Predictive modeling algorithms for liver metastasis in colorectal cancer: A systematic review of the current literature

This study aims to assess the quality and performance of predictive models for colorectal cancer liver metastasis (CRCLM). A systematic review was performed to identify relevant studies from various databases. Studies that described or validated predictive models for CRCLM were included. The methodological quality of the predictive models was assessed. Model performance was evaluated by the reported area under the receiver operating characteristic curve (AUC). Of the 117 articles screened, seven studies comprising 14 predictive models were included. The distribution of included predictive models was as follows: radiomics (n = 3), logistic regression (n = 3), Cox regression (n = 2), nomogram (n = 3), support vector machine (SVM, n = 2), random forest (n = 2), and convolutional neural network (CNN, n = 2). Age, sex, carcinoembryonic antigen, and tumor staging (T and N stage) were the most frequently used clinicopathological predictors for CRCLM. The mean AUCs ranged from 0.697 to 0.870, with 86% of the models demonstrating clear discriminative ability (AUC > 0.70). A hybrid approach combining clinical and radiomic features with SVM provided the best performance, achieving an AUC of 0.870. The overall risk of bias was identified as high in 71% of the included studies. This review highlights the potential of predictive modeling to accurately predict the occurrence of CRCLM. Integrating clinicopathological and radiomic features with machine learning algorithms demonstrates superior predictive capabilities.

The impact of hospital volume on liver resection: A systematic review and Bayesian network meta-analysis

BACKGROUND

This study aims to compare the outcomes of high-volume, medium-volume, and low-volume hospitals performing hepatic resections using a network meta-analysis.

METHODS

A literature search until June 2023 was conducted across major databases to identify studies comparing outcomes in high-volume, medium-volume, and low-volume hospitals for liver resection. Bayesian network meta-analysis was conducted, and surface under cumulative ranking area values, odds ratio, and mean difference with 95% credible intervals were reported for postoperative mortality, failure-to-rescue, morbidity, length of stay, and hospital costs.

RESULTS

Twenty studies comprising 248,707 patients undergoing liver resection were included. For the primary mortality outcome, overall and subgroup analyses were performed: group I: high-volume = 5 to 20 resections/year; group II: high-volume = 21 to 49 resections/year; group III: high-volume ≥50 resections/year. Results demonstrated a significant association between hospital volume and mortality (overall-high-volume versus medium-volume: odds ratio 0.66, 95% credible interval 0.49-0.87; high-volume versus low-volume: odds ratio 0.52, 95% credible interval 0.41-0.65; group I-high-volume versus low-volume: odds ratio 0.34, 95% credible interval 0.22-0.50; medium-volume versus low-volume: odds ratio 0.56, 95% credible interval 0.33-0.92; group II-high-volume versus low-volume: odds ratio 0.67, 95% credible interval 0.45-0.91), as well as length of stay (high-volume versus low-volume: mean difference -1.24, 95% credible interval -2.07 to -0.41), favoring high-volume hospitals. No significant difference was observed in failure-to-rescue, morbidity, or hospital costs across the 3 groups.

CONCLUSION

This study supports a positive relationship between hospital volume and surgical outcomes in liver resection. Patients from high-volume hospitals experience superior outcomes in terms of lower postoperative mortality and shorter lengths of stay than medium-volume and low-volume hospitals.

A reduction in hospital length of stay reduces costs for colorectal surgery: an economic evaluation of the National Surgical Quality Improvement Program in Singapore

PURPOSE

In 2017, the National Surgical Quality Improvement Program (NSQIP) was introduced in the Department of Colorectal Surgery at Singapore General Hospital as a pilot quality improvement initiative. This study aimed to examine the cost-effectiveness of NSQIP by evaluating its effects on surgical outcomes, length of stay (LOS), and costs.

METHODS

We retrospectively reviewed patients undergoing colorectal surgery (2017-2020). Patients were divided into two cohorts: pre-NSQIP (2017-2018) and post-NSQIP (2019-2020). Outcomes evaluated were 30-day postoperative complications, LOS, and costs. Total cost-savings from NSQIP intervention's impact on LOS were estimated using a decision model with a one-way sensitivity analysis. Multivariate logistic regression was performed to identify factors for prolonged LOS.

RESULTS

1905 patients underwent colorectal surgery, with 996 in the pre-NSQIP cohort and 909 in the post-NSQIP cohort. A significant reduction in overall postoperative complications of 4.7% was observed in the post-NSQIP cohort (36.5% vs. 31.8%, p = 0.029). Patients in the post-NSQIP cohort had a shorter median LOS (8.0 vs. 6.0 days, p < 0.001). The implementation of NSQIP resulted in an 8.5% decrease in prolonged LOS > 6 days (p < 0.001), saving S$0.31 million on LOS. Total costs per case were reduced by 20.8% following NSQIP (S$39,539.05 vs. S$31,311.93, p < 0.001).

CONCLUSION

Implementing NSQIP has significantly reduced overall postoperative complications, LOS, and costs and achieved cost savings following colorectal surgery.

Clinical outcomes and cost comparison of laparoscopic versus open surgery in elderly colorectal cancer patients over 80 years

PURPOSE

The growth of Singapore's geriatric population, coupled with the rise in colorectal cancer (CRC), has increased the number of colorectal surgeries performed on elderly patients. This study aimed to compare the clinical outcomes and costs of laparoscopic versus open elective colorectal resections in elderly CRC patients over 80 years.

METHODS

A retrospective cohort study using data from the American College of Surgeons National Surgery Quality Improvement Program (ACS-NSQIP) identified patients over 80 years undergoing elective colectomy and proctectomy between 2018 and 2021. Patient demographics, length of stay (LOS), 30-day postoperative complications, and mortality rates were analysed. Cost data in Singapore dollars were obtained from the finance database. Univariate and multivariate regression models were used to determine cost drivers. The 5-year overall survival (OS) for the entire octogenarian CRC cohort with and without postoperative complications was estimated using the Kaplan-Meier curves.

RESULTS

Of the 192 octogenarian CRC patients undergoing elective colorectal surgery between 2018 and 2021, 114 underwent laparoscopic resection (59.4%), while 78 underwent open surgery (40.6%). The proportion of proctectomy cases was similar between laparoscopic and open groups (24.6% vs. 23.1%, P = 0.949). Baseline characteristics, including Charlson Comorbidity Index, albumin level, and tumour staging, were comparable between both groups. Median operative duration was 52.5 min longer in the laparoscopic group (232.5 vs. 180.0 min, P < 0.001). Both groups had no significant differences in postoperative complications and 30-day and 1-year mortality rates. Median LOS was 6 days in the laparoscopic group compared to 9 days in the open group (P < 0.001). The mean total cost was 11.7% lower in the laparoscopic group (S$25,583.44 vs. S$28,970.85, P = 0.012). Proctectomy (P = 0.024), postoperative pneumonia (P < 0.001) and urinary tract infection (P < 0.001), and prolonged LOS > 6 days (P < 0.001) were factors contributing to increased costs in the entire cohort. The 5-year OS of octogenarians with minor or major postoperative complications was significantly lower than those without complications (P < 0.001).

CONCLUSION

Laparoscopic resection is associated with significantly reduced overall hospitalization costs and decreased LOS compared to open resection among octogenarian CRC patients, with comparable postoperative outcomes and 30-day and 1-year mortality rates. The extended operative time and higher consumables costs from laparoscopic resection were mitigated by the decrease in other inpatient hospitalization costs, including ward accommodation, daily treatment fees, investigation costs, and rehabilitation expenditures. Comprehensive perioperative care and optimised surgical approach to mitigate the impact of postoperative complications can improve survival in elderly patients undergoing CRC resection.

Elderly patients over 80 years undergoing colorectal cancer resection: Development and validation of a predictive nomogram for survival

BACKGROUND

Surgery remains the primary treatment for localized colorectal cancer (CRC). Improving surgical decision-making for elderly CRC patients necessitates an accurate predictive tool.

AIM

To build a nomogram to predict the overall survival of elderly patients over 80 years undergoing CRC resection.

METHODS

Two hundred and ninety-five elderly CRC patients over 80 years undergoing surgery at Singapore General Hospital between 2018 and 2021 were identified from the American College of Surgeons – National Surgical Quality Improvement Program (ACS-NSQIP) database. Prognostic variables were selected using univariate Cox regression, and clinical feature selection was performed by the least absolute shrinkage and selection operator regression. A nomogram for 1- and 3-year overall survival was constructed based on 60% of the study cohort and tested on the remaining 40%. The performance of the nomogram was evaluated using the concordance index (C-index), area under the receiver operating characteristic curve (AUC), and calibration plots. Risk groups were stratified using the total risk points derived from the nomogram and the optimal cut-off point. Survival curves were compared between the high- and low-risk groups.

RESULTS

Eight predictors: Age, Charlson comorbidity index, body mass index, serum albumin level, distant metastasis, emergency surgery, postoperative pneumonia, and postoperative myocardial infarction, were included in the nomogram. The AUC values for the 1-year survival were 0.843 and 0.826 for the training and validation cohorts, respectively. The AUC values for the 3-year survival were 0.788 and 0.750 for the training and validation cohorts, respectively. C-index values of the training cohort (0.845) and validation cohort (0.793) suggested the excellent discriminative ability of the nomogram. Calibration curves demonstrated a good consistency between the predictions and actual observations of overall survival in both training and validation cohorts. A significant difference in overall survival was seen between elderly patients stratified into low- and high-risk groups (P < 0.001).

CONCLUSION

We constructed and validated a nomogram predicting 1- and 3-year survival probability in elderly patients over 80 years undergoing CRC resection, thereby facilitating holistic and informed decision-making among these patients.

Acute hospital-community hospital care bundle for elderly orthopedic surgery patients: A propensity score-matched economic analysis

BACKGROUND

While Singapore attains good health outcomes, Singapore’s healthcare system is confronted with bed shortages and prolonged stays for elderly people recovering from surgery in acute hospitals. An Acute Hospital-Community Hospital (AH-CH) care bundle has been developed to assist patients in postoperative rehabilitation. The core concept is to transfer patients out of AHs when clinically recommended and into CHs, where they can receive more beneficial dedicated care to aid in their recovery, while freeing up bed capacities in AHs.

AIM

To analyze the AH length of stay (LOS), costs, and savings associated with the AH-CH care bundle intervention initiated and implemented in elderly patients aged 75 years and above undergoing elective orthopedic surgery.

METHODS

A total of 862 1:1 propensity score-matched patients aged 75 years and above who underwent elective orthopedic surgery in Singapore General Hospital (SGH) before (2017-2018) and after (2019-2021) the care bundle intervention period was analyzed. Outcome measures were AH LOS, CH LOS, hospitalization metrics, postoperative 30-d mortality, and modified Barthel Index (MBI) scores. The costs of AH inpatient hospital stay in the matched cohorts were compared using cost data in Singapore dollars.

RESULTS

Of the 862 matched elderly patients undergoing elective orthopedic surgery before and after the care bundle intervention, the age distribution, sex, American Society of Anesthesiologists classification, Charlson Comorbidity Index, and surgical approach were comparable between both groups. Patients transferred to CHs after the surgery had a shorter median AH LOS (7 d vs 9 d, P < 0.001). The mean total AH inpatient cost per patient was 14.9% less for the elderly group transferred to CHs (S$24497.3 vs S$28772.8, P < 0.001). The overall AH U-turn rates for elderly patients within the care bundle were low, with a 0% mortality rate following orthopedic surgery. When elderly patients were discharged from CHs, their MBI scores increased significantly (50.9 vs 71.9, P < 0.001).

CONCLUSION

The AH-CH care bundle initiated and implemented in the Department of Orthopedic Surgery appears to be effective and cost-saving for SGH. Our results indicate that transitioning care between acute and community hospitals using this care bundle effectively reduces AH LOS in elderly patients receiving orthopedic surgery. Collaboration between acute and community care providers can assist in closing the care delivery gap and enhancing service quality.

Cost-effectiveness comparison of minimally invasive, robotic and open approaches in colorectal surgery: a systematic review and bayesian network meta-analysis of randomized clinical trials

PURPOSE

This study compares the cost-effectiveness of open, laparoscopic (LAP), laparoscopic-assisted (LAPA), hand-assisted laparoscopic (HAL), and robotic colorectal surgery using a network meta-analysis.

METHODS

Randomized clinical trials (RCTs) evaluating the cost-effectiveness of comparing the five different approaches in colorectal surgery were included in a literature search until September 2022. Bayesian network meta-analysis was conducted, and surface under cumulative ranking area (SUCRA) values, odds ratio (OR), and 95% credible intervals (CrIs) were reported for total costs, surgical costs, operating time, length of stay (LOS), and postoperative outcomes. Cluster analysis was performed to examine the similarity and classification of surgical approaches into homogeneous clusters. The cophenetic correlation coefficient (cc) was evaluated to identify the most cost-effective clustering method. The primary outcomes assessed were: costs-morbidity, costs-mortality, and costs-efficacy, measuring total costs against postoperative complications, mortality rate, and LOS, respectively.

RESULTS

22 RCTs with 4239 patients were included. Open surgery had the lowest total costs, surgical costs, and operating time but the longest LOS and most postoperative complications. LOS was significantly decreased in LAP compared to open surgery (OR 0.67, 95% CrI 0.46-0.96). Robotic surgery resulted in the highest total costs, surgical costs, and most extended operative duration but the shortest LOS and lowest mortality. LAPA and robotic surgery were superior in the costs-morbidity analysis. HAL was associated with the worst costs-mortality profile. LAP, LAPA, and HAL were better in terms of costs-efficacy.

CONCLUSION

Overall, LAP and LAPA are the most cost-effective approaches for colorectal surgery in terms of overall postoperative complications, mortality, and LOS.