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Although seagrass meadows are intense carbon sinks, information on the regional variability in seagrass blue carbon stocks and carbon sequestration remains limited. We estimated the organic carbon (Corg) stocks and carbon accumulation rates (CAR) of seven seagrass meadows along the subtropical coast of China's Zhanjiang City and analyzed the driving factors of variability in sediment Corg stocks in three seagrass meadows. Results showed that most Corg (99.83 %) was stored in the sediments, and the contribution of living biomass was minor. The average Corg stocks of living biomass and sediments across all sites were 0.04 ± 0.01 and 42.03 ± 25.07 Mg C ha-1, respectively, which were significantly lower than the world average (2.52 ± 0.48 and 194.2 Mg C ha-1). The sediment Corg stocks of the upper 1 m ranged from 24.26 to 157.12 Mg C ha-1 with substantial variability among sites: Liusha Bay (64.93 ± 22.31 Mg C ha-1) > Donghai Island (33.8 ± 10.65 Mg C ha-1) > Dongshen Ferry (27.35 ± 4.15 Mg C ha-1). The average sediment CAR was 53.47 g C m-2 yr-1, and the total CAR of 864.18 ha seagrass meadows was 260.76 ± 4.86 Mg C yr-1 in these studied sites. Physicochemical factors, such as high moisture content, salinity, CaCO3 content, and low dry bulk density, jointly inhibited the mineralization rate of Corg in sediments. Our study provides data from understudied regions to a growing dataset on seagrass carbon stocks and sequestration rates and highlights the significance of local and regional differences in seagrass blue carbon storage to accurately assess the climate change mitigation potential of seagrass ecosystems.

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Background: Induction chemotherapy (ICT) has become an initial treatment for head and neck squamous cell carcinoma (HNSCC). However, myelosuppression, an unavoidable side effect of ICT, significantly impacts follow-up treatment and prognosis. The main objective of this study is to identify the risk factors and predictors of myelosuppression and its different severity after ICT for ICT. Methods: We retrospectively reviewed medical records of 102 patients with hypopharyngeal cancer or oropharyngeal cancer who received initial ICT from 2013 to 2022. Univariate and multivariate logistic regression analyses were performed to identify risk factors for myelosuppression. Receiver-operating characteristic (ROC) curves were generated using the results of multiple logistic regression analysis to identify data with the highest sensitivity and lowest false-negative rate. Results: Pretreatment lymphocyte count (PLC) and the pretreatment platelet count (PPC) were identified as independent risk factors of myelosuppression (P < .05). Pretreatment hemoglobin count (PHC) was an independent risk factor for predicting myelosuppression in patients with grades III to IV disease. Patients with myelosuppression after ICT are more sensitive to chemotherapy. Conclusions: The PLC and PPC predicted myelosuppression in patients with HNSCC-administered ICT, and the PHC predicted grades III to IV myelosuppression. Myelosuppressed patients were more chemosensitive after ICT.

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OBJECTIVE: To compare the survival outcomes of early-stage oropharyngeal cancer (OPC) patients treated with upfront surgery versus definitive radiotherapy (RT). STUDY DESIGN: Retrospective observational study. SETTING: Publicly available database. METHODS: A total of 1877 patients with T1-2N0-1M0 OPC were retrieved from the Surveillance, Epidemiology, and End Results database. Primary endpoints were cancer-specific and noncancer mortalities, which were estimated using cumulative incidence function and compared by Gray's test. Univariate and multivariate Fine-Gray subdistribution hazard models were used to estimate the effects of treatment modality on mortality. Subgroup analyses were performed in propensity-score-matched cohorts. All the analyses were conducted separately in human papillomavirus (HPV)-negative and HPV-positive cohorts. RESULTS: In the HPV-negative cohort, definitive RT was independently associated with increased risk of cancer-specific mortality (adjusted subdistribution hazard ratio [SHR], 2.29; 95% confidence interval [CI], 1.42-3.68; p = .001) and noncancer mortality (adjusted SHR, 2.74; 95% CI, 1.50-5.02; p = .001). In the HPV-positive cohort, definitive RT and upfront surgery could achieve similar cancer-specific and noncancer survival outcomes. CONCLUSION: Upfront surgery is associated with lower cancer-specific and noncancer mortality in HPV-negative early-stage OPC patients. However, in the setting of HPV-positive early-stage OPC with better prognosis, the 2 treatment modalities have similar efficacy in terms of cancer-specific and noncancer survival outcomes. In the future, carefully designed prospective clinical trials are needed to confirm our findings.

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OBJECTIVES/HYPOTHESIS: This study aimed to examine the prognostic value of elective neck dissection (END) in T1-2 clinical negative cervical lymph node (cN0 ) oropharyngeal cancer (OPC) patients. STUDY DESIGN: An observational retrospective study. METHODS: This retrospective study included 845 patients diagnosed with T1-2 cN0 OPC during 2010-2015 from Surveillance, Epidemiology, and End Results database. Univariable and multivariable Cox regression models were used to evaluate the prognostic roles of END. Furthermore, propensity score matching was used to balance the covariates between the END and observation (OBS) groups, and subgroup analyses were conducted in the matched cohorts. The primary endpoint was overall survival (OS). RESULTS: Our study showed that END was an independent prognostic factor associated with a better 3-year OS compared with OBS in human papillomavirus (HPV)-positive cohort (adjusted hazard ratio [HR], 0.464; 95% confidence interval [CI], 0.235-0.916; P = .027). However, we found no prognostic value of END in HPV-negative cohort (adjusted HR, 0.837; 95% CI, 0.535-1.310; P = .435). In the subgroup analyses, we found that younger patients (≤65 years old) and patients with nontonsillar tumors in HPV-positive cohort were more likely to benefit from END, while patients with tonsillar tumors in HPV-negative cohort may benefit from END. CONCLUSIONS: We found that patients with HPV-positive T1-2 cN0 OPC could benefit from END in terms of OS, especially younger patients and those with nontonsillar tumors. Patients with HPV-negative T1-2 cN0 OPC could not benefit from END in terms of OS, while those with tonsillar tumors may benefit from END. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:1205-1212, 2022.

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OBJECTIVE: To investigate the role of ferroptosis, an iron-dependent form of non-apoptotic cell death, in the head and neck squamous cell carcinoma (HNSCC) immune microenvironment. MATERIALS AND METHODS: A list of ferroptosis-related genes was obtained from the FerrDb database. Gene expression data were acquired from the cancer genome atlas (TCGA) and analyzed using the R language. Protein-protein interaction analysis was conducted using STRING and GeneMANIA. The correlations between gene expression levels and a patient's survival were analyzed using GEPIA, the Kaplan-Meier estimate, and a multivariate Cox proportional hazards model. The expression results were verified using Oncomine and Human Protein Atlas data. We used the TIMER, GEPIA2, GEPIA2021, and TIMER2 databases to investigate the relationships between gene expression and infiltrating immune cells. RESULTS: Analysis of differentially expressed genes (DEGs) identified nine each ferroptosis drivers and ferroptosis suppressors, among which four genes correlated with survival as follows: two drivers (SOCS1, CDKN2A) associated with better survival and two suppressors (FTH1, CAV1) associated with poorer survival. Multivariate Cox survival analysis identified SOCS1 and FTH1 as independent prognostic factors for HNSCC, and their higher expression levels were verified using Oncomine and HPA data. The results acquired using TIMER, GEPIA2, GEPIA2021, and TIMER2 data revealed that the driver SOCS1 and the suppressor FTH1 independently correlated with M1 and M2 macrophage infiltration. CONCLUSIONS: The ferroptosis driver SOCS1 and suppressor FTH1 are independent prognostic factors and that correlate with M1 and M2 macrophage infiltration in HNSCC. Targeting ferroptosis-immunomodulation may serve as a strategy to enhance the activity of immunotherapy.

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Ferritin is the most important iron storage form and is known to influence tumor immunity. We previously showed that expression of ferritin light chain (FTL) and ferritin heavy chain (FTH1) subunits is increased in head and neck squamous cell carcinoma (HNSC). Here, we analyzed solid tumor datasets from The Cancer Genome Atlas and Genotype-Tissue Expression databases to investigate correlations between FTL and FTH1 expressions and (i) patient survival, using univariate, multivariate, Kaplan-Meier and Receiver Operator Characteristic analysis; and (ii) tumor-infiltrating immune cell subsets, using the bioinformatics tools Estimation of Stomal and Immune cells in Malignant Tumor tissues, Microenvironment Cell Population-counter, Tumor Immune Estimation Resource, and Tumor Immunology Miner. We found that FTL and FTH1 are upregulated and downregulated, respectively, in most of the human cancers analyzed. Tumor FTL levels were associated with prognosis in patients with lower grade glioma (LGG), whereas FTH1 levels were associated with prognosis in patients with liver hepatocellular carcinoma, HNSC, LGG, and kidney renal papillary cell carcinoma. In many cancers, FTL and FTH1 levels was significantly positively correlated with tumor infiltration by tumor-associated macrophages and T regulatory cells. These results suggest an important role for FTL and FTH1 in regulating tumor immunity to solid cancers.

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Vehicle emissions have become one of the key factors affecting the urban air quality and climate change in the Pearl River Delta (PRD) region, so it is important to design policies of emission reduction based on quantitative Co-benefits for air pollutants and greenhouse gas (GHG). Emissions of air pollutants and GHG by 2020 was predicted firstly based on the no-control scenario, and five vehicle emissions reduction scenarios were designed in view of the economy, technology and policy, whose emissions reduction were calculated. Then Co-benefits between air pollutants and GHG were quantitatively analyzed by the methods of coordinate system and cross-elasticity. Results show that the emissions reduction effects and the Co-benefits of different measures vary greatly in 2015-2020. If no control scheme was applied, most air pollutants and GHG would increase substantially by 20-64% by 2020, with the exception of CO, VOC and PM2.5. Different control measures had different reduction effects for single air pollutant and GHG. The worst reduction measure was Eliminating Motorcycles with average reducing rate 0.09% for air pollutants and GHG, while the rate from Updated Emission Standard was 41.74%. Eliminating Yellow-label Vehicle scenario had an obvious reduction effect for every single pollutant in the earlier years, but Co-benefits would descent to zero in later by 2020. From the perspective of emission reductions and co-control effect, Updated Emission Standard scenario was best for reducing air pollutants and GHG substantially (tanα=1.43 and Els=1.77).

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