Assessment of lymph node involvement in colorectal cancer

Machine learning and deep learning models for preoperative detection of lymph node metastasis in colorectal cancer: a systematic review and meta-analysis

OBJECTIVE

To evaluate the diagnostic performance of Machine Learning (ML) and Deep Learning (DL) models for predicting preoperative Lymph Node Metastasis (LNM) in Colorectal Cancer (CRC) patients.

METHODS

A systematic review and meta-analysis were conducted following PRISMA-DTA and AMSTAR-2 guidelines. We searched PubMed, Web of Science, Embase, and Cochrane Library databases until February 16, 2024. Study quality and risk of bias were assessed using the QUADAS-2 tool. Data were analyzed using STATA v18, applying random-effects models to all analyses.

RESULTS

Twelve studies involving 8321 patients were included, with most published in 2021-2024 (9/12). The pooled AUC of ML models for predicting LNM in CRC patients was 0.87 (95% CI: 0.82-0.91, I2:86.17) with a sensitivity of 78% (95% CI: 69-87%) and a specificity of 77% (95% CI: 64%-90%). In addition, when assessing the AUC reported by radiologists, both junior and senior radiologists had similar performance, significantly lower than the ML models. (P < 0.001). Subgroup analysis revealed higher AUCs in prospective studies (0.95, 95% CI: 0.87-1) compared to retrospective studies (0.85, 95% CI: 0.81-0.89) (P = 0.03). Studies without external validation exhibited significantly higher AUCs than those with external validation (P < 0.01). While there was no significant difference in AUC and sensitivity between the T1-T2 and T2-T4 stages, specificity was significantly higher in the T2-T4 stages than the low stages of T1 and T2 (95%, 95% CI: 92-98% vs. 61%, 95% CI: 44-78%; P < 0.01).

CONCLUSION

ML models demonstrate strong potential for preoperative LNM staging and treatment planning in CRC, potentially reducing the need for additional surgeries and related health and financial burdens. Further prospective multicenter studies, with standardized reporting of algorithms, modality parameters, and LNM staging, are needed to validate these findings.

Breaking Myths: Comparable Outcomes in Lymph Node Analysis Across Surgical Methods

BACKGROUND/OBJECTIVES

Colorectal cancer is the third most common cancer worldwide, making lymph node recovery critical for treatment decisions and prognosis. The relationship between body mass index (BMI) and the number of lymph nodes retrieved during laparoscopic and open surgeries remains controversial. This study aimed to evaluate whether surgical approach and BMI influence lymph node retrieval in colon cancer surgeries.

METHODS

A retrospective analysis was conducted on 560 patients who underwent colon cancer surgery at a single institution between 2018 and 2023. The average number of lymph nodes retrieved during laparoscopic and open procedures was compared. Distribution analysis using violin plots was performed to assess the pattern of lymph node yield between surgical approaches. Additionally, the impact of BMI on lymph node recovery was assessed. All surgeries were performed by a standardized surgical team using consistent fat clearance techniques.

RESULTS

The mean number of lymph nodes retrieved was 15.89 ± 0.84 for laparoscopic surgeries and 15.98 ± 0.50 for open surgeries, with no statistically significant difference (p = 0.9166). The violin plot analysis confirmed overlapping distributions between the two surgical approaches, with no significant difference (p = 0.6270). BMI also showed no significant effect on the number of lymph nodes removed during surgery. The consistency in outcomes was attributed to standardized surgical practices across all cases.

CONCLUSIONS

Laparoscopic and open surgical approaches yield comparable lymph node recovery in colon cancer surgeries, both in terms of mean values and overall distribution patterns, regardless of patient BMI. These findings emphasize the importance of standardized surgical techniques in ensuring reliable outcomes and suggest that both approaches are equally effective in meeting oncological standards for lymph node retrieval.

Prediction of lymph node metastasis in stage I-III colon cancer patients younger than 40 years

AIMS

Developing a clinical model to predict the individual risk of lymph node metastasis (LNM) in young colon cancer (CC) patients may address an unmet clinical need.

METHODS

A total of 2,360 CC patients under 40 years old were extracted from the SEER database and randomly divided into development and validation cohorts. Risk factors for LNM were identified by using a logistic regression model. A weighted scoring system was built according to beta coefficients (β) calculated by a logistic regression model. Model discrimination was evaluated by C-statistics, model calibration was evaluated by H-L test and calibration plot.

RESULTS

Risk factors were identified as T stage, tumor site, grade and histology. The area under the receiver operating characteristic curve (AUC-ROC) was 0.66 in both cohorts, indicating acceptable discriminatory power. The H-L test showed good calibration in the development cohort (χ2=2.869, P=0.837) and validation cohort (χ2=10.103, P=0.120) which also had been proved by calibration plot. Patients with total risk score of 0-1, 2-3 and 4-6 were considered as low, medium and high risk group.

CONCLUSION

This clinical risk prediction model is accurate enough to identify young CC patients with high risk of LNM and can further provide individualized clinical reference.

Lymph node yield as a surrogate marker for tumour biology and prognosis in colon cancer

BACKGROUND

We interrogated two large national databases to explore the underlying mechanisms and institutional effects of the known association of enhanced survival with a higher lymph node yield (LNY) in non-metastatic colon cancer.

METHOD

Clinical and pathological data for stage I-III colon adenocarcinomas were extracted from the CORECT-R (England, 2010-2020) and SEER database (USA, 2000-2020). A lymph node (LN) cut-off for the lack of clinically significant increase in nodal positivity was identified. A multivariable Cox-regression model was developed to study the effect of LNY on overall survival. Furthermore, institutional variations in LNY and their impact on survival were explored.

RESULTS

Patients were retrospectively included from the CORECT-R (n = 84,116) and SEER (n = 287,974) databases. No significant increase in nodal positivity was noted after a LN cut-off of 9. However, improved survival was noted in node-negative and node-positive cancers beyond this cut-off. A 1% risk-reduction concerning overall survival was reported for every node counted. We identified ten outlying institutions across England with an observed LNY greater or less than the expected, with no impact on overall survival.

DISCUSSIONS

We advocate incorporating LNY into patient and clinician discussions as a surrogate marker of tumour biology and prognosis rather than using LNY as a quality indicator.

Clinicopathological and radiological characteristics and prediction of survival in colon cancer

There are various histological characteristics which have been proposed to predict the survival rate in colon cancer. However, there is no definitive model to accurately predict the survival. Therefore, it is important to find out one model for the prediction of survival in colon cancer which may also include the preoperative, and operative factors in addition to histopathology.

Feasibility of robotic surgery in elderly patients with rectal cancer: a meta-analysis

Rectal cancer's prevalence increases with an aging population, disproportionately affecting the elderly. The suitability of surgical interventions for this demographic is contentious due to underrepresentation during surgery. This study examines the practicality of utilizing Da Vinci surgery for rectal cancer patients who are 70 years and older. Information was gathered from PubMed, Embase, Scopus and the Cochrane Library, with a focus on English-language publications. Statistical analysis was performed using RevMan 5.4, presenting outcomes for categorical variables in risk ratios. Out of 890 patients across 5 studies, 240 were categorized as elderly, while 650 fell into the younger age group. Notable distinctions were noted in harvested lymph nodes, BMI, and postoperative outcomes, whereas factors like the length of hospital stay, Clavien-Dindo classification, and radial resection margin did not display significance. Although age increases postoperative risk, evidence emphasizes frailty, not age alone, as the primary determining factor.

F-18 FDG PET/CT based Preoperative Machine Learning Prediction Models for Evaluating Regional Lymph Node Metastasis Status of Patients with Colon Cancer

OBJECTIVE

This study aimed to develop a simple machine-learning model incorporating lymph node metastasis status with F-18 Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) and clinical information for predicting regional lymph node metastasis in patients with colon cancer.

METHODS

This retrospective study included 193 patients diagnosed with colon cancer between January 2014 and December 2017. All patients underwent F-18 FDG PET/CT and blood test before surgery. One categorical variable (lymph node FDG uptake [LNFDG]) and six continuous variables (age, neutrophil-to-lymphocyte ratio [NLR], carcinoembryonic antigen [CEA], carbohydrate antigen 19-9 [CA19-9], C-reactive protein, and maximal standardized uptake value (SUVmax) of the primary tumor) were used as input variables. Four supervised machine learning methods were used to build predictive models: logistic regression (LR), random forest (RF), gradient boosting machine (GBM), and support vector machine (SVM). Area under the receiver operating characteristic curve (AUC) of the validation set were used for evaluating and comparing model performance.

RESULTS

The number of patients with lymph node metastasis were 63 (33%). The mean number of harvested lymph nodes was 28.8 ± 11.4. The mean CEA, CA19-9, and CRP levels were 4.8 ± 9.3 ng/ml, 15.6 ± 42.8 U/ml, and 1.0 ± 3.0 mg/dl, respectively. The mean NLR was 2.2 ± 1.2. The mean SUVmax levels of the primary tumor were 15.2 ± 7.9. Fifty-one (26%) patients showed FDG uptake in the pericolic lymph nodes.  The mean AUC of the LR, RF, GBM, and SVM methods for the LNFDG model was 0.7046, 0.7047, 0.7040, and 0.7058, respectively. The mean AUC of the LR, RF, GBM, and SVM methods for the LNFDG plus clinical information model was 0.7046, 0.7302, 0.7444, and 0.7097, respectively.

CONCLUSION

Machine learning methods using LNFDG and clinical information could predict the lymph node metastasis status in patients with colon cancer with higher accuracy than a model using only FDG uptake of the lymph nodes.

State-of-the-art performance of deep learning methods for pre-operative radiologic staging of colorectal cancer lymph node metastasis: a scoping review

OBJECTIVES

To assess the current state-of-the-art in deep learning methods applied to pre-operative radiologic staging of colorectal cancer lymph node metastasis. Specifically, by evaluating the data, methodology and validation of existing work, as well as the current use of explainable AI in this fast-moving domain.

DESIGN

Scoping review.

DATA SOURCES

Academic databases MEDLINE, Embase, Scopus, IEEE Xplore, Web of Science and Google Scholar were searched with a date range of 1 January 2018 to 1 February 2024.

ELIGIBILITY CRITERIA

Includes any English language research articles or conference papers published since 2018 which have applied deep learning methods for feature extraction and classification of colorectal cancer lymph nodes on pre-operative radiologic imaging.

DATA EXTRACTION AND SYNTHESIS

Key results and characteristics for each included study were extracted using a shared template. A narrative synthesis was then conducted to qualitatively integrate and interpret these findings.

RESULTS

This scoping review covers 13 studies which met the inclusion criteria. The deep learning methods had an area under the curve score of 0.856 (0.796 to 0.916) for patient-level lymph node diagnosis and 0.904 (0.841 to 0.967) for individual lymph node assessment, given with a 95% confidence interval. Most studies have fundamental limitations including unrepresentative data, inadequate methodology, poor model validation and limited explainability techniques.

CONCLUSIONS

Deep learning methods have demonstrated the potential for accurately diagnosing colorectal cancer lymph nodes using pre-operative radiologic imaging. However, several methodological and validation flaws such as selection bias and lack of external validation make it difficult to trust the results. This review has uncovered a research gap for robust, representative and explainable deep learning methods that are end-to-end from automatic lymph node detection to the diagnosis of lymph node metastasis.

Is There a Correlation Between Platelet Count, Mesenteric Lymph Node Involvement, and Hematogenous Metastases in Advanced Stage Ovarian Cancer?

BACKGROUND/AIM

Ovarian cancer remains a major cause of death in women worldwide, mainly due to late diagnosis and the lack of a reliable screening test for early detection of the disease. In this context, attention has been focused on the identification of other prognostic factors that might allow a better identification of cases with worse long-term outcome.

PATIENTS AND METHODS

Data of patients who underwent cytoreductive surgery between 2014-2019 were retrospectively reviewed and 57 patients were considered eligible for this study. These cases were further classified according to preoperative platelet count, with a cut-off value of 335,000/μl as a positive predictive value for long-term survival.

RESULTS

According to this value, there were 27 cases with a preoperative platelet count lower than 335,000/μl and 30 cases with a preoperative platelet count higher than 335,000/μl. Cases in the second group had a significantly higher peritoneal carcinomatosis index (p=0.002), a higher proportion of digestive serosa involvement (p<0.001), and a higher proportion of mesenteric lymph node involvement and hematogenous metastases (p=0.005 and p=0.001, respectively). When analyzing long-term outcomes, all these factors had a significant impact on overall survival.

CONCLUSION

Preoperative thrombocytosis appears to be positively associated with gastrointestinal serosa involvement, mesenteric lymph node invasion, and the presence of hematogenous metastases, thus significantly influencing the long-term outcome of patients with advanced ovarian cancer.

The role of robotic-assisted surgery in the management of rectal cancer: a systematic review and meta-analysis

BACKGROUND

Rectal cancer poses a significant global health burden. There is a lack of concrete evidence concerning the benefits of robotic-assisted surgery (RAS) for rectal cancer surgery as compared to laparoscopic and open techniques. To address this gap, we conducted a meta-analysis to assess the intraoperative, postoperative, and safety outcomes of robotic surgery in this context.

RESEARCH METHODOLOGY

A search of MEDLINE, Scopus and the Cochrane Library. Randomized and non-randomized studies up to February 2, 2024 comparing robotic surgery versus laparoscopic or open surgery for rectal cancer. The outcomes of interest were operative time, blood loss, harvested lymph nodes, conversion rate, postoperative hospital stay, survival to hospital discharge, urinary retention rate, and anastomotic leakage rate. A random-effects meta-analysis was performed to pool means and dichotomous data to derive weighted mean differences and odds ratios, respectively.

RESULTS

A total of 56 studies were shortlisted after the study selection process with a total of 25 458 rectal cancer patients. From the intraoperative outcomes, RAS was significantly associated with an increased operative time (WMD: 41.04, P <0.00001), decreased blood loss (WMD: -24.56, P <0.00001), decreased conversion rates (OR: 0.39, P <0.00001), lesser stay at the hospital (WMD: -1.93, P <0.00001), and no difference was found in lymph nodes harvested. Similarly, RAS group had a significantly greater survival to hospital discharge (OR: 1.90, P =0.04), decreased urinary retention rate (OR: 0.59, P =0.002), and no difference was seen in anastomotic leakage rate.

CONCLUSION

RAS demonstrates favorable outcomes for rectal cancer patients, contributing to global prevention and control efforts, health promotion, and addressing non-communicable disease risk factors. Further research and public awareness are needed to optimize RAS utilization in this context.

Structural changes in the organs of the lymphoid system in terms of induced carcinogenesis

Colorectal cancer is the third most common cancer in the world. Despite recent therapeutic advances, it causes more than 500,000 deaths each year. The immune system plays a crucial role in protecting the body from cancer. However, cancer cells are able to evade immune detection and destruction. For example, they can downregulate antigen expression, produce immunosuppressive molecules, or recruit immune cells that perform regulatory or inhibitory functions. Understanding the complex interactions between the immune system and carcinogenesis is crucial for developing effective cancer treatments. The study aimed to determine the morphological changes in the thymus, spleen, and lymph nodes under N,N-dimethylhydrazine-induced carcinogenesis. The study was performed on 77 male outbred albino rats weighing 190-230 g, kept in standard vivarium conditions. Colon adenocarcinoma was modeled by administration of N,N-dimethylhydrazine hydrochloride for 30 weeks. To study the peculiarities of morphological and functional changes in lymphoid organs in the dynamics of colon tumor lesions, animals were withdrawn from the experiment every 30 days. Paraffin sections of the thymus, spleen, and lymph nodes 5-6 μm thick were made on a rotary microtome and stained with hematoxylin and eosin. The experimental investigation unveiled the character and extent of histological alterations within the lymphoid system organs under conditions of N,N-dimethylhydrazine-induced colon adenocarcinomatosis. As the experiment progressed, there was a noticeable escalation in the severity of detrimental and degenerative modifications observed in the thymus, spleen, and lymph nodes. These modifications were evident in the disruption of blood circulation within the examined organs, leading to vascular wall impairment and hemorrhaging, the disarray of morphofunctional elements and the development of fibrosis. Given the significant role played by the thymus, spleen, and lymph nodes in regulating carcinogenesis and maintaining immune balance, it is extremely important to delve into understanding the changes in their structure and function. Obtained results indicate that carcinogenesis is accompanied by pronounced morphological changes in the structural components of the lymphoid system organs, the degree of which increases in direct proportion to the duration of exposure to the oncogenic factor.

Biomarkers of lymph node metastasis in colorectal cancer: update

Colorectal cancer (CRC) ranks as the second leading cause of cancer-related deaths globally, trailing only behind lung cancer, and stands as the third most prevalent malignant tumor, following lung and breast cancers. The primary cause of mortality in colorectal cancer (CRC) stems from distant metastasis. Among the various routes of metastasis in CRC, lymph node metastasis predominates, serving as a pivotal factor in both prognostication and treatment decisions for patients. This intricate cascade of events involves multifaceted molecular mechanisms, highlighting the complexity underlying lymph node metastasis in CRC. The cytokines or proteins involved in lymph node metastasis may represent the most promising lymph node metastasis markers for clinical use. In this review, we aim to consolidate the current understanding of the mechanisms and pathophysiology underlying lymph node metastasis in colorectal cancer (CRC), drawing upon insights from the most recent literatures. We also provide an overview of the latest advancements in comprehending the molecular underpinnings of lymph node metastasis in CRC, along with the potential of innovative targeted therapies. These advancements hold promise for enhancing the prognosis of CRC patients by addressing the challenges posed by lymph node metastasis.

Early drain site tumor recurrence post adjuvant chemotherapy for locally advanced colon carcinoma: Case report and literature review

INTRODUCTION

Colon carcinoma is the most common type of gastro-intestinal cancer. Despite radical surgery, locoregional recurrence has been observed in 4-11.5 % of patients. Abdominal wall metastasis at the drainage site is an extremely rare finding and only a few cases are described in the literature. The mechanism of this metastasis is unknown, and its management remains unclear due to the rarity of the condition.

CASE PRESENTATION

A 66-year-old patient underwent left colectomy for locally advanced colonic adenocarcinoma. Eight months after the end of adjuvant chemotherapy, the patient complained of a progressive mass of the left lumbar centered on the previous drain site scar. Abdominal wall recurrence was suspected. The patient had R0 mass excision. Histopathologic examination showed a parietal infiltration by a colloid adenocarcinoma. The patient underwent adjuvant chemotherapy. No recurrence was observed.

DISCUSSION

Since 1999 only six cases of colon cancer drainage site metastasis have been reported. Metachronous solitary abdominal wall metastasis after radical colectomy may occur via cancer cell implantation, lymphatic or hematogenous route, or direct invasion. In case of drain site metastasis, the most likely hypothesis is the implantation of tumor cells into the abdominal wall through the drainage route performed during surgery.

CONCLUSION

The appearance of abdominal wall mass after colon cancer resection must always be considered suspicious. To reduce the risk of abdominal wall metastasis we recommend minimizing tumor manipulation, resection the route of previous percutaneous drainage and performing a radical surgery. Metastasis resection combined with chemotherapy is the appropriate approach to treat these metastases.

"GLI1 Subcellular Localization and Overexpression as Prognostic Factors for Disease-Free Survival in Colorectal Carcinoma"

PURPOSE

Glioma-associated oncogene homolog-1 (GLI1) is amplified in human glioblastoma, and there is growing evidence suggesting its significant role in tumor development and metastasis. Our aim was to investigate the role of the GLI-1 gene in the progression of colorectal cancer (CRC) and its correlation with various clinicopathological features. Additionally, we examined the impact of the GLI-1 gene and other factors on the prognosis of CRC.

METHODS

We analyzed a total of 98 confirmed CRC cases and adjacent normal tissue controls. Patients suspected of having colon cancer underwent a colonoscopy and targeted biopsy, while those with rectal cancer underwent CT scans and MRI. GLI1 expression was detected using real-time PCR assay, Western blotting, and immunohistochemistry.

RESULTS

The GLI1 gene was observed to be overexpressed in tumor tissues at both the protein and mRNA levels (p < 0.05). In addition, GLI1 overexpression was significantly associated with various factors such as tumor invasion (T3/T4), presence of lymph nodes, lymph node metastasis (LNM), stage (III/IV), tumor site (colon), tumor size (≥ 3 cm), localization (nucleocytoplasmic), strong staining intensity and recurrence (p < 0.05). The results of survival analysis showed that the patients with overexpression of GLI1 had a significantly lower DFS rate which was 21 months compared to those with normal expression who had 31 months (p < 0.05). Moreover, individuals with early onset disease (15 months) were more likely to have cytoplasmic localization of the GLI1 gene as opposed to nucleo-cytoplasmic localization of GLI1 which presented late-onset disease( 23 months) (p < 0.05). Finally, Stage and PNI (p < 0.05) were found to independently affect outcomes of CRC according to Cox regression analysis.

CONCLUSION

High expression of GLI-1 in CRC is associated with adverse pathology and poor prognosis for patients. The correlation between cytoplasmic localization of GLI-1 and reduced disease-free survival holds potential for guiding prognosis and treatment. Further research is needed to develop strategies targeting GLI-1 for improved outcomes.

Lymph Node Metastasis in Gastrointestinal Carcinomas: A View from a Proteomics Perspective

Lymph node metastasis (LNM) is one of the major prognostic factors in human gastrointestinal carcinomas (GICs). The lymph node-positive patients have poorer survival than node-negative patients. LNM is directly associated with the recurrence and poor survival of patients with GICs. The early detection of LNM in patients and designing effective therapies to suppress LNM may significantly impact the survival of these patients. The rapid progress made in proteomic technologies could be successfully applied to identify molecular targets for cancers at high-throughput levels. LC-MS/MS analysis enables the identification of proteins involved in LN metastasis, which can be utilized for diagnostic and therapeutic applications. This review summarizes the studies on LN metastasis in GICs using proteomic approaches to date.

Predicting lymph node metastasis in colorectal cancer patients: development and validation of a column chart model

Lymph node metastasis (LNM) is one of the crucial factors in determining the optimal treatment approach for colorectal cancer. The objective of this study was to establish and validate a column chart for predicting LNM in colon cancer patients. We extracted a total of 83,430 cases of colon cancer from the Surveillance, Epidemiology, and End Results (SEER) database, spanning the years 2010-2017. These cases were divided into a training group and a testing group in a 7:3 ratio. An additional 8545 patients from the years 2018-2019 were used for external validation. Univariate and multivariate logistic regression models were employed in the training set to identify predictive factors. Models were developed using logistic regression, LASSO regression, ridge regression, and elastic net regression algorithms. Model performance was quantified by calculating the area under the ROC curve (AUC) and its corresponding 95% confidence interval. The results demonstrated that tumor location, grade, age, tumor size, T stage, race, and CEA were independent predictors of LNM in CRC patients. The logistic regression model yielded an AUC of 0.708 (0.7038-0.7122), outperforming ridge regression and achieving similar AUC values as LASSO regression and elastic net regression. Based on the logistic regression algorithm, we constructed a column chart for predicting LNM in CRC patients. Further subgroup analysis based on gender, age, and grade indicated that the logistic prediction model exhibited good adaptability across all subgroups. Our column chart displayed excellent predictive capability and serves as a useful tool for clinicians in predicting LNM in colorectal cancer patients.

Association of Clinicopathological Factors With MMP13 (rs2252070) Gene Polymorphism in Swedish Patients With Colorectal Cancer

BACKGROUND/AIM

Matrix metalloproteinase 13 (MMP13) has been reported to be involved in tumor development and progression, including of colorectal cancer (CRC). This study aimed at evaluating whether the MMP13 rs2252070 gene polymorphism is associated with clinicopathological factors and its influence on long-term survival in Swedish patients with CRC.

PATIENTS AND METHODS

A total of 723 patients with CRC were genotyped using TaqMan single nucleotide polymorphism assays based on polymerase chain reaction.

RESULTS

Assessing clinicopathological factors, we demonstrated that having the G/G genotype for MMP13 rs2252070 was significantly associated with poor differentiation, higher serum level of carcinoembryonic antigen and higher lymph node status. Moreover, the presence of a G allele was significantly related to larger tumor size in rectal cancer but had a significantly protective role against mucinous cancer, perineural invasion and lymphovascular invasion. Kaplan-Meier analysis showed no difference between genotypes regarding cancer-specific survival.

CONCLUSION

Our findings highlight the potential of MMP13 rs2252070 polymorphism as a useful predictor of poor differentiation, serum level of carcinoembryonic antigen, lymph node status, tumor size, mucinous cancer, perineural invasion and lymphovascular invasion in patients with CRC.

Lymphatic spread patterns in young versus elderly patients with stage III colon cancer

BACKGROUND

The anatomical pattern of lymph nodes spread differs between young (aged 45 years or younger) and elderly (aged 80 years or older) patients with stage III colon cancer and is poorly investigated.

METHODS

Two groups of patients (young and elderly) with stage III colon cancer who underwent upfront extensive (D3) lymphadenectomy at eight Japanese centres between 1998 and 2018 were retrospectively analysed. The primary endpoint was the proportion of positive central lymph nodes. The lymph nodes spreading pattern and its prognostic impact on recurrence-free survival and overall survival in the two groups were also compared.

RESULTS

Two hundred and ten young patients and 348 elderly patients were identified and compared. The total number of lymph nodes harvested and the total number of invaded lymph nodes were significantly higher in younger patients compared with elderly patients (median of 31.5 (3-151) versus 21 (3-116), P < 0.001 and median of 3 (1-21) versus 2 (1-25), P < 0.001 respectively). The proportion of positive central lymph nodes were higher in younger patients than in elderly patients (9.52% (95% c.i. 6.24 to 14.2%) versus 4.59% (95% c.i. 2.84 to 7.31%), P = 0.012). In multivariate models for recurrence-free survival, central lymph nodes invasion were identified as a poor prognostic factor in younger patients (HR 5.21 (95% c.i. 1.76 to 15.39)) but not in elderly patients (HR 1.73 (95% c.i. 0.80 to 3.76)).

CONCLUSION

Young patients with stage III colon cancer have a higher risk of central lymph nodes invasion, suggesting a more aggressive disease biology. The presence of central lymph nodes invasion are associated with a worse outcome in young patients.

Short- and long-term outcomes after surgical treatment of 5918 patients with splenic flexure colon cancer by extended right colectomy, segmental colectomy and left colectomy: a systematic review and meta-analysis

BACKGROUND

Colorectal cancer is among the most common cancers in the world, and splenic flexure colon cancer accounts for about 2-5% of them. There is still no consensus on the surgical treatment of splenic flexure colon cancer (SFCC), and the extent of surgical resection and lymph node dissection for SFCC is still controversial.

AIM

To compare the postoperative and long-term oncologic outcomes of extended right colectomy (ERC), segmental colectomy (SC) and left colectomy (LC) for SFCC.

METHOD

Up to March 2024, retrospective and prospective studies of ERC, SC, and LC for SFCC were searched through databases. Pooled weighted/standardized mean difference (WMD/SMD), odds ratio (OR) and hazard ratio (HR) with 95% confidence interval (CI) were calculated using a fixed effects model or random effects model, and meta-analysis was performed using Stata.

RESULTS

This meta-analysis includes 5,918 patients from 13 studies with more lymph node harvest (OR:6.29; 95%Cl: 3.66-8.91; Z=4.69, P=0), more operation time (WMD: 22.53; 95%Cl: 18.75-26.31; Z=11.68, P=0), more blood loss (WMD:58.44; 95%Cl: 20.20-96.68; Z=2.99, P=0.003), longer hospital stay (WMD:1.74; 95%Cl: 0.20-3.29; Z=2.21, P=0.03), longer time to return to regular diet (WMD:3.17; 95%Cl: 2.05-4.30; Z=5.53, P=0), longer first flatus time (WMD:1.66; 95%Cl: 0.96-2.37; Z=4.61, P=0) in ERC versus SC. More lymph node harvest (WMD: 3.52; 95% Cl: 1.59-5.44; Z=3.58, P=0) in ERC versus LC and LC versus SC (WMD: 1.97; 95% CI: 0.53-3.41; Z=2.68, P=0.007), respectively. There is no significant difference between anastomotic leakage, postoperative ileus, total postoperative complication, severe postoperative complication, wound infection, reoperations, R0 resection, postoperative mortality, 5-year overall survival (OS), 5-year disease-free survival (DFS) in three group of patients. In LC versus SC and ERC versus LC, there is no difference between operation time, blood loss, hospital stay, return to regular diet, and first flatus.

CONCLUSION

In the included studies, SC and LC may be more advantageous, with fewer postoperative complications and faster recovery. ERC harvests more lymph nodes, but there is no significant difference in long-term OS and DFS between the three surgical approaches. Given that the included studies were retrospective, more randomized controlled trials are needed to validate this conclusion.

Sufficient Regional Lymph Node Examination for Staging Adenocarcinoma of the Appendix

BACKGROUND

The presence of lymph node (LN) metastasis is a known negative prognostic factor in appendix cancer (AC) patients. However, currently the minimum number of LNs required to adequately determine LN negativity is extrapolated from colorectal studies and data specific to AC is lacking. We aimed to define the lowest number of LNs required to adequately stage AC and assess its impact on oncologic outcomes.

METHODS

Patients with stage II-III AC from the National Cancer Database (NCDB 2004-2019) undergoing surgical resection with complete information about LN examination were included. Multivariable logistic regression assessed the odds of LN positive (LNP) disease for different numbers of LNs examined. Multivariable Cox regressions were performed by LN status subgroups, adjusted by prognostic factors, including grade, histologic subtype, surgical approach, and documented adjuvant systemic chemotherapy.

RESULTS

Overall, 3,602 patients were included, from which 1,026 (28.5%) were LNP. Harvesting ten LNs was the minimum number required without decreased odds of LNP compared with the reference category (≥ 20 LNs). Total LNs examined were < 10 in 466 (12.9%) patients. Median follow-up from diagnosis was 75.4 months. Failing to evaluate at least ten LNs was an independent negative prognostic factor for overall survival (adjusted hazard ratio 1.39, p < 0.01).

CONCLUSIONS

In appendix adenocarcinoma, examining a minimum of ten LNs was necessary to minimize the risk of missing LNP disease and was associated with improved overall survival rates. To mitigate the risk of misclassification, an adequate number of regional LNs must be assessed to determine LN status.

Essentials of macroscopic evaluation of specimens from gastrointestinal tract

An astute macroscopic examination, coupled with correlating the gross findings with clinical indication and operative notes along with judicious, yet all pertinent sectioning for pathological examination is crucial for an accurate histopathological diagnosis, eventually leading to optimal patient care. This succinct review highlights the general concepts that lay the foundation of evaluating and grossing specimens from the luminal gastrointestinal (GI) tract. We also discuss the gross evaluation and sectioning of small therapeutic resections, along with a systematic approach and rationale when grossing and submitting histological sections from larger oncological resections from the luminal GI tract. Selected site-specific considerations, for example, grossing treated rectal and oesophageal cancers or taking sections from mucinous tumours of the appendix, among others, are also discussed.

What is your count? An observational study of lymph node counting in 2,028 colorectal cancer resections

BACKGROUND

Lymph node status and lymph node count (LNC) are predictors of colorectal cancer outcome. Under-sampling of lymph nodes may lead to clinically relevant stage migration.

METHODS

Colorectal cancer (CRC) cases with a synoptic report, accessioned 2012-2020 at a regional laboratory, were extracted and retrospectively studied. LNC, positive lymph node count (PLNC), tumour deposits present (TDpos), and 'y' (staging) prefix (YS) were retrieved and tabulated by pathologist using custom software. Statistical analyses were done with R.

DATA AND RESULTS

The cohort had 2,543 CRC resections. Seventeen pathologists interpreted >50 cases (range: 56-356) each and collectively saw 2,074. After cases with unavailable data were purged, 2,028 cases remained with 43,996 lymph nodes, of which 2,637/43,996 were positive. 368 cases had a 'y' prefix, and 379 had TDpos. The 17 pathologists' median LNC/case was 19.0 (range: 14.0-24.0), and the mean PLNC per case was 1.4 (range: 1.0-2.0). Kruskal-Wallis rank sum tests showed there were differences in LNC (p<0.001) among pathologists; however, PLNC did not show this association (p = 0.2917). T-tests showed that mean LNC (p<0.001) and PLNC (p<0.035) differed between YS. 138 of 2,028 cases had less than the 12 LNC target. Logistic regression revealed a strong association between meeting the LNC target and pathologist (p<0.001) but TDpos was non-predictive (p = 0.4736).

CONCLUSIONS

Positive lymph node call rate has a good consistency in the laboratory; however, lymph node count varies significantly between pathologists. Standardized counting criteria are needed to improve uniformity and could be aided by synoptic reporting data.

Acetone compression improves lymph node yield and metastasis detection in colorectal cancer

Lymph node status is one of the most important prognostic factors in colorectal cancer, and accurate pathological nodal staging and detection of lymph node metastases is crucial for determination of post-operative management. Current guidelines, including the TNM staging system and European Society for Medical Oncology (ESMO) guidelines, recommend examination of at least 12 lymph nodes. However, identification of an adequate number of lymph nodes can be challenging, especially in the setting of neoadjuvant treatment, which may reduce nodal size. In this study, we investigated 384 colorectal cancer resections that were processed at our department of pathology between January 2012 and December 2022, in which the number of detected lymph nodes was less than 12 subsequent to conventional preparation of mesocolic fat tissue. By means of acetone compression, lymph node harvest increased significantly (p < 0.0001), and the intended number of ≥ 12 lymph nodes was achieved in 98% of resection specimens. The number of nodal positive cases increased significantly from n = 95 (24.7%) before versus n = 131 (34.1%) after acetone compression due to additionally identified lymph node metastases (p < 0.001). In 36 patients (9.4%) initially considered as nodal negative, acetone compression led to a staging adjustment to a nodal positive category and thereby drove a recommendation to offer post-operative therapy. In conclusion, acetone compression is a reliable and useful method implementable in routine surgical pathology for the retrieval of lymph nodes in colorectal cancer specimen, allowing for an adequate lymph node sampling and an increase in nodal staging reliability.

Radial resection margin distinguishes between superficial versus deep resection in colorectal cancer: a retrospective study

Randomized studies showed that robotic surgery was short-term useful and safe for cancer patients. We investigated whether robots improve deep resection margins or superficial resection margins for radial resection margins in terms of short-term results. From an institutional database, we selected all superficial groups (≤ 3 mm) and deeper groups (≥ 4 mm) with rectal cancer treated with resection for a year. We evaluated the short-term post-operative 90-day outcomes on a radial resection size-based margin differentiation, including the first bowel movement, length of hospital stay, sepsis, and harvested lymph node. The main results were grades III-IV on the Clavien-Dindo scale and complications. We found 120 patients who had oncologic resection of rectal cancer; 42 patients with a superficial radial resection margin of ≤ 3 mm, all the following outcomes improved: the harvested lymph node, proximal resection margin, TME, flatus time, liquid diet duration, anastomotic leakage, and sepsis. Among these advantages were a reduced risk of metastasis and an overall reduction in local recurrence.

Prognostic Impact of Mesenteric Lymph Node Status on Digestive Resection Specimens During Cytoreductive Surgery for Ovarian Peritoneal Metastases

BACKGROUND

The most common mode of ovarian cancer (OC) spread is intraperitoneal dissemination, with the peritoneum as the primary site of metastasis. Cytoreductive surgery (CRS) with chemotherapy is the primary treatment. When necessary, a digestive resection can be performed, but the role of mesenteric lymph nodes (MLNs) in advanced OC remains unclear, and its significance in treatment and follow-up evaluation remains to be determined. This study aimed to evaluate the prevalence of MLN involvement in patients who underwent digestive resection for OC peritoneal metastases (PM) and to investigate its potential prognostic value.

METHODS

This retrospective, descriptive study included patients who underwent CRS with curative intent for OC with PM between 1 January 2007 and 31 December 2020. The study assessed MLN status and other clinicopathologic features to determine their prognostic value in relation to overall survival (OS) and progression-free survival (PFS).

RESULTS

The study enrolled 159 women with advanced OC, 77 (48.4%) of whom had a digestive resection. For 61.1% of the patients who underwent digestive resection, MLNs were examined and found to be positive in 56.8%. No statistically significant associations were found between MLN status and OS (p = 0.497) or PFS ((p = 0.659).

CONCLUSIONS

In anatomopathologic studies, MLNs are not systematically investigated but are frequently involved. In the current study, no statistically significant associations were found between MLN status and OS or PFS. Further prospective studies with a systematic and standardized approach should be performed to confirm these findings.

Association of hemicolectomy with survival in stage II colorectal cancer: a retrospective cohort study

To compare the oncological survival outcomes of partial colectomy (PC) and hemicolectomy (HC) in patients with stage II colon cancer. A total of 18,795 patients with stage II colon cancer who underwent hemicolectomy (n = 12,022) or partial colectomy (n = 6773) from 2010 to 2019 were included in the the Surveillance, Epidemiology, and End Results (SEER) database. Overall survival (OS) and cancer-specific survival (CSS) were compared between the two groups, and the threshold of harvested lymph nodes was determined. The results showed that age, gender, race, tumor site, scope of regional lymph nodes, postoperative chemotherapy, postoperative radiotherapy, harvested lymph nodes, and tumor size were significantly different between the PC and HC groups (all P < 0.05). The OS rate was slightly lower in hemicolectomy patients than in partial colectomy patients (69.9% vs. 74.5%, respectively, P < 0.001), but CSS was similar between the two groups (87.9% vs. 88.1%, respectively, P = 0.32). After propensity score matching (PSM) was performed, the OS and CSS rates in the two groups were significantly different (CSS 84.3% vs. 88.0%, P < 0.001; OS 62.2% vs. 72.5%, P < 0.001). The survminer R package determined that the optimum threshold for the harvested lymph node count in stage II colon cancer patients was 16. CSS was significantly different between patients with ≥ 12 lymph nodes harvested and patients with ≥ 16 lymph nodes harvested (P = 0.043). Univariate and multivariate Cox regression and survival analyses of stage II colon cancer patients showed that the survival benefit of stage II colon cancer patients receiving partial colectomy was superior to that of patients receiving hemicolectomy. Partial colectomy has significant oncological benefits over hemicolectomy in the treatment of stage II colon cancer patients, even in the case of pT4b or tumor deposits. Removal of 16 lymph nodes during colectomy for stage II colon cancer correlated with improved survival, and this threshold was more effective than the standard threshold of 12 lymph nodes in distinguishing between patients with good and poor prognoses.

The topographical distribution of lymph node metastases in colon cancer resections

In accordance with international guidelines all lymph nodes in colon cancer specimens must be examined to obtain accurate staging. This study aimed to determine the topographical location of lymph node metastases and evaluate if a more limited sampling approach could be an alternative. Partial colectomies received at the Department of Pathology, Zealand University Hospital during a six-month period were included. At the macroscopic examination, each specimen was divided into three different segments: a segment containing the index tumor and the tumor-feeding artery, an oral and an anal segment. The number of lymph nodes and lymph node metastases were registered separately for each segment. Resections from 93 patients were included. Of 2466 lymph nodes, 1839 (74.6 %) were located in the tumor segment, 308 (12.5 %) in the oral, and 319 (12.9 %) in the anal segment, respectively. In 133 (5,4 %) lymph nodes a metastasis was present. Of these 129 (97.0 %) were located in the tumor segment, one (0.8 %) in the oral segment, and three (2.3 %) in the anal segment. No patients had metastasis in the oral or anal segments without metastases also being present in the tumor segment leading to consideration of the need for lymph node harvest of the complete specimen upon initial examination. As such, the segment containing the index tumor and tumor-feeding artery could be regarded as a sentinel segment indicating a potential need for lymph node dissection in the oral and anal segments.

Sentinel lymph node assessment in melanoma: current state and future directions

Assessment of sentinel lymph node status is an important step in the evaluation of patients with melanoma for both prognosis and therapeutic management. Pathologists have an important role in this evaluation. The methodologies have varied over time, from the evaluation of dimensions of metastatic burden to determination of the location of the tumour deposits within the lymph node to precise cell counting. However, no single method of sentinel lymph node tumour burden measurement can currently be used as a sole independent predictor of prognosis. The management approach to sentinel lymph node-positive patients has also evolved over time, with a more conservative approach recently recognised for selected cases. This review gives an overview of past and current status in the field with a glimpse into future directions based on prior experiences and clinical trials.

Benefits of minimally invasive surgery for rectal cancer in older adults compared with younger adults: a retrospective study

Randomized research demonstrated that robotic surgery was oncologically safe and beneficial in the short term. We investigated whether older adults benefit from robotics more than younger adults do in terms of short-term outcomes. We identified all older (≥ 70 years old) and younger (≤ 70) adults with rectal cancer treated with resection between 2019 and 2022 from an institutional database. We assessed the short-term post-operative 90-day outcomes, which included the first bowel movement, length of hospital duration, sepsis, and harvested lymph node on an age-based differentiation. The key outcomes were complications and grades III-IV on the Clavien-Dindo scale. We identified 298 individuals treated with oncologic resection of rectal cancer: 108 (36.6%) were older adults, while 190 (63.4%) were younger adults. Older adults treated with robotic surgery include 45 (41.6%), whereas 63 (58.3%) older adults were treated with laparoscopic surgery, and 85 (44.7%) younger adults were treated with robotic surgery, while 105 (55.2%) younger adults were treated with laparoscopic surgery. The Clavien-Dindo grading system exposes a substantial P < 0.05 in younger group, whereas grade III-IV patients are seen more frequently in laparoscopic surgery than robotic surgery. Younger and older persons both benefited differently from robotic surgery when compared to laparoscopic surgery in terms of major post-operative complications.

Fluorescence-based sentinel lymph node mapping and lymphography evaluation: results from the IHU-IRCAD-EAES EURO-FIGS registry

BACKGROUND

The identification of metastatic lymph nodes is one of the most important prognostic factors in gastrointestinal (GI) cancers. Near-infrared fluorescence (NIRF) imaging has been successfully used in GI tumors to detect the lymphatic pathway and the sentinel lymph node (SLN), facilitating fluorescence image-guided surgery (FIGS) with the purpose to achieve a correct nodal staging. The aim of this study was to analyze the current results of NIRF SLN navigation and lymphography through data collected in the EURO-FIGS registry.

METHODS

Prospectively collected data regarding patients and ICG-guided lymphadenectomies were analyzed. Additional analyses were performed to identify predictors of metastatic SLN and determinants of fluorescence positivity and nodal metastases outside the boundaries of standard lymphadenectomies.

RESULTS

Overall, 188 patients were included by 18 surgeons from 10 different centers. Colorectal cancer was the most reported pathology (77.7%), followed by gastric (19.1%) and esophageal tumors (3.2%). ICG was injected with higher doses (p < 0.001) via extraparietal side (63.3%), and with higher volumes (p < 0.001) via endoluminal side (36.7%). Overall, NIRF SLN navigation was positive in 75.5% of all cases and 95.5% of positive SLNs were retrieved, with a metastatic rate of 14.7%. NIRF identification of lymph nodes outside standard lymphatic stations occurred in 52.1% of all cases, 43.8% of which were positive for metastatic involvement. Positive NIRF SLN identification was an independent predictor of metastasis outside standard lymphatic stations (OR = 4.392, p = 0.029), while BMI independently predicted metastasis in retrieved SLNs (OR = 1.187, p = 0.013). Lower doses of ICG were protective against NIRF identification outside standard of care lymphadenectomy (OR = 0.596, p = 0.006), while higher volumes of ICG were predictive of metastatic involvement outside standard of care lymphadenectomy (OR = 1.597, p = 0.001).

CONCLUSIONS

SLN mapping helps identifying potentially metastatic lymph nodes outside the boundaries of standard lymphadenectomies. The EURO-FIGS registry is a valuable tool to share and analyze European surgeons' practices.

Rectal Cancer: Are 12 Lymph Nodes the Limit?

Lymph node dissection is a crucial element of oncologic rectal surgery. Many guidelines regard the removal of at least 12 lymph nodes as the quality criterion in rectal cancer. However, this recommendation remains controversial. This study examines the factors influencing the lymph node yield and the validity of the 12-lymph node limit. Patients with rectal cancer who underwent low anterior resection or abdominoperineal amputation between 2000 and 2010 were analyzed. In total, 20,966 patients from 381 hospitals were included. Less than 12 lymph nodes were found in 20.53% of men and 19.31% of women (p = 0.03). The number of lymph nodes yielded increased significantly from 2000, 2005 and 2010 within the quality assurance program for all procedures. The univariate analysis indicated a significant (p < 0.001) correlation between lymph node yield and gender, age, pre-therapeutic T-stage, risk factors and neoadjuvant therapy. The multivariate analyses found T3 stage, female sex, the presence of at least one risk factor and neoadjuvant therapy to have a significant influence on yield. The probability of finding a positive lymph node was proportional to the number of examined nodes with no plateau. There is a proportional relationship between the number of examined lymph nodes and the probability of finding an infiltrated node. Optimal surgical technique and pathological evaluation of the specimen cannot be replaced by a numeric cut-off value.

Identification of Spatial Proteomic Signatures of Colon Tumor Metastasis: A Digital Spatial Profiling Approach

Over 150,000 Americans are diagnosed with colorectal cancer (CRC) every year, and annually >50,000 individuals are estimated to die of CRC, necessitating improvements in screening, prognostication, disease management, and therapeutic options. CRC tumors are removed en bloc with surrounding vasculature and lymphatics. Examination of regional lymph nodes at the time of surgical resection is essential for prognostication. Developing alternative approaches to indirectly assess recurrence risk would have utility in cases where lymph node yield is incomplete or inadequate. Spatially dependent, immune cell-specific (eg, tumor-infiltrating lymphocytes), proteomic, and transcriptomic expression patterns inside and around the tumor-the tumor immune microenvironment-can predict nodal/distant metastasis and probe the coordinated immune response from the primary tumor site. The comprehensive characterization of tumor-infiltrating lymphocytes and other immune infiltrates is possible using highly multiplexed spatial omics technologies, such as the GeoMX Digital Spatial Profiler. In this study, machine learning and differential co-expression analyses helped identify biomarkers from Digital Spatial Profiler-assayed protein expression patterns inside, at the invasive margin, and away from the tumor, associated with extracellular matrix remodeling (eg, granzyme B and fibronectin), immune suppression (eg, forkhead box P3), exhaustion and cytotoxicity (eg, CD8), Programmed death ligand 1-expressing dendritic cells, and neutrophil proliferation, among other concomitant alterations. Further investigation of these biomarkers may reveal independent risk factors of CRC metastasis that can be formulated into low-cost, widely available assays.

Predicting lymph node metastasis from primary tumor histology and clinicopathologic factors in colorectal cancer using deep learning

BACKGROUND

Presence of lymph node metastasis (LNM) influences prognosis and clinical decision-making in colorectal cancer. However, detection of LNM is variable and depends on a number of external factors. Deep learning has shown success in computational pathology, but has struggled to boost performance when combined with known predictors.

METHODS

Machine-learned features are created by clustering deep learning embeddings of small patches of tumor in colorectal cancer via k-means, and then selecting the top clusters that add predictive value to a logistic regression model when combined with known baseline clinicopathological variables. We then analyze performance of logistic regression models trained with and without these machine-learned features in combination with the baseline variables.

RESULTS

The machine-learned extracted features provide independent signal for the presence of LNM (AUROC: 0.638, 95% CI: [0.590, 0.683]). Furthermore, the machine-learned features add predictive value to the set of 6 clinicopathologic variables in an external validation set (likelihood ratio test, p < 0.00032; AUROC: 0.740, 95% CI: [0.701, 0.780]). A model incorporating these features can also further risk-stratify patients with and without identified metastasis (p < 0.001 for both stage II and stage III).

CONCLUSION

This work demonstrates an effective approach to combine deep learning with established clinicopathologic factors in order to identify independently informative features associated with LNM. Further work building on these specific results may have important impact in prognostication and therapeutic decision making for LNM. Additionally, this general computational approach may prove useful in other contexts.

Left-Sided Colon Cancer and Right-Sided Colon Cancer: Are They the Same Cancer or Two Different Entities?

Background Colon cancer is one of the most common cancers in the world and one of the main causes of cancer-related deaths. In Morocco, it occupies the first place among digestive cancers. Right-sided and left-sided colon cancers have different embryological, epidemiological, pathological, genetic, and clinical characteristics. This distinction leads to differences in the evolution and prognosis of the disease. This study aimed to identify epidemiological factors and clinical and pathological characteristics that can influence perioperative and prognostic outcomes in patients with right-sided colon cancer compared to those with left-sided colon cancer. Methodology We conducted a retrospective cohort study over a period of nine years from January 2012 until December 2020. We included 277 patients divided into two groups, namely, right colon cancer (group 1) (n = 99) and left colon cancer (group 2) (n = 178). Results The average age of our series was 57.4 years, with extremes ranging from 19 to 89 years old (SD = ±13.6451 years). The average age in the right colon group was 55.97 (SD = ±13.341 years). The average age in the left colon group was 58.18 (SD = ±13.69 years). The male gender had a predominance, with a sex ratio of 1.3 for both groups. Among the patients in group 2, 65% showed lymph node involvement on the CT scan, whereas only 34% of patients in group 1 displayed the same condition. The recurrence rate in the right-sided colon cancer group was 22.2% compared to 24.9% in the left-sided group. The five-year overall survival was estimated for the right-sided and left-sided colon cancer groups at 87% and 96.5%, respectively. In patients with stage III and IV cancer, overall survival was better for those who underwent surgery for left-sided colon cancer compared to those who underwent surgery for right-sided colon cancer (p = 0.029). In the case of vascular emboli or involvement of the perineural sheath, there was no significant difference in overall survival (p = 0.446 and p = 0.655, respectively). The three-month survival without recurrence was almost identical in both groups (31% for right-sided colon cancers and 30.9% for left-sided colon cancers). Age over 61 years was a predictive factor of poor prognosis in recurrence-free survival (hazard ratio = 3.245; p = 0.023). Conclusions We identified factors that can influence perioperative outcomes and prognosis in patients with right-sided colon cancer compared to those with left-sided colon cancer. Our findings suggest that age and lymph node involvement along with other factors play a role in the overall survival and recurrence outcomes of these patients. Further research is necessary to explore these differences and develop personalized treatment plans for patients with colon cancer.

Lymph node yield in colorectal cancer specimens and its impact on pathological staging: Does number matter?

Introduction

Regional lymph node involvement is an important predictor of outcome in colorectal cancer (CRC). The lymph node yield in resected specimens varies from case to case.

Aim

To assess whether clinicopathologic factors have an impact on the number of lymph nodes harvested from surgical resection specimens of CRCs To assess whether the total number of lymph nodes retrieved has a bearing on the positivity of lymph nodes and hence the N category.

Materials and Methods

All resection specimens of treatment naïve CRC received in the department of pathology during a 2 year period (2017-2019) were reviewed. The lymph node yield was correlated with age, sex, type of surgical procedure, length of resected segment, tumor location, histological type and grade, T and N categories. The statistical tests used were Spearman rank, Mann-Whitney U, Kruskal-Wallis, and Chi-square tests.

Results

A total of 51 resections were studied. The mean age was 59.64 years with 72.55% being male. About 76.47% were hemicolectomies and 23.52% were rectosigmoid surgeries. The lymph node yield ranged from 0 to 38, the mean being 12.67. None of the parameters studied had a significant correlation with the lymph node yield except histological grade, specimens with higher-grade tumors yielding more number of nodes (P = 0.0242). There was no significant correlation between node positivity and the average number of lymph nodes (P = 0.0883). There was no significant correlation between total yield in cases with ≥12 lymph nodes and N category (P = 0.180). Furthermore, there was no significant correlation between total yield in node-positive cases with ≥12 lymph nodes and N category (P = 0.216). There was no significant difference in the sizes of the lymph nodes in node-positive and negative cases (P = 0.3930 and 0.2355, respectively).

Conclusion

Among the parameters affecting lymph node yield, the current study found a significant correlation between histological grade and lymph node yield. There was no significant difference in the size of lymph nodes between node-positive and negative cases. The total lymph node yield did not have a bearing on node positivity and this shows that a lower lymph node yield may be accepted as adequate after thorough examination of the specimen.

Metastasis prevention: How to catch metastatic seeds

Despite considerable advances in the evolution of anticancer therapies, metastasis still remains the main cause of cancer mortality. Therefore, current strategies for cancer cure should be redirected towards prevention of metastasis. Targeting metastatic pathways represents a promising therapeutic opportunity aimed at obstructing tumor cell dissemination and metastatic colonization. In this review, we focus on preclinical studies and clinical trials over the last five years that showed high efficacy in suppressing metastasis through targeting lymph node dissemination, tumor cell extravasation, reactive oxygen species, pre-metastatic niche, exosome machinery, and dormancy.

A Deep Neural Network-Based Decision Support Tool for the Detection of Lymph Node Metastases in Colorectal Cancer Specimens

The identification of lymph node metastases in colorectal cancer (CRC) specimens is crucial for the planning of postoperative treatment and can be a time-consuming task for pathologists. In this study, we developed a deep neural network (DNN) algorithm for the detection of metastatic CRC in digitized histologic sections of lymph nodes and evaluated its performance as a diagnostic support tool. First, the DNN algorithm was trained using pixel-level annotations of cancerous areas on 758 whole slide images (360 with cancerous areas). The algorithm's performance was evaluated on 74 whole slide images (43 with cancerous areas). Second, the algorithm was evaluated as a decision support tool on 288 whole slide images covering 1517 lymph node sections, randomized in 16 batches. Two senior pathologists (C.K. and C.O.) assessed each batch with and without the help of the algorithm in a 2 × 2 crossover design, with a washout period of 1 month in between. The time needed for the evaluation of each node section was recorded. The DNN algorithm achieved a median pixel-level accuracy of 0.952 on slides with cancerous areas and 0.996 on slides with benign samples. N+ disease (metastases, micrometastases, or tumor deposits) was present in 103 of the 1517 sections. The algorithm highlighted cancerous areas in 102 of these sections, with a sensitivity of 0.990. Assisted by the algorithm, the median time needed for evaluation was significantly shortened for both pathologists (median time for pathologist 1, 26 vs 14 seconds; P < .001; 95% CI, 11.0-12.0; median time for pathologist 2, 25 vs 23 seconds; P < .001; 95% CI, 2.0-4.0). Our DNN showed high accuracy for detecting metastatic CRC in digitized histologic sections of lymph nodes. This decision support tool has the potential to improve the diagnostic workflow by shortening the time needed for the evaluation of lymph nodes in CRC specimens without impairing diagnostic accuracy.

Molecular and cellular pathways in colorectal cancer: apoptosis, autophagy and inflammation as key players

BACKGROUND

Colorectal carcinogenesis (CRC) is one of the most aggressive forms of cancer, particularly in developing countries. It accounts for the second and third-highest reason for cancer-induced lethality in women and men respectively. CRC involves genetic and epigenetic modifications in colonic epithelium, leading to colon adenocarcinoma. The current review highlights the pathogenic mechanisms and multifactorial etiology of CRC, influenced by apoptosis, inflammation, and autophagy pathways.

METHODS

We have carried out a selective literature review on mechanisms contributing to the pathogenesis of CRC.

RESULTS

Resistance to senescence and apoptosis of the mesenchymal cells, which play a key role in intestinal organogenesis, morphogenesis and homeostasis, appears important for sporadic CRC. Additionally, inflammation-associated tumorigenesis is a key incident in CRC, supported by immune disruptors, adaptive and innate immune traits, environmental factors, etc. involving oxidative stress, DNA damage and epigenetic modulations. The self-digesting mechanism, autophagy, also plays a twin role in CRC through the participation of LC3/LC3-II, Beclin-1, ATG5, other autophagy proteins, and Inflammatory Bowel Disease (IBD) susceptibility genes. It facilitates the promotion of effective surveillance pathways and stimulates the generation of malignant tumor cells. The autophagy and apoptotic pathways undergo synergistic or antagonistic interactions in CRC and bear a critical association with IBD that results from the pro-neoplastic effects of persistent intestinal inflammation. Conversely, pro-inflammatory factors stimulate tumor growth and angiogenesis and inhibit apoptosis, suppressing anti-tumor activities.

CONCLUSION

Hence, research attempts for the development of potential therapies for CRC are in progress, primarily based on combinatorial approaches targeting apoptosis, inflammation, and autophagy.

A retrospective study of post-operative complications and cost analysis in robotic rectal resection versus laparoscopic rectal resection

Background

Robotic rectal cancer surgery has proven to be a viable alternative to laparoscopic surgery in treating rectal cancer. This study assessed the short-term operative measures of robotic versus laparoscopic surgery.

Material

Data was obtained retrospectively from July 2019 to November 2021. Patient demographics, pre-and post-operative features, initial bowel movement, length of hospital stay, and short-term postoperative outcomes such as harvested lymph node, sepsis, Clavien–Dindo Classification, and cost were evaluated.

Results

A total of 155 patients were treated for colorectal cancer, with 64 receiving robotic surgery and 91 receiving laparoscopic surgery. According to the Clavien–Dindo classification, there is a significant P < 0.05 between robotic and laparoscopic rectal surgery, with robotic having fewer patients in grade III-IV than laparoscopic. Despite this, laparoscopic surgery is associated with more sepsis patients (P < 0.05), and harvested lymph nodes are likewise associated with significant results.

Conclusion

With respect to post-operative complication and cost analysis, our finding imply that robotic rectal resection achieves better-quality short-term outcome but more costly than laparoscopic as well as Clavien–Dindo classification plays a crucial role in assessing postoperative rectal cancer complications and considerably impacts the quality of life.

Pattern of recurrence and survival after D2 right colectomy for cancer: is there place for a routine more extended lymphadenectomy?

BACKGROUND

Conventional Right Colectomy with D2 lymphadenectomy (RC-D2) currently represent the most common surgical treatment of right-sided colon cancer (RCC). However, whether it should be still considered a standard of care, or replaced by a routine more extended D3 lymphadenectomy remains unclear. In the present study, we aim to critically review the patterns of relapse and the survival outcomes obtained from our 11-year experience of RC-D2.

METHODS

Clinical data of 489 patients who underwent RC-D2 for RCC at two centres, from January 2009 to January 2020, were retrospectively reviewed. Patients with synchronous distant metastases and/or widespread nodal involvement at diagnosis were excluded. Post-operative clinical-pathological characteristics and survival outcomes were evaluated including the pattern of disease relapse.

RESULTS

We enrolled a total of 400 patients with information follow-up. Postoperative morbidity was 14%. The median follow-up was 62 months. Cancer recurrence was observed in 55 patients (13.8%). Among them, 40 patients (72.7%) developed systemic metastases, and lymph-node involvement was found in 7 cases (12.8%). None developed isolated central lymph-node metastasis (CLM), in the D3 site. The estimated 3- and 5-year relapse-free survival were 86.1% and 84.4%, respectively. The estimated 3- and 5-year cancer-specific OS were 94.5% and 92.2%, respectively.

CONCLUSIONS

The absence of isolated CLM, as well as the cancer-specific OS reported in our series, support the routine use of RC-D2 for RCC. However, D3 lymphadenectomy may be recommended in selected patients, such as those with pre-operatively known CLM, or with lymph-node metastases close to the origin of the ileocolic vessels.

Lymph node yield in the pathological staging of resected nonmetastatic colon cancer: The more the better?

INTRODUCTION

Guidelines recommend regional lymphadenectomy with a lymph node yield (LNY) of at least 12 lymph nodes (LN) for adequate colon cancer (CC) staging. LNY ≥22LN may improve survival, especially in right-sided CC [Lee et al., Surg Oncol, 27(3), 2018]. This multicentric retrospective cohort study evaluated the impact of LNY and tumor laterality on CC staging and survival.

MATERIALS AND METHODS

Patients with stage I-III CC that underwent surgery from 2012 to 2018 were grouped according to LNY: <22 and ≥ 22. Primary outcomes were LN positivity (N+ rate) and disease-free survival (DFS). Overall survival (OS) was the secondary outcome. Exploratory analyses were performed for laterality and stage.

RESULTS

We included 795 patients (417 < 22LN, 378 ≥ 22LN); 53% had left-sided CC and 29%/37%/38% had stage I/II/III tumors. There was no association between LNY ≥22LN and N+ rate after adjustment for grade, T stage, lymphovascular invasion (LVI) and perineural invasion; a trend for a higher N+ rate in left-sided CC was identified (interaction p = 0.033). With a median follow-up of 63.6 months for DFS and 73.2 months for OS, 254 patients (31.9%) relapsed and 207 (26.0%) died. In multivariate analysis adjusted for age, ASA score, laparoscopic approach, T/N stage, mucinous histology, LVI and adjuvant chemotherapy, LNY ≥22LN was significantly associated with both DFS (HR 0.75, p = 0.031) and OS (HR 0.71, p = 0.025). Restricted cubic spline analysis showed a more significant benefit for right-sided CC.

CONCLUSION

LNY ≥22LN was associated with longer DFS and OS in patients with operable CC, especially for right-sided CC.

Modelling of magnetic microbubbles to evaluate contrast enhanced magnetomotive ultrasound in lymph nodes - a pre-clinical study

OBJECTIVES

Despite advances in MRI the detection and characterisation of lymph nodes in rectal cancer remains complex, especially when assessing the response to neoadjuvant treatment. An alternative approach is functional imaging, previously shown to aid characterisation of cancer tissues. We report proof of concept of the novel technique Contrast-Enhanced Magneto-Motive Ultrasound (CE-MMUS) to recover information relating to local perfusion and lymphatic drainage, and interrogate tissue mechanical properties through magnetically induced deformations.

METHODS

The feasibility of the proposed application was explored using a combination of experimental animal and phantom ultrasound imaging, along with finite element analysis. First, contrast-enhanced ultrasound imaging on one wild type mouse recorded lymphatic drainage of magnetic microbubbles after bolus injection. Second, tissue phantoms were imaged using MMUS to illustrate the force- and elasticity dependence of the magnetomotion. Third, the magnetomechanical interactions of a magnetic microbubble with an elastic solid were simulated using finite element software.

RESULTS

Accumulation of magnetic microbubbles in the inguinal lymph node was verified using contrast enhanced ultrasound, with peak enhancement occurring 3.7 s post-injection. The magnetic microbubble gave rise to displacements depending on force, elasticity, and bubble radius, indicating an inverse relation between displacement and the latter two.

CONCLUSION

Combining magnetic microbubbles with MMUS could harness the advantages of both techniques, to provide perfusion information, robust lymph node delineation and characterisation based on mechanical properties.

ADVANCES IN KNOWLEDGE

(a) Lymphatic drainage of magnetic microbubbles visualised using contrast-enhanced ultrasound imaging and (b) magnetomechanical interactions between such bubbles and surrounding tissue could both contribute to (c) robust detection and characterisation of lymph nodes.

Contrast enhanced magneto-motive ultrasound in lymph nodes - modelling and pre-clinical imaging using magnetic microbubbles

Despite advances in MRI, the detection and characterisation of lymph nodes in rectal cancer remains complex, especially when assessing the response to neo-adjuvant treatment. An alternative approach is functional imaging, previously shown to aid characterization of cancer tissues. We report proof-of-concept of the novel technique Contrast-Enhanced Magneto-Motive Ultrasound (CE-MMUS) to recover information relating to local perfusion and lymphatic drainage, and interrogate tissue mechanical properties through magnetically induced tissue deformations. The feasibility of the proposed application was explored using a combination of pre-clinical ultrasound imaging and finite element analysis. First, contrast enhanced ultrasound imaging on one wild type mouse recorded lymphatic drainage of magnetic microbubbles after bolus injection. Second, preliminary CE-MMUS data were acquired as a proof of concept. Third, the magneto-mechanical interactions of a magnetic microbubble with an elastic solid were simulated using finite element software. Accumulation of magnetic microbubbles in the inguinal lymph node was verified using contrast enhanced ultrasound, with peak enhancement occurring 3.7 s post-injection. Preliminary CE-MMUS indicates the presence of magnetic contrast agent in the lymph node. The finite element analysis explores how the magnetic force is transferred to motion of the solid, which depends on elasticity and bubble radius, indicating an inverse relation with displacement. Combining magnetic microbubbles with MMUS could harness the advantages of both techniques, to provide perfusion information, robust lymph node delineation and characterisation based on mechanical properties. Clinical Relevance- Robust detection and characterisation of lymph nodes could be aided by visualising lymphatic drainage of magnetic microbubbles using contrast enhanced ultrasound imaging and magneto-motion, which is dependent on tissue mechanical properties.

In-House Validated Map of Lymph Node Stations in a Prospective Cohort of Colorectal Cancer: A Tool for a Better Preoperative Staging

Preoperative staging of colorectal cancer (CRC) based on imaging techniques such as computed tomography (CT) or magnetic resonance imaging (MRI) is crucial for identification and then removal of the positive lymph nodes (LNs). The aim of this study was to evaluate the correlation between preoperatively seen morphologic criteria (number, size, shape, structure, borders, or enhancement patterns) and histopathological features of LNs using an in-house validated map of nodal stations. A total of 112 patients with CRC that underwent surgery were preoperatively evaluated by CT scans. The locoregional, intermediate, and central LNs were CT-mapped and then removed during open laparotomy and examined under microscope. The analysis of correlations was interpreted using the suspicious-to-positive ratio (SPR) parameter. The greatest correlation was found in tumors located in the sigmoid colon, descending colon and middle rectum; SPR value was 1.12, 1.18, and 1.26, respectively. SPR proved to be 0.59 for cases of the transverse colon. Regarding the enhancement type, the dotted pattern was mostly correlated with metastatic LNs (OR: 7.84; p < 0.0001), while the homogenous pattern proved a reliable indicator of nonmetastatic LNs (OR: 1.99; p < 0.05). A total of 1809 LNs were harvested, with a median value of 15 ± 1.34 LNs/case. Transdisciplinary approach of CRC focused on pre-, intra-, and postoperatively mapping of LNs might increase the accuracy of detecting metastasized nodes for tumors of the distal colon and middle rectum but not for those of the transverse colon. In addition to morphologic criteria, the enhancement pattern of LNs can be used as a predictor of nodal involvement improving the CT-based preoperative staging.

Robot-Assisted vs Laparoscopic Right Hemicolectomy in Octogenarians

OBJECTIVE

With increasing age, there is greater need for right-sided colonic resections than its left-sided counterparts. Older age is associated with limited physical and functional status, which carries greater operative risk. Improvements in robotic surgery questions its role, especially in older adults, compared with laparoscopy. The objective is to investigate whether robotic right hemicolectomy (RRH) is as safe and effective as laparoscopic right hemicolectomy (LHR) in octogenarians (age >80 years).

DESIGN

Retrospective cross-sectional analysis.

SETTINGS AND PARTICIPANTS

Octogenarians who underwent elective RRH and LRH by the Tweed Colorectal Group over 5 years.

METHODS

Complications within 30 days, age, gender, smoking status, immunocompromised status, presence of diabetes, American Society of Anesthesiologists (ASA) physical status score, preoperative Eastern Cooperative Oncology Group (ECOG) performance status, mFI-5 (modified frailty index), operative time, method of anastomosis, postoperative length of stay (LOS), need for rehabilitation, and short-term oncologic data using the TNM criteria were compared using univariate and multivariate analysis.

RESULTS

Seventy-eight elective patients were included. LRH and RRH groups had similar median ages, gender distribution, and comorbidities. Across the entire cohort, 61.5% had no 30-day complications. RRH had nonsignificantly shorter operative time but significantly shorter LOS (5 vs 8 days) and fewer minor complications (24.5% vs 34.5%). Major complications and overall complications were not significantly different between the groups. Lower ASA and ECOG status were associated with lower complication rates across both groups. Oncologic resection outcomes were similar for both approaches.

CONCLUSIONS AND IMPLICATIONS

RRH does not confer an increased risk of complications compared to LRH in the octogenarians and may be a viable alternative in the field of minimally invasive surgery for older patients. Future research should focus on intracorporeal anastomoses, as it is a potential confounder leading to the shorter inpatient LOS shown in our robotic group.

Current Perspectives on the Importance of Pathological Features in Prognostication and Guidance of Adjuvant Chemotherapy in Colon Cancer

There is not a clear consensus on which pathological features and biomarkers are important in guiding prognosis and adjuvant therapy in colon cancer. The Pathology in Colon Cancer, Prognosis and Uptake of Adjuvant Therapy (PiCC UP) Australia and New Zealand questionnaire was distributed to colorectal surgeons, medical oncologists and pathologists after institutional board approval. The aim of this study was to understand current specialist attitudes towards pathological features in the prognostication of colon cancer and adjuvant therapy in stage II disease. A 5-scale Likert score was used to assess attitudes towards 23 pathological features for prognosis and 18 features for adjuvant therapy. Data were analysed using a rating scale and graded response model in item response theory (IRT) on STATA (Stata MP, version 15; StataCorp LP). One hundred and sixty-four specialists (45 oncologists, 86 surgeons and 33 pathologists) participated. Based on IRT modelling, the most important pathological features for prognosis in colon cancer were distant metastases, lymph node metastases and liver metastases. Other features seen as important were tumour rupture, involved margin, radial margin, CRM, lymphovascular invasion and grade of differentiation. Size of tumour, location, lymph node ratio and EGFR status were considered less important. The most important features in decision making for adjuvant therapy in stage II colon cancer were tumour rupture, lymphovascular invasion and microsatellite instability. BRAF status, size of tumour, location, tumour budding and tumour infiltrating lymphocytes were factored as lesser importance. Biomarkers such as CDX2, EGFR, KRAS and BRAF status present areas for further research to improve precision oncology. This study provides the most current status on the importance of pathological features in prognostication and recommendations for adjuvant therapy in Australia and New Zealand. Results of this nationwide study may be useful to help in guiding prognosis and adjuvant treatment in colon cancer.

Postoperative Quality Assessment Score Can Select Patients with High Risk for Locoregional Recurrence in Colon Cancer

BACKGROUND

Monitoring surgical quality has been shown to reduce locoregional recurrence (LRR). We previously showed that the arterial stump length (ASL) after complete mesocolic excision (CME) is a reproducible quality instrument and correlates with the lymph-node (LN) yield. We hypothesized that generating an LRR prediction score by integrating the ASL would predict the risk of LRR after suboptimal surgery.

METHODS

502 patients with curative resections for stage I-III colon cancer were divided in two groups (CME vs. non-CME) and compared in terms of surgical data, ASL-derived parameters, pathological parameters, LRR and LRR-free survival. A prediction score was generated to stratify patients at high risk for LRR.

RESULTS

The ASL showed significantly higher values (50.77 mm ± 28.5 mm) with LRR vs. (45.59 mm ± 28.1 mm) without LRR (p < 0.001). Kaplan-Meier survival analysis showed a significant increase in LRR-free survival at 5.58 years when CME was performed (Group A: 81%), in contrast to non-CME surgery (Group B: 67.2%).

CONCLUSIONS

The prediction score placed 76.6% of patients with LRR in the high-risk category, with a strong predictive value. Patients with long vascular stumps and positive nodes could benefit from second surgery to complete the mesocolic excision.

Upstaging nodal status in colorectal cancer using ex vivo fluorescence sentinel lymph node mapping: preliminary results

BACKGROUND

Sentinel lymph node (SLN) mapping using near-infrared fluorescence (NIRF) imaging is a recent technique to improve nodal staging in several tumors. The presence of colorectal cancer (CRC) micro-metastases has recently been defined as N1 disease and no longer as N1mi, determining the need for adjuvant chemotherapy. In CRC, the reported rate of SLN micro-metastases detected by ultrastaging techniques is as high as 30%. The aim of this prospective study is to report the preliminary results of the sensitivity analysis of NIRF imaging for ex vivo SLN mapping and the research of micro-metastases in CRC, in patients with node-negative disease (NND).

MATERIAL AND METHODS

On the specimen of 22 CRC patients, 1 mL of ICG (5 mg/mL) was injected submucosally around the tumor to identify SLNs. NND SLNs were further investigated with ultrastaging techniques.

RESULTS

Three-hundred and sixty-three lymph nodes were retrieved (59 SLNs; mean per case: 2.7). The detection, sensitivity and false-negative rate were 100%, 100% and 0% respectively. Ultrastaging investigations showed no micro-metastases in the NND SLNs.

CONCLUSIONS

The ex vivo SLN fluorescence-based detection in CRC was confirmed to be easy to perform and reliable. In this preliminary results report of an ongoing study, the SLN assay was congruent with the nodal status, as confirmed by histological investigations.