Cox Regression Proportional Hazard Analysis Research Articles

Radiotherapy for patients with esophageal cancer aged 80 years or older: A 16-year experience.

Radiotherapy (RT) plays an important role in esophageal cancer (EC) patients aged ≥80 years. However, the survival modality and prognostic factors remain poorly understood. Thus, this study aimed to evaluate the tolerance and long-term overall survival (OS) of patients aged ≥80 years who were diagnosed with EC and underwent definitive RT. A total of 213 consecutive patients with EC over 80 years old who were treated with curative intent RT between February 1999 and December 2015 at our institution were retrospectively reviewed. The clinical prognostic variables were analyzed against OS in univariate analyses using log-rank tests and in a multivariate model using Cox regression proportional hazards analysis. The median patient age was 82 (range: 80-94) years. Atotal of 192 patients (90.1%) completed the definitive RT (median: 60 Gy, range: 50-72 Gy), and 11 patients had grade 4 or higher acute toxicity, including esophagitis, a cardiac event, infections, and sudden death. Atotal of 168 deaths (78.9%) were observed with a median follow up of 47 months (range: 0-153 months). The OS rates were 50.3%, 17.6%, and 13.2% at 1, 3, and 5 years, respectively. Multivariable analysis identified that tumors located in the cervical and upper thorax, a shorter tumor lesion, RT treatment of 50-60Gy, and a better response to treatment were the factors associated with longer OS. Definitive RT could be considered as an effective treatment for patients with EC who are older than 80 years, and 50-60 Gy seems to be a reasonable dose for these patients.

Surface-Enhanced Raman Spectroscopy of Pretreated Plasma Samples Predicts Disease Recurrence in Muscle-Invasive Bladder Cancer Patients Undergoing Neoadjuvant Chemotherapy and Radical Cystectomy.

ObjectiveTo explore the value of surface-enhanced Raman spectroscopy analysis of pretreated plasma samples in prediction of bladder cancer (BCa) recurrence after neoadjuvant chemotherapy (NAC) and radical cystectomy (RC).Patients and MethodsSERS was used to analyze plasma samples collected before biopsy and treatment in BCa patients undergoing NAC and RC. The value of clinicopathological parameters and distinctive SERS peaks in the prediction of disease recurrence were analyzed in Cox regression proportional hazard analysis and Log rank test. Principal component analysis and linear discriminant analysis (PCA-LDA) were employed to process spectral data and construct diagnostic algorithms.ResultsA total of 88 patients with 440 plasma SERS spectra were collected. The SRES spectra from recurrent patients were compared with patients who remained recurrence free. The SERS demonstrated higher levels of circulating free nucleic acid components in recurrent population, which is represented by significantly higher intensities at SERS peaks of 725 cm−1, 1328 cm−1 and 1455 cm−1. The SERS also detected significantly lower levels of tryptophan shown as lower significantly intensities at the 1558 cm−1, which is proved to be an independent predictor of BCa recurrence. The addition of SERS peaks of 1558 cm−1 to classic clinicopathological predictors including pathological tumor stage, lymph node metastasis and pathological downstaging can significantly enhance the power of the predictive model from 0.66 to 0.76 in the area under curve (AUC) of receiver operating characteristic (ROC) curves. Meanwhile, the PCA-LDA diagnostic model based on SERS spectra reveals a high accuracy of 85.2% in prediction of disease recurrence and the AUC of 0.92 in the ROC curve. When validated in the leave-one-out cross-validation method, the accuracy of the model remained 84.1%.ConclusionWe show that SERS analysis of plasma before NAC treatment can accurately classify patients with different risks of disease recurrence after surgery and improve the power of clinicopathological predictive models, thus refining clinical decision-making.

A Simpler Creatinine Index Can Predict Long-Term Survival in Chinese Hemodialysis Patients.

BackgroundLow lean body mass (LBM) is an indicator of malnutrition inflammation syndrome, which is common in hemodialysis (HD) patients. The creatinine index (CI) has been validated as a reliable method to estimate LBM and evaluate the protein-energy status of HD patients. However, the traditional creatinine index formula was complex. We sought to investigate the impact of CI derived from a new simple formula on Chinese HD patient outcomes.MethodsIn this retrospective cohort study, we enrolled 1269 patients who initiated HD between February 1981 and February 2012 and followed them until the end of February 2013. CI was calculated using the simple creatinine kinetic model (CKM) formula. Multiple linear regression analysis and Cox regression proportional hazard analysis were used to define independent variables and compare survival between groups.ResultsThe 1269 HD patients were categorized into 3 groups according to the tertiles of calculated CI between men and women. Each group consisted of 423 patients (50.6% men, 49.4% women). Patients in the highest sex-specific tertile of CI had longer overall survival (HR, 0.46; P 0.002). BMI did not significantly associate with survival after adjustment (HR,0.99; P 0.613).ConclusionsCI derived from the simple CKM formula serves as a good parameter than BMI to predict the survival of HD patients. The formula could extend its convenient use in clinical practice for HD patients.

Lymph node ratio may predict the benefit of postoperative radiotherapy in node-positive cervical cancer.

The standard treatment for node-positive cervical cancer after radical hysterectomy is pelvic radiotherapy and concurrent chemotherapy. Given the potential toxicity of postoperative radiotherapy, we used the lymph node ratio (LNR) to assess the benefit of postoperative radiotherapy in lymph node-positive cervical cancer patients. Data from the Surveillance Epidemiology and End Results database (1988–2010) were analyzed using Kaplan–Meier and Cox regression proportional hazard analysis. A total of 2,269 eligible patients were identified (median follow-up, 78.0 months); 1,863 (82.1%) patients received postoperative radiotherapy. In both univariate and multivariate analysis multivariate analysis, a higher LNR was significantly associated with a poorer outcome. A LNR > 0.16 was associated with poorer cervical cancer-related survival (CCSS) (hazard Ratio [HR] 1.376, confidence interval [CI] 1.082–1.750; P < 0.001) and overall survival (OS) (HR 1.287, CI 1.056–1.569; P = 0.012). Postoperative radiotherapy was only associated with survival benefits in patients with a LNR > 0.16 (CCSS, P < 0.001; OS, P < 0.001) and not in patients with a LNR ≤ 0.16 (CCSS, P = 0.620; OS, P = 0.167); these trends were not affected by number of removed lymph nodes. A higher LNR is associated with a poorer survival in lymph node-positive cervical cancer. The survival benefits of postoperative radiotherapy appear to be limited to patients with a LNR > 0.16.

Association of Body Mass Index and Body Mass Index Change with Mortality in Incident Peritoneal Dialysis Patients.

Although high body mass index (BMI) appears to confer a survival advantage in hemodialysis patients, the association of BMI with mortality in continuous ambulatory peritoneal dialysis (CAPD) patients is uncertain. We enrolled incident CAPD patients and BMI was categorized according to World Health Organization classification for Asian population. BMI at baseline and one year after the initiation of peritoneal dialysis (PD) treatment was assessed to calculate the BMI change (∆BMI). Patients were split into four categories according quartiles of ∆BMI. Kaplan-Meier method and Cox regression proportional hazard analysis were performed to assess the association of BMI on outcomes. A total of 1263 CAPD patients were included, with a mean age of 47.8 ± 15.0 years, a mean BMI of 21.58 ± 3.13 kg/m2. During a median follow-up of 25.3 months, obesity was associated with increased risk for cardiovascular diseases (CVD) death (adjusted hazard ratio (AHR) 2.01; 95% CI 1.14, 3.54), but not all-cause mortality. Additionally, patients with more BMI decline (>0.80%) during the first year after CAPD initiation had an elevated risk for both all-cause (AHR: 2.21, 95% CI 1.23–3.95) and CVD mortality (AHR 2.31, 95% CI 1.11, 4.84), which was independent of baseline BMI values.

Preoperative White Matter Lesions Are Independent Predictors of Long-Term Survival after Internal Carotid Endarterectomy

Background: Cerebral white matter lesions (WMLs) predict long-term survival of conservatively treated acute stroke patients with etiology other than carotid stenosis. In carotid endarterectomy patients, WMLs are associated with severe carotid stenosis and unstable plaques, with the risk of perioperative complications and with increased 30-day perioperative risk of death. However, no data exist on their effect on postoperative long-term survival, a factor important when considering the net benefit from carotid endarterectomy. Whether this effect is independent of classical risk factors and indications for surgery is not known either. We hypothesized that WMLs could be evaluated from preoperative routine computed tomography (CT) scans and are predictors of postoperative survival, independent of classical cardiovascular risk factors, indication category and degree of carotid stenosis. Methods: A total of 353 of 481 (73.4%) consecutive patients subjected to carotid endarterectomy due to different indications, i.e. asymptomatic stenosis (n = 28, 7.9%), amaurosis fugax (n = 52, 14.7%), transient ischemic attack (n = 135, 38.2%) or ischemic stroke (n = 138, 39.1%), from prospective vascular registries during the years 2001-2010 with digital preoperative CT scans, were included in the study. WMLs were rated by a radiologist (Wahlund criteria) in a blinded fashion. Internal carotid artery (ICA) stenoses were angiographically graded (<50, 50-69, 70-99 and 100%). Odds ratios (ORs) and hazard ratios (HRs) are reported (ORs and HRs ≤1 indicate a beneficial effect). The median follow-up time was 67 months (interquartile range 45.5, range 0-129 months). Spearman's rho was used to estimate intraobserver agreement. Binary logistic regression was performed to analyze the association of risk factors with WMLs. Cox regression proportional hazards analysis was used to study the effect of different factors on survival. Results: WML severity could be assessed with a substantial intraobserver agreement (Spearman's rho 0.843, p < 0.0001). Only age (OR 1.10, 95% CI 1.06-1.15; p < 0.0001 per year), degree of ipsilateral ICA stenosis (OR 2.22, 95% CI 1.08-4.55; p < 0.05 per stenosis grade) and indication category (OR 1.63, 95% CI 1.19-2.24; p < 0.01 per category) remained independently associated with WMLs. Age (HR 1.04, 95% CI 1.01-1.08; p < 0.05 per year), diabetes (HR 1.59, 95% CI 1.01-2.49; p < 0.05), peripheral arterial disease (HR 2.47, 95% CI 1.46-4.15; p < 0.01), degree of ipsilateral ICA stenosis (HR 2.56, 95% CI 1.12-5.87; p < 0.05 per stenosis grade) and WMLs (HR 3.83, 95% CI 1.17-12.5; p < 0.05) remained independently associated with increased long-term mortality. Conclusions: WMLs in a preoperative CT scan provide a substantially reliable estimate of postoperative long-term survival of carotid endarterectomy patients independent of currently used criteria, i.e. cardiovascular risk factors, indication category and degree of ipsilateral ICA stenosis.

Lean Body Mass Predicts Long-Term Survival in Chinese Patients on Peritoneal Dialysis

BackgroundReduced lean body mass (LBM) is one of the main indicators in malnutrition inflammation syndrome among patients on dialysis. However, the influence of LBM on peritoneal dialysis (PD) patients’ outcomes and the factors related to increasing LBM are seldom reported.MethodsWe enrolled 103 incident PD patients between 2002 and 2003, and followed them until December 2011. Clinical characteristics, PD-associated parameters, residual renal function, and serum chemistry profiles of each patient were collected at 1 month and 1 year after initiating PD. LBM was estimated using creatinine index corrected with body weight. Multiple linear regression analysis, Kaplan–Meier survival analysis, and Cox regression proportional hazard analysis were used to define independent variables and compare survival between groups.ResultsUsing the median LBM value (70% for men and 64% for women), patients were divided into group 1 (n = 52; low LBM) and group 2 (n = 51; high LBM). Group 1 patients had higher rates of peritonitis (1.6 vs. 1.1/100 patient months; p<0.05) and hospitalization (14.6 vs. 9.7/100 patient months; p<0.05). Group 1 patients also had shorter overall survival and technique survival (p<0.01). Each percentage point increase in LBM reduced the hazard ratio for mortality by 8% after adjustment for diabetes, age, sex, and body mass index (BMI). Changes in residual renal function and protein catabolic rate were independently associated with changes in LBM in the first year of PD.ConclusionsLBM serves as a good parameter in addition to BMI to predict the survival of patients on PD. Preserving residual renal function and increasing protein intake can increase LBM.

Extensive White Matter Changes Predict Stroke Recurrence up to 5 Years after a First-Ever Ischemic Stroke

Background: White matter changes (WMCs), a surrogate for small-vessel disease (SVD), have been shown to be associated with a major negative influence on cognition, mood and functioning in daily life. We aimed to investigate whether severe WMCs are a risk factor for recurrent ischemic stroke in a long-term follow-up. Methods: 320 consecutive patients admitted to hospital with a first-ever ischemic stroke were included in the study and followed up for 12 years using extensive national registers. Patients were aged between 55 and 85 years, with a mean age of 70.8 years. WMCs were rated using MRI and stratified into two grades: absent to moderate WMCs versus severe WMCs. Univariate analysis was performed using binary logistic regression analysis, Kaplan-Meier log rank analysis and life table function. To control for factors such as age, education and cardiovascular risk factors, a multivariate Cox regression proportional hazards analysis was made with forced entry. Results: At least one recurrent stroke, nonfatal or fatal, was diagnosed in 76 (23.8%) patients at 5 years and in 127 (39.7%) patients at 12 years. In univariate analysis, only advancing age was associated with WMCs. The cumulative 5-year recurrence risk was 24.5% [95% confidence interval (95% CI) 23.8–25.2] for patients with absent to moderate WMCs and 39.1% (95% CI 38.1–40.1) for patients with severe WMCs. The cumulative 12-year recurrence risk was 48.1% (95% CI 45.5–50.7) for patients with absent to moderate WMCs and 60.9% (95% CI 56.7–65.1) for patients with severe WMCs. In Cox regression proportional hazards analysis, independent predictors of recurrent stroke at 5 years were severe WMCs [hazard ratio (HR) 1.80, 95% CI 1.11–2.95], atrial fibrillation (HR 1.81, 95% CI 1.09–3.02), hypertension (HR 1.69, 95% CI 1.05–2.71) and peripheral arterial disease (HR 1.89, 95% CI 1.06–3.38). At 12 years, only increasing age remained as an independent predictor (HR 1.04, 95% CI 1.02–1.07). In receiver operating characteristic analysis, the area under the curve for severe WMCs was 0.58 (95% CI 0.51–0.65) for the prediction of stroke recurrence within 5 years. Conclusions: In our well-defined cohort of poststroke patients, the presence of severe WMCs was an indicator of stroke recurrence up to 5 years after a first-ever ischemic stroke. WMCs can be considered as an SVD marker that summarizes the effects of several classical risk factors on the small-vessel brain network and therefore can be used as a score for risk stratification of stroke recurrence. Our findings further underline the poor long-term prognosis of cerebral SVD.

Uncovertebral hypertrophy is a significant risk factor for the occurrence of heterotopic ossification after cervical disc replacement: survivorship analysis of Bryan disc for single-level cervical arthroplasty

The purpose of this study is to investigate the incidence of heterotopic ossification (HO) in the Bryan cervical arthroplasty group and to identify associations between preoperative factors and the development of HO. We performed a retrospective review of clinical and radiological data on patients who underwent single-level cervical arthroplasty with Bryan prosthesis between January 2005 and September 2007. Patients were postoperatively followed-up at 1, 3, 6, 12 months and every year thereafter. The clinical assessment was conducted using Odom's criteria. The presence of HO was evaluated on the basis of X-ray at each time-point according to the McAfee classification. In this study, we focused on survivorship of Bryan prosthesis for single-level arthroplasty. The occurrence of ROM-affecting HO was defined as a functional failure and was used as an endpoint for determining survivorship. Through the analysis of 19 cases of Bryan disc arthroplasty for cervical radiculopathy and/or myelopathy, we revealed that ROM-affecting HO occurs in as many as 36.8% of cases and found that 37% of patients had ROM-affecting HO within 24 months following surgery. The overall survival time to the occurrence of ROM-affecting HO was 36.4 ± 4.4 months. Survival time of the prosthesis in the patient group without preoperative uncovertebral hypertrophy was significantly longer than that in the patient group with preoperative uncovertebral hypertrophy (47.2 months vs 25.5 months, p = 0.02). Cox regression proportional hazard analysis illustrated that preoperative uncovertebral hypertrophy was determined as a significant risk factor for the occurrence of ROM-affecting HO (hazard ratio = 12.30; 95% confidential interval = 1.10-137.03; p = 0.04). These findings suggest that the condition of the uncovertebral joint must be evaluated in preoperative planning for Bryan cervical arthroplasty.

Post‐stroke delirium in relation to dementia and long‐term mortality

Delirium is a frequent post-stroke complication that compromises effective rehabilitation and has been associated with poor outcome. We aimed to investigate whether delirium is associated with increased risk of post-stroke dementia and long-term mortality once confounding is taken into account. The study comprised 263 consecutive acute ischemic stroke patients aged 55-85 years admitted to the emergency department of a university hospital. The cohort included three-month survivors followed up for 10 years. The diagnosis of post-stroke delirium during the first 7 days after stroke was based on the DSM-IV criteria. Of all the patients, 50 (19.0%) were diagnosed with delirium. Low education, pre-stroke cognitive decline, and severe stroke indicated by a Modified Rankin score between 3 and 5 were risk factors for post-stroke delirium, which was also associated with diagnosis of dementia at 3 months post-stroke. In the Kaplan-Meier analysis, delirium was associated with poor long-term survival (6.1 versus 9.1 years). In the stepwise Cox regression proportional hazards analysis adjusted for demographic factors and risk factors, advanced age (hazard ratio [HR] 1.08) and stroke severity (HR 1.83), but not post-stroke delirium, were associated with poor survival. In our well-defined cohort of post-stroke patients, acute stage delirium was diagnosed in one in five patients and associated with dementia at 3 months. Advanced age and stroke severity were related to the higher long-term mortality among patients with post-stroke delirium.

Depression–Executive Dysfunction Syndrome Relates to Poor Poststroke Survival

The aim of this study was to investigate the influence of poststroke depression and executive dysfunction on long-term survival after acute stroke. A total of 257 consecutive acute ischemic stroke patients were included in the study and followed up to 12 years. Depression was diagnosed 3 months after stroke in 99 patients (38.5%). In Kaplan-Meier analysis, there was no difference in survival of patients with and without poststroke depression (8.7 versus 8.3 years). Instead, patients with both depression and executive dysfunction had shorter median survival than patients with neither depression nor executive dysfunction (6.6 versus 10.3 years). Comparison between all patients with executive dysfunction and patients without it, not regarding depressive status, showed that executive dysfunction in itself was strongly associated with poor poststroke survival (6.4 versus 10.6 years). In stepwise Cox regression proportional hazards analysis adjusted with covariates, poststroke depression with executive dysfunction (hazard ratio [HR] 1.63) and advanced age (HR 1.11) remained as independent predictors of poor long-term survival. The authors' well-defined poststroke cohort with long-term follow-up indicates that in poststroke depression, the depression-executive dysfunction syndrome is the predictor of poor long-term survival rather than depression in itself.

Poststroke dementia predicts poor survival in long-term follow-up: influence of prestroke cognitive decline and previous stroke

Background:The aim of this study was to investigate the influence of poststroke dementia on long-term survival after acute stroke and also to assess the possible influence of prestroke cognitive decline...