survival rate estimation in patients with colorectal cancer by applying fuzzy product limit estimator

Introduction: the survival probability curve is used to show the progress of the disease and the effect of treatments. estimating survival probabilities, especially in the presence of highly censored data is challenging. in this study, the fuzzy product limit estimator (fple) is applied to mitigate the challenge in colorectal cancer (crc) survival data. methods: in a longitudinal study, data from 173 crc patients were analyzed. to estimate survival probabilities, mean and median survival time, the fple and kaplan – meier (km) methods, were applied to the data. the fple uses the information contained in the data and the knowledge of user to provides a smooth survival probability curve. results: one-year survival rate for crc patients was estimated to be 83% using the fple and km methods. the five-year survival rate was estimated to be 37% and 52% by the fple and km methods, respectively. the largest observed time in data (71.96 months) was censored, so the survival rate after 71.96 months was not estimable by the km method. but 10-year and 20-year survival rates estimates by fple was 0.21 and 0.09, respectively. the mean (median) survival time was estimated 45.97 (65) and 82.69 (41.70) months by km and fple methods, respectively. conclusion: the fple method gives a smooth survival curve for crc patients. the curve provides an estimate at each time point event after the largest observed time. these probabilities could be informative about the future status of the crc patients. the smaller estimates by the fple at 5-year could be considered as warning that the actual survival rate is lower than that reported by the km method.