HPV circulating tumor DNA to monitor the efficacy of anti‐PD‐1 therapy in metastatic squamous cell carcinoma of the anal canal: A case report

Squamous cell carcinoma of the anal canal (SCCA) is a rare HPV‐associated cancer with limited sensitivity to standard chemotherapy. In a phase 2 study, nivolumab, an anti PD‐1 immune checkpoint inhibitor, demonstrated significant efficacy as single‐agent therapy in metastatic SCCA patients. Nevertheless, imaging assessment by standard RECIST criteria of the efficacy of immune therapy can be difficult in some patients due to tumor immune cell infiltration, and biomarkers of treatment efficacy are needed. We have previously developed a quantitative droplet digital PCR (ddPCR) technique to detect HPV circulating tumor DNA (HPV ctDNA), with excellent sensitivity and specificity. Here, we report, for the first time, the kinetics of HPV ctDNA during therapy in a patient with metastatic SCCA, who obtained sustained partial response to single‐agent nivolumab. We observed an early and very significant decrease of HPV ctDNA during therapy from the baseline level of 3713 copies/ml plasma to 564 copies/ml plasma at 4 weeks, and 156 copies/ml at 6 weeks, followed by a plateau. This observation provides proof‐of‐concept that HPV ctDNA can be used as a noninvasive early dynamic biomarker to monitor the efficacy of new immunotherapy agents.     

Comparison of salivary and plasma antioxidant levels in lichen planus patients and healthy subjects

J Oral Pathol Med (2012) 41 : 524–526 Introduction: Oral lichen planus (OLP) is a chronic, mucocutaneous, inflammatory disease. It has become more evident that the immune system plays a primary role in the development of this disease. The aim of the present study was to evaluate the total antioxidant status (TAS) of saliva and serum in patients with erosive OLP. Method and Materials: This study was designed as case‐control. In total, 48 patients with erosive OLP (34 women and 14 men) were enrolled as case group, and 44 self‐admitted healthy people (34 women and 10 men) were selected as control group. Measurement of total antioxidant status was carried out in saliva and plasma. t‐test was used for statistical analysis with significant level set at P < 0.05. Results: The mean ± SD of salivary TAS in case group was 0.98 ± 0.12, and in control group was 1.32 ± 0.18 mM, respectively, and there were significant differences between groups (P < 0.02). The mean ± SD of the plasma TAS in the case group and the control group was 1.24 ± 0.17 and 1.84 ± 0.34 mM, respectively. There were significant differences between two groups (P < 0.01). Conclusion: Our results showed that salivary and plasma levels of total antioxidant status in erosive OLP patients were lower than those in healthy subjects.