for local ablation regarding oligometastasis in head and neck cancer. We also describe the challenges and opportunities in patient selection and discuss the role of radiotherapy and immunotherapy combinations to enhance anti-tumor immunity.

Abstract

A minority of patients with metastatic head and neck squamous cell carcinoma (HNSCC) present with oligometastatic disease. Oligometastasis not only reflects a disease state, but might also present an opportunity for cure in the metastatic setting. Radical ablation of all oligometastatic sites may confer prolonged survival and possibly achieve cure in some patients. However, substantial debate remains about whether patients with oligometastatic disease could benefit from curative intent therapy or whether aggressive treatments expose some patients to futile toxicity. Optimal selection of patients, carefully balancing the currently known prognostic factors against the risks of toxicity is critical. Emerging evidence suggests that patients with a limited burden of disease, viral-related pharyngeal cancer, metachronous metastasis and lung-only metastasis may benefit most from this approach. Efforts are underway to identify biomarkers that can detect oligometastasis and better select patients who would derive the maximum benefit from an aggressive radical approach. The combination of radiotherapy and immunotherapy promises to enhance the anti-tumoral immune response and help overcome resistance. However, optimization of management algorithms, including patient selection, radiation dose and sequencing, will be critical in upcoming clinical trials. This review summarizes recent knowledge about the characteristics and investigational efforts regarding oligometastasis in HNSCC.

Curative intent Stereotactic Ablative Radiation Therapy (SABR) for treatment of lung oligometastases from head and neck squamous cell carcinoma (HNSCC): a multi-institutional retrospective study

OBJECTIVES

The aim of this retrospective study was to assess outcomes of SABR for metachronous isolated lung oligometastases from HNSCC.

METHODS

For patients who developed isolated, 1 or 2 lungs lesions (<5cm) consistent with metastases from HNSCC, the indication of SABR was validated in a multidisciplinary tumor board. All patients were monitored by CT or PET CT after SABR (Stereotactic Ablative Body Radiation) for HNSCC.

RESULTS

Between November 2007 and February 2018, 52 patients were treated with SABR for metachronous lung metastases. The median time from the treatment of the primary HNSCC to the development of lung metastases was 18 months (3-93). The cohort's median age was 65.5 years old (50-83). The vast majority (94.2%) received 60 Gy in three fractions. Forty-one patients (78.5%) presented a solitary lung metastasis, while 11 patients (21.5%) had two lung metastases. With a median follow-up of 45.3 months, crude local and metastatic control rates were 74 and 38%, respectively. 1 year and 2 year Overall Survival (OS) were 85.8 and 65.9%, respectively. The median OS was 46.8 months. About one-fourth of patients were retreated by SABR for distant pulmonary recurrence. The treatment was well tolerated with only one patient who reported ≥ grade 3 toxicity (1.9%).

CONCLUSION

In selected metastatic HNSCC patients, early detection and treatment of lung metastases with SABR is effective and safe. Prospective studies are required to validate this potential shift.

ADVANCES IN KNOWLEDGE

Patients with oligometastases and controlled primary HNSCC seem to benefit from metastasis directed therapies.

Current Therapy for Metastatic Head and Neck Cancer: Evidence, Opportunities, and Challenges

Management of metastatic head and neck squamous cell carcinoma is evolving as new systemic therapies have led to improvements in survival, and as advances in locoregional therapy and the increased numbers of patients with HPV-associated cancers who develop oligometastases raise the possibility of ablation of limited numbers of metastases. We review the data regarding first-line immunotherapy in PD-L1-expressing metastatic head and neck squamous cell carcinoma, the experience with aggressive local management of oligometastases, and promising novel immunotherapies, targeted therapies, and HPV-specific treatments. For patients with metastatic head and neck squamous cell carcinoma that is PD-L1 expressing, first-line systemic therapy is pembrolizumab or pembrolizumab with chemotherapy. Inclusion of chemotherapy is associated with higher objective response proportion in all biomarker subgroups and may have a greater impact on survival in HPV-associated cancers. For patients with oligometastatic disease, particularly when metastases are metachronous, current evidence supporting the role of local ablation is limited to a small number of retrospective studies. Based on retrospective data, patients with a smaller number of metastases, lung metastases, and/or virally associated head and neck squamous cell carcinoma are most likely to benefit from an aggressive ablative approach. Additionally, we review emerging evidence for targeted therapy in metastatic head and neck squamous cell carcinoma, including with agents that inhibit mutant HRAS or NOTCH1, or overexpressed EGFR. Studies of antiangiogenic agents in combination with immune checkpoint blockade, and combination immunotherapy, are also under study.

A Novel Radiotherapeutic Approach to Treat Bulky Metastases Even From Cutaneous Squamous Cell Carcinoma: Its Rationale and a Look at the Reliability of the Linear-Quadratic Model to Explain Its Radiobiological Effects

Introduction

Metastatic cutaneous squamous cell carcinoma (cSCC) is a very rare condition. The lack of definition of an oligometastatic subgroup means that there is no consensus for its treatment, unlike the mucosal head and neck counterpart. Like the latter, the cutaneous form is able to develop bulky tumor masses. When this happens, the classic care approach is just for palliative intent due to a likely unfavorable benefit–risk balance typical of aggressive treatments. Here we proposed a novel radiotherapy (RT) technique to treat bulky metastases from cSCC in the context of an overall limited tumor burden and tried to explain its clinical outcome by the currently available mathematical radiobiological and ad hoc developed models.

Methods

We treated a case of facial cSCC with three metastases: two of them by classic stereotactic RT and the other by lattice RT supported by metabolic imaging (¹⁸F-FDG PET) due to its excessively large dimensions. For the latter lesion, we compared four treatment plans with different RT techniques in order to define the best approach in terms of normal tissue complication probability (NTCP) and tumor control probability (TCP). Moreover, we developed an ad hoc mathematical radiobiological model that could fit better with the characteristics of heterogeneity of this bulky metastasis for which, indeed, a segmentation of normoxic, hypoxic, and necrotic subvolumes might have been assumed.

Results

We observed a clinical complete response in all three disease sites; the bulky metastasis actually regressed more rapidly than the other two treated by stereotactic RT. For the large lesion, NTCP predictions were good for all four different plans but even significantly better for the lattice RT plan. Neither the classic TCP nor the ad hoc developed radiobiological models could be totally adequate to explain the reported outcome. This finding might support a key role of the host immune system.

Conclusions

PET-guided lattice RT might be safe and effective for the treatment of bulky lesions from cSCC. There might be some need for complex mathematical radiobiological models that are able to take into account any immune system’s role in order to explain the possible mechanisms of the tumor response to radiation and the relevant key points to enhance it.

Recent Research on Combination of Radiotherapy with Targeted Therapy or Immunotherapy in Head and Neck Squamous Cell Carcinoma: A Review for Radiation Oncologists

Radiotherapy plays an important role of managing head and neck squamous cell carcinoma (HNSCC). Concurrent radiotherapy with radiosensitizing cisplastin chemotherapy is the standard of care (SOC) for non-operable locally advanced HNSCC. Cetuximab, a monoclonal antibody of epidermal growth factor receptor, was the most extensively studied targeted therapy as a chemo-sparing agent that was used concurrently with radiotherapy. Immunotherapy is used in the treatment of metastatic HNSCC. There is evidence to support the synergistic effect when combining radiotherapy with immunotherapy to potentiate anti-tumor immune response. There has been increasing interest to incorporate immune checkpoint inhibitor (ICI) with radiotherapy in the curative setting for HNSCC. In this review, we discuss the latest evidence that supports concurrent radiotherapy with cisplatin which remains the SOC for locally advanced HNSCC (LA-HNSCC). Cetuximab is suitable for patients who are not fit for cisplatin. We then summarize the clinical trials that incorporate ICI with radiotherapy for LA-HNSCC in concurrent, neoadjuvant, and adjuvant settings. We also discuss the potential of combining immunotherapy with radiotherapy as a treatment de-escalating strategy in HPV-associated oropharyngeal carcinoma. Finally, the pre-clinical and clinical evidence of the abscopal effect when combining stereotactic body radiotherapy with ICIs is presented.

Definitive radiotherapy for extracranial oligoprogressive metastatic renal cell carcinoma as a strategy to defer systemic therapy escalation

OBJECTIVE

To study whether delivering definitive radiotherapy (RT) to sites of oligoprogression in metastatic renal cell carcinoma (mRCC) enabled deferral of systemic therapy (ST) changes without compromising disease control or survival.

PATIENTS AND METHODS

We identified patients with mRCC who received RT to three or fewer sites of extracranial progressive disease between 2014 and 2019 at a large tertiary cancer centre. Inclusion criteria were: (1) controlled disease for ≥3 months before oligoprogression, (2) all oligoprogression sites treated with a biologically effective dose of ≥100 Gy, and (3) availability of follow-up imaging. Time-to-event end-points were calculated from the start of RT.

RESULTS

A total of 72 patients were identified (median follow-up 22 months, 95% confidence interval [CI] 19-32 months), with oligoprogressive lesions in lung/mediastinum (n = 35), spine (n = 30), and non-spine bone (n = 5). The most common systemic therapies before oligoprogression were none (n = 33), tyrosine kinase inhibitor (n = 23), and immunotherapy (n = 13). At 1 year, the local control rate was 96% (95% CI 87-99%); progression-free survival (PFS), 52% (95% CI 40-63%); and overall survival, 91% (95% CI 82-96%). At oligoprogression, ST was escalated (n = 16), maintained (n = 49), or discontinued (n = 7), with corresponding median (95% CI) PFS intervals of 19.7 (8.2-27.2) months, 10.1 (6.9-13.2) months, and 9.8 (2.4-28.9) months, respectively. Of the 49 patients maintained on the same ST at oligoprogression, 21 did not subsequently have ST escalation.

CONCLUSION

Patients with oligoprogressive mRCC treated with RT had comparable PFS regardless of ST strategy, suggesting that RT may be a viable approach for delaying ST escalation. Randomised controlled trials comparing treatment of oligoprogression with RT vs ST alone are needed.

Treatment of Oligometastatic Disease in Squamous Cell Carcinoma of the Head and Neck

OBJECTIVE

No surgical or radiotherapeutic treatment guidelines exist for oligometastatic head and neck squamous cell carcinoma (oHNSCC), and only recently have interventions with curative intent been studied. Herein, we sought to elucidate survival rates among patients with oHNSCC to determine if treatment with curative intent is warranted in this population.

STUDY DESIGN

Retrospective chart review.

METHODS

We retrospectively reviewed cases of oHNSCC treated between March 1998 and March 2018. Fisher's exact test was used to compare patients treated with radiotherapy (RT) to those who underwent surgical excision and to compare outcomes of patients with oligometastases at the time of initial presentation to those that developed oligometastatic disease after primary treatment.

RESULTS

Eighty one patients with metastases to the lungs, ribs, pelvis, vertebral column, liver, clavicle, and sternum were included. Overall, 32 patients (40%) were alive 5 years post-treatment. The site of metastasis, the modality of treatment, and the time of development of oligometastatic disease did not significantly affect 5-year survival.

CONCLUSION

Herein, we demonstrate that multi-modality treatment of oHNSCC is warranted for some patients with an estimated 40% 5-year survival. Aggressive treatment of the primary and regional sites is necessary in addition to treatment of the metastatic site and incurs a survival benefit compared to patients with metastatic HNSCC treated with systemic therapy alone. oHNSCC should be approached separately from polymetastatic disease. Patients should be counseled about the possibility for long-term survival, and aggressive initial treatment with the intention for cure should be considered in this population.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E1476-E1480, 2021.

Oligometastatic head and neck cancer: Which patients benefit from radical local treatment of all tumour sites?

Background

There is a large lack of evidence for optimal treatment in oligometastatic head and neck cancer and it is especially unclear which patients benefit from radical local treatment of all tumour sites.

Methods

40 patients with newly diagnosed oligometastatic head and neck cancer received radical local treatment of all tumour sites from 14.02.2008 to 24.08.2018. Primary endpoint was overall survival. Time to occurrence of new distant metastases and local control were evaluated as secondary endpoints as well as prognostic factors in univariate und multivariate Cox’s regression analysis. To investigate the impact of total tumour volume on survival, all tumour sites were segmented on baseline imaging.

Results

Radical local treatment included radiotherapy in 90% of patients, surgery in 25% and radiofrequency ablation in 3%. Median overall survival from first diagnosis of oligometastatic disease was 23.0 months, 2-year survival was 48%, 3-year survival was 37%, 4-year survival was 24% and 5-year survival was 16%. Median time to occurrence of new distant metastases was 11.6 months with freedom from new metastases showing a tail pattern after 3 years of follow-up (22% at 3, 4- and 5-years post-treatment). In multivariate analysis, better ECOG status, absence of bone and brain metastases and lower total tumour volume were significantly associated with improved survival, whereas the number of metastases and involved organ sites was not.

Conclusions

Radical local treatment in oligometastatic head and neck cancer shows promising outcomes and needs to be further pursued. Patients with good performance status, absence of brain and bone metastases and low total tumour volume were identified as optimal candidates for radical local treatment in oligometastatic head and neck cancer and should be considered for selection in future prospective trials.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-021-01790-w.

Oligometastases in head and neck carcinoma and their impact on management

Historically, patients with head and neck squamous cell carcinoma (HNSCC) with distant metastases were regarded as palliative. Oligometastasis (OM) refers to patients with a limited number of distant metastatic deposits. Treatment of patients with OMs has been reported in patients with lung, colon, breast, prostate and brain malignancies. Selected patients with oligometastatic HNSCC have a higher probability of durable disease control and cure and these patients should be treated aggressively. Treatment options for patients with HNSCC OMs include single or combinations of the three arms of cancer treatment, that is surgery, radiotherapy and chemotherapy/immunotherapy. To date, there are limited studies reporting the management of OM with head and neck malignancy. This review will give insights into the management of OMs in HNSCC.

Prognosis and management of recurrent and/or metastatic head and neck adenoid cystic carcinoma

Adenoid cystic carcinoma (ACC) is a rare tumor, usually arising in the salivary gland, accounting for 1% of all head and neck cancers. ACC may have a long-term poor prognosis, as about 40% of radically treated patients will recur locoregionally and up to 60% will develop distant metastasis. Factors influencing risk of recurrence have been well studied, but few data exist about prognostic factors in Recurrent/Metastatic (RM) setting. Moreover, treatment of RM ACC is often a challenge for clinicians, in the context of a rare disease, which may have an indolent clinical behavior or less frequently a quicker growth and with a paucity of available clinical trials. This review critically analyzes pathological and molecular prognostic factors in RM ACC and make an overview on actual therapeutic choices and future direction of therapy. Recognized prognostic factors in RM ACC are the presence and site of distant metastasis (lung vs other), the presence of nodal metastasis and of extranodal extension, skull base recurrence, disease free interval, lymphovascular invasion, solid histotypes and grading of disease, and the presence of mutation of NOTCH1 family, PI3K, and TP53. Due to disappointing results with chemotherapy, new approaches are under study, also on the basis of biomolecular research. Ongoing clinical trials are evaluating treatment targeting MYB and NOTCH1 alterations, immunotherapy or combination of targeted treatments and immune checkpoint inhibitors.

Metastasis-directed stereotactic body radiation therapy in the management of oligometastatic head and neck cancer

INTRODUCTION

Recently major efforts have been made to define the oligometastatic setting, but for head and neck cancer (HNC) limited data are available. We aimed to evaluate outcome of oligometastatic HNC treated with Stereotactic body radiotherapy (SBRT) as metastasis-directed therapy.

MATERIALS AND METHODS

We analyzed patients treated with SBRT on a maximum of five oligometastases from HNC, in up to two organs. Concomitant treatment was allowed. End points were toxicity, local control of treated metastases (LC), progression-free survival (PFS) and overall survival (OS).

RESULTS

48 consecutive patients and 71 lesions were treated. With a follow-up of 20.2 months, most common primary tumors were larynx (29.2%) and salivary glands (29.2%), while common site of metastases was lung (59.1%). Median dose was 48 Gy (21-75) in 3-8 fractions. Treatment was well tolerated, with two patients reporting mild pain and nausea. LC rates at 1 and 2 years were 83.1% and 70.2%. Previous local therapy (HR 4.97; p = 0.002), oligoprogression (HR 4.07; p = 0.031) and untreated metastases (HR 4.19; p = 0.027) were associated with worse LC. PFS at 1 and 2 years were 42.2% and 20.0%. Increasing age (HR 1.03; p = 0.010), non-adenoid cystic carcinoma (HR 2.57; p = 0.034) and non-lung metastases (HR 2.20; p = 0.025) were associated with worse PFS. One- and 2-years OS were 81.0% and 67.1%. Worse performance status (HR 2.91; p = 0.049), non-salivary primary (HR 19.9; p = 0.005), non-lung metastases (HR 2.96; p = 0.040) were correlated with inferior OS.

CONCLUSIONS

SBRT can be considered a safe metastasis-directed therapy in oligometastatic HNC. Efficacy of the treatment seems to be higher when administered upfront in the management of metastatic disease; however, selection of patients need to be improved due to the relevant risk of appearance of new metastatic site after SBRT.

Oligometastatic Disease Management: Finding the Sweet Spot

Hematogenous dissemination represents a common manifestation of squamous cell carcinoma of the head and neck, and the recommended therapeutic options usually consist of systemically administered drugs with palliative intent. However, mounting evidence suggests that patients with few and slowly progressive distant lesions of small size may benefit from various local ablation techniques, which have already been established as standard-of-care modalities for example in colorectal and renal cell carcinomas and in sarcomas. In principle, serving as radical approaches to eradicate cancer, these interventions can be curative. Their impact on local control and overall survival has been shown in numerous retrospective and prospective studies. The term oligometastatic refers to the number of distant lesions which should generally not surpass five in total, ideally in one organ. Currently, surgical resection remains the method of choice supported by the majority of published data. More recently, stereotactic (ablative) body radiotherapy (SABR/SBRT) has emerged as a viable alternative. In cases technically amenable to such local interventions, several other clinical variables need to be taken into account also, including patient-related factors (general health status, patient preferences, socioeconomic background) and disease-related factors (primary tumor site, growth kinetics, synchronous or metachronous metastases). In head and neck cancer, patients presenting with late development of slowly progressive oligometastatic lesions in the lungs secondary to human papillomavirus (HPV)-positive oropharyngeal cancer are the ideal candidates for metastasectomy or other local therapies. However, literature data are still limited to say whether there are other subgroups benefiting from this approach. One of the plausible explanations is that radiological follow-up after primary curative therapy is usually not recommended because its impact on survival has not been unequivocal, which is also due to the rarity of oligometastatic manifestations in this disease. At the same time, aggressive treatment of synchronous metastases early in the disease course should be weighed against the risk of futile interventions in a disease with already multimetastatic microscopic dissemination. Therefore, attentive treatment sequencing, meticulous appraisal of cancer extension, refinement of post-treatment surveillance, and understanding of tumor biology and kinetics are crucial in the management of oligometastases.

Metastatic salivary gland carcinoma: A role for stereotactic body radiation therapy? A study of AIRO-Head and Neck working group

OBJECTIVES

The role of radiotherapy (RT) for oligometastases is currently established in different oncological settings but data on salivary gland cancer (SGC) are lacking. We evaluated the role of RT in oligometastatic SGC patients, focusing on stereotactic body radiation therapy (SBRT).

MATERIALS AND METHODS

We performed a retrospective, multicentric study of oligometastatic SGC treated with palliative RT or SBRT. Endpoints included response evaluation and local control (LC).

RESULTS

Between 2006 and 2016, 64 patients were collected from 9 Italian Cancer Centers, on behalf of the Italian Association of Radiotherapy and Clinical Oncology (AIRO) Head and Neck Working Group. 37 patients (57.8%) were suffering from adenoid cystic carcinoma (ACC) and 27 patients (42.2%) had non-ACC. Thirty-four patients underwent palliative RT (53,1%), and 30 received SBRT (46,9%). Most common metastatic sites were bone for palliative RT and lung for SBRT. Among patients treated with SBRT, an objective response or a stability was observed in all treated lesions. After a median follow-up of 29.2 months (range 2.3-117.1), LC at 12 months was 57.5% for patients treated with SBRT and was higher in ACC subgroup.

CONCLUSION

We confirmed the potential role of SBRT in the management of oligometastatic SGC patients to control limited burden of disease considering the absence of effective systemic therapies.

Head and Neck Cancers, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology

Treatment is complex for patients with head and neck (H&N) cancers with specific site of disease, stage, and pathologic findings guiding treatment decision-making. Treatment planning for H&N cancers involves a multidisciplinary team of experts. This article describes supportive care recommendations in the NCCN Guidelines for Head and Neck Cancers, as well as the rationale supporting a new section on imaging recommendations for patients with H&N cancers. This article also describes updates to treatment recommendations for patients with very advanced H&N cancers and salivary gland tumors, specifically systemic therapy recommendations.

Metastatic disease in head & neck oncology

The head and neck district represents one of the most frequent sites of cancer, and the percentage of metastases is very high in both loco-regional and distant areas. Prognosis refers to several factors: a) stage of disease; b) loco-regional relapses; c) distant metastasis. At diagnosis, distant metastases of head and neck cancers are present in about 10% of cases with an additional 20-30% developing metastases during the course of their disease. Diagnosis of distant metastases is associated with unfavorable prognosis, with a median survival of about 10 months. The aim of the present review is to provide an update on distant metastasis in head and neck oncology. Recent achievements in molecular profiling, interaction between neoplastic tissue and the tumor microenvironment, oligometastatic disease concepts, and the role of immunotherapy have all deeply changed the therapeutic approach and disease control. Firstly, we approach topics such as natural history, epidemiology of distant metastases and relevant pathological and radiological aspects. Focus is then placed on the most relevant clinical aspects; particular attention is reserved to tumours with distant metastasis and positive for EBV and HPV, and the oligometastatic concept. A substantial part of the review is dedicated to different therapeutic approaches. We highlight the role of immunotherapy and the potential effects of innovative technologies. Lastly, we present ethical and clinical perspectives related to frailty in oncological patients and emerging difficulties in sustainable socio-economical governance.