Preoperative evaluation and oncologic principles of colon cancer surgery

Impact of frailty on short-term postoperative outcomes in patients undergoing colorectal cancer surgery: A systematic review and meta-analysis

BACKGROUND

Colorectal cancer is a major global health challenge that predominantly affects older people. Surgical management, despite advancements, requires careful consideration of preoperative patient status for optimal outcomes.

AIM

To summarize existing evidence on the association of frailty with short-term postoperative outcomes in patients undergoing colorectal cancer surgery.

METHODS

A literature search was conducted using PubMed, EMBASE and Scopus databases for observational studies in adult patients aged ≥ 18 years undergoing planned or elective colorectal surgery for primary carcinoma and/or secondary metastasis. Only studies that conducted frailty assessment using recognized frailty assessment tools and had a comparator group, comprising nonfrail patients, were included. Pooled effect sizes were reported as weighted mean difference or relative risk (RR) with 95% confidence intervals (CIs).

RESULTS

A total of 24 studies were included. Compared with nonfrail patients, frailty was associated with an increased risk of mortality at 30 d (RR: 1.99, 95%CI: 1.47-2.69), at 90 d (RR: 4.76, 95%CI: 1.56-14.6) and at 1 year (RR: 5.73, 95%CI: 2.74-12.0) of follow up. Frail patients had an increased risk of any complications (RR: 1.81, 95%CI: 1.57-2.10) as well as major complications (Clavien-Dindo classification grade ≥ III) (RR: 2.87, 95%CI: 1.65-4.99) compared with the control group. The risk of reoperation (RR: 1.18, 95%CI: 1.07-1.31), readmission (RR: 1.70, 95%CI: 1.36-2.12), need for blood transfusion (RR: 1.67, 95%CI: 1.52-1.85), wound complications (RR: 1.49, 95%CI: 1.11-1.99), delirium (RR: 4.60, 95%CI: 2.31-9.16), risk of prolonged hospitalization (RR: 2.09, 95%CI: 1.22-3.60) and discharge to a skilled nursing facility or rehabilitation center (RR: 3.19, 95%CI: 2.0-5.08) was all higher in frail patients.

CONCLUSION

Frailty in colorectal cancer surgery patients was associated with more complications, longer hospital stays, higher reoperation risk, and increased mortality. Integrating frailty assessment appears crucial for tailored surgical management.

Epidemiological and Clinical Aspects in a Cohort of Colorectal Cancer Patients

We conducted a retrospective, observational study, based on 91 patients diagnosed with colorectal cancer (CRC), hospitalized and evaluated within the Surgical and the 2nd Internal Medicine Clinic, the Clinical Emergency County Hospital Craiova, between October 2020 and October 2022. We aimed in this study to analyze the epidemiological aspects and clinical characteristics of patients with CRC. In our study group, the patients' ages were between 30-89 years, with mean a of 68.06 (±9.39) years. The incidence of CRC cases in young patients was relatively low. 56.04% of all patients lived in urban areas. In 57.14% of cases, tumors were found on the left colon. The histopathological (HP) examination revealed the net predominance of adenocarcinoma. Depending on the HP grade, the tumor formations were represented predominantly by moderate and poorly differentiated tumors, having G2 and G3 grades. The T3 tumors predominated the total tumors identified. We observed that obstructions have the highest percentages on the left colon, while haemorrhages and perforations have higher percentages on the right side of the colon. The results obtained in our study largely validated the hypothesis proposed at the beginning of the study, according to which, using the clinical, paraclinical, and HP data, we can create a typology of the patient with CRC, from the Craiova Reference Center, to guide us in identifying some measures to decrease the percentage of CRC, as well as to improve the efficiency of the surgical treatment for these cases.

Treatment response prediction of neoadjuvant chemotherapy for rectal cancer by deep learning of colonoscopy images

In current clinical practice, several treatment methods, including neoadjuvant therapy, are being developed to improve overall survival or local recurrence rates for locally advanced rectal cancer. The response to neoadjuvant therapy is usually evaluated using imaging data collected before and after preoperative treatment or postsurgical pathological diagnosis. However, there is a need to accurately predict the response to preoperative treatment before treatment is administered. The present study used a deep learning network to examine colonoscopy images and construct a model to predict the response of rectal cancer to neoadjuvant chemotherapy. A total of 53 patients who underwent preoperative chemotherapy followed by radical resection for advanced rectal cancer at the Osaka University Hospital between January 2011 and August 2019 were retrospectively analyzed. A convolutional neural network model was constructed using 403 images from 43 patients as the learning set. The diagnostic accuracy of the deep learning model was evaluated using 84 images from 10 patients as the validation set. The model demonstrated a sensitivity, specificity, accuracy, positive predictive value and area under the curve of 77.6% (38/49), 62.9% (22/33), 71.4% (60/84), 74.5% (38/51) and 0.713, respectively, in predicting a poor response to neoadjuvant therapy. Overall, deep learning of colonoscopy images may contribute to an accurate prediction of the response of rectal cancer to neoadjuvant chemotherapy.

Clinical presentation, management, screening and surveillance for colorectal cancer during the COVID-19 pandemic

Management of colorectal cancer (CRC) was severely affected by the changes implemented during the pandemic, and this resulted in delayed elective presentation, increased emergency presentation, reduced screening and delayed definitive therapy. This review was conducted to analyze the impact of the coronavirus disease 2019 (COVID-19) pandemic on management of CRC and to identify the changes made in order to adapt to the pandemic. We performed a literature search in PubMed, Medline, Index Medicus, EMBASE, SCOPUS, Reference Citation Analysis (https://www.referencecitationanalysis.com/) and Google Scholar using the following keywords in various combinations: Colorectal cancer, elective surgery, emergency surgery, stage upgrading, screening, surveillance and the COVID-19 pandemic. Only studies published in English were included. To curtail the spread of COVID-19 infection, there were modifications made in the management of CRC. Screening was limited to high risk individuals, and the screening tests of choice during the pandemic were fecal occult blood test, fecal immunochemical test and stool DNA testing. The use of capsule colonoscopy and open access colonoscopy was also encouraged. Blood-based tests like serum methylated septin 9 were also encouraged for screening of CRC during the pandemic. The presentation of CRC was also affected by the pandemic with more patients presenting with emergencies like obstruction and perforation. Stage migration was also observed during the pandemic with more patients presenting with more advanced tumors. The operative therapy of CRC was altered by the pandemic as more emergencies surgeries were done, which may require exteriorization by stoma. This was to reduce the morbidity associated with anastomosis and encourage early discharge from the hospital. There was also an initial reduction in laparoscopic surgical procedures due to the fear of aerosols and COVID-19 infection. As we gradually come out of the pandemic, we should remember the lessons learned and continue to apply them even after the pandemic passes.

Raman Spectroscopy: A Personalized Decision-Making Tool on Clinicians' Hands for In Situ Cancer Diagnosis and Surgery Guidance

Accurate in situ diagnosis and optimal surgical removal of a malignancy constitute key elements in reducing cancer-related morbidity and mortality. In surgical oncology, the accurate discrimination between healthy and cancerous tissues is critical for the postoperative care of the patient. Conventional imaging techniques have attempted to serve as adjuvant tools for in situ biopsy and surgery guidance. However, no single imaging modality has been proven sufficient in terms of specificity, sensitivity, multiplexing capacity, spatial and temporal resolution. Moreover, most techniques are unable to provide information regarding the molecular tissue composition. In this review, we highlight the potential of Raman spectroscopy as a spectroscopic technique with high detection sensitivity and spatial resolution for distinguishing healthy from malignant margins in microscopic scale and in real time. A Raman spectrum constitutes an intrinsic "molecular finger-print" of the tissue and any biochemical alteration related to inflammatory or cancerous tissue state is reflected on its Raman spectral fingerprint. Nowadays, advanced Raman systems coupled with modern instrumentation devices and machine learning methods are entering the clinical arena as adjunct tools towards personalized and optimized efficacy in surgical oncology.

The Specific Gravity-Free Method for the Isolation of Circulating Tumor KRAS Mutant DNA and Exosome in Colorectal Cancer

Background: Circulating tumor DNA (ctDNA) and exosome have been widely researched in the field of medical technology and diagnosis platforms. The purpose of our study was to improve the capturing properties of ctDNA and exosome, which involved combining two beads using approaches that may provide a new method for cancer diagnoses. Methods: We present a dual isolation system including a polydopamine (PDA)–silica-coated alginate bead for circulating tumor DNA (ctDNA) capture and an anti-CD63 immobilized bead for exosome capture. We examined the ctDNA mutation in pre-operative plasma samples obtained from 91 colorectal cancer (CRC) patients using a droplet digital PCR (ddPCR). Results: The area under the curve (AUROC) of ctKRAS G12D mutation in the buffy coat was 0.718 (95% CI: 0.598−0.838; p = 0.001). Patients with CRC that had unmethylation of MLH1 and MSH2 showed significantly higher buffy coat ctKRAS G12D mutations, ascites ctKRAS G12D mutations, miR-31-5, and mixed scores than the patients with a methylation of MLH1 and MSH2. Conclusion: Our proposed alginate bead using the specific gravity-free method suggests that the screening of mutated ctKRAS DNA and miR-31-5 by liquid biopsy aids in identifying the patients, predicting a primary tumor, and monitoring in the early detection of a tumor.

[Palliative Surgery in Colorectal Cancer - Which Factors Should Influence the Choice of the Surgical Procedure?]

BACKGROUND

The surgical procedure for patients with colorectal cancer (CRC) in the palliative situation cannot be adequately standardised. The present study was initiated to identify criteria for the decision for resection of the malignancy with or without anastomosis.

PATIENTS/MATERIAL AND METHODS

In a unicentric retrospective analysis, 103 patients after palliative resection with or without anastomosis due to CRC were examined. Using univariate and logistic regression analysis, the influence of a total of 40 factors on postoperative morbidity and mortality was assessed.

RESULTS

In 46 cases, resection with primary anastomosis and in 57 cases a discontinuity resection was performed. Postoperative morbidity was 44.7% and mortality 17.5%. After one-stage resection with anastomosis, nicotine abuse (OR 4.2; p = 0.044), hypalbuminaemia (OR 4.0; p = 0.012), ASA score > 2 (OR 3.7; p = 0.030) and liver remodelling/cirrhosis (OR 3.6; p = 0.031) increased the risk for postoperative complications. Hypalbuminaemia (OR 1.8; p = 0.036), cachexia (OR 1.8; p = 0.043), anaemia (OR 1.5; p = 0.038) and known alcohol abuse (OR 1.9; p = 0.023) were identified as independent risk factors for early postoperative mortality. After discontinuity resection, renal failure (OR 2.1; p = 0.042) and cachexia (OR 1.5; p = 0.045) led to a significant increase in the risk of postoperative morbidity, alcohol abuse (OR 1.8; p = 0.041) in mortality. Hypalbuminaemia (OR 2.8; p = 0.019) and an ASA score > 2 (OR 2.6; p = 0.004) after resection and reconstruction increased the risk of major complications according to Clavien-Dindo, while pre-existing renal failure (OR 1.6; p = 0.023) increased the risk after discontinuity resection. In univariate analysis, an ASA score > 2 (p = 0.038) after simultaneous tumour resection and reconstruction, and urgent surgery in both groups with or without primary anastomosis were additionally identified as significant parameters with a negative influence on mortality (p = 0.010 and p = 0.017).

CONCLUSION

Palliative resections of colorectal carcinomas have high morbidity and mortality. Especially in cases of pre-existing alcohol abuse and/or urgent indication for surgery, more intensive monitoring should be performed. In the case of anaemia, cachexia, hypalbuminemia and an ASA score > 2, discontinuity resection may be the more appropriate procedure.

Colorectal Cancer Early Detection in Stool Samples Tracing CpG Islands Methylation Alterations Affecting Gene Expression

Colorectal cancer (CRC) is a major cause of cancer mortality. Early diagnosis is relevant for its prevention and treatment. Since DNA methylation alterations are early events in tumourigenesis and can be detected in cell-free DNA, they represent promising biomarkers for early CRC diagnosis through non-invasive methods. In our previous work, we identified 74 early altered CpG islands (CGIs) associated with genes involved in cell cross-talking and cell signalling pathways. The aim of this work was to test whether methylation-based biomarkers could be detected in non-invasive matrices. Our results confirmed methylation alterations of GRIA4 and VIPR2 in CRC tissues, using MethyLight, as well as in stool samples, using a much more sensitive technique as droplet digital PCR. Furthermore, we analysed expression levels of selected genes whose promoter CGIs were hypermethylated in CRC, detecting downregulation at mRNA and protein levels in CRC tissue for GRIA4, VIPR2, SPOCK1 and SLC6A3. Most of these genes were already lowly expressed in colon normal tissues supporting the idea that cancer DNA methylation targets genes already barely expressed in the matched normal tissues. Our study suggests GRIA4 and VIPR2 as biomarkers for early CRC diagnosis using stool samples and confirms downregulation of genes hypermethylated in CRC.

Molecular and Immunohistochemical Markers with Prognostic and Predictive Significance in Liver Metastases from Colorectal Carcinoma

Despite the significant recent achievements in the diagnosis and treatment of colorectal cancer (CRC), the prognosis of these patients has currently plateaued. During the past few years, the opportunity to consider multiple treatment modalities (including surgery and other locoregional treatments, systemic therapy, and targeted therapy) led to the research of novel prognostic and predictive biomarkers in CRC liver metastases (CRCLM) patients. In this review, we seek to describe the current state of knowledge of CRCLM biomarkers and to outline impending clinical perspectives, in particular focusing on the cutting-edge tools available for their characterization.

Surgical stress response and promotion of metastasis in colorectal cancer: a complex and heterogeneous process

Surgery remains the curative treatment modality for colorectal cancer in all stages, including stage IV with resectable liver metastasis. There is emerging evidence that the stress response caused by surgery as well as other perioperative therapies such as anesthesia and analgesia may promote growth of pre-existing micro-metastasis or potentially initiate tumor dissemination. Therapeutically targeting the perioperative period may therefore reduce the effect that surgical treatments have in promoting metastases, for example by combining β-adrenergic receptor antagonists and cyclooxygenase-2 (COX-2) inhibitors in the perioperative setting. In this paper, we highlight some of the mechanisms that may underlie surgery-related metastatic development in colorectal cancer. These include direct tumor spillage at the time of surgery, suppression of the anti-tumor immune response, direct stimulatory effects on tumor cells, and activation of the coagulation system. We summarize in more detail results that support a role for catecholamines as major drivers of the pro-metastatic effect induced by the surgical stress response, predominantly through activation of β-adrenergic signaling. Additionally, we argue that an improved understanding of surgical stress-induced dissemination, and more specifically whether it impacts on the level and nature of heterogeneity within residual tumor cells, would contribute to the successful clinical targeting of this process. Finally, we provide a proof-of-concept demonstration that ex-vivo analyses of colorectal cancer patient-derived samples using RGB-labeling technology can provide important insights into the heterogeneous sensitivity of tumor cells to stress signals. This suggests that intra-tumor heterogeneity is likely to influence the efficacy of perioperative β-adrenergic receptor and COX-2 inhibition, and that ex-vivo characterization of heterogeneous stress response in tumor samples can synergize with other models to optimize perioperative treatments and further improve outcome in colorectal and other solid cancers.

Development and Validation of a Risk Calculator for Renal Complications after Colorectal Surgery Using the National Surgical Quality Improvement Program Participant Use Files

Postoperative acute renal failure is a major cause of morbidity and mortality in colon and rectal surgery. Our objective was to identify preoperative risk factors that predispose patients to postoperative renal failure and renal insufficiency, and subsequently develop a risk calculator. Using the National Surgical Quality Improvement Program Participant Use Files database, all patients who underwent colorectal surgery in 2009 were selected (n = 21,720). We identified renal complications during the 30-day period after surgery. Using multivariate logistic regression analysis, a predictive model was developed. The overall incidence of renal complications among colorectal surgery patients was 1.6 per cent. Significant predictors include male gender (adjusted odds ratio [OR]: 1.8), dependent functional status (OR: 1.5), preoperative dyspnea (OR: 1.5), hypertension (OR: 1.6), preoperative acute renal failure (OR: 2.0), American Society of Anesthesiologists class ≥3 (OR: 2.2), preoperative creatinine >1.2 mg/dL (OR: 2.8), albumin <3.5 g/dL (OR: 1.8), and emergency operation (OR: 1.5). This final model has an area under the curve (AUC) of 0.79 and was validated with similar excellent discrimination (area under the curve: 0.76). Using this model, a risk calculator was developed with excellent predictive ability for postoperative renal complications in colorectal patients and can be used to aid clinical decision-making, patient counseling, and further research on measures to improve patient care.

Transanal endoscopic video-assisted excision: application of single-port access

Transanal endoscopic video-assisted excision of benign and malignant rectal lesions with pneumorectal distension appears to optimize the visual field and avert several of the pitfalls commonly associated with transanal endoscopic microsurgery.

Background:

Transanal endoscopic microsurgery is a safe and efficacious surgical approach for local excision of benign adenomas and early-stage rectal cancer. However, utilization of the technique has been limited due to the unavailability of high-priced specialized instrumentation at many institutions and the technically demanding training required. To avoid these obstacles, we have explored an alternative approach called Transanal Endoscopic Video-Assisted excision, which combines the merits of single-port access and local transanal excision.

Methods:

A disposable single-incision port is inserted into the anal canal for transanal access. The port contains 3 cannulae for introducing instrumentation into the rectal lumen, and a supplementary cannula for carbon dioxide insufflation. Pneumorectum results in rectal distention and optimizes the visual field during the procedure. Standard laparoscopic instrumentation is utilized for visualization and transanal excision of rectal pathologies.

Conclusions:

Transanal endoscopic video-assisted excision is an innovative approach to local excision of benign and malignant rectal lesions. The approach averts several of the pitfalls commonly experienced with transanal endoscopic microsurgery. Continued investigation and development of this novel modality will be important in establishing its role in minimally invasive surgery.

Identifying risk factors for renal failure and myocardial infarction following colorectal surgery

BACKGROUND

The development of acute renal failure and myocardial infarction (MI) following colectomy prolongs recovery and is associated with worse outcomes. The purpose of this study is to identify perioperative factors that predispose patients to an adverse cardiac or renal complication.

MATERIALS AND METHODS

We conducted a retrospective review of colectomies from 2001 to 2009. Patients were evaluated based upon the electronic inpatient record and followed to determine the incidence of acute renal failure (creatinine elevation over 50% of baseline) and myocardial injury.

RESULTS

A total of 339 inpatient records were reviewed, of which 134 were female (40%) and 205 male (60%). The mean age was 61.96 ± 16.2 years with 39.5% right hemicolectomies, 22.7% sigmoidectomy, 13.9% Left hemicolectomy, 11.5% total abdominal colectomy, and 6.2% for ileocectomy and transverse colectomy. Within the cohort, 13.9% had baseline renal insufficiency (Cr > 1.4), 7.1% sustained anastomotic leak, 23.9% required postoperative intubation, 15% sustained postoperative sepsis, 11.2% postoperative MI, and 5% clinically significant acidosis. Excluding patients with an anastomotic leak, postoperative intubation, and sepsis, we found that the need for blood product transfusion was associated with postoperative acute renal failure (OR= 7.15 [2.4-20.7]). Preoperative creatinine > 1.5, limited functional capacity, and preoperative systolic blood pressure < 90 mm Hg were all associated with increased MI rates (OR= 15.7 [3.6-66.8], 9.5 [2.1-42.2], 12.0 [5.523-26.072], and 40.6 [1.7-968], respectively).

CONCLUSION

This study demonstrates that several potentially modifiable preoperative and intraoperative factors exist that predispose patients to postoperative cardiac and renal dysfunction in the absence of major surgical complications.