ABSTRACT
BACKGROUND: We investigated the impact of the COVID-19 pandemic on oral cancer (OC), comparing diagnosis and number of pre-operative days in the diagnosis of OC in 2019 (pre-COVID-19) and that in 2020 (during the COVID-19 pandemic). METHODS: Using data from a cancer registry-based study on the impact of COVID-19 on cancer care in Osaka (CanReCO), we collected details of sex, age, residential area, cancer site, date of diagnosis, clinical stage at first treatment and number of pre-operative days in OC patients. RESULTS: A total of 1470 OC cases were registered. Incidence of OC before and during COVID-19 was 814 and 656 cases, respectively. During the first wave of the pandemic (March to May 2020), incidence was about half that in the same period in 2019 (2019; n = 271, 2020; n = 145). Number of pre-operative days (median number of days between the first hospital visit and surgery date) was significantly shorter during the COVID-19 year (24.5 days) than in the pre-COVID-19 year (28 days, p = 0.0015). CONCLUSIONS: Incidence of OC during the COVID-19 pandemic was lower than in pre-COVID-19. Despite disruption in the healthcare system, the number of pre-operative days for OC cases was shorter during the pandemic.
Subject(s)
COVID-19 , Mouth Neoplasms , Humans , Pandemics , Japan/epidemiology , COVID-19/epidemiology , Mouth Neoplasms/epidemiology , Mouth Neoplasms/surgery , CognitionABSTRACT
This paper presents a study of the size distributions of colloidal nanoparticles using an online dynamic light scattering (DLS) unit with a uni-tau multi-bit correlator (UMC) combined with a centrifugal field-flow fractionation (CF3) separator. Conventionally, the FFF-UV-MALS system utilizing field-flow fractionation (FFF) combined with a UV detector and multi-angle light scattering instrument (MALS) could be used to obtain the particle size distribution of colloidal nanoparticles. Lately, DLS as a technique to measure the size distributions of colloid materials has become prevalent. However, the DLS instrument will practically measure only the large particles in a multi-modal particle mixture. Therefore, the CF3-DLS w/UMC system that was developed consisted of a CF3 unit connected to an online DLS instrument with UMC. The system could measure the volume- or number-based size distribution with highly quantitative and accurate histograms for multi-modal samples. The size distributions were validated with size distributions obtained by images of an atomic force microscope (AFM). Two types of colloidal silica nanoparticles with different distribution widths were used in this study.
ABSTRACT
OBJECTIVES: To examine whether lactate dehydrogenase (LDH) can predict the prognosis of oral cavity squamous cell carcinoma (OSCC) and to determine the optimal cut-off values for LDH. METHODS: This retrospective study included 184 patients with OSCC, treated with surgery between 2006 and 2014. The association between LDH and T, N classification was investigated using the Mann-Whitney test. Cut-off values for LDH were determined with a recursive partitioning analysis (RPA). Survival rates were estimated using the Kaplan-Meier method. A Cox hazard model was used to assess the prognostic capability of LDH. RESULTS: There was no association between LDH and T or N classification (p = .657, .619, respectively). RPA determined the cut-off values for LDH as 160 and 220 IU/L. The five year survival for low-, moderate-, and high-LDH groups were 87.7, 73.7, and 50.9%, respectively (p < .001). The hazard ratios (HRs) for death in moderate- and high-LDH groups were 2.92 (95%CI =1.02-12.30, p = .001) and 7.36 (95%CI =2.54-31.20, p < .001), respectively. The model including LDH-based stratification (Akaike's information criterion (AIC) = 516) was better than the model including clinical stage (AIC =528). CONCLUSION: Pretreatment serum LDH is an independent prognostic factor for overall survival in patients with OSCC.
