Risk prediction models for postoperative outcomes of colorectal cancer surgery in the older population - a systematic review

Association of cancer diagnosis with disability status among older survivors of colorectal cancer: a population-based retrospective cohort study

Background

Older cancer survivors likely experience physical function limitations due to cancer and its treatments, leading to disability and early mortality. Existing studies have focused on factors associated with surgical complications and mortality risk rather than factors associated with the development of poor disability status (DS), a proxy measure of poor performance status, in cancer survivors. We aimed to identify factors associated with the development of poor DS among older survivors of colorectal cancer (CRC) and compare poor DS rates to an age-sex-matched, non-cancer cohort.

Methods

This retrospective cohort study utilized administrative data from the Texas Cancer Registry Medicare-linked database. The study cohort consisted of 13,229 survivors of CRC diagnosed between 2005 and 2013 and an age-sex-matched, non-cancer cohort of 13,225 beneficiaries. The primary outcome was poor DS, determined by Davidoff's method, using predictors from 12 months of Medicare claims after cancer diagnosis. Multivariable Cox proportional hazards regression was used to identify risk factors associated with the development of poor DS.

Results

Among the survivors of CRC, 97% were 65 years or older. After a 9-year follow-up, 54% of survivors of CRC developed poor DS. Significant factors associated with future poor DS included: age at diagnosis (hazard ratio [HR] = 3.50 for >80 years old), female sex (HR = 1.50), race/ethnicity (HR = 1.34 for Hispanic and 1.21 for Black), stage at diagnosis (HR = 2.26 for distant metastasis), comorbidity index (HR = 2.18 for >1), and radiation therapy (HR = 1.21). Having cancer (HR = 1.07) was significantly associated with developing poor DS in the pooled cohorts; age and race/ethnicity were also significant factors.

Conclusions

Our findings suggest that a CRC diagnosis is independently associated with a small increase in the risk of developing poor DS after accounting for other known factors. The study identified risk factors for developing poor DS in CRC survivors, including Hispanic and Black race/ethnicity, age, sex, histologic stage, and comorbidities. These findings underscore the importance of consistent physical function assessments, particularly among subsets of older survivors of CRC who are at higher risk of disability, to prevent developing poor DS.

Performance of models for predicting 1-year to 3-year mortality in older adults: a systematic review of externally validated models

Mortality prediction models support identifying older adults with short life expectancy for whom clinical care might need modifications. We systematically reviewed external validations of mortality prediction models in older adults (ie, aged 65 years and older) with up to 3 years of follow-up. In March, 2023, we conducted a literature search resulting in 36 studies reporting 74 validations of 64 unique models. Model applicability was fair but validation risk of bias was mostly high, with 50 (68%) of 74 validations not reporting calibration. Morbidities (most commonly cardiovascular diseases) were used as predictors by 45 (70%) of 64 of models. For 1-year prediction, 31 (67%) of 46 models had acceptable discrimination, but only one had excellent performance. Models with more than 20 predictors were more likely to have acceptable discrimination (risk ratio [RR] vs <10 predictors 1·68, 95% CI 1·06-2·66), as were models including sex (RR 1·75, 95% CI 1·12-2·73) or predicting risk during comprehensive geriatric assessment (RR 1·86, 95% CI 1·12-3·07). Development and validation of better-performing mortality prediction models in older people are needed.

Systematic review of preoperative and intraoperative colorectal Anastomotic Leak Prediction Scores (ALPS)

OBJECTIVE

To systematically review preoperative and intraoperative Anastomotic Leak Prediction Scores (ALPS) and validation studies to evaluate performance and utility in surgical decision-making. Anastomotic leak (AL) is the most feared complication of colorectal surgery. Individualised leak risk could guide anastomosis and/or diverting stoma.

METHODS

Systematic search of Ovid MEDLINE and Embase databases, 30 October 2020, identified existing ALPS and validation studies. All records including >1 risk factor, used to develop new, or to validate existing models for preoperative or intraoperative use to predict colorectal AL, were selected. Data extraction followed CHecklist for critical Appraisal and data extraction for systematic Reviews of prediction Modelling Studies guidelines. Models were assessed for applicability for surgical decision-making and risk of bias using Prediction model Risk Of Bias ASsessment Tool.

RESULTS

34 studies were identified containing 31 individual ALPS (12 colonic/colorectal, 19 rectal) and 6 papers with validation studies only. Development dataset patient populations were heterogeneous in terms of numbers, indication for surgery, urgency and stoma inclusion. Heterogeneity precluded meta-analysis. Definitions and timeframe for AL were available in only 22 and 11 ALPS, respectively. 26/31 studies used some form of multivariable logistic regression in their modelling. Models included 3-33 individual predictors. 27/31 studies reported model discrimination performance but just 18/31 reported calibration. 15/31 ALPS were reported with external validation, 9/31 with internal validation alone and 4 published without any validation. 27/31 ALPS and every validation study were scored high risk of bias in model analysis.

CONCLUSIONS

Poor reporting practices and methodological shortcomings limit wider adoption of published ALPS. Several models appear to perform well in discriminating patients at highest AL risk but all raise concerns over risk of bias, and nearly all over wider applicability. Large-scale, precisely reported external validation studies are required.

PROSPERO REGISTRATION NUMBER

CRD42020164804.

Development and internal validation of a model for postoperative morbidity in adults undergoing major elective colorectal surgery: the peri-operative quality improvement programme (PQIP) colorectal risk model

Over 1.5 million major surgical procedures take place in the UK NHS each year and approximately 25% of patients develop at least one complication. The most widely used risk-adjustment model for postoperative morbidity in the UK is the physiological and operative severity score for the enumeration of mortality and morbidity. However, this model was derived more than 30 years ago and now overestimates the risk of morbidity. In addition, contemporary definitions of some model predictors are markedly different compared with when the tool was developed. A second model used in clinical practice is the American College of Surgeons National Surgical Quality Improvement Programme risk model; this provides a risk estimate for a range of postoperative complications. This model, widely used in North America, is not open source and therefore cannot be applied to patient populations in other settings. Data from a prospective multicentre clinical dataset of 118 NHS hospitals (the peri-operative quality improvement programme) were used to develop a bespoke risk-adjustment model for postoperative morbidity. Patients aged ≥ 18 years who underwent colorectal surgery were eligible for inclusion. Postoperative morbidity was defined using the postoperative morbidity survey at postoperative day 7. Thirty-one candidate variables were considered for inclusion in the model. Death or morbidity occurred by postoperative day 7 in 3098 out of 11,646 patients (26.6%). Twelve variables were incorporated into the final model, including (among others): Rockwood clinical frailty scale; body mass index; and index of multiple deprivation quintile. The C-statistic was 0.672 (95%CI 0.660-0.684), with a bootstrap optimism corrected C-statistic of 0.666 at internal validation. The model demonstrated good calibration across the range of morbidity estimates with a mean slope gradient of predicted risk of 0.959 (95%CI 0.894-1.024) with an index-corrected intercept of -0.038 (95%CI -0.112-0.036) at internal validation. Our model provides parsimonious case-mix adjustment to quantify risk of morbidity on postoperative day 7 for a UK population of patients undergoing major colorectal surgery. Despite the C-statistic of &lt; 0.7, our model outperformed existing risk-models in widespread use. We therefore recommend application in case-mix adjustment, where incorporation into a continuous monitoring tool such as the variable life adjusted display or exponentially-weighted moving average-chart could support high-level monitoring and quality improvement of risk-adjusted outcome at the population level.

Evaluating methodological quality of prognostic prediction models on patient reported outcome measurements after total hip replacement and total knee replacement surgery: a systematic review protocol

BACKGROUND

Prediction models for poor patient-reported surgical outcomes after total hip replacement (THR) and total knee replacement (TKR) may provide a method for improving appropriate surgical care for hip and knee osteoarthritis. There are concerns about methodological issues and the risk of bias of studies producing prediction models. A critical evaluation of the methodological quality of prediction modelling studies in THR and TKR is needed to ensure their clinical usefulness. This systematic review aims to (1) evaluate and report the quality of risk stratification and prediction modelling studies that predict patient-reported outcomes after THR and TKR; (2) identify areas of methodological deficit and provide recommendations for future research; and (3) synthesise the evidence on prediction models associated with post-operative patient-reported outcomes after THR and TKR surgeries.

METHODS

MEDLINE, EMBASE, and CINAHL electronic databases will be searched to identify relevant studies. Title and abstract and full-text screening will be performed by two independent reviewers. We will include (1) prediction model development studies without external validation; (2) prediction model development studies with external validation of independent data; (3) external model validation studies; and (4) studies updating a previously developed prediction model. Data extraction spreadsheets will be developed based on the CHARMS checklist and TRIPOD statement and piloted on two relevant studies. Study quality and risk of bias will be assessed using the PROBAST tool. Prediction models will be summarised qualitatively. Meta-analyses on the predictive performance of included models will be conducted if appropriate. A narrative review will be used to synthesis the evidence if there are insufficient data to perform meta-analyses.

DISCUSSION

This systematic review will evaluate the methodological quality and usefulness of prediction models for poor outcomes after THR or TKR. This information is essential to provide evidence-based healthcare for end-stage hip and knee osteoarthritis. Findings of this review will contribute to the identification of key areas for improvement in conducting prognostic research in this field and facilitate the progress in evidence-based tailored treatments for hip and knee osteoarthritis.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42021271828.

Technical efficiency evaluation of colorectal cancer care for older patients in Dutch hospitals

BACKGROUND

Preoperative colorectal cancer care pathways for older patients show considerable practice variation between Dutch hospitals due to differences in interpretation and implementation of guideline-based recommendations. This study aims to report this practice variation in preoperative care between Dutch hospitals in terms of technical efficiency and identifying associated factors.

METHODS

Data on preoperative involvement of geriatricians, physical therapists and dieticians and the clinicians' judgement on prehabilitation implementation were collected using quality indicators and questionnaires among colorectal cancer surgeons and specialized nurses. These data were combined with registry-based data on postoperative outcomes obtained from the Dutch Surgical Colorectal Audit for patients aged ≥75 years. A two-stage data envelopment analysis (DEA) approach was used to calculate bias-corrected DEA technical efficiency scores, reflecting the extent to which a hospital invests in multidisciplinary preoperative care (input) in relation to postoperative outcomes (output). In the second stage, hospital care characteristics were used in a bootstrap truncated regression to explain variations in measured efficiency scores.

RESULTS

Data of 25 Dutch hospitals were analyzed. There was relevant practice variation in bias-corrected technical efficiency scores (ranging from 0.416 to 0.968) regarding preoperative colorectal cancer surgery. The average efficiency score of hospitals was significantly different from the efficient frontier (p = <0.001). After case-mix correction, higher technical efficiency was associated with larger practice size (p = <0.001), surgery performed in a general hospital versus a university hospital (p = <0.001) and implementation of prehabilitation (p = <0.001).

CONCLUSION

This study showed considerable variation in technical efficiency of preoperative colorectal cancer care for older patients as provided by Dutch hospitals. In addition to higher technical efficiency in high-volume hospitals and general hospitals, offering a care pathway that includes prehabilitation was positively related to technical efficiency of hospitals offering colorectal cancer care.

Penicillin disrupts mitochondrial function and induces autophagy in colorectal cancer cell lines

Colorectal cancer is a common malignant tumor of the gastrointestinal tract. Currently, the main treatment is surgical resection, which can be combined with other treatments. However, treatment efficacy is poor, and colorectal cancer is prone to relapse and metastasis; thus, identifying an effective anti-cancer drug is an urgent requirement. The present study examined the antagonistic effect of penicillin on cultured colorectal cancer cells and the related mechanism. A MTT assay was used to assess the growth of the colorectal cancer cells treated with penicillin and to determine the optimal drug concentration. The wound healing and Transwell invasion assays were performed to investigate the effect of penicillin on the migration and invasion of the colorectal cancer cells. Live cell mitochondrial energy metabolism analysis was performed to detect changes in mitochondrial energy metabolism of the colorectal cancer cells, while western blot analysis was used to measure the expression of cytochrome c and autophagy-related protein, LC3. RFP-GFP-LC3 lentivirus was used to detect autophagic flux, and autophagosomes were observed using a transmission electron microscope, while flow cytometry was used to analyze the effect of penicillin on cell cycle progression and apoptosis of the colorectal cancer cells. After penicillin treatment, the growth, migration and invasion ability of the colorectal cancer cells were inhibited. The mitochondrial energy metabolism of the cell was impaired, and the basic respiratory capacity, maximum respiratory capacity, respiratory potential, and ATP production were all reduced. The protein expression levels of the autophagy-related proteins, LC3-II/LC3-I increased in a dose- and time-dependent manner. In addition, autophagy flux and the number of autophagosomes increased, and mitochondrial structural damage was observed. The cell cycle was arrested at the G₁ phase, the number of early apoptotic cells increased and the protein expression level of cleaved caspase-3 increased, while penicillin-induced apoptosis was blocked by the autophagy inhibitor 3-MA. In conclusion, penicillin disrupted mitochondrial function and energy metabolism in the colorectal cancer cells, which resulted in the induction of autophagic apoptosis and ultimately the inhibition of cancer cell growth and metastasis.

Safety of Reconstructive Microsurgery in the Elderly Population: a Multicentric Prospective Study

BACKGROUND

Safety of reconstructive microsurgery in elderly patients is still a topic of debate, because no conclusive evidence exists that provides indications and risk evaluation in elderly patients. The purpose of this study, which the Italian Society for Plastic, Reconstructive, and Aesthetic Surgery (SICPRE) has promoted, is to evaluate the safety and the complication risk of elective reconstructive microsurgery in elderly patients as well as to identify patient- or procedure-related risk factors. The secondary aim is to evaluate the predictive role for complications of the Geriatric 8 score (G8).

METHODS

A total of 194 consecutive patients from 18 centers, aged 65 or older, who received an elective microsurgical flap between April 2018 and April 2019 were prospectively evaluated. Patient-related, treatment-related, and outcomes data were recorded and statistically analyzed through multiple-adjusted logistic regression models.

RESULTS

Our study showed an increased risk of complications and a longer hospitalization in patients aged ≥75 years with the American Society of Anesthesiologists (ASA) score ≥3 (or G8 score ≤11) as compared to patients >65 years of age and <75 years of age who undergo reconstruction with a microsurgical flap. Instead, flap survival did not significantly vary with age, but was associated only with ASA score ≥3 (or G8 score ≤11) and surgeries that last longer than 480 min; however, flap survival (92.3%) was slightly lower than that commonly reported for in the general population.

CONCLUSIONS

Reconstructive microsurgery in the elderly is generally safe. The ASA score is easier and quicker than the G8 score and equally useful for risk stratification.

A Prediction Model for Severe Complications after Elective Colorectal Cancer Surgery in Patients of 70 Years and Older

Introduction Older patients have an increased risk of morbidity and mortality after colorectal cancer (CRC) surgery. Existing CRC surgical prediction models have not incorporated geriatric predictors, limiting applicability for preoperative decision-making. The objective was to develop and internally validate a predictive model based on preoperative predictors, including geriatric characteristics, for severe postoperative complications after elective surgery for stage I-III CRC in patients ≥70 years.

PATIENTS AND METHODS

A prospectively collected database contained 1088 consecutive patients from five Dutch hospitals (2014-2017) with 171 severe complications (16%). The least absolute shrinkage and selection operator (LASSO) method was used for predictor selection and prediction model building. Internal validation was done using bootstrapping.

RESULTS

A geriatric model that included gender, previous DVT or pulmonary embolism, COPD/asthma/emphysema, rectal cancer, the use of a mobility aid, ADL assistance, previous delirium and polypharmacy showed satisfactory discrimination with an AUC of 0.69 (95% CI 0.73-0.64); the AUC for the optimism corrected model was 0.65. Based on these predictors, the eight-item colorectal geriatric model (GerCRC) was developed.

CONCLUSION

The GerCRC is the first prediction model specifically developed for older patients expected to undergo CRC surgery. Combining tumour- and patient-specific predictors, including geriatric predictors, improves outcome prediction in the heterogeneous older population.

Lymphocyte-White Cell Ratio Is a Novel Marker of Morbidity Following Colorectal Cancer Surgery

BACKGROUND

A preoperative marker for morbidity in patients with colorectal cancer would help to risk stratify patients and allow for timely intervention to avert poor outcomes. We conducted this study to evaluate preoperative lymphocyte-white blood cell ratio (LWR) as a marker of postoperative morbidity.

METHODS

A prospective cohort of patients who underwent elective surgery for colorectal cancer was reviewed. Three morbidity-related outcomes were described-overall morbidity, multiple morbidities, and severe morbidity, defined as Clavien-Dindo Class ≥3. Univariable and multivariable analyses of presurgical predictors of these three outcomes were performed. Preoperative variables included hemoglobin levels, neoadjuvant therapy, albumin levels, white blood cell count, lymphocyte count, LWR, neutrophil-lymphocyte ratio, and prognostic nutritional index.

RESULTS

Of 177 patients, 31.6% (56/177) suffered at least one morbidity, 15.3% (27/177) had multiple morbidities, 7.9% (14/177) suffered severe morbidity. On multivariate analysis, only LWR <0.180 (odds ratio [OR] 2.53, 95% confidence interval [CI] 1.15-5.55) and neoadjuvant therapy (OR 2.49, 95% CI 1.16-5.24) were associated with overall morbidity. For multiple morbidities and severe morbidity, only LWR <0.180 was significantly associated on multivariate analysis with an OR of 2.92 (95% CI 1.19-7.13) and 4.62 (95% CI 1.45-14.73), respectively.

CONCLUSIONS

LWR is a preoperative marker which can be conveniently applied using standard preoperative blood tests. LWR is an independent risk factor for overall morbidity, multiple morbidities, as well as severe morbidity when used with a cut-off of LWR<1.80.