P40 CONDITIONAL SURVIVAL AFTER CURATIVE TREATMENT OF ESOPHAGEAL CANCER

Abstract

Abstract Aim To assess conditional survival and design a nomogram predicting the conditional probability of survival for esophageal cancer patients after surgery. Background and methods Conditional survival accounts for the time already survived after surgery and may be informative in addition to conventional static survival estimates during follow-up. Consecutive patients with esophageal cancer who received neoadjuvant chemoradiation followed by an esophagectomy between January 2004 and 2019 in the Amsterdam UMC, The Netherlands were included. Conditional survival was defined as the probability of surviving “y” years after already surviving for “x” years. Cox proportional hazard models were used to evaluate predictors for overall survival. A nomogram was constructed to predict 5-year survival correcting for time already survived. Results 660 patients were included in this study. The median overall survival was 46.4 months (95%CI 39.1–53.8). The probability to achieve 5-year overall survival after resection increased from 46% directly after surgery to 55%, 67%, 79% and 88% per additional year survived. ypN-stage was the strongest predictor for overall survival (HR6.50, p<0.001, for ypN3 with ypN0 as reference), followed by pulmonary complications (HR1.16, p=0.002), cardiac comorbidity (HR1.27, p=0.040) and ypT-stage (HR1.461, p=0.039 for ypT2-3 with ypT0 as reference). These variables were included in the nomogram (figure 1), which predicts survival with a C-statistic of 0.70. Conclusion The proposed nomogram showed an accurate prediction of survival in patients after esophageal cancer surgery, taking the years already survived after surgery into account. This nomogram can be helpful in counselling patients in the follow-up after esophageal cancer surgery.