Tumor volume and cancer stem cell expression as prognostic markers for high-dose loco-regional failure in head and neck squamous cell carcinoma - A DAHANCA 19 study

BACKGROUND AND PURPOSE

Reliable and accessible biomarkers for patients with Head and Neck Squamous Cell Carcinoma (HNSCC) are warranted for biologically driven radiotherapy (RT). This study aimed to investigate the prognostic value of putative cancer stem cell (CSC) markers, hypoxia, and tumor volume using loco-regional high-dose failure (HDF) as endpoint.

MATERIALS AND METHODS

Tumor tissue was retrieved from patients treated with primary chemo-(C-)RT and nimorazole for HNSCC in the Danish Head and Neck Cancer Study Group (DAHANCA) 19 study. Tumor volume, hypoxic classification, and expression of CSC markers CD44, SLC3A2, and MET were analyzed. For patients with eligible data on all parameters (n = 340), the risk of HDF following primary chemo-(C-)RT were analyzed by these biomarkers as a whole and stratified for p16-positive oropharynx (p16 + OPSCC) vs p16-negative (p16-) tumors (oral cavity, p16- oropharynx, hypopharynx and larynx).

RESULTS

Higher risk of HDF was seen for patients with larger primary and nodal volume (>25 cm3, Hazard Ratio (HR): 3.00 [95 % CI: 1.73-5.18]), high SLC3A2 (HR: 2.99 [1.28-6.99]), CD44 (>30 % positive, HR: 2.29 [1.05-5.00]), and p16- tumors (HR: 2.53 [1.05-6.11]). p16- tumors had a higher CSC marker expression than p16 + OPSCC. The factors associated with the highest risk of HDF were larger volume (HR: 3.29 [1.79-6.04]) for p16- tumors (n = 178) and high SLC3A2 (HR: 6.19 [1.58-24.23]) for p16 + OPSCC (n = 162).

CONCLUSION

Tumor volume, p16, and CSC markers are potential biomarkers for HDF for patients with HNSCC treated with (C-)RT. Lower expression of CSC in p16 + OPSCC may contribute to better tumor control.

Separating distant recurrences from second primaries in head and neck squamous cell carcinomas - A DAHANCA group analysis on paired tumor samples

BACKGROUND

In head and neck squamous cell carcinomas (HNSCC), there is no clinically available method to separate distant metastases (DMs) from SCC secondary primary tumors. The study aimed to assess the genetic relationship in paired tumor samples.

METHODS

Patients with pairs of solid biopsies from the primary HNSCC and suspected DMs were identified (2007-2017). Targeted next-generation sequencing of 22 genes was applied, including TP53, supplemented with human papillomavirus (HPV) genotyping.

RESULTS

Of 55 pairs obtained, 33 were successfully analyzed. Distant biopsies included lung, liver, and bone. A genetic match was found in 23/33 (70%) patients, primarily with identical TP53 mutations or HPV genotypes. In 10/33 patients (30%), the genetic relationship was absent, all with lung involvement. In patients with no lung involvement, 8/8 had a match.

CONCLUSIONS

One-third of patients with DMs in HNSCC lack a genetic relationship with the primary tumors. The risk of misclassification is most prominent for patients with lung involvement.

HPV testing versus p16 immunohistochemistry in oropharyngeal squamous cell carcinoma: results from the DAHANCA 19 study

INTRODUCTION

The prognosis after primary (chemo-)radiotherapy for oropharyngeal squamous cell carcinoma (OPSCC) is affected by Human Papillomavirus (HPV) status, with a better prognosis in HPV-positive OPSCC. HPV-status is routinely assessed by p16 immunohistochemistry (IHC), but additional HPV DNA testing is debated. Also, there are numerous HPV genotypes, which prognostic role may need clarification. The purpose of this study was: (1) to test a custom-made targeted HPV next generation sequencing (NGS) panel in OPSCC, (2) to determine correlation with p16 IHC, and (3) to assess the impact of HPV DNA testing on outcome in the prospectively randomized clinical trial DAHANCA 19.

MATERIALS AND METHODS

We included 271 patients with OPSCC treated with primary (chemo-)radiotherapy in the DAHANCA 19 trial. Of these, 199 (73%) were p16-positive. HPV-status was determined by targeted HPV next generation sequencing (NGS), using a custom-made HPV genotyping panel.

RESULTS

HPV was detected in 194 tumor samples. p16 IHC and NGS HPV status were concordant in 265 (98%) of 271 patients, whereas we did not detect HPV DNA in 5 p16-positive tumors. HPV16 accounted for 169 of 194 HPV-positive cases (87%). HPV genotypes 18, 31, 33, 35, and 59 were also detected.Loco-regional failure and overall survival were similar whether patients were separated by p16 IHC, or HPV DNA status (p < 0.0001 for all) and did not depend on HPV genotype (p = 0.9 and p = 0.7).

CONCLUSION

In the present study, HPV DNA testing or typing in a Danish OPSCC cohort did not add additional information to p16 IHC, the most widely used and accepted prognostic indicator.

Characterization and radiosensitivity of HPV-related oropharyngeal squamous cell carcinoma patient-derived xenografts

Background: Oropharyngeal squamous cell carcinomas (OPSCC) are rising rapidly in incidence due to Human Papillomavirus (HPV) and/or tobacco smoking. Prognosis is better for patients with HPV-positive disease, but may also be influenced by tobacco smoking and other factors. There is a need to individualize treatment to minimize morbidity and improve prognosis. Patient-derived xenografts (PDX) is an emerging pre-clinical research model that may more accurately reflect the human disease, and is an attractive platform to study disease biology and develop treatments and biomarkers. In this study we describe the establishment of PDX models, compare PDX tumors to the human original, and assess the suitability of this model for radiotherapy research and biomarker development. Material and methods: Tumor biopsies from 34 patients with previously untreated OPSCC were implanted in immunodeficient mice, giving rise to 12 squamous cell carcinoma PDX models (7 HPV+, 5 HPV-). Primary and PDX tumors were characterized extensively, examining histology, immunohistochemistry, cancer gene sequencing and gene expression analysis. Radiosensitivity was assessed in vivo in a growth delay assay. Results: Established PDX models maintained histological and immunohistochemical characteristics as well as HPV-status of the primary tumor. Important cancer driver gene mutations, e.g., in TP53, PIK3CA and others, were preserved. Gene expression related to cancer stem cell markers and gene expression subtype were preserved, while gene expression related to hypoxia and immune response differed. Radiosensitivity studies showed high concordance with clinical observations. Conclusion: PDX from OPSCC preserves important molecular characteristics of the human primary tumor. Radiosensitivity were in accordance with clinically observed treatment response. The PDX model is a clinically relevant surrogate model of head and neck cancer. Perspectives include increased understanding of disease biology, which could lead to development of novel treatments and biomarkers.

Pediatric malignancies presenting in the head and neck

OBJECTIVES

Childhood cancer is rare and often difficult to diagnose. In the head and neck region, benign diseases are much more common. The aim of this study was to estimate the proportion of childhood cancer cases with a primary head and neck presentation, to describe symptoms, physical findings, diagnostic interval and tentative diagnoses.

METHODS

Registry-based retrospective cohort study, with patients identified in the Danish Childhood Cancer Registry. Review of medical records, imaging reports and pathology reports. All childhood cancer patients less than 15 years of age with primary disease presentation in the head and neck region from the Central Danish Region in the years 2003-2013. Outcome measures were proportion of patients with a primary head and neck presentation; frequency of physical findings; diagnostic intervals; and frequency of tentative diagnoses.

RESULTS

85 patients (15% of all childhood cancers) had primary disease presentation in the head & neck region (95% confidence interval [CI]: 12 - 18%). A total of 24% (CI: 21 - 28%) of patients had any symptoms or findings from the head and neck region at presentation. Most common symptoms and findings were a swelling or a tumor, and possibly general symptoms. Diagnostic interval was more than three weeks in three out of four of patients. Primary suspicion was most commonly an infectious disease.

CONCLUSIONS

A substantial proportion of patients with childhood cancer have disease presentation in the head and neck. Worth noting is, that symptoms and findings are easily mistaken for an infectious disease, which probably explains the significant diagnostic interval.

[Sublingual haematoma as a result of dysregulated peroral anticoagulant therapy]

We describe a case of spontaneous sublingual haematoma secondary to warfarin toxicity, leading to impending airway obstruction. The case was handled with the administration of vitamin K and fresh frozen plasma, and without invasive airway handling. Furthermore, we discuss the presentation of the condition and the signs of impending airway obstruction. Preferred management includes a safe airway and reversion of coagulopathy. The prognosis is good when treatment is prompt and correct.