Comparison of PD-L1 and VISTA expression status in primary and recurrent/refractory tissue after (chemo)radiotherapy in head and neck cancer.

BACKGROUND: PD-L1 and VISTA are thought to play a role in escape from the immune system, tumor progression, and treatment response in tumoral tissue. The current study aimed to evaluate the effects of radiotherapy (RT) and chemoradiotherapy (CRT) on PD-L1 and VISTA expression in head and neck cancers. METHODS: PD-L1 and VISTA expression were compared between the primary biopsy taken at the time of diagnosis and refractory tissue biopsies of patients who received definitive CRT or recurrent tissue biopsies of patients who had surgery followed by adjuvant RT or CRT. RESULTS: In total, 47 patients were included. Radiotherapy had no effect on the expression levels of PD-L1 and VISTA in patients with head and neck cancer (p = 0.542 and p = 0.425, respectively). A positive correlation was found between PD-L1 and VISTA expression (p < 0.001; r = 0.560). PD-L1 and VISTA expression in the first biopsy were found to be significantly higher in clinical lymph node-positive patients compared to node-negative patients (PD-L1 p = 0.038; VISTA p = 0.018). The median overall survival of patients with ≥ 1% VISTA expression in the initial biopsy was significantly shorter than that of patients with < 1% VISTA expression (52.4 vs. 110.1 months, respectively; p = 0.048). CONCLUSION: It was found that PD-L1 and VISTA expression did not change with RT or CRT. Further studies are needed to evaluate the relationship of PD-L1 and VISTA expression with RT and CRT.

Lysyl Oxidase Like-4 (LOXL4) as a tumor marker and prognosticator in advanced stage laryngeal cancer.

INTRODUCTION: Lysyl oxidase-like 4 is an amine oxidase from the lysyl oxidase family that was previously shown to be overexpressed in head and neck cancer and upregulated in response to hypoxia. The possible role of lysyl oxidase-like 4 as a tumor marker in advanced stage larynx cancer was investigated. OBJECTIVE: To investigate the expression of lysyl Oxidase-Like 4 protein in advanced stage laryngeal cancer and elucidate its possible role as a tumor marker, predictor of treatment response and prognosticator. METHODS: Diagnostic specimens of 72 patients treated for stage III-IV laryngeal squamous cell carcinoma were evaluated for lysyl oxidase-like 4 expression by immunohistochemistry. RESULTS: Lysyl oxidase-like 4 expression was correlated with advanced tumor stage (p = 0.041) and better differentiation (p = 0.025) but was independent of tumor diameter (p = 0.456). Response to induction chemotherapy or the need for salvage laryngectomy were not affected by lysyl oxidase-like 4 expression (p = 0.999, p = 0.070 respectively). Increased lysyl oxidase-like 4 expression was associated with better 2 year overall survival in both univariate (p = 0.036) and multivariate analyses (p = 0.014). CONCLUSION: Lysyl oxidase-like 4 expression emerges with advancing stages, is lost with worsening differentiation, and may have tumor suppressive properties in larynx cancer.

Methylation status of TSHr in well-differentiated thyroid cancer by using cytologic material.

BACKGROUND: The role of methylation status of the thyroid stimulating hormone receptor gene (TSHr) in the discrimination of benign and malignant thyroid nodules has already been studied using paraffin blocks and cell lines. As cytological sampling plays an important role in assessment of thyroidal nodules, we have investigated the potential clinical use of TSHr methylation status of fine needle aspiration specimens reported according to Bethesda System. METHOD: Sixty nine patients who had both cytological and pathological diagnosis of the same nodule were selected. Four groups were composed according to cytological and pathological diagnoses: Benign (B), papillary thyroid carcinoma (PTC), atypia of unknown significance (AUS) and follicular neoplasia (FN). The latter 2 groups were further sub-classified into 2 as benign (AUS-B and FN-B) and malignant (AUS-M and FN-M) according to final pathological diagnosis. DNAs were isolated from the fine needle aspiration cytology specimens and the methylation status of TSHr promotor region was investigated by using methylation specific polymerase chain reaction. RESULTS: Overall, TSHr methylation was present in 58% of cases; 71% of malignant and 46% of benign nodules. PTC group showed the highest TSHr methylation rate (87%), followed by 61% in AUS, 44% in B, and 30% in FN (p = 0.016). TSHr methylation rate was significantly higher in PTC group when compared to B (p = 0.013) and FN-B (p = 0.004) groups; but not in FN-M (p = 0.115) or AUS (p = 0.096) groups. All 9 cases of papillary thyroid carcinoma with lymph node metastasis showed TSHr methylation. Positive predictive value, negative predictive value, sensitivity and specificity of TSHr methylation in determination of malignancy were calculated as 60, 66, 71 and 54%, respectively. CONCLUSION: The eminent ratio of TSHr methylation in well-differentiated thyroid carcinoma against benign thyroidal nodules adduced that TSHr methylation status can be utilized as a tumor marker for well-differentiated thyroid cancer; however, it has a limited value. The determination of methylation status of TSHr gene had no efficiency on decision of the malignant potential for the nodules which are cytologically classified as atypia of undetermined significance.