Evaluation of prognostic factors effect on survival time in patients with colorectal cancer, based on weibull competing-risks model

Aim: The aim of this study was to assess the association between survival of patients with colorectal cancer and prognostic factors in a competing risk parametric model using Weibull distribution

Background: The prognosis of colorectal cancer is relatively good in terms of survival time. In many prognostic studies, patients may be exposed to several types of competing events. These different causes of death are called competing risks

Methods: Data was recorded from 372 patients with colorectal cancer who registered in the Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences [Tehran, Iran] from 2004 to 2015 in a retrospective study. Analysis was performed using competing risks model and Weibull distribution. Software used for data analysis was R, and significance level was regarded as 0.05

Results: The result indicated that, at the end of follow-up, 111 [29.8%] deaths were from colorectal cancer and 14 [3.8%] deaths were due to other diseases. The average body mass index [BMI] was 24.61[SD 3.98]. The mean survival time for a patient in 372 was 62.05[SD 48.78] month with median equals to 48 months. According to competing-risks method, only stageIII [HR, 1.69; 95% CI, 1.246-2.315], stageIV[HR, 4.51; 95% CI,2.91-6.99 ] and BMI[HR, 0.96; 95% CI, 0.96-0.975] have a significant efect on patient's survival time

Conclusion: This study indicated pathologic stage[III,IV] and BMI as the prognosis, using a Weibull model with competing risks analysis, while other models without the competing events lead to significant predictors which may be due to over-estimation

Systematic review of pancreatic cancer epidemiology in Asia-Pacific Region: major patterns in GLOBACON 2012

Pancreatic cancer is one of the deadliest cancers with short-term survival rates. Trends for pancreatic cancer incidence and mortality varied considerably in the world. To date, the causes of pancreatic cancer are not known sufficiently, although certain risk factors have been identified such as, smoking, obesity, life style, diabetes mellitus, alcohol, dietary factors and chronic pancreatitis. Since there are no current screening recommendations for pancreatic cancer, primary prevention is very important. Therefore, up-to-date statistics on pancreatic cancer occurrence and outcome are essential for the primary prevention of this disease. Due to the lack of information on epidemiology of pancreatic cancer in most Asian countries, and limited of statistics and registration system in this area, we conducted a systematic review study to evaluate the most recent data concerning epidemiology of pancreatic cancer in Asia-Pacific region. In this review we focused on collected recent data on incidence, mortality, survival and risk factors of pancreatic cancer in this region. In addition, we reviewed and used the data of GLOBOCAN 2012 in this paper to complete the information as a source of compiling pancreatic cancer incidence and mortality rate

Burden of gastrointestinal cancers and problem of the incomplete information; how to make up the data?

Cancer registration is an important source for measuring the burden of cancer in a population. In practice, however, quite frequently incorrect patients are registered or data items can be inaccurately recorded or not recorded at all. Also the process or quality of these registrations varies among countries. In this paper, we briefly discussed some statistical techniques including; Mortality and Incidence Analysis Model [MIAMOD], Prevalence and Incidence Analysis Model [PIAMOD], Bayesian Inference and Capture-recapture methods, which provide tools to re-correct the incomplete or misclassified cancer statistics with regards to gastrointestinal cancers

Years of life lost due to gastric cancer is increased after Bayesian correcting for misclassification in Iranian population

Aim: To estimate the change in years of life lost [YLL] due to gastric cancer mortality after correcting formisclassification in registering causes of death using the Bayesian method

Background: For evaluating the health status of a country and determining priority of risk factors, some epidemiologicindicators are needed. Due to premature death, YLL is one of the most widely used indicators. To have an exact estimate ofYLL, an accurate death registry data is needed, but the Iranian death registry is subject to misclassification error

Material and methods: Gastric cancer mortality data from 2006 to 2010 for Iran were extracted from national deathstatistics. The rate of misclassification in registered causes of deaths was estimated, using Bayesian method for eachyear. Then YLL of gastric cancer is estimated for different age-sex categories before and after implementing Bayesianmethod

Results: Using Bayesian method, the estimated misclassification rate for gastric cancer in cancer without label group were 5%,3%, 3%, 7% and 7% respectively from 2006 to 2010. Estimated Years of life lost due to gastric cancer before correctingmisclassification were respectively 111684.93, 114957.31, 112391.93, 112250.53 and 113300.92 person-years for years 2006to 2010. After correcting misclassification, the total YLL of gastric cancer increased to 1535.19, 921.11, 908.39, 2566.39 and2507.00 person-years, respectively from 2006 to 2010

Conclusion: If health policy makers ignore the existence of misclassification in registered causes of death, they mayunderestimate the burden of some causes of death and overestimate some others