Temporal and spatial patterns of recurrence in oral squamous cell carcinoma, a single-center retrospective cohort study in China.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is an invasive cancer with a high recurrence rate. Most clinical studies have focused on the prognosis of patients with OSCC, few have investigated the causes and interventions that affect the recurrence. Our study is to explore the temporal and spatial patterns of recurrence in OSCC. METHODS: 234 OSCC patients with recurrence in our hospital and 64 OSCC patients with recurrence in TCGA database were included in the study. Log-rank test and Multivariate Cox Regression Analysis were used to determine whether there was a significant difference between each selected demographic or clinical factors and recurrence. The Kaplan-Meier method was used to plot survival curves for each recurrence interval. RESULTS: The proportion of OSCC patients in clinical and TCGA with early recurrence was 93.6% and 84.4%, respectively. Age, chewing betel nut, previous radiotherapy, histopathological grading of the primary tumor (poorly differentiated), lymph node metastasis and postoperative infection were found to be associated with the timing of recurrence. It was found that tongue cancer has more regional recurrences, while buccal cancer is mostly local and loco-regional recurrences. The earlier the recurrence, the greater the possibility of local-regional recurrence and the worse the prognosis. CONCLUSION: Most of recurrent OSCC patients present early recurrence (< 18 months) with poor prognosis, and early recurrence is more prone to local recurrence. Moreover, recurrence site is related with primary site of OSCC.

Evaluation of the effects of reservoir construction on the relationship between runoff and sediment load in the upper reaches of the Yellow River.

In order to evaluate the impact of the Longyangxia Reservoir construction on the relationship between runoff and sediment load (RRSL) in the upper reaches of the Yellow River, the runoff and sediment load monitoring data are used to identify variation point by sliding correlation coefficient method. Then with Copula function, the various countering situations of runoff and sediment load before and after variation are proposed to innovatively reveal their changing relations. The results demonstrate that (1) the reservoir construction exerts a great impact on the RRSL in the upper reaches of the Yellow River with the occurring variation point in 1987. The correlation of runoff and sediment load is presented better before variation but tends to worse decrease after variation. (2) Either before or after variation, runoff follows the generalized extreme value distribution, while sediment load before variation obeys the normal distribution, but the lognormal distribution after variation. Meanwhile, Frank Copula function accurately simulates the RRSL before variation, whereas Clayton Copula function is selected after variation. (3) The probability of synchronous rich and poor runoff and sediment load is higher before variation. After variation, the RRSL decreases significantly; their synchronous probability decreases by 45.67%. Meanwhile, the asynchronous probability of their extreme events evidently increases. The joint recurrence and co-recurrence intervals before variation are smaller than those after variation, along with the decreasing of their volume peak. This study provides new knowledge of runoff and sediment load influenced by reservoir construction, and also offers guidance for flood control and sediment load-discharge schemes of reservoir.

Evaluation of ammonia and nitrate distribution and reduction within stormwater green infrastructure with different woody plants under multiple influencing factors.

The impact of stormwater green infrastructures (GIs) with different woody plants on nitrogen (N) distribution is still poorly understood. Laboratory experiments were conducted for GIs without or with Sophora japonica and Malus baccata to investigate the distribution of NH3-N and NO3-N. The test data was utilized to calibrate and validate the HYDRUS-2D. The validated model was subsequently used to analyze the distribution of NH3-N and NO3-N within the different GIs under three different rainfall conditions: inflow/runoff pollutant concentration, rainfall recurrence interval (runoff amount of a rainfall event), and number of dry days (during which no rainwater infiltrates into the soil). The average NH3-N and NO3-N concentrations in the upper soil (0-30 cm) of the GIs were about 4.8 and 2.4 times those of the lower layer (30-60 cm). Compared to the control (Vc), the average NH3-N concentrations in soil with Sophora japonica (Vs) and Malus baccata (Vm) decreased by 15.8% and 35.1% while those of NO3-N decreased by 15.5% and 27.2%, respectively. Degrees of influence by the three factors on the average soil NH3-N and NO3-N concentrations were inflow concentration > number of dry days > recurrence interval. The number of dry days was the smallest influence factor for the overflow N load while the inflow concentration was the most significant influence factor for the outflow, bio-utilization, and soil nitrogen loads. Compared to the control, outflow (groundwater recharge) loads of NO3-N from the Vs and Vm increased by 14.0-16.6% and 3.7-6.8%, respectively under different conditions. The overflow (runoff) loads from Vs and Vm decreased by 16.8-36.3% and 6.6%-8.4%, respectively. A multiple regression equation was used to establish a quantitative coupling relationship between N pollutant load reduction rates and influence factors (R2 ≥ 0.83). This relationship can be used to estimate the runoff treatment effectiveness of green infrastructure on target pollutants.

The efficacy and safety of thalidomide on the recurrence interval of continuous recurrent aphthous ulceration: A randomized controlled clinical trial.

BACKGROUND: Recurrent aphthous ulceration (RAU) is the most common oral mucosal disease. Some patients have almost continuous oral ulcers which influence the quality of life. The aim of this study was to observe the efficacy and safety of thalidomide on the recurrence interval of continuous RAU. METHODS: A randomized controlled clinical trial was designed, and 60 continuous RAU patients were randomly assigned to the experimental group (n = 32, taking thalidomide before bed at a dose of 100 mg/d for 10 days, then 50 mg/d for 10 days, and 25 mg/d for 10 days) and the control group (n = 28, taking 0.4 mg/kg/d prednisone every morning for 15 days and then 0.2 mg/kg/d for 15 days). The clinical outcomes consisted of the primary outcome (recurrence interval) and the secondary outcomes (pain level, number of ulcers, and days for ulcer healing), and they were measured at every visit. Adverse reactions were recorded. RESULTS: A total of 54 and 51 patients presented at the first and second return visit, respectively. After 1 month, the increase in the recurrence interval was not shown to differ between the two groups (P = .12). However, the improvement in the recurrence interval was significantly greater in the experimental group (P < .001) at the second return visit. The improvement in the secondary outcomes was identical between two groups at each return visit (P > .05). The incidence of adverse reactions was similar between two groups (P = .50). CONCLUSIONS: Thalidomide had a long-term effect of extending the recurrence interval of continuous RAU.

Clinicopathologic features of remnant gastric cancer after curative distal gastrectomy according to previous reconstruction method: a retrospective cohort study.

BACKGROUND: Survival rate of patients treated for gastric cancer has increased due to early detection and improvements of surgical technique and chemotherapy. Increase in survival rate has led to an increase in the risk for remnant gastric cancer (RGC). The purpose of this study was to investigate clinicopathologic features of RGC according to previous reconstruction method and factors affecting the interval from previous curative distal gastrectomy for gastric cancer to RGC occurrence. METHODS: Medical records of patients diagnosed with RGC at Yeungnam University Medical Center from January 2000 to December 2017 who had a history of distal gastrectomy with D2 LN dissection due to gastric cancer were reviewed retrospectively. RESULTS: Forty-eight patients were enrolled in this study. The mean interval of 48 RGC patients was 105.6 months (8.8 years). RGC after Billroth II reconstruction recurred more often at anastomosis site than RGC after Billroth I reconstruction (p = 0.001). The mean interval of RGC after Billroth I reconstruction was 67 months, shorter than 119 months of RGC after Billroth II reconstruction (p = 0.003). On the contrary, interval showed no difference according to stage of previous gastric cancer, remnant gastric cancer, or sex (p = 0.810, 0.145, and 0.372, respectively). CONCLUSIONS: RGC after Billroth I reconstruction tends to arise earlier at non-anastomosis site than RGC after Billroth II. Therefore, we should examine non-anastomosis site carefully from the beginning of surveillance after gastric cancer surgery with Billroth I reconstruction for better outcome.

Effectiveness of Conservation Measures in Reducing Runoff and Soil Loss Under Different Magnitude-Frequency Storms at Plot and Catchment Scales in the Semi-arid Agricultural Landscape.

In this study, multi-year stormflow data collected at both catchment and plot scales on an event basis were used to evaluate the efficiency of conservation. At the catchment scale, soil loss from YDG, an agricultural catchment with no conservation measures, was compared with that from CZG, an agricultural catchment with an implementation of a range of conservation measures. With an increase of storm recurrence intervals in the order of <1, 1-2, 2-5, 5-10, 10-20, and >20 years, the mean event sediment yield was 639, 1721, 5779, 15191, 19627, and 47924 t/km(2) in YDG, and was 244, 767, 3077, 4679, 8388, and 15868 t/km(2) in CZG, which represented a reduction effectiveness of 61.8, 55.4, 46.7, 69.2, 57.2, and 66.8 %, respectively. Storm events with recurrence intervals greater than 2 years contributed about two-thirds of the total runoff and sediment in both YDG and CZG catchments. At the plot scale, soil loss from one cultivated slopeland was compared with that from five conservation plots. The mean event soil loss was 1622 t/km(2) on the cultivated slopeland, in comparison to 27.7 t/km(2) on the woodland plot, 213 t/km(2) on the grassland plot, 467 t/km(2) on the alfalfa plot, 236 t/km(2) on the terraceland plot, and 642 t/km(2) on the earthbank plot. Soil loss per unit area from all the plots was significantly less than that from the catchments for storms of all categories of recurrence intervals.

A critical look at prospective surveillance using a scan statistic.

The scan statistic is a very popular surveillance technique for purely spatial, purely temporal, and spatial-temporal disease data. It was extended to the prospective surveillance case, and it has been applied quite extensively in this situation. When the usual signal rules, as those implemented in SaTScan(TM) (Boston, MA, USA) software, are used, we show that the scan statistic method is not appropriate for the prospective case. The reason is that it does not adjust properly for the sequential and repeated tests carried out during the surveillance. We demonstrate that the nominal significance level α is not meaningful and there is no relationship between α and the recurrence interval or the average run length (ARL). In some cases, the ARL may be equal to ∞, which makes the method ineffective. This lack of control of the type-I error probability and of the ARL leads us to strongly oppose the use of the scan statistic with the usual signal rules in the prospective context.

Geological and historical evidence of irregular recurrent earthquakes in Japan.

Great (M∼8) earthquakes repeatedly occur along the subduction zones around Japan and cause fault slip of a few to several metres releasing strains accumulated from decades to centuries of plate motions. Assuming a simple 'characteristic earthquake' model that similar earthquakes repeat at regular intervals, probabilities of future earthquake occurrence have been calculated by a government committee. However, recent studies on past earthquakes including geological traces from giant (M∼9) earthquakes indicate a variety of size and recurrence interval of interplate earthquakes. Along the Kuril Trench off Hokkaido, limited historical records indicate that average recurrence interval of great earthquakes is approximately 100 years, but the tsunami deposits show that giant earthquakes occurred at a much longer interval of approximately 400 years. Along the Japan Trench off northern Honshu, recurrence of giant earthquakes similar to the 2011 Tohoku earthquake with an interval of approximately 600 years is inferred from historical records and tsunami deposits. Along the Sagami Trough near Tokyo, two types of Kanto earthquakes with recurrence interval of a few hundred years and a few thousand years had been recognized, but studies show that the recent three Kanto earthquakes had different source extents. Along the Nankai Trough off western Japan, recurrence of great earthquakes with an interval of approximately 100 years has been identified from historical literature, but tsunami deposits indicate that the sizes of the recurrent earthquakes are variable. Such variability makes it difficult to apply a simple 'characteristic earthquake' model for the long-term forecast, and several attempts such as use of geological data for the evaluation of future earthquake probabilities or the estimation of maximum earthquake size in each subduction zone are being conducted by government committees.

Tumor Recurrence and Follow-Up Intervals in Oral Squamous Cell Carcinoma.

Tumor recurrence in oral squamous cell carcinoma (OSCC) is frequent. However, no consensus about follow-up interval is available. The aim of this study was to analyze the recurrence pattern, detection method and associated parameters for possible risk stratification. Histopathological and epidemiological features were obtained retrospectively and correlated with tumor recurrence and overall survival, distant and lymph node metastases. A total of 760 patients were included, of which 216 patients showed tumor recurrence (mean after 24 ± 26 months). Within the first 12 months, 24% of the recurrences were detected. The primary detection method was clinical examination (n = 123, 57%). Tumor recurrence significantly correlated with advanced histopathological grading (G2/3 vs. G1, p < 0.000) and lymph node metastasis (p = 0.004). Tumor recurrence was frequent. Clinical examination was the primary detection method and manifestation within the first 6−12 months was high. The degree of histopathological grading may be useful for risk stratification.

Seismic history of western Anatolia during the last 16 kyr determined by cosmogenic 36Cl dating.

Western Anatolia is one of the most seismically active regions worldwide. To date, the paleoseismic history of many major faults, in terms of recurrence intervals of destructive earthquakes, their magnitude, displacement, and slip rates is poorly understood. Regional crustal extension has produced major horst-graben systems bounded by kilometer-scale normal faults locally in carbonates, along which vertical crustal displacements occurred. In this study, we explore the seismic history of western Anatolia using 36Cl exposure dating through study of well-preserved carbonate normal fault scarps. To accomplish this, 36Cl concentrations in 214 samples from fault plane transects on the Rahmiye and Ören fault scarps were measured and compared with existing 36Cl measurements of 370 samples on five fault scraps in western Anatolia. At least 20 seismic events have been reconstructed over the past 16 kyr. The age correlation of the seismic events implies four phases of high seismic activity in western Anatolia, at around 2, 4, 6, and 8 ka. Slips are modeled ranging between 0.6 to 4.2 m per seismic event, but are probably the result of clustered earthquakes of maximum magnitude 6.5 to 7.1. While the average slip rates have values of 0.3 to 1.9 mm/yr, incremental slip rates of the faults range greater than 0.1 to 2.2 mm/yr, showing more activity mostly through late Holocene. Our finding reveals high capability of cosmogenic 36Cl dating to explore seismic behavior of active faults beyond the existing earthquake records. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s00015-022-00408-x.

Design parameters and treatment efficiency of a retrofit bioretention system on runoff nitrogen removal.

Mixed media design is key factor that affects the operation of bioretention systems. In this study, four types of modifiers, namely, water treatment residual (WTR), green zeolite, fly ash, and coconut bran, were mixed with traditional bioretention soil (65% sand + 30% soil + 5% sawdust, by mass). Consequently, four kinds of modified media were obtained. Ten pilot-scale bioretention basins were constructed by setting different configurations. The steady infiltration rates of the modified packing bioretention systems were 3.25~62.78 times that of plant soil, which was 2.88~55.75 m/day. Results showed that the average concentration removal (ACR) of both mixed and layered fly ash and WTR were better than those of the other media, and the effects could reach over 61.92%. In the bioretention basins with WTR as the modifier, the treatment efficiency of nitrogen under the submerged zone height of 150 mm was relatively optimal, and ACR could reach 65.46%. Outflow total nitrogen (TN) load was most influenced by inflow load, and the correlation coefficient was above 0.765. Relative to the change of inflow concentration (IC), the change of recurrence interval (RI) and discharge ratio (DR) was more sensitive to TN load reduction. The reduction rate of TN load decreased by approximately 15% when the recurrence interval increased from 0.5 to 3 years. It decreased by approximately 12% when the discharge ratio increased from 10 to 20. This study will provide additional insights into the treatment performance of retrofit bioretention systems, and thus, can guide media and configuration design, effect evaluation, and related processes.

Paleoseismic study of the Kamishiro Fault on the northern segment of the Itoigawa-Shizuoka Tectonic Line, Japan.

The Mw 6.2 (Mj 6.8) Nagano (Japan) earthquake of 22 November 2014 produced a 9.3-km long surface rupture zone with a thrust-dominated displacement of up to 1.5 m, which duplicated the pre-existing Kamishiro Fault along the Itoigawa-Shizuoka Tectonic Line (ISTL), the plate-boundary between the Eurasian and North American plates, northern Nagano Prefecture, central Japan. To characterize the activity of the seismogenic fault zone, we conducted a paleoseismic study of the Kamishiro Fault. Field investigations and trench excavations revealed that seven morphogenic paleohistorical earthquakes (E2-E8) prior to the 2014 Mw 6.2 Nagano earthquake (E1) have occurred on the Kamishiro Fault during the last ca. 6000 years. Three of these events (E2-E4) are well constrained and correspond to historical earthquakes occurring in the last ca. 1200 years. This suggests an average recurrence interval of ca. 300-400 years on the seismogenic fault of the 2014 Kamishiro earthquake in the past 1200 years. The most recent event prior to the 2014 earthquakes (E1) is E2 and the penultimate and antepenultimate faulting events are E3 and E4, respectively. The penultimate faulting event (E3) occurred during the period of AD 1800-1400 and is associated with the 1791 Mw 6.8 earthquake. The antepenultimate faulting event (E4) is inferred to have occurred during the period of ca. AD 1000-700, likely corresponding to the AD 841 Mw 6.5 earthquake. The oldest faulting event (E8) in the study area is thought to have occurred during the period of ca. 5600-6000 years. The throw rate during the early Holocene is estimated to be 1.2-3.3 mm/a (average, 2.2 mm/a) with an average amount of characteristic offset of 0.7-1.1 m produced by individual event. When compared with active intraplate faults on Honshu Island, Japan, these slip rates and recurrence interval estimated for morphogenic earthquakes on the Kamishiro Fault along the ISTL appear high and short, respectively. This indicates that present activity on this fault is closely related to seismic faulting along the plate boundary between the Eurasian and North American plates.

Evaluation of risk factors for the recurrence of ovarian endometriomas.

OBJECTIVES: To evaluate the risk factors for the recurrence of ovarian endometrioma after laparoscopic cystectomy. STUDY DESIGN: Reproductive aged patients who underwent laparoscopic ovarian endometriotic cystectomy and with histopathologically confirmed diagnosis of ovarian endometrioma were evaluated retrospectively. Histopathologic specimens were reevaluated and histopathologic characteristics of ovarian endometriotic cysts (thickness of cyst wall, thickness of fibrosis [ToF], thickness of ovarian tissue, the number of follicles per cyst, the depth of penetration [DoP] of endometrial tissue into the cyst wall) were determined. Along the determined histopathologic findings, demographic characteristics (age at surgery, number of pregnancies), clinical symptoms (dysmenorrhea, infertility), intraoperative findings (revised American Society for Reproductive Medicine [rASRM] stage), imaging features (bilaterality, cyst diameter), and biochemical parameters (Ca125, Ca19.9, Ca15.3) were evaluated as possible risk factors for the recurrence of endometrioma. The variables with p<0.2 in univariate analysis were introduced into regression analysis to determine the risk factors for recurrence. RESULTS: There were statistically significant differences in age group (≤35 years and >35 years), the ToF and DoP between patients with recurrence and those with no recurrence. In Cox regression analysis, age ≤35 years and DoP were significant risk factors for presence of recurrence. DoP, ToF, preoperative cyst diameters in ultrasonographic examination were inversely correlated with recurrence interval. In multivariate regression analysis, the DoP was found the only significant risk factor for the recurrence interval. 1.2mm of DoP was found as the optimum cut off value for presence of recurrence according to Youden index criteria in ROC curve analyze. The sensitivity (62.9%), specificity (75%) were obtained at the cut off value of 1.2mm for DoP. CONCLUSION: Histopathological features of ovarian endometriotic cyst may have important roles on predicting the recurrence of the endometrioma. Predicting the recurrence risk of particular patient is very important in future management of the disease. Knowing the recurrence risk of an endometrioma will help in deciding the optimal treatment modalities for each individual patient. High risk patients should be offered appropriate treatments according to the clinical status without delay and low risk patients should be protected from overtreatment.

Predictive factors and the prognosis of recurrence of colorectal cancer within 2 years after curative resection.

PURPOSE: Because predicting recurrence intervals and patterns would allow for appropriate therapeutic strategies, we evaluated the clinical and pathological characteristics of early and late recurrences of colorectal cancer. METHODS: Patients who developed recurrence after undergoing curative resection for colorectal cancer stage I-III between January 2000 and May 2006 were identified. Early recurrence was defined as recurrence within 2 years after primary surgery of colorectal cancer. Analyses were performed to compare the clinicopathological characteristics and overall survival rate between the early and late recurrence groups. RESULTS: One hundred fifty-eight patients experienced early recurrence and 64 had late recurrence. Multivariate analysis revealed that the postoperative elevation of carbohydrate antigen 19-9 (CA 19-9), venous invasion, and N stage correlated with the recurrence interval. The liver was the most common site of early recurrence (40.5%), whereas late recurrence was more common locally (28.1%), or in the lung (32.8%). The 5-year overall survival rates for early and late recurrence were significantly different (34.7% vs. 78.8%; P < 0.001). Survival rates after the surgical resection of recurrent lesions were not different between the two groups. CONCLUSION: Early recurrence within 2 years after surgery was associated with poor survival outcomes after colorectal cancer recurrence. An elevated postoperative CA 19-9 level, venous invasion, and advanced N stage were found to be significant risk factors for early recurrence of colorectal cancer.