• The Korean Journal of Applied Statistics
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• v.34 no.2
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• pp.255-266
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• 2021

The purpose of this study is to compare the effects of treatment on stage III stomach cancer data obtained from the SEER program of the National Cancer Institute and to identify the significant risk factors for the survival rates of stage III stomach cancer. Since the proportional hazards assumption was violated for treatment, we used the restricted mean survival time as an alternative to the proportional hazards model. The restricted mean survival time was estimated using pseudo-observations, and the effects of treatment were compared using a test statistic based on the estimated restricted mean survival times. We conducted the regression analysis using a generalized linear model to investigate the significant predictors for the restricted mean survival time of patients with stage III stomach cancer. We found that there was a significant difference between the restricted mean survival times of treatment groups. Age at diagnosis, race, substage, grade, tumor size, surgery, and treatment were significant predictors for the restricted mean survival time of patients with stage III stomach cancer. Surgery was the most significant predictor for increasing the restricted mean survival time of patients with stage III stomach cancer.

• Korean Journal of Radiology
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• v.23 no.5
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• pp.495-499
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• 2022

• Tuberculosis and Respiratory Diseases
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• v.42 no.3
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• pp.314-321
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• 1995

Background: Flow cytometric study has been used to measure the DNA content of solid tumors for the last decade. DNA ploidy is an important property commonly measured by flow cytometry. The possibility to study archival paraffin-embedded tumors has hastened an appreciation of prognostic utility of this method. The aim of this study is to look for biologic prognostic indicator for survival time of patients with small cell carcinoma of lung in addition to the well known clinical prognostic factors. Method: DNA ploidy was measured by flow cytometric method using tumor cells isolated from paraffin embedded tissue. To evaluate the prognostic significance, DNA ploidy of small cell lung cancer was analysed in 42 patients who died after receiving anticancer chemotherapy. Results: 1) Mean survival time of all patients was 190(${\pm}156$) days. Survival time was shortened, when TNM stage and PS scale were advanced. 2) 62% of all patients was DNA aneuploidy. DNA ploidy had nothing to do with advance of TNM stage and PS scale. 3) Mean survival time of aneuploid tumor was significantly shorter($138{\pm}90$ days) than that of diploid tumors($272{\pm}197$ days).(p<0.001) 4) To exclude the influence of clinical prognostic factors such as TNM stage and PS scale, the analysis was restricted to subgroups of identical stage. We were able to find the same tendency. Conclusion: DNA ploidy is an independent prognostic factor in small cell lung cancer.