Journal of School of Public Health and

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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.

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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.

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  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.

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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.

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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.