Novel Prognostic Score for recurrent or metastatic head and neck cancer patients treated with Nivolumab

Although several prognostic factors in nivolumab therapy have been reported in recurrent or metastatic head and neck cancer (RM-HNC) patients, these factors remain controversial. Here, we conducted a multicenter retrospective cohort study to investigate the impact of clinico-hematological factors on survival in RM-HNC patients treated with nivolumab. We reviewed 126 RM-HNC patients from seven institutes. We evaluated the prognostic effects of clinico-hematological factors on survival. The median overall survival (OS) was 12.3 months, and the 1 year-OS rate was 51.2%. Patients without immune-related adverse events, lower relative eosinophil count, worse best overall response, higher performance status, and higher modified Glasgow Prognostic Score had worse survival. The score, generated by combining these factors, was associated with survival. Patients with score of 4–5 had worse survival than those with score of 2–3 and 0–1 [adjusted HR for PFS: score of 4–5, 7.77 (3.98–15.15); score of 2–3, 3.44 (1.95–6.06), compared to score of 0–1], [adjusted HR for OS: score of 4–5, 14.66 (4.28–50.22); score of 2–3, 7.63 (2.29–25.37), compared to score of 0–1]. Our novel prognostic score utilizing clinico-hematological factors might be useful to establish an individual treatment strategy in RM-HNC patients treated with nivolumab therapy.

Efficacy of gemcitabine and cetuximab combination treatment in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) may be curable with surgery, radiation and chemotherapy in its early stages. However, recurrence and metastasis often prevail following primary treatment in advanced stage cases and are associated with significant morbidity and mortality. In this study we investigated the combination therapy of gemcitabine and cetuximab for HNSCC. The UM-SCC-6 and UM-SCC-23 HNSCC cell lines were analyzed following treatment with gemcitabine and cetuximab. To determine the mechanism of action of this combination treatment, the cell cycle distributions following gemcitabine and/or cetuximab treatment were analyzed by flow cytometry and apoptosis assay. Gemcitabine and cetuximab combination treatment exerted an enhanced cytotoxic effect. The cell cycle analysis demonstrated that cells accumulated in the S phase following gemcitabine treatment and G1 arrest occurred following cetuximab treatment. An increase in sub-G1 phase cells was also observed following treatment with the two drugs. In an apoptosis assay, caspase 3/7 activity was found to be higher when administering a combination of gemcitabine and cetuximab compared to each agent administered alone. Gemcitabine and cetuximab are individually effective against HNSCC and an enhanced growth inhibitory effect may be expected when these agents are used in combination.

Positive and negative regulation of podoplanin expression by TGF-β and histone deacetylase inhibitors in oral and pharyngeal squamous cell carcinoma cell lines

OBJECTIVES

Podoplanin, a transmembrane sialomucin-like glycoprotein, is known to express at high frequency in oral squamous cell carcinomas (OSCC) and possess metastasis-promoting activity such as increased invasion and platelet-aggregating activity. However, the regulatory mechanism of podoplanin expression in OSCC remains unknown.

MATERIALS AND METHODS

In the present study, we investigated the podoplanin expression in both clinical specimens from total 80 patients (50 OSCC and 30 pharyngeal SCC) and in 4 OSCC cell lines in vitro.

RESULTS

Immunohistochemical analysis of surgically resected specimens of OSCC revealed podoplanin expression in 70% of OSCC cases with localization primarily in the basal layer of squamous cancer nest and the expression was inversely correlated with squamous cell differentiation. In vitro analysis of OSCC cell lines revealed 36 that podoplanin expression was decreased in response to the squamous cell differentiation (Cytokeratin 10 expression as a marker) induced by treatment with histone deacetylase (HDAC) inhibitors such as sodium butyrate and trichostatin. Furthermore, transforming growth factor-β (TGF-β) significantly enhanced podoplanin expression in OSCC cell lines in line with increased phosphorylation of Smad2. A TGF-β type I receptor inhibitor (SB431542) significantly inhibited such induction of podoplanin expression by TGF-β at both the protein and mRNA level. However, in a subset of OSCC cell line, its expression was only weakly dependent on TGF-β and squamous differentiation.

CONCLUSION

These results suggest that regulation of podoplanin is not simple, but in the majority of OSCC cell lines, its expression is positively and negatively regulated by TGF-β receptor/Smad signaling pathway and epigenetic mechanism leading to squamous differentiation, respectively.