Background: Surgical treatment for esophageal cancer is a high risk procedure. Prediction of  postoperative adverse events could aid in stratification of patients thus improving outcomes as well as achieving  optimal use of resources. The Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity (POSSUM) is a prediction model which utilises both physiological and operative parameters to assess risk.This study evaluates the effectiveness of POSSUM, P-POSSUM and O-POSSUM scoring systems in predicting postoperative morbidity and mortality in Indian patients operated for esophageal cancers.

Patients and Methods: It is a retrospective study conducted in a tertiary care teaching hospital with data collected from esophagectomies performed from January 2015 to January 2019.  The calibration and discriminative abilities of the scores to predict 30 day morbidity and mortality were analyzed using the HosmerLemeshow test, Observed to Predicted ratios (O/E) and the Receiver operating curve  tests.

Results: A total of 60 patients were included.  The 30 day mortality and morbidity were 6.67% (4/60) and 46.66% (28/60) respectively.  POSSUM morbidity showed good calibration and discrimination (O/E 0.86) with modest predictive ability (AUC 0.701).  While analyzing mortality, though all scores displayed good calibration, O-POSSUM displayed superior predictive ability.(O/E 1.02).  The Possum score over-predicted mortality by nearly twice (O/E0.52) while P-POSSUM under-predicted it.(O/E 1.71).   All scores showed moderate discrimination with P-POSSUM outperforming other tests (AUC 0.825).

Conclusions:The POSSUM scoring system was useful in predicting morbidity risk following esophageal resection for cancer, with O-POSSUM more accurate for mortality prediction in this group of patients.