The impact of the surgical Apgar score on oncological outcomes in patients with colorectal cancer: a propensity score-matched study

BACKGROUND: The surgical Apgar score (SAS) predicts postoperative complications (POCs) following gastrointestinal surgery. Recently, the SAS was reported to be a predictor of not only POCs but also prognosis. However, the impact of the SAS on oncological outcomes in patients with colorectal cancer (CRC) has not been fully examined. The present study therefore explored the oncological significance of the SAS in patients with CRC, using a propensity score matching (PSM) method. METHODS: We retrospectively analyzed 639 patients who underwent radical surgery for CRC. The SAS was calculated based on three intraoperative parameters: estimated blood loss, lowest mean arterial pressure, and lowest heart rate. All patients were classified into 2 groups based on the SAS (≤6 and >6). The association of the SAS with the recurrence-free survival (RFS), overall survival (OS), and cancer-specific survival (CSS) was analyzed. RESULTS: After PSM, each group included 156 patients. Univariate analyses revealed that a lower SAS (≤6) was significantly associated with a worse OS and CSS. A multivariate analysis revealed that the age ≥75 years old, ASA-Physical Status ≥3, SAS ≤6, histologically undifferentiated tumor type, and an advanced pStage were independent factors for the OS, and open surgery, a SAS ≤6, histologically undifferentiated tumor type and advanced pStage were independent factors for the CSS. CONCLUSIONS: A lower SAS (≤6) was an independent prognostic factor for not only the OS but also the CSS in patients with CRC, suggesting that the SAS might be a useful biomarker predicting oncological outcomes in patients with CRC.