Impact of perioperative blood transfusions on oncologic outcomes after radical cystectomy: A systematic review and meta-analysis of comparative studies

Machine learning enables automated screening for systematic reviews and meta-analysis in urology

PURPOSE

To investigate and implement semiautomated screening for meta-analyses (MA) in urology under consideration of class imbalance.

METHODS

Machine learning algorithms were trained on data from three MA with detailed information of the screening process. Different methods to account for class imbalance (Sampling (up- and downsampling, weighting and cost-sensitive learning), thresholding) were implemented in different machine learning (ML) algorithms (Random Forest, Logistic Regression with Elastic Net Regularization, Support Vector Machines). Models were optimized for sensitivity. Besides metrics such as specificity, receiver operating curves, total missed studies, and work saved over sampling were calculated.

RESULTS

During training, models trained after downsampling achieved the best results consistently among all algorithms. Computing time ranged between 251 and 5834 s. However, when evaluated on the final test data set, the weighting approach performed best. In addition, thresholding helped to improve results as compared to the standard of 0.5. However, due to heterogeneity of results no clear recommendation can be made for a universal sample size. Misses of relevant studies were 0 for the optimized models except for one review.

CONCLUSION

It will be necessary to design a holistic methodology that implements the presented methods in a practical manner, but also takes into account other algorithms and the most sophisticated methods for text preprocessing. In addition, the different methods of a cost-sensitive learning approach can be the subject of further investigations.

Impact of perioperative blood transfusion on prognosis after nephrectomy in patients with renal cell carcinoma: A meta-analysis and systematic review

BACKGROUND

Perioperative blood transfusion (PBT) has been associated with worse prognosis in several malignancies. For renal cell carcinoma (RCC), the effect of PBT is still debated.

OBJECTIVE

To evaluate the impact of PBT on prognosis after nephrectomy in patients with RCC.

METHODS

This study is A systematic review and meta-analysis of published article data (PRISMA protocol) for literature related to PBT and RCC through extensive search of EMBASE, Medline via PubMed, Web of Science and Cochrane Library, language limited to English, with no time constraint until May 20, 2022. We pooled the results of multivariable cox regression analyses from each study, with subgroup analyses by dose and timing of transfusion. All analyses were done using Stata14.

RESULTS

A total of 12 studies involving 27,683 participants were included. Our meta-analysis pooled the results of multivariable cox regression analysis in each study, showing that PBT is associated with higher overall Mortality (OM; hazard ratio [HR] = 1.34, 1.23-1.44), cancer-specific mortality (CSM; HR = 1.35, 1.20-1.51), and disease recurrence (HR = 1.54, 1.18-1.89). when only patients with nonmetastatic RCC were included, PBT was still associated with higher OM (HR = 1.29, 1.11-1.47) and disease recurrence (HR = 1.58, 1.18-1.98), but the association with CSM (HR = 1.26, 0.99-1.52) was not statistically significant. In subgroup analysis by transfusion dose, small (1-2) units of PBT were not associated with CSM (HR = 1.84, 0.95-2.73), but large (≥3) units were associated with higher CSM (HR = 2.98, 1.74-4.22) and disease recurrence (HR = 1.99, 1.31-2.67). Each additional unit of PBT resulted in a higher CSM (HR = 1.07, 1.04-1.10). In subgroup analysis by transfusion timing, intraoperative transfusion was associated with higher CSM and disease recurrence, but postoperative transfusion was not.

CONCLUSIONS

PBT is associated with higher OM, CSM and disease recurrence. This adverse effect seems to be particularly significant in high-dose intraoperative transfusion. It is necessary to limit the overuse of PBT, especially high-dose intraoperative transfusion, in order to improve the prognosis of patients undergoing nephrectomy for RCC.

Oncological impact of perioperative blood transfusion in bladder cancer patients undergoing radical cystectomy: Do we need to consider storage time of blood units, donor age, or gender matching?

BACKGROUND

The oncological impact of perioperative blood transfusions (PBTs) of patients undergoing radical cystectomy (RC) because of bladder cancer (BCa) has been a controversial topic discussed in recent years. The main cause for the contradictory findings of existing studies might be the missing consideration of the storage time of red blood cell units (BUs), donor age, and gender matching.

STUDY DESIGN AND METHODS

We retrospectively analyzed BCa patients who underwent RC in our department between 2004 and 2021. We excluded patients receiving BUs before RC, >10 BUs, or RC in a palliative setting. We assessed the effect of blood donor characteristics and storage time on overall survival (OS) and cancer-specific survival (CSS) through univariate and multivariable Cox regression analysis. We also performed a propensity score matching with patients who received BUs and patients who did not on a 1:1 ratio.

RESULTS

We screened 1692 patients and included 676 patients for the propensity score matching. In the multivariable analysis, PBT was independently associated with worse OS and CSS (p < .001). Postoperative transfusions were associated with better OS (p = .004) and CSS (p = .008) compared to intraoperative or mixed transfusions. However, there was no influence of blood donor age, storage time, or gender matching on prognosis.

DISCUSSION

In our study of BCa patients undergoing RC, we demonstrate that PBT, especially if administered intraoperatively, is an independent risk factor for a worse prognosis. However, storage time, donor age, or gender matching did not negatively affect oncological outcomes. Therefore, the specific selection of blood products does not promise any benefits.

Incidence and predictors of hypophosphataemia after ferric carboxymaltose use-A 3-year experience from a single institution in Singapore

Ferric carboxymaltose (FCM) administration helps reduce transfusion requirements in the perioperative situation, which improves patient outcomes and reduces healthcare costs. However, there is increasing evidence of hypophosphataemia after FCM use. We aim to determine the incidence of hypophosphataemia after FCM administration and elucidate potential biochemical factors associated with the development of subsequent hypophosphataemia. A retrospective review of anonymised data of all FCM administrations in a single institution was conducted from August 2018 to August 2021. Each unique FCM dose administered was examined to assess its effect on Hb and serum phosphate levels within the subsequent 28 days from each FCM administration. Phosphate levels were repeatedly measured within the 28-day interval and the lowest phosphate level within that period was determined. Patients' serum phosphate levels within 28 days of FCM administration were compared against normal serum phosphate levels within 2 weeks before FCM administration. The odds ratios of various pre-FCM serum markers were calculated to elucidate potential biochemical predictors of post-FCM hypophosphataemia. In 3 years, a total of 1296 doses of FCM were administered to 1069 patients. The mean improvement in Hb was 2.45 g/dL (SD = 1.94) within 28 days of FCM administration, with the mean time taken to peak Hb levels being 6.3 days (SD = 8.63), which is earlier than expected, but was observed in this study and hence reported. The incidence of hypophosphataemia <0.8 mmol/L was 22.7% (n = 186), and <0.4 mmol/L was 1.6% (n = 9). This figure is lower than the numbers reported in previously published meta-analyses given that routine checks of serum phosphate levels were not conducted initially and hence could possibly be higher. The odds of developing hypophosphataemia (<0.8 mmol/L) were 27.7 (CI: 17.3-44.2, p < 0.0001) if baseline serum phosphate was less than 1 mmol/L. The odds of developing hypophosphataemia (<0.8 mmol/L) were 1.3 (CI: 1.08-1.59, p < 0.01) if the change in Hb levels observed after FCM administration were more than 4 g/dL. Hypophosphataemia after FCM administration is significant and FCM should be used by clinicians with caution.

The effect of different timing of blood transfusion on oncological outcomes of patients undergoing radical cystectomy for bladder cancer: a systematic review and meta-analysis

Highlights

This meta-analysis and systematic review aim to analyze the association between BT and oncological outcomes of patients undergoing RC for bladder cancer, and tries to find out whether the timing of blood transfusion could also have an effect on this relationship. A total of 20 retrospective studies from online databases and other sources are identified and enrolled in this study. The results show that BT administration during RC operation or perioperative period is significantly associated with worse oncological outcomes including ACM, CSM and DR.

Background

Bladder cancer is one of the most common urological malignancies. Radical cystectomy (RC) remains the main treatment for localized muscle-invasive bladder cancer (MIBC) or high-grade non-muscle-invasive bladder cancer (NMIBC). In the process of RC, the administration of blood transfusion (BT) is sometimes needed, however, it may cause transfusion-related complications or lead to worse oncological outcomes. This meta-analysis and systematic review aims to give a comprehensive insight into the association between BT and oncological outcomes of patients undergoing RC, and tries to find out whether the timing of blood transfusion could also have an impact on this association.

Methods

This systematic review and meta-analysis were carried out according to the PRISMA 2020 reporting guideline. We have searched four bibliographic databases including PubMed (Medline), EMBASE, Cochrane Library, and Web of Science with no language limitation. Studies investigating the association between BT and oncological outcomes of patients undergoing RC are identified and included in this research from inception through March 20, 2023. This research calculates the pooled hazard ratios (pHR) and 95% confidence intervals (95% CI) of all-cause mortality (ACM), cancer-specific mortality (CSM) and disease recurrence (DR) using Random Effects models or Fixed Effects models. Subgroup analyses stratified by parameters such as timing of transfusion are also conducted. This meta-analysis was registered with PROSPERO, CRD42022381656.

Results

A total of 20 retrospective studies from online databases and other sources are identified and enrolled in this study. Results show that blood transfusion significantly increased the risks for ACM (HR = 1.33, 95% CI: 1.23-1.44), CSM (HR = 1.25, 95% CI: 1.15 - 1.35) and DR (HR = 1.26, 95% CI: 1.15 - 1.38). However, when stratified by the timing of BT, we find that only intraoperative and perioperative transfusion significantly increased in risks for worse prognosis, while postoperative transfusion raised none of the risks of ACM (HR = 1.26, 95% CI: 0.92-1.73), CSM (HR = 1.08, 95% CI: 0.93-1.26) nor DR (HR = 1.08, 95% CI: 0.90-1.29) significantly.

Conclusion

BT administration during RC operation or perioperative period is significantly associated with worse oncological outcomes including ACM, CSM and DR. Clinicians should consider carefully when deciding to administrate BT to patients undergoing RC and carry out according to current guidelines.

Comorbidity Scores and Machine Learning Methods Can Improve Risk Assessment in Radical Cystectomy for Bladder Cancer

BACKGROUND

Pre-operative risk assessment in radical cystectomy (RC) is an ongoing challenge especially in elderly patients.

OBJECTIVE

To evaluate the ability of comorbidity indices and their combination with clinical parameters in machine learning models to predict mortality and morbidity after RC.

METHODS

In 392 patients who underwent open RC, complication and mortality rates were reported. The predictive values of the age-adjusted Charlson Comorbidity index (aCCI), the Elixhauser Index (EI), the Physical Status Classification System (ASA) and Gagne's combined comorbidity Index (GCI) were evaluated using regression analyses. Various machine learning models (Gaussian naïve bayes, logistic regression, neural net, decision tree, random forest) were additionally investigated.

RESULTS

The aCCI, ASA and GCI showed significant results for the prediction of complications (χ2 = 8.8, p < 0.01, χ2 = 15.7, p < 0.01 and χ2 = 4.6, p = 0.03) and mortality (χ2 = 21.1, p < 0.01, χ2 = 25.8, p < 0.01 and χ2 = 2.4, p = 0.04) after RC while the EI showed no significant prediction. However, areas under receiver characteristic curves (AUROCs) revealed good performance only for the prediction of mortality by the aCCI and ASA (0.81 and 0.78, CGI 0.63) while the prediction of complications was poor (aCCI 0.6, ASA 0.63, CGI 0.58). The combination of ASA, age, body mass index and sex in machine learning models showed a better prediction. Gaussian naïve bayes (0.79) and logistic regression (0.76) showed the best performance using a hold-out test set.

CONCLUSIONS

The ASA and aCCI show good prediction of mortality after RC but fail predicting complications accurately. Here, the combination of comorbidity indices and clinical parameters in machine learning models seems promising.

Updates on enhanced recovery after surgery for radical cystectomy

Enhanced Recovery after Surgery (ERAS) is a multimodal pathway that provides evidence-based guidance for improving perioperative care and outcomes in patients undergoing surgery. In 2013, the ERAS society released its original guidelines for radical cystectomy (RC) for bladder cancer (BC), adopting much of its supporting data from colorectal literature. In the last decade, growing interest in ERAS has increased RC-specific ERAS research, including prospective randomized controlled trials (RCTs). Collective data suggest ERAS contributes to improved complication rates, decreased hospital length-of-stay, and/or time to bowel recovery. Various institutions have adopted modified versions of the ERAS pathway, yet there remains a lack of consensus on the efficacy of specific ERAS items and standardization of the protocol. In this review, we summarize updated evidence and practice patterns of ERAS pathways for RC since the introduction of the original 2013 guidelines. Novel target interventions, including use of immunonutrition, prehabilitation, alvimopan, and methods of local analgesia are reviewed. Finally, we discuss barriers to implementing and future steps in advancing the ERAS movement.