Comparison of P-POSSUM and O-POSSUM in predicting mortality after oesophagogastric resections

Feasibility of esophagectomy for esophageal cancer in elderly patients: a case-control study

PURPOSE

Surgery in elderly patients with esophageal cancer is challenging due to high mortality and limited survival. This study aimed to evaluate the safety and effectiveness of curative esophagectomy in elderly patients with esophageal cancer.

METHODS

This study included 77 and 112 patients with esophageal cancer aged ≥ 70 and 40-64 years, respectively, who underwent R0 esophagectomy between January 1998 and December 2016. Patient characteristics, intraoperative outcomes, postoperative complications, and long-term survival were compared.

RESULTS

The proportions of comorbid diseases (85.7% vs. 57.1%; P < 0.001), the American Society of Anesthesiologists score (1/2/3; 2.6%/94.8%/2.6% vs. 42.9%/57.1%/0%; P < 0.001), the preoperative systemic inflammation score (SIS) (0/1/2; 20.8%/48.1%/31.2% vs. 38.4%/38.4%/23.2%; P = 0.036), and postoperative complications (Clavien-Dindo grade ≥ III) (33.8% vs. 20.5%; P = 0.041) were significantly higher in the elderly group than those in the non-elderly group. However, long-term overall survival (OS) and relapse-free survival were not significantly different between the groups. On multivariate analysis, SIS (hazard ratio, 3.06; P = 0.037) and severe postoperative complications (hazard ratio, 2.01; P = 0.039) were significantly correlated with OS in the elderly group.

CONCLUSIONS

As SIS and severe postoperative complications lead to poor prognosis after R0 esophagectomy in elderly patients, selecting appropriate patients for esophagectomy and preventing severe postoperative complications is essential.

The statistical importance of P-POSSUM scores for predicting mortality after emergency laparotomy in geriatric patients

Background

Geriatric patients frequently undergo emergency general surgery and accrue a greater risk of postoperative complications and fatal outcomes than the general population. It is highly relevant to develop the most appropriate care measures and to guide patient-centered decision-making around end-of-life care.

Portsmouth - Physiological and Operative Severity Score for the enumeration of Mortality and morbidity (P-POSSUM) has been used to predict mortality in patients undergoing different types of surgery. In the present study, we aimed to evaluate the relative importance of the P-POSSUM score for predicting 90-day mortality in the elderly subjected to emergency laparotomy from statistical aspects.

Methods

One hundred and fifty-seven geriatric patients aged ≥65 years undergoing emergency laparotomy between January 1st, 2015 and December 31st, 2016 were included in the study. Mortality and 27 other patient characteristics were retrieved from the computerized records of Örebro University Hospital in Örebro, Sweden. Two supervised classification machine methods (logistic regression and random forest) were used to predict the 90-day mortality risk. Three scalers (Standard scaler, Robust scaler and Min-Max scaler) were used for variable engineering. The performance of the models was evaluated using accuracy, sensitivity, specificity and area under the receiver operating characteristic curve (AUC). Importance of the predictors were evaluated using permutation variable importance and Gini importance.

Results

The mean age of the included patients was 75.4 years (standard deviation =7.3 years) and the 90-day mortality rate was 29.3%. The most common indication for surgery was bowel obstruction occurring in 92 (58.6%) patients. Types of post-operative complications ranged between 7.0–36.9% with infection being the most common type. Both the logistic regression and random forest models showed satisfactory performance for predicting 90-day mortality risk in geriatric patients after emergency laparotomy, with AUCs of 0.88 and 0.93, respectively. Both models had an accuracy > 0.8 and a specificity ≥0.9. P-POSSUM had the greatest relative importance for predicting 90-day mortality in the logistic regression model and was the fifth important predictor in the random forest model. No notable change was found in sensitivity analysis using different variable engineering methods with P-POSSUM being among the five most accurate variables for mortality prediction.

Conclusion

P-POSSUM is important for predicting 90-day mortality after emergency laparotomy in geriatric patients. The logistic regression model and random forest model may have an accuracy of > 0.8 and an AUC around 0.9 for predicting 90-day mortality. Further validation of the variables’ importance and the models’ robustness is needed by use of larger dataset.

Impact of preoperative risk factors on outcome after gastrectomy

Background

Gastrectomy is associated with relevant postoperative morbidity. However, outcome of surgery can be improved by careful selection of patients. The objective of the current study was therefore to identify preoperative risk factors that might impact on patients’ further outcome after surgical resection.

Methods

Preoperative risk factors having respectively different surgical risk scores for major complex surgery (including Cologne Risk Score, p-/o-POSSUM, and NSQIP risk score) of patients that underwent gastrectomy for AEG II/III tumors and gastric cancer were correlated with complications according to Clavien-Dindo and outcome. Patients who underwent surgery in palliative intention were excluded from further analysis.

Results

Subtotal gastrectomy was performed in 23%, gastrectomy in 59%, and extended gastrectomy in 18% in a total of 139 patients (mean age: 64 years old). Thirty six percent experienced a minor complication (Dindo I-II) and 24% a major complication (Dindo III-V), which resulted in a prolonged hospital stay (p < 0.001). In-hospital mortality (=Dindo V) was 2.5%. Besides age, type of surgical procedure impacted on complications with extended gastrectomy showing the highest risk (p = 0.005). The o-POSSUM score failed to predict mortality accurately. We observed a highly positive correlation between predicted morbidity respectively mortality and occurrence of complications estimated by p-POSSUM (p = 0.005), Cologne Risk (p = 0.007), and NSQIP scores (p < 0.001).

Conclusion

The results demonstrate a significant association between different risk scores and occurrence of complications following gastrectomy. The p-POSSUM, Cologne Risk, and NSQIP score exhibited superior performance than the o-POSSUM score. Therefore, these scores might allow identification and selection of high-risk patients and thus might be highly useful for clinical decision making.

Predicting morbidity of liver resection

PURPOSE

Multiple models have attempted to predict morbidity of liver resection (LR). This study aims to determine the efficacy of American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) surgical risk calculator and the Physiological and Operative Severity Score in the enUmeration of Mortality and Morbidity (POSSUM) in predicting post-operative morbidity in patients who underwent LR.

METHODS

A retrospective analysis was conducted on patients who underwent elective LR. Morbidity risk was calculated with the ACS-NSQIP surgical risk calculator and POSSUM equation. Two models were then constructed for both ACS-NSQIP and POSSUM-(1) the original risk probabilities from each scoring system and (2) a model derived from logistic regression of variables. Discrimination, calibration, and overall performance for ACS-NSQIP and POSSUM were compared. Sub-group analysis was performed for both primary and secondary liver malignancies.

RESULTS

Two hundred forty-five patients underwent LR. Two hundred twenty-three (91%) had malignant liver pathologies. The post-operative morbidity, 90-day mortality, and 30-day mortality rate were 38.3%, 3.7%, and 2.4% respectively. ACS-NSQIP showed superior discriminative ability, calibration, and performance to POSSUM (p = 0.03). Hosmer-Lemeshow plot demonstrated better fit of the ACS-NSQIP model than POSSUM in predicting morbidity.

CONCLUSION

In patients undergoing LR, the ACS-NSQIP surgical risk calculator was superior to POSSUM in predicting morbidity risk.

Prediction models for patients with esophageal or gastric cancer: A systematic review and meta-analysis

Background

Clinical prediction models are increasingly used to predict outcomes such as survival in cancer patients. The aim of this study was threefold. First, to perform a systematic review to identify available clinical prediction models for patients with esophageal and/or gastric cancer. Second, to evaluate sources of bias in the included studies. Third, to investigate the predictive performance of the prediction models using meta-analysis.

Methods

MEDLINE, EMBASE, PsycINFO, CINAHL, and The Cochrane Library were searched for publications from the year 2000 onwards. Studies describing models predicting survival, adverse events and/or health-related quality of life (HRQoL) for esophageal or gastric cancer patients were included. Potential sources of bias were assessed and a meta-analysis, pooled per prediction model, was performed on the discriminative abilities (c-indices).

Results

A total of 61 studies were included (45 development and 16 validation studies), describing 47 prediction models. Most models predicted survival after a curative resection. Nearly 75% of the studies exhibited bias in at least 3 areas and model calibration was rarely reported. The meta-analysis showed that the averaged c-index of the models is fair (0.75) and ranges from 0.65 to 0.85.

Conclusion

Most available prediction models only focus on survival after a curative resection, which is only relevant to a limited patient population. Few models predicted adverse events after resection, and none focused on patient’s HRQoL, despite its relevance. Generally, the quality of reporting is poor and external model validation is limited. We conclude that there is a need for prediction models that better meet patients’ information needs, and provide information on both the benefits and harms of the various treatment options in terms of survival, adverse events and HRQoL.

Prognosis impact of clinical characteristics in patients with inoperable esophageal squamous cell carcinoma

Background

Patients with inoperable esophageal squamous cell carcinoma (ESCC) were not homogeneous and their outcomes were widely divergent. There was a lack of identified clinical factors related to prognosis; and there were no previous studies constructing prognosis score to predict survival and guide treatment.

Methods

In this retrospective cohort study, twelve clinical characteristics of one hundred and twenty inoperable ESCC patients were collected at diagnosis and analyzed by Cox regression model. Various methods including univariate analysis, confounding adjusted multivariate analysis and model selection were applied to determine factors associated with poor prognosis; and prognosis score was built on established factors.

Results

Four characters were identified as poor prognosis factors, including mid- and low-thoracic tumor (aHR = 2.20, 95% CI = 1.03, 4.72), abdominal and retroperitoneal lymph node metastasis (aHR = 1.62, 95% CI = 1.00, 2.64), albumin no more than 39g/L (aHR = 2.81, 95% CI = 1.24, 6.41) and hematogenous metastasis (aHR = 1.61, 95% CI = 0.97, 2.69). Patients were stratified into three groups by prognosis score, that was, good survival with none of four identified factors (score zero), poor survival with three to four factors (score three to four) and median with one to two factors (score one to two), survival of three groups were statistically different (p_trend = 0.020).

Conclusion

Prognosis score based on selected clinical characteristics could predict survival among inoperable ESCC patients, which was critical for individualized treatment and central of precise medicine.

Risk adjustment models for short-term outcomes after surgical resection for oesophagogastric cancer

BACKGROUND

Outcomes for oesophagogastric cancer surgery are compared with the aim of benchmarking quality of care. Adjusting for patient characteristics is crucial to avoid biased comparisons between providers. The study objective was to develop a case-mix adjustment model for comparing 30- and 90-day mortality and anastomotic leakage rates after oesophagogastric cancer resections.

METHODS

The study reviewed existing models, considered expert opinion and examined audit data in order to select predictors that were consequently used to develop a case-mix adjustment model for the National Oesophago-Gastric Cancer Audit, covering England and Wales. Models were developed on patients undergoing surgical resection between April 2011 and March 2013 using logistic regression. Model calibration and discrimination was quantified using a bootstrap procedure.

RESULTS

Most existing risk models for oesophagogastric resections were methodologically weak, outdated or based on detailed laboratory data that are not generally available. In 4882 patients with oesophagogastric cancer used for model development, 30- and 90-day mortality rates were 2·3 and 4·4 per cent respectively, and 6·2 per cent of patients developed an anastomotic leak. The internally validated models, based on predictors selected from the literature, showed moderate discrimination (area under the receiver operating characteristic (ROC) curve 0·646 for 30-day mortality, 0·664 for 90-day mortality and 0·587 for anastomotic leakage) and good calibration.

CONCLUSION

Based on available data, three case-mix adjustment models for postoperative outcomes in patients undergoing curative surgery for oesophagogastric cancer were developed. These models should be used for risk adjustment when assessing hospital performance in the National Health Service, and tested in other large health systems.

Evaluation of O-POSSUM vs ASA and APACHE II scores in patients undergoing oesophageal surgery

BACKGROUND AND AIMS

Risk and prognostic scores quantify the patient's risk of death or complication according to the severity of his illness. The aim of this study was to evaluate the predictive accuracy of O-POSSUM vs ASA and APACHE II models on patients undergoing oesophageal surgery.

MATERIAL AND METHOD

In this observational retrospective study 55 patients were enrolled who had undergone surgical interventions of excision and reconstruction of the oesophagus for neoplastic oesophageal stenosis, in the Surgical Clinics (I and II) of the Clinical County Emergency Hospital Mures, between January 2011 and January 2014. By using patients file records after extracting the data we calculated the predictive mortality, according to the prognostic scores O-POSSUM, ASA and APACHE II and we analyzed its correlations with the postoperative evolution. We evaluated the discriminatory power of the three scores using the ROC (receiver-operating characteristic) curves. According to the cut-off value corresponding to each score, we compared the Kaplan Meier survival curves during the hospitalization period.

RESULTS

ROC curves analysis revealed that O-POSSUM had a better discriminatory power for mortality compared to the other two scores: AUC = 0.73 for O-POSSUM, AUC = 0.57 for APACHE II and AUC = 0.64 for ASA (p < 0.001). The cut-off value was statistically significant only in case of O-POSSUM, as it derives from the statistical analysis of the survival curves (p = 0.035).

CONCLUSION

O-POSSUM predicts mortality more accurately compared to ASA or APACHE II in patients undergoing oesophageal surgery.

Anesthesia for esophagectomy

Esophagectomy is a high-risk operation with significant perioperative morbidity and mortality. Attention to detail in many areas of perioperative management should lead to an aggregation of marginal gains and improvement in postoperative outcome. This review addresses preoperative assessment and patient selection, perioperative care (focusing on pulmonary prehabilitation, ventilation strategies, goal-directed fluid therapy, analgesia, and cardiovascular complications), minimally invasive surgery, and current evidence for enhanced recovery in esophagectomy.

A novel multivariate scoring system for determining the prognosis of lymph node-negative esophageal squamous cell carcinoma following surgical therapy: an observational study

BACKGROUND

Identifying patients with esophageal squamous cell carcinoma (ESCC) with negative prognostic factors, which have an extremely low survival rate, has been problematic.

METHODS

We retrospectively collected clinical data for 648 patients with lymph node-negative ESCC who were treated at the Sun Yat-Sen University Cancer Center from 1990 to 2005. Survival difference was compared using Kaplan-Meier analysis and multivariate Cox regression analysis.

RESULTS

We identified advancing age, smoking history, alcohol consumption history, decreased forced expiratory volume in 1 s (FEV1), surgical procedure, tumor location, number of resected lymph nodes, poor tumor differentiation, and surgical stage as independent prognostic risk factors. Furthermore, based on the results of multivariate analysis, we constructed a novel scoring system that included the factors of age, smoking history, alcohol consumption history, number of resected lymph nodes, tumor differentiation, and surgical stage. Risk score (RS) was computed with the scoring system, and patients were divided into Class A (RS: 0-5) and Class B (RS: 6-10). P < 0.001 indicated statistical significance. A significant difference (p < 0.001) demonstrated that Class B was strongly related to a low survival rate and poor prognosis.

CONCLUSION

We developed a new simple flexible scoring system of high prognostic significance, which has the potential to guide postoperative therapeutic strategies and follow-up frequency and to provide better prognostic information for patients and their families.

A comparison of POSSUM and GPS models in the prediction of post-operative outcome in patients undergoing oesophago-gastric cancer resection

BACKGROUND

There is some evidence that a patient's pre-operative condition influences short-term and long-term post-operative outcomes. The aim of the present study is to compare the physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM) and modified Glasgow prognostic score (mGPS) models in the prediction of post-operative outcome, both short term and long term, in patients undergoing resection of oesophago-gastric cancer.

PATIENTS AND METHODS

Patients who underwent curative resection for oesophago-gastric cancer from January 2005 to May 2009 and who had data to score the POSSUM, P-POSSUM, O-POSSUM and mGPS models were included in the study. Observed morbidity and mortality rates were compared with predicted outcome in different risk groups. Both short-term outcome and long-term survival were recorded.

RESULTS

Observed morbidity was 49%, whereas POSSUM predicted post-operative morbidity in 60%, giving an overall standardised morbidity ratio of 0.82. Only male sex [hazard ratio (HR) 3.61, 95% confidence interval (CI) 1.38-9.46, P = 0.009] and POSSUM physiology score (HR 2.13, 95% CI 1.11-4.08, P = 0.023) were independently associated with post-operative morbidity. The post-operative mortality rates predicted by POSSUM, P-POSSUM and O-POSSUM were 16.5, 5.8 and 9.9%, respectively, giving a standardised mortality ratio of 0.25, 0.71 and 0.42. Only mGPS (HR 1.96, 95% CI 1.09-3.54, P = 0.025) and tumour-node-metastasis (TNM) stage (HR 2.21, 95% CI 1.44-3.38, P < 0.001) were independently associated with cancer-specific survival.

CONCLUSIONS

The POSSUM physiology score was useful in predicting post-operative morbidity, and the mGPS was useful in predicting cancer-specific survival, in patients undergoing surgery for oesophago-gastric cancer.

IL-6 serum levels predict postoperative morbidity in gastric cancer patients

BACKGROUND

Despite progress in surgical techniques and perioperative care, gastrectomy remains a procedure of significant morbidity. Several scoring systems and clinical measures have been adopted to predict postoperative complications in gastric cancer patients. The aim of this study was to investigate whether high serum levels of interleukin 6 (IL-6) in the early postoperative period may be a prognostic factor of postoperative morbidity.

METHODS

A group of 99 consecutive patients with resectable gastric cancer were enrolled. The mean age was 62.9 years and the male/female ratio was 72:27. Subtotal gastric resection was performed in 22 patients and total gastric resection in 77. The IL-6 serum level was measured on the 1st postoperative day (POD).

RESULTS

Complications were recorded in 28 patients (28.3%). The observed case-fatality rate was 3.03%. An IL-6 serum level of >288.7 pg/ml on the 1st POD in univariate and multivariate Cox proportional hazard models was an independent prognostic factor for overall complications and infective complications.

CONCLUSION

Our study showed an association between perioperative IL-6 serum levels and postoperative morbidity in gastric cancer patients. The IL-6 serum level on the 1st POD was shown to be an independent prognostic factor for both overall complications and infective complications.

POSSUM and its related models as predictors of postoperative mortality and morbidity in patients undergoing surgery for gastro-oesophageal cancer: a systematic review

BACKGROUND

Gastro-oesophageal surgery is associated with appreciable postoperative morbidity and mortality. POSSUM (Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity) and its related models P-POSSUM and O-POSSUM have been developed to predict such events in general surgery. The aim was to undertake the first systematic review of the use of these models in gastro-oesophageal surgery patients.

METHODS

An online database search was carried out from 1991 to December 2008.

RESULTS

Twenty-two published studies in gastro-oesophageal cancer surgery were identified. Twelve studies were found not to address the above aim, leaving ten relevant publications for analysis. Pooled data from these studies showed the weighted observed-to-expected ratio (O/E) for postoperative mortality using POSSUM (n = 1189), P-POSSUM (n = 2314), and O-POSSUM (n = 1755) was 0.37, 0.83, and 0.51, respectively. The weighted O/E for morbidity using POSSUM (n = 1038) was 0.86.

CONCLUSION

POSSUM and O-POSSUM most significantly overestimated postoperative mortality in gastro-oesophageal cancer patients. In contrast, P-POSSUM had the least overestimation and may be the most useful predictor of likely postoperative mortality in these patients.

Risk prediction scores for postoperative mortality after esophagectomy: validation of different models

BACKGROUND

Different prediction models for operative mortality after esophagectomy have been developed. The aim of this study is to independently validate prediction models from Philadelphia, Rotterdam, Munich, and the ASA.

METHODS

The scores were validated using logistic regression models in two cohorts of patients undergoing esophagectomy for cancer from Switzerland (n = 170) and Australia (n = 176).

RESULTS

All scores except ASA were significantly higher in the Australian cohort. There was no significant difference in 30-day mortality or in-hospital death between groups. The Philadelphia and Rotterdam scores had a significant predictive value for 30-day mortality (p = 0.001) and in-hospital death (p = 0.003) in the pooled cohort, but only the Philadelphia score had a significant prediction value for 30-day mortality in both cohorts. Neither score showed any predictive value for in-hospital death in Australians but were highly significant in the Swiss cohort. ASA showed only a significant predictive value for 30-day mortality in the Swiss. For in-hospital death, ASA was a significant predictor in the pooled and Swiss cohorts. The Munich score did not have any significant predictive value whatsoever.

CONCLUSION

None of the scores can be applied generally. A better overall predictive score or specific prediction scores for each country should be developed.