Analysis of POSSUM score and postoperative morbidity in patients with rectal cancer undergoing surgery

The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) and later modifications (P-POSSUM y CR-POSSUM) have been used to predict morbidity and mortality rates among patients with rectal cancer undergoing surgery. These calculations need some adjustment, however. The aim of this study was to assess the applicability of POSSUM to a group of patients with rectal cancer undergoing surgery, analysing surgical morbidity by means of several variables.

between January 1995 and December 2004, 273 consecutive patients underwent surgery for rectal cancer. Information was gathered about the patients, tumour and therapy. To assess the prediction capacity of POSSUM, subgroups for analysis were created according to variables related to operative morbidity and mortality.

The global morbidity rate was 23.6% (31.2% predicted by POSSUM). The mortality rate was 0.7% (6.64, 1.95 and 2.08 predicted by POSSUM, P-POSSUM and CR-POSSUM respectively). POSSUM predictions may be more accurate for patients younger than 51 years, older than 70 years, with low anaesthetic risk (ASA I/II), DUKES stage C and D, surgery duration of less than 180 minutes and for those receiving neoadjuvant therapy.

POSSUM is a good instrument to make results between different institutions and publication comparable. We found prediction errors for some variables related to morbidity. Modifications of surgical variables and specifications for neoadjuvant therapy as well as physiological variables including life style may improve future prediction of surgical risk. More research is needed to identify further potential risk factors for surgical complications.