Showing 12 results for Survival
H Zeraati , M Mahmoudi , K Mohammad, A Kazemnejad, M.a Mohagheghi , M.r Mir ,
Volume 3, Issue 4 (7-2005)
Abstract
In recent years the patterns of mortality have changed in Iran, and cancers are playing
a greater role in this regard in this country. Various reports indicate that gastric cancer
is highly prevalent it is the second most common cancer in men, and fourth in the
general population. The purpose of this study was to determine the five-year survival
rate of gastric cancer patients who had undergone surgical treatment at one of the
most important cancer treatment centers, the Iran Cancer Institute, and to assess its
associated factors.
Three hundred and 30 patients with gastric cancer who had been admitted to and
operated on at the Iran Cancer Institute between January 1996 and April 2000 were
enrolled in this study. The patients’ life expectancy after surgery was determined, and
its relationship with variables of age at the time of surgery, gender, and factors related
to the disease such as the cancer site, pathologic type, stage, presence of metastasis,
and sites of metastases were assessed.
The five-year survival rate and the median life expectancy in the studied patients were
23.6% and 19.90 months, respectively. Univariate analysis showed that gender,
cancer site, and pathologic type did not affect life expectancy significantly. But the
five-year survival rate significantly decreases with age. As expected, those involved
with metastasis had a significantly lower five-year survival rate, and the disease stage
significantly affected the patients’ life expectancy (P<0.001). The Cox proportional
hazards model was used to assess the effect of different variables simultaneously, and
it showed that age, distance metastasis, and disease stage influenced the rate of
survival.
Gastric cancer patients in Iran have a low five-year survival rate. One of the most
important reasons seems to be delayed consultation and diagnosis. Most patients are
seen first with the disease in the late stages. At this point, most have lymph node and
liver metastasis which makes treatment even more complex. Thus, it is necessary to
employ mass media for extensive public education about the early warning signs of
the disease and performing periodic examinations.
A Bakhtiari , K Hajian ,
Volume 5, Issue 2 (5-2007)
Abstract
Background and Aim: Breast cancer is an increasingly important social problem throughout the world. Rate of disease-free survival can be used to evaluate the effects of treatment and disease outcome and assess indices of disease prevention, diagnosis and treatment. With this aim in mind we made an assessment of 5-year disease-free survival in breast cancer patients.
Material and Methods: 403 breast cancer patients attending the radiotherapy-chemotherapy center at Rajaii Hospital, Babolsar were studied with regard to first-time recurrence over a period of 5 years. Data were gathered through questionnaires and statistical analysis included the Kaplan-Meier method and the Cox regression model.
Results: The median local/regional recurrence time was 15.9±5.2 months and the median systemic recurrence time was 22±14.8 months. The most common sites of recurrence were bones (46.6%), especially the lumbar vertebrae. The median disease-free survival time was 38.2±22 month. The total rate for 5-year disease-free survival was 45%. The rate ranged from 85% for stage 1 tumors to 5% for stage 4 disease. Age ≤35 years, disease stage, and lymph node involvement were found to be independent prognostic factors in time of the first recurrence of disease.
Conclusion: Comparison of our results with those from of European and American countries showed lower rates of disease-free survival. This could be related to higher disease stage and younger age at diagnosis. These findings stress the importance of planning for earlier diagnosis and appropriate.
M Behzadpoor, H Zeraati, M Mahmoudi, A Rahimi,
Volume 7, Issue 1 (8-2009)
Abstract
Background and Aim: Like other cancers, gastric cancer is due to uncontrolled growth of tissues. Although there are different therapy methods to treat it, such as surgery, radiation therapy, chemotherapy, and multimodality therapy, relapse and death may occur. Reports show that in Iran gastric cancer is the first cause of death among deaths due to cancers. The purpose of this study was to determine the two-year survival rate after relapsing and its associated factors among gastric cancer patients who had undergone surgical treatment in Iran Cancer Institute, one of the most important cancer treatment centers in Iran.
Methods and Materials: A total of 330 patients with gastric cancer who had been admitted to and operated on at the Iran Cancer Institute between January 1996 and April 2000 were enrolled in this study. The patients' life expectancy after relapse was determined. Survival was defined as the elapsed time between the two successive events, relapse and death, neither of which can be determined exactly therefore the data are doubly censored failure time data. Thus, the relationships between life expectancy at relapse and such variables as age, gender, and factors related to the disease, such as the cancer site, pathologic type, stage, and sites of metastases were determined using the Cox proportional hazards model.
Results: The two-year survival rate after relapsing and the median life expectancy after relapsing were 15% and 10.15 months, respectively. Univariate analysis showed that except disease stage, no other variable (age, gender, cancer site, pathologic type and sites of metastases) affected life expectancy after relapsing significantly. The Cox proportional hazards model for doubly censored failure time data showed that age, gender, and pathologic type had the highest influence, in a decreasing order, on the rate of survival after relapsing.
Conclusion: Two-year survival rate after relapsing is very low in gastric cancer patients. One of the most important reasons seems to be delayed consultation and diagnosis. Most patients seek medical advice first with the disease in the late stages, when most have lymph node, liver or even distant metastasis which makes treatment even more complex, and when the risk of relapse and death would be increased. Thus, early diagnosis and therapy for a common stomach illness could help prevent a potential gastric cancer.
H Kashani, M Mahmoodi, H Zeraati, A Rahimi, A Jalali,
Volume 8, Issue 4 (2-2011)
Abstract
Background and Aim: Many researchers have studied survival (time to death) of gastric cancer patients. Although gastric cancer diagnosed in early stages can be cured by surgery, chance of relapse still exists after operation. Hence, we should consider both events, that is, relapse of the disease and death, in order to be able to make a more precise estimation for survival of the patients. The purpose of this study was to use the competing risks method to estimate the cumulative incidence functions (CIF) of the relapse of disease and death and consequently to estimate the postoperative disease-free survival.
Materials and Methods: A total of 330 patients admitted to Iran Cancer Institute and operated between March 1995 and March 1999 were enrolled in the study. They were followed up for at least 5 years to estimate their 5-year disease-free survival. Information on their demographic, clinical, and therapeutic characteristics, as well as on the type and time of occurrence of the first event (relapse of disease or death) after surgery was collected from their medical records. The direct parametric method was applied to estimate CIFs of relapse of the disease and death, while to adjust the effects of some covariates the parametric regression model was used. Data analysis was done using the R software and a p-value <0.05 was considered statistically significant. The findings were compared with the results obtained on the basis of data analysis in which the competing events were not considered.
Results: The median follow-up time was 37.9 months. Of all the patients 13% experienced relapse and 60.9% death as the first event after surgery. The CIFs of relapse of disease and death 5 years after operation, with due consideration of covariates, were estimated at 11.0% and 68.6%, respectively. Age, stage of disease, and complementary treatment were statistically associated with the CIF of death, while only complementary treatment was related to the CIF of relapse. Older patients and those in more advanced stages of disease were more likely to die after operation. Moreover, while complementary treatment after operation decreased the CIF of relapse of disease, it increased the CIF of death. The disease-free survival of patients 5 years after surgery was 20.(consideringtheeffectsofsomecovariates).
Conclusion: The competing risks method is recommended for analyzing survival data because of its capability in considering different events and, therefore, making it possible to make more precise estimations. By using this method, considering smaller variance estimates for model parameters and also narrow confidence intervals for the cumulative incidence functions of competing events, it is expected to obtain more precise results. Unfortunately, the results have revealed that the disease-free survival of gastric cancer patients is low in Iran.
Maryam Nazemipour, Mahmood Mahmoodi, Hojjat Zeraati, Abbas Rahimi Foroushani,
Volume 11, Issue 2 (11-2013)
Abstract
Background and Aim: In many diagnostic studies, including surveying the survival of patients with gastric cancer where each individual after surgery can experience more than one type of event, and the occurrence of one type of event hinders the occurrence of other types of events, the question of competing risk is raised. For checking the effect of each covariate on the occurrence of any event and estimating the hazard function, Cox and Fine and Gray models are used. In the event that the assumptions of two models do not hold, using them will be an incorrect course of action. One way to overcome this problem is to use models that have higher flexibility.
Materials and Methods: In this study, the demographic, clinical and therapeutic characteristics of 330 patients with gastric cancer who referred from January 1996 to April 2000 to the Cancer Institute of Iran Imam Khomeini Hospital and underwent surgery, including their type, and the time of occurrence of the first event (locoreginal replace/death) for each patient from medical records were collected and evaluated. Using this information, the cumulative hazard function of relapse of disease was plotted by means of three models Cox, Fine and Gray and the flexible one, and was checked against the observed cumulative incidence function of recurrence of disease and, finally, their performance was evaluated.
Results: Nearly, for each event, the proportionality assumption holds for all the variables . According to the graph of cumulative incidence function for the event of interest (recurrence), it can be seen that the Cox model, has overestimated the cumulative incidence function and the curves of two other models are very similar and also similar to the observed curve. However, the cumulative incidence function of the flexible model is smoother than the others.
Conclusion: In the competing risk framework, Cox model is not very useful in practice while it seems that the flexible model is not only a good alternative to the Fine and Gray model but will also be superior to it when the assumption of proportionality does not hold.
Elham Madreseh, Mahmood Mahmoodi, Seyed Mostafa Hosseini, Hojjat Zeraati, Iraj Najafi,
Volume 11, Issue 4 (3-2014)
Abstract
Background and Aim: In many medical studies along with longitudinal data, which are repeatedly measured during a certain time period, survival data are also recorded. In these situations, using models such as, mixed effects models or GEE method for longitudinal data and Cox model for survival data, are not appropriate because some necessary assumptions are not met. Instead, the joint models have been introduced, to consider: 1- measurement error in time-dependent covariates 2-monotone and non-ignorable missing data which occurs after an event and 3- relation between longitudinal and survival outcomes, simultaneously. At this paper, joint model Puts longitudinal response (i.e. creatinine) as a time dependent variable, along with other covariates in survival sub model, to investigate dialysis patients survival.
Materials and Methods: This research contained information about 417 patients affected to chronic renal failure, under treatment of continuous ambulatory peritoneal dialysis (CAPD) method. Patients were referred to three medical centers in Tehran (Shariati, Modares and Shafa) between 1997 to 2009.In this study longitudinal data and time dependent covariate were used Therefore, different variables for each person at certain time have been measured. In first some information was gathered from patient’s file, and then effective factors on survival of patients have been determined by using joint model. Results were compared with naive analysis (extended Cox model). For data analyzing, R software and significant level of 0.05 have been used.
Results: with using joint model sex, age, diabetes, diastolic blood pressure, haemoglobin, urea, LdL, and creatinine covariates were significant. In extended Cox model, only age and Diastolic blood pressure covariates were considered as effective factors on hazard of death in patients.
Conclusion: Joint model assess the effective factors on both endpoints simultaneously. Also it considers missing data that appeared due to an event, and covariates which were measured with error. Therefore in these cases, using joint models that led to better results and more knowledge about dieses, are necessary.
Mahmoud Reza Gohari, Parisa Mokhtari Hesari, Zeynab Moghaddami Fard, Reza Khoda Bakhshi,
Volume 12, Issue 1 (5-2014)
Abstract
Background and Aim : identifying the risk factors for metastasis is major concern for treatment processes of cancer patients. Metastasis makes patients frail and increase hazard of death. It also decreases physical and psychological quality of life of patients. Aim of this study is determining of prognostic factors for metastasis of breast cancer using conditional regression model.
Materials and Methods: in this survival study, hospital records of 246 women with breast cancer who underwent surgery and treatment at hospital Fayyazbakhsh were used. Patients were followed until 2012 May and their final situations recorded. Metastasis free survival estimated with Kaplan-myier method. To determine the prognostic factors, a conditional regression model called PWP fitted. All statistical analysis was conducted with R software, version 2.10.
Results: 202 patients (82.1%) were alive until follow up and 44 patients (17.9%) died.54patients experience metastasis. 11 patients (4.7%) had two metastases. Most of metastases were shown in bone, liver, lung and brain. Median metastasis free survival (MFS) estimated 64 month. One, two and three year MFS were 88%, 80.1% and 76.6%, respectively. Lymph node involvement and HER2 were shown as prognostic factors for metastasis. Age, Esterogen Receptor, Prosterogen Receptor, Grade and tumor size were not significant ( P> 0.05).
Conclusion: number of lymph nodes involvement as a prognostic factor involve more nodes and increase risk of metastasis and death. Thus prognosis and treatment of cancer in early stages increase survival of patients.
Elahe Zarean, Mehdi Yaseri, Mahmood Mahmoodi, Rasoul Entezar Mahdi,
Volume 15, Issue 4 (3-2018)
Abstract
Background and Aim: Gastric cancer is one the most common gastrointestinal tract cancers in Iran, with East-Azerbaijan Province ranking second in the country. The objectives of this research were to determine the feasibility of using cure models in survival analysis and factors affecting short-term and long-term patient survival rates using the mixture cure cox model.
Materials and Methods: We used the available information on 184 patients diagnosed with gastric cancer in East-Azerbaijan Province cities referring to medical centers during the period 2009-2010 and followed up for 5 years.
Results: The median of survival time was 8.33 months (95% CI = 5.9-10.6). Fitting the univariate and final cox cure models showed that in the short-term survival the effect of the chemotherapy factor was statistically significant (Hazard ratio =0.49, 95% CI = 0.34, 0.69, p-value <0.001).
Conclusion: If the population under study consists of two groups of susceptible and non-susceptible individuals for the intended incident, the mixture cure models can be used for the discrete analysis of long-term and short-term survival of patients diagnosed with gastric cancer and identification of variables affecting the two survival rates.
Marzieh Mohammadpour, Mehdi Yaseri, Mahmoud Mahmoudi, Rasoul Entezar Mahdi,
Volume 16, Issue 1 (6-2018)
Abstract
Background and Aim: Breast cancer is one of the most prevalent cancers in women and is the second cause of mortality due to cancer in women, with lung cancer being the first.
Materials and Methods: In this study we followed all the cases for 5 years, patients from West-Azerbaijan and East-Azerbaijan Provinces that diagnosed with breast cancer in 2009 and 2010 that attended to health cares. Using multivariate cure cox model for the influence of variables in this study.
Results: In this study 171 cases which suffering from breast cancer had the mean age of 55.9 ± 12.9 and the range of 23 to 89 years, in time of cancer diagnosis. Mean of patients follow-up was 51.7± 23.4 months with range of 11 days to 78 months. Overalls 52 death occurred and patient survival rate of 5 years was estimated 60. 6 percent. Eventually the two variables which are economic status and emergency hospitalization were found the two factors of pre-warning in long term survival of patient suffering from breast cancer.
Conclusion: Due to the findings, it seems using cure model in patients suffering from breast cancer was better than classical survival models.
Rabeae Hesami, Rasoul Entezar Mahdi, Hamid Reza Khalkhali, Omid Asnaashari,
Volume 17, Issue 1 (6-2019)
Abstract
Background and Aims: Gastric cancer is the fifth most common cancer and the third cause of cancer death globally. This cancer ranks first and fourth in Iranian men and women, respectively. Assessment of survival rate and factors influencing it will make it possible to determine the burden of disease in the population and the relationships between different factors and the survival rate. The present study was performed to estimate the survival rate and determine its prognostic factors in patients with gastric cancer in West Azerbaijan Province, Iran.
Materials and Methods: In this study 930 cases of gastric cancer were investigated during the period 2011-2012 and the first half of 2013. The Kaplan-Meier method and Log-rank test were used to determine the survival rate and compare survivor functions, respectively; for data fitting A Cox’s proportional hazards model was used. The data were analyzed using the Stata v.11 software
Results: The average age of the patients (more than 69% males) was 66.43±12.5 years. The one-, three- and five-year survival rates were 37%, 14% and 11%, respectively. Multivariate analysis revealed that age (p=0.01) and tumor metastasis (p=0.001) were the most important prognostic factors.
Conclusion: While the survival rates in gastric cancer patients in the West Azarbaijan province, Iran were very low, a significantly higher survival rate was observed in younger patients with no tumor metastasis.
Mostafa Peyvand, Hossein Ansari, , , Mohamad Ali Yadegari, Hossein Moein,
Volume 21, Issue 3 (12-2023)
Abstract
Background and Aim Cardiovascular complications in diabetes mellitus are one of the most common complications of this disease. The aim of this study was to determine the cumulative probability of occurrence of cardiac complications in type 2 diabetes mellitus using survival analysis in patients referring to the Diabetes Clinic, Bu-Ali Hospital, Zahedan, Iran.
Materials and Methods: This was a descriptive and analytical historical cohort study using the survival analysis method in 2020 on 410 patients referring to the Diabetes Clinic, Bu-Ali Hospital, Zahedan, Iran. Data were collected and analyzed using the SPSS-v21 software, the statistical tests being descriptive tests, followed by the Kaplan-Meier method and the Cox proportional hazards model of survival.
Results: The results of this study showed that 122 individuals (29.7%) of the diabetic patients had cardiac complications. The median survival time (in months) of the occurrence of cardiac complications was found to be related to fasting and two-hour postprandial blood sugar levels (p<0.05). Further analysis of the data showed that two variables, namely fasting blood sugar and regular visits, remained in the final model of the multiple Cox regression.
Conclusion: The findings of this study showed that the cardiac complications of diabetes in the population studies are relatively high. Therefore, it is essential to plan and implement interventions aiming to change lifestyle and control regularly blood pressure, cholesterol and blood sugar in the patients in order to prevent the disease
Mohammad Amin Mirzaei, Majid Sartipi, Mehdi Mohammadi,
Volume 21, Issue 4 (3-2024)
Abstract
Background and Aim: Kidney transplantation is the treatment of choice in most patients with kidney disease. It is a surgical operation in which a person’s kidney with chronic failure is replaced with a healthy kidney. The present study was conducted with the aim of estimating the survival probability of a transplanted kidney in patients with chronic kidney failure in Zahedan city, Iran.
Materials and Methods: This was a descriptive-analytical retrospective cohort study using the survival analysis method carried out in 2020. The sample size was estimated to be 211 patients.
Data were analyzed with SPSS.VER22 software using descriptive tests, the Kaplan-Meier method and the Cox proportional hazards model of survival.
Results: The data obtained showed that in general 45 (21.3%) clients had been rejected. In the multiple logistic regression model of kidney transplantation several variables, including survival time, patient survival variables, marital status, donor status, blood pressure and diabetes remained in the model (P<0.05). Further analysis of the data revealed that in the kidney disease patients with transplant survival in Zahedan city, only donor status variables, high blood pressure and diabetes remained in the final multiple Cox regression model.
Conclusion: Based on the results, it can be said that the probability of survival of kidney disease patients is independent of the type of donor and the characteristics of the recipient, which indicates the evolution of kidney transplant management over the past few years; dialysis before kidney transplantation also has an effect on the probability of survival. These factors can help to increase the probability of kidney transplant survival.
