prognostic factors affecting short- and long-term recurrence-free survival of patients with rectal cancer using cure models: a cohort study

Background: understanding the prognostic factors affecting the recurrence-free survival (rfs) of patients with rectal cancer (rc) is the mainstay of care. the present study aimed to identify factors affecting both short and long-term rfs of patients with rc using semi-parametric mixture cure models. methods: the data were obtained from the database of the colorectal research center of shiraz university of medical sciences, shiraz, iran, which was collected during 2007-2017. to determine the factors affecting recurrence, cure models were applied to short-term and long-term rfs of patients with rc separately. the cure rate was calculated using the smcure package in r 3.5.1 (2018-07-02) software. results: out of the 376 eligible patients with rc, 75.8% of men and 74.5% of women were long-term survivors. the mean age of the patients was 57.0±13.8 years. lymph node ratio (lnr)≤0.2 increased the probability of short-term rfs. the prominent factors affecting long-term rfs were body mass index (bmi). conclusion: the results showed that factors affecting short-term rfs might be different from long-term rfs. a lower bmi was related to a poorer prognosis in patients with rc. early diagnosis leads to a lower tnm stage and could increase the probability of long-term rfs.