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Objectives/Hypothesis: Early‐stage laryngeal squamous cell carcinoma (LSCC) has yielded local control rates of 75% after radiotherapy. DNA methylation, in which DNA methyltransferases play an important role, has influence on tumorigenesis. In this study, we investigated the association between the expression of DNA methyltransferase 1 (DNMT1) and local control in early‐stage LSCC treated with radiotherapy. Study Design: Retrospective cohort study. Methods: We analyzed a well‐defined homogeneous series of 125 LSCC patients treated with radiotherapy with curative intent. The association of immunohistochemical expression of DNMT1 with local control was evaluated using Cox proportional hazard regression models. Results: With a median follow‐up of 58 months, 29 local recurrences (23%) were observed. On univariate analysis, worse local control was associated with high DNMT1 expression (hazard ratio [HR] 2.57, 95% confidence interval [CI] 1.10–6.01). Also, higher T‐stage (HR 2.48, 95% CI 1.06–5.80) and positive N‐status (HR 2.62, 95% CI 1.06–6.47) were associated with worse local control. Multivariate Cox regression demonstrated that high DNMT1 (HR 2.81; 95% CI 1.20–6.58) was independently associated with worse local control. Conclusions: We found an association between high DNMT1 expression and worse local control in a homogeneous well‐defined cohort of early‐stage LSCC patients treated with definitive radiotherapy. The association between DNA methylation status as determined by DNMT1 expression and local control suggests that DNMT1 acts as a potential prognostic tumor marker in treatment decision‐making in early‐stage laryngeal carcinoma. Level of evidence: NA Laryngoscope, 132:801–805, 2022 [ABSTRACT FROM AUTHOR]

Objectives: Most early stage laryngeal squamous cell carcinomas (LSCC) are treated with radiotherapy. Discovery of new biomarkers are needed to improve prediction of outcome after radiotherapy and to identify potential targets for systemic targeted therapy. The ataxia telangiectasia mutated (ATM) gene plays a critical role in DNA damage response induced by ionizing radiation.Methods: The prognostic value of immunohistochemical expression of pATM, pChk2, and p53 were investigated in 141 patients with T1-T2 LSCC curatively treated with external beam radiotherapy. Uni- and multivariable Cox regression analyses were performed to examine the relation between expression levels of markers and local control.Results: Local control was significantly worse in cases with high levels of pATM (HR 2.14; 95% CI, 1.08-4.24; P = .03). No significant associations with local control were found for pChk2 and p53 expression. The association of high pATM expression with poor local control was only found for supraglottic LSCC (HR 10.9; 95% CI, 1.40-84.4; P = .02).Conclusion: Our findings suggest a potential role for ATM in response to radiotherapy in early stage supraglottic LSCC and imply ATM inhibition as a possibility to improve response to radiotherapy.Level Of Evidence: NA Laryngoscope, 130: 1954-1960, 2020. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to establish the prognostic value of the epidermal growth factor receptor (EGFR) and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression on local control in patients with early stage supraglottic laryngeal squamous cell carcinoma (LSCC) treated with radiotherapy only. Study design: Retrospective cohort study. Methods: Immunohistochemical staining for EGFR and PTEN was performed on pretreatment biopsies of a selected well‐defined homogeneous group of 52 patients with T1–T2 supraglottic LSCC treated with radiotherapy between 1990 and 2008. Kaplan–Meier analysis and univariate and multivariate Cox Regression analyses were performed to correlate clinical data and expression levels of EGFR and PTEN with local control. Results: Kaplan–Meier survival analysis and Cox Regression analysis showed a significant association between PTEN expression and local control (hazard ratio [HR] = 3.26, 95% confidence interval [CI] = 1.14–9.33, P =.027) and between lymph node status and local control (HR = 3.60, 95% CI = 1.26–10.31, P =.017). Both were independent prognostic factors in a multivariate analysis (HR = 3.28, 95% CI = 1.14–9.39, P =.027 and HR = 3.62, 95% CI = 1.26–10.37, P =.017, respectively). There was no significant association between EGFR expression and local control (HR = 1.32, 95% CI = 1.17–10.14, P =.79). Conclusion: This study showed an association between both high PTEN expression and the presence of lymph node metastasis and deteriorated local control in early stage supraglottic LSCC treated with radiotherapy. Level of Evidence: NA [ABSTRACT FROM AUTHOR]

Background and purpose 18 F-fluoroazomycinarabinoside ( 18 F-FAZA) is a promising hypoxia radiopharmaceutical agent with outstanding biokinetic parameters. We aimed to determine the accuracy of 18 F-FAZA-PET/CT scan in detecting hypoxic regions within the tumor using immunohistochemical markers in a pilot study. Patients and methods Eleven patients with primary or recurrent laryngeal squamous cell carcinoma were indicated for total laryngectomy (TLE). Patients underwent 18 F-FAZA-PET/CT scan before TLE. Hypoxic regions inside the laryngeal tumor were determined. After TLE, regions with high uptake on 18 F-FAZA-PET scan were selected for immunohistochemical examination for exogenous (pimonidazole) and endogenous (HIF1α, CA-IX and GLUT-1) hypoxia markers. To assess the accuracy of 18 F-FAZA-PET scanning, radiopharmacon accumulation was related with immunohistochemical expression of hypoxia markers. Results Inter- and intratumoral heterogeneity of tumor hypoxia was observed on 18 F-FAZA-PET scan. Nine of the eleven tumors were hypoxic with 18 F-FAZA-PET. Hypoxia could also be detected with pimonidazole, HIF1α, CA-IX and GLUT-1 expression in some tumors. No clear association was observed between 18 F-FAZA uptake and hypoxia markers. Conclusions This pilot study could not prove the accuracy of 18 F-FAZA-PET in determining hypoxic subvolumes in laryngeal cancer. Further study is required to investigate the benefit of 18 F-FAZA-PET imaging in radiotherapy planning. [ABSTRACT FROM AUTHOR]