[Evaluation of POSSUM scoring system in radical gastrectomy for gastric cancer patients]

To assess the accuracy of POSSUM scoring system in predicting surgical risk in patients with gastric cancer, and provide a feasible reference to clinical decision.

Clinical data of 310 patients suffered from gastric cancer were analyzed retrospectively, including 278 cases in laparoscopic group and 32 cases in open group, between April 2009 and April 2014 in the department of minimally invasive gastrointestinal surgery, Peking University Cancer Hospital. Preoperative physiology score(PS), operative score(OS) and predictive morbidity rate(R1) were calculated according to POSSUM scoring system, which were used to assess the accuracy of R1 in open group. Two different scoring systems (R1traditional and R1modified according to adjustment of operative excision area) were applied in the laparoscopic group, and were compared for predicting the accuracy of R1 in the laparoscopic group. Besides, postoperative morbidities were compared between the two groups of patients with different preoperative physiological status(low risk group: PS≤20, high risk group: PS≥21).

The predictive accuracy for open group patients were acceptable, and the ratio of expected and observed(E/O) was 1.2. In the laparoscopic group, the R1modified was 29.1%, and observed morbidity was 23.4% with an E/O of 1.2. The R1modified was more accurate than R1traditional(38.5%, E/O traditional was 1.6). Both modified and traditional POSSUM scoring system predicted well in low risk patients in the laparoscopic and open group, and E/O was 1.0. However, it overestimated morbidities in median and high risk patients for both laparoscopic and open group. E/O was 1.6, and 1.9 in laparoscopic group, as well as 1.2 and 1.3 in open group. For patients in poor preoperative physiological status(PS≥21), the morbidity in laparoscopic group was lower than that in open group(27.3% vs. 5/7, P=0.020).

Modified POSSUM scoring system predicted morbidity more accurately in the laparoscopic group than traditional system. As for patients in poor preoperative physiological status, laparoscopic assisted gastrectomy procedure might reduce postoperative morbidities.