Development of a high-performance multi-probe droplet digital PCR assay for high-sensitivity detection of human papillomavirus circulating tumor DNA from plasma.

OBJECTIVES: To develop a high-performance droplet digital PCR (ddPCR) assay capable of enhancing the detection of human papillomavirus (HPV) circulating tumor DNA (ctDNA) in plasma from patients with HPV-associated oropharyngeal squamous cell carcinoma (HPV+ OPSCC). MATERIALS AND METHODS: Plasma samples from subjects with HPV+ OPSCC were collected. We developed a high-performance ddPCR assay designed to simultaneously target nine regions of the HPV16 genome. RESULTS: The new assay termed 'ctDNA HPV16 Assessment using Multiple Probes' (CHAMP- 16) yielded significantly higher HPV16 counts compared to our previously validated 'Single-Probe' (SP) assay and a commercially available NavDx® assay. Analytical validation demonstrated that the CHAMP-16 assay had a limit of detection (LoD) of 4.1 copies per reaction, corresponding to < 1 genome equivalent (GE) of HPV16. When tested on plasma ctDNA from 21 patients with early-stage HPV+ OPSCC and known HPV16 ctDNA using the SP assay, all patients were positive for HPV16 ctDNA in both assays and the CHAMP-16 assay displayed 6.6-fold higher HPV16 signal on average. Finally, in a longitudinal analysis of samples from a patient with recurrent disease, the CHAMP-16 assay detected HPV16 ctDNA signal âˆ¼ 20 months prior to the conventional SP assay. CONCLUSION: Increased HPV16 signal detection using the CHAMP-16 assay suggests the potential for detection of recurrences significantly earlier than with conventional ddPCR assays in patients with HPV16+ OPSCC. Critically, this multi-probe approach maintains the cost-benefit advantage of ddPCR over next generation sequencing (NGS) approaches, supporting the cost-effectiveness of this assay for both large population screening and routine post-treatment surveillance.

The future of circulating tumor DNA as a biomarker in HPV related oropharyngeal squamous cell carcinoma.

Human papillomavirus (HPV) related oropharyngeal squamous cell carcinoma (OPSCC) is associated with improved outcomes compared to non-virally mediated disease. Clinical trials are actively investigating de-escalation strategies to maintain excellent survival outcomes while minimizing toxicity. Delivery of effective precision medicine-based therapeutic approaches are strengthened by the identification of biomarkers to predict treatment response. Plasma circulating tumor (ct) DNA is the most studied liquid biomarker in head and neck cancer and has shown great promise in the ability to determine treatment response and monitor for disease recurrence. In this review, we examine the emerging evidence for ctDNA as a biomarker in HPV related OPSCC and discuss opportunities for future investigation and integration into clinical practice.

Prognostic value of CD103+ tumor-infiltrating lymphocytes and programmed death ligand-1 (PD-L1) combined positive score in recurrent laryngeal squamous cell carcinoma.

OBJECTIVES: In an evolving era of immunotherapeutic options for persistent or recurrent laryngeal squamous cell carcinoma (LSCC), there is a need for improved biomarkers of treatment response and survival to inform optimal treatment selection and prognostication. Herein, our primary objective was to explore correlations between tumor infiltrating lymphocytes (TILs) and PD-L1 Combined Positive Score (CPS). Secondarily, we sought to explore their combined association with survival outcomes in patients with persistent or recurrent LSCC treated with salvage surgery. MATERIALS AND METHODS: This was a retrospective cohort study at a single academic medical center. Immunohistochemistry staining for TILs and PD-L1 was performed on a tissue microarray of persistent or recurrent LSCC pathologic specimens. Correlations between TIL subsets and PD-L1 CPS were examined using Pearson's correlation coefficient and survival outcomes were analyzed with the Kaplan-Meier method and log-rank tests. RESULTS: Only CD103+ TILs showed a statistically significant, weakly-positive correlation with PD-L1 CPS (r2 = 0.264, p < 0.015). No other TIL subsets correlated with PD-L1 CPS in our cohort. The most favorable survival outcomes were seen in patients with pathologic N0 tumors showing high CD103+ TILs and/or high PD-L1 CPS staining. CONCLUSION: Among patients with persistent or recurrent LSCC, CD103+ TILs only modestly correlated with PD-L1 CPS. A combined biomarker score incorporating CD103+ TILs and PD-L1 CPS greatly enhanced survival discrimination. This model may have additional utility in predicting the clinical benefit of immunotherapies in persistent or recurrent LSCC in the future.

From VA Larynx to the future of chemoselection: Defining the role of induction chemotherapy in larynx cancer.

Organ preservation protocols utilizing induction chemotherapy as a selection agent have played a critical role in the treatment of advanced laryngeal squamous cell carcinoma (LSCC). The selection of patients who will have a good response to chemoradiation allows for organ preservation in a significant group of patients and minimizes the rate of surgical salvage. While there remains debate regarding its utility when compared to surgery or other organ preservation regimens, the data does suggest an important role for induction chemotherapy in LSCC. In addition, there are continued opportunities to identify pretreatment biomarkers for induction chemotherapy, whether genetic, epigenetic or cellular, that could predict response to treatment and select patients to therapy (whether organ preservation or surgery). As our understanding of the biology of larynx cancer advances, induction paradigms have utility for the development and adoption of novel agents and therapeutics. The background of induction chemotherapy as a selection agent and future directions of this approach are discussed.