Bone metastases from head and neck malignancies: Prognostic factors and skeletal-related events

Advancing Treatment of Bone Metastases through Novel Translational Approaches Targeting the Bone Microenvironment

Bone metastases represent a lethal condition that frequently occurs in solid tumors such as prostate, breast, lung, and renal cell carcinomas, and increase the risk of skeletal-related events (SREs) including pain, pathologic fractures, and spinal cord compression. This unique metastatic niche consists of a multicellular complex that cancer cells co-opt to engender bone remodeling, immune suppression, and stromal-mediated therapeutic resistance. This review comprehensively discusses clinical challenges of bone metastases, novel preclinical models of the bone and bone marrow microenviroment, and crucial signaling pathways active in bone homeostasis and metastatic niche. These studies establish the context to summarize the current state of investigational agents targeting BM, and approaches to improve BM-targeting therapies. Finally, we discuss opportunities to advance research in bone and bone marrow microenvironments by increasing complexity of humanized preclinical models and fostering interdisciplinary collaborations to translational research in this challenging metastatic niche.

Association of circulating protein biomarkers with clinical outcomes of durvalumab in head and neck squamous cell carcinoma

The potential for durvalumab, a programmed cell death ligand-1 (PD-L1)-blocking monoclonal antibody, to treat head and neck squamous cell carcinoma (HNSCC) is being evaluated in multiple clinical trials. We assessed circulating proteins at baseline to identify potential biomarkers and to understand pathways related to clinical outcomes for durvalumab. Prior to treatment, 66 serum proteins were measured using multiplex immunoassays for 158 durvalumab-treated HNSCC patients in the phase II HAWK and CONDOR trials as a discovery dataset and 209 durvalumab-treated HNSCC patients in the phase III EAGLE trial as a validation dataset. Multivariate Cox modeling of HAWK and CONDOR datasets established that higher baseline concentrations of interleukin-6 (IL-6), C-reactive protein, S100 calcium-binding protein A12, and angiopoietin-2 (ANGPT2) were associated with shorter overall survival (OS), while higher concentrations of osteocalcin correlated with longer OS after durvalumab treatment (p < .05). All five proteins remained significantly correlated with OS after adjusting for baseline clinical factors, with consistent results across clinical efficacy endpoints based on univariate correlation analyses. The validation dataset from the EAGLE trial confirmed the independent association of IL-6 and osteocalcin with OS, and preserved directional trends for the other biomarkers identified in the discovery dataset. Our results demonstrate the important role of immunosuppressive proteins in the resistance of HNSCC to durvalumab treatment. Osteocalcin showed a positive correlation with clinical outcomes, which remains to be further investigated.

High Prevalence and Early Occurrence of Skeletal Complications in EGFR Mutated NSCLC Patients With Bone Metastases

Objectives

The prevalence of Skeletal Related Adverse Events (SREs) in EGFR mutated non-small cell lung cancer (NSCLC) patients with bone metastases, treated with modern tyrosine kinase inhibitors (TKIs), has been scarcely investigated.

Materials and Methods

We retrospectively evaluated the data of EGFR mutated NSCLC patients with bone metastases treated with TKIs in 12 Italian centers from 2014 to 2019, with the primary aim to explore type and frequency of SREs.

Results

Seventy-seven out of 274 patients enrolled (28%) developed at least one major SRE: 55/274 (20%) bone fractures, 30/274 (11%) spinal cord compression, 5/274 (2%) hypercalcemia. Median time to the onset of SRE was 3.63 months. Nine patients (3%) underwent bone surgery and 150 (55%) radiation therapy on bone. SREs were more frequently observed within the 12 months from TKI start than afterwards (71 vs 29%, p 0.000). Patient Performance Status and liver metastases where independently associated with the risk of developing SREs. Median TKI exposure and overall survival were 11 and 28 months, respectively. Bone resorption inhibitors were associated with a lower risk of death (HR 0.722, 95% CI: 0.504–1.033, p = 0.075) although not statistically significant at multivariate analysis.

Conclusion

Bone metastatic NSCLC patients with EGFR mutated disease, treated with EGFR TKIs, have a relatively long survival expectancy and are at high risk to develop SREs. The early SRE occurrence after the TKI start provides the rationale to administer bone resorption inhibitors.

The Role of Palliative Radiotherapy in the Treatment of Spinal Bone Metastases from Head and Neck Tumors-A Multicenter Analysis of a Rare Event

This retrospective multi-center analysis aimed to assess the clinical response and stabilizing effects of palliative radiotherapy (RT) for spinal bone metastases (SBM) in head and neck cancer (HNC), and to establish potential predictive factors for stability and overall survival (OS). Patients included in this analysis were treated at the University Hospitals of Mainz, Freiburg, and Heidelberg between 2001 and 2019. Clinical information was taken from the medical records. The stability of affected vertebral bodies was assessed according to the validated spine instability neoplastic score (SINS) based on CT-imaging before RT, as well as 3 and 6 months after RT. OS was quantified as the time between the start of palliative RT and death from any cause or last follow-up. Potential predictive factors for stability and OS were analyzed using generalized estimating equations and Cox regression for time-varying covariates to take into account multiple observations per patient. The mean follow-up time of 66 included patients after the first palliative RT was 8.1 months (range 0.3–85.0 months). The majority of patients (70%; n = 46) had squamous cell carcinomas (SCC) originating from the pharynx, larynx and oral cavity, while most of the remaining patients (26%; n = 17) suffered from salivary glands tumors. A total of 95 target volumes including 178 SBM were evaluated that received a total of 81 irradiation series. In patients with more than one metastasis per irradiated region, only the most critical bone metastasis was analyzed according to the SINS system. Prior to RT, pain and neurologic deficits were present in 76% (n = 72) and 22% (n = 21) of irradiated lesions, respectively, and 68% of the irradiated lesions (n = 65) were assessed as unstable or potentially unstable prior to RT. SBM-related pain symptoms and neurologic deficits responded to RT in 63% and 47% of the treated lesions, respectively. Among patients still alive at 3 and 6 months after RT with potentially unstable or unstable SBM, a shift to a better stability class according to the SINS was observed in 20% and 33% of the irradiated SBM, respectively. Pathological fractures of SBM were frequently detected before the start of irradiation (43%; n = 41), but after RT, new fractures or increasing vertebral body sintering within the irradiated region occurred rarely (8%; n = 8). A pathological fracture before RT was negatively associated with stabilization 6 months after RT (OR 0.1, 95% CI 0.02–0.49, p = 0.004), while a Karnofsky performance score (KPS) ≥ 70% was associated positively with a stabilization effect through irradiation (OR 6.09, 95% CI 1.68–22.05, p = 0.006). Mean OS following first palliative RT was 10.7 months, and the KPS (≥70% vs. <70%) was shown to be a strong predictive factor for OS after RT (HR 0.197, 95% CI 0.11–0.35, p < 0.001). There was no significant difference in OS between patients with SCC and non-SCC. Palliative RT in symptomatic SBM of HNC provides sufficient symptom relief in the majority of patients, while only about one third of initially unstable SBM show re-stabilization after RT. Since patients in our multi-center cohort exhibited very limited OS, fractionation schemes should be determined depending on the patients’ performance status.

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.