Local recurrence of colorectal cancer: the problem, mechanisms, management and adjuvant therapy

Mitochondria-Modulating Liposomes Reverse Radio-Resistance for Colorectal Cancer

Complete remission of colorectal cancer (CRC) is still unachievable in the majority of patients by common fractionated radiotherapy, leaving risks of tumor metastasis and recurrence. Herein, clinical CRC samples demonstrated a difference in the phosphorylation of translation initiation factor eIF2α (p-eIF2α) and the activating transcription factor 4 (ATF4), whose increased expression by initial X-ray irradiation led to the resistance to subsequent radiotherapy. The underlying mechanism is studied in radio-resistant CT26 cells, revealing that the incomplete mitochondrial outer membrane permeabilization (iMOMP) triggered by X-ray irradiation is key for the elevated expression of p-eIF2α and ATF4, and therefore radio-resistance. This finding guided to discover that metformin and 2-DG are synergistic in reversing radio resistance by inhibiting p-eIF2α and ATF4. Liposomes loaded with metformin and 2-DG (M/D-Lipo) are thus prepared for enhancing fractionated radiotherapy of CRC, which achieved satisfactory therapeutic efficacy in both local and metastatic CRC tumors by reversing radio-resistance and preventing T lymphocyte exhaustion.

Controversy in the initial nodal staging of rectal cancer (MRI or PET/CT?)

OBJECTIVE

To compare the usefulness of MRI and PET/CT in nodal staging (N) of patients with locally advanced rectal cancer (LARC).

MATERIAL AND METHODS

Retrospective study of patients with LARC, who completed their initial staging with PET/CT, between January-20 and March-23. Regional nodes were assessed, and N was determined using both techniques according to TNM criteria. Concordance between MRI and PET/CT was analyzed. The accuracy of both techniques was calculated for those patients who underwent direct surgery. Non-regional pelvic lymph nodes were evaluated by both modalities.

RESULTS

Among the 73 patients, 48 were ultimately diagnosed with a locally advanced stage. Of these, 39 underwent neoadjuvant treatment (chemoradiotherapy) followed by surgery, and 9 direct surgery. In 25, the PET/CT extension study revealed distant disease, leading to systemic treatment. Weak concordance was observed between MRI and PET/CT in determining N (k=0.286; p<0.005). Out of 73 patients, 31(42%) exhibited concordance, and 42(58%) showed discordance. In 83% of the discordant cases, MRI overstaged compared to PET/CT, with 17 cases indicating nodal involvement (N+) by MRI and N0 by PET/CT. Diagnostic accuracy was 78% for both techniques. Sensitivity, specificity, positive predictive value, and negative predictive value were 80%, 75%, 80%, and 75% for MRI, and 60%, 100%, 100%, and 67%, for PET/CT. PET/CT identified pelvic metastatic adenopathies in 8 patients that were not visible/doubtful by MRI.

CONCLUSIONS

In the initial nodal staging of rectal cancer MRI overstages relative to PET/CT. Both modalities are complementary, PET/CT offers higher specificity and MRI higher sensitivity.

Reactive oxygen species in colorectal cancer adjuvant therapies

Colorectal cancer (CRC), a prevalent global malignancy, often necessitates adjuvant therapies such as chemotherapy, radiotherapy, targeted therapy, and immunotherapy to mitigate tumor burden in advanced stages. The efficacy of these therapies is significantly influenced by reactive oxygen species (ROS). Previous research underscores the pivotal role of ROS in gut pathology, targeted therapy, and drug resistance. ROS-mediated CRC adjuvant therapies encompass a myriad of mechanisms, including cell death and proliferation, survival and cell cycle, DNA damage, metabolic reprogramming, and angiogenesis. Preliminary clinical trials have begun to unveil the potential of ROS-manipulating therapy in enhancing CRC adjuvant therapies. This review aims to provide a comprehensive synthesis of studies exploring the role of ROS in CRC adjuvant therapies.

Factors Affecting the Efficiency of Near-Infrared Indocyanine Green (NIR/ICG) in Lymphatic Mapping for Colorectal Cancer: A Systematic Review

As laparoscopy gained global popularity in oncologic surgery, the challenge of detecting lymph nodes spurred researchers to explore innovative techniques and approach the situation from a fresh perspective. While many proposed methods have faded into obscurity, the utilization of indocyanine green (ICG) in the surgical treatment of oncologic patients has continued to advance. The immense potential of this dye is widely acknowledged, yet its full extent and limitations in lymphatic mapping for colorectal cancer remain to be precisely determined. This article aims to assess the magnitude of its potential and explore the constraints based on insights from clinical studies published by pioneering researchers. A systematic review of the existing literature, comprising articles in English, was conducted using the Scopus, PubMed, and Springer Link databases. The search employed keywords such as "colorectal cancer" AND/OR "indocyanine green," "fluorescence" AND/OR "lymphatic mapping" AND/OR "lymph nodes." Initially identifying 129 articles, the application of selection criteria narrowed down the pool to 10 articles, which served as the primary sources of data for our review. Despite the absence of a standardized protocol for the application of ICG in colorectal cancer, particularly in the context of lymphatic mapping, the detection rates have exhibited considerable variation across studies. Nevertheless, all authors unanimously regarded this technique as beneficial and promising. Additionally, it is advocated as an adjunctive tool to enhance the accuracy of cancer staging. Near-infrared (NIR)-enhanced surgery holds the promise of transforming the landscape of oncologic surgery, emerging as a valuable tool for surgeons. However, the absence of a standardized technique and the subjective nature of result assessment impose limitations on the potential of this method. Consequently, it can be inferred that the establishment of a universally accepted protocol, encompassing parameters such as dose, concentration, technique, and site of administration of ICG, along with the optimal time needed for fluorescence visualization, would enhance the outcomes. Emphasizing the accurate selection of patients is crucial to prevent the occurrence of false-negative results.

Exploring extracellular matrix and prostaglandin pathway alterations across varying resection margin distances of right-sided colonic adenocarcinoma

BACKGROUND

Surgical resection followed by indicated adjuvant therapy offers potential curative treatment in colonic adenocarcinoma. Beyond the well-established seed and soil theory of colon cancer progression, the 'normal-appearing' tissues near the tumor are not genuinely normal and remain as remnants in patients following surgery. Our objective was to elucidate the alteration of gene expression and pathways across various distances of resection margins in right-sided colonic adenocarcinoma.

METHODS

Twenty-seven fresh samples of primary cancer and 56 matched non-tumor tissues adjacent to the tumor (NAT) were collected from patients with resectable right-sided colon cancer. NAT were systematically obtained at varying distances (1, 5, and 10 cm) on both proximal and distal sides. Comprehensive gene expression analysis was performed using 770-gene PanCancer Progression Panel, delineating distinctive pathways and functional predictions for each region.

RESULTS

Distinctive gene signatures and pathways exhibited by normal-appearing tissues were discovered at varying distances from cancer. Notably, SFRP2, PTGDS, COL1A1, IL1B, THBS2, PTGIS, COL1A2, NPR1, and BGN were upregulated, while ENPEP, MMP1, and NRCAM were downregulated significantly in 1-cm tissue compared to farther distances. Substantial alterations in the extracellular matrix (ECM) and prostaglandin/thromboxane synthesis were significantly evident at the 1-cm distance. Functional analysis indicated enhanced cell viability and survival, alongside reduced cellular death and apoptosis.

CONCLUSIONS

Different distances exerted a significant impact on gene alteration within the normal-looking mucosa surrounding primary cancer, influenced by various mechanisms. These findings may highlight potential therapeutic targets related to the ECM and prostaglandin/thromboxane pathways for treatment strategies.

Tumor microbiome analysis provides prognostic value for patients with stage III colorectal cancer

Introduction

Although patients with colorectal cancer (CRC) can receive optimal treatment, the risk of recurrence remains. This study aimed to evaluate whether the tumor microbiome can be a predictor of recurrence in patients with stage III CRC.

Methods

Using 16S rRNA gene sequencing, we analyzed the microbiomes of tumor and adjacent tissues acquired during surgery in 65 patients with stage III CRC and evaluated the correlation of the tissue microbiome with CRC recurrence. Additionally, the tumor tissue microbiome data of 71 patients with stage III CRC from another center were used as a validation set.

Results

The microbial diversity and abundance significantly differed between tumor and adjacent tissues. In particular, Streptococcus and Gemella were more abundant in tumor tissue samples than in adjacent tissue samples. The microbial diversity and abundance in tumor and adjacent tissues did not differ according to the presence of recurrence, except for one genus in the validation set. Logistic regression analysis revealed that a recurrence prediction model including tumor tissue microbiome data had a better prediction performance than clinical factors (area under the curve [AUC] 0.846 vs. 0.679, p = 0.009), regardless of sex (male patients: AUC 0.943 vs. 0.818, p = 0.043; female patients: AUC 0.885 vs. 0.590, p = 0.017). When this prediction model was applied to the validation set, it had a higher AUC value than clinical factors in female patients.

Conclusion

Our results suggest that the tumor microbiome of patients with CRC be a potential predictor of postoperative disease recurrence.

Risk factors and clinical characteristics of rectal cancer recurrence after radical surgical treatment

<b><br>Introduction:</b> Recurrence of rectal cancer affects from 4% to even 50% of patients after surgical treatment. The incidence may be influenced by numerous factors depending on the patient, the characteristics of the tumor and the type and quality of the surgical technique used.</br> <b><br>Aim:</b> The aim of this study was to assess the clinical characteristics of rectal cancer recurrence, identify potential risk factors and role of patient surveillance after primary resection of rectal cancer.</br> <b><br>Materials and methods:</b> The study comprised patients operated on due to recurrence of rectal cancer at the Department of General and Colorectal Surgery of Medical University of Lodz between 2014 and 2020, who were in the follow-up program at the hospital's outpatient clinic after the primary surgery. Risk factors for disease recurrence were sought by analyzing the characteristics of the primary tumor, treatment history and postoperative care.</br> <b><br>Results:</b> Twenty-nine patients were included in the study, the majority (51.7%) of the patients were men. The largest group was represented by patients with stage II and III disease. The most frequently performed primary surgery was low anterior resection (LAR) (62.8%). 35% of patients received neoadjuvant treatment prior to primary surgery. We demonstrated that the lack of neoadjuvant treatment before primary surgery increases the risk of cancer recurrence nine times. Higher stage of disease at the point of primary surgery is associated with nearly seven times the risk of recurrence compared to stage I disease.</br> <b><br>Conclusions:</b> Optimal preoperative staging, reasonable neoadjuvant treatment, proper surgical technique and precise follow-up regimen are essential for further improvement of rectal cancer outcomes.</br>.

Clinicopathological Characteristics of Anastomotic Recurrence After Curative Resection for Colorectal Cancer: Comparison With Nonanastomotic Local Recurrences

BACKGROUND

Anastomotic recurrence is thought to be caused by implantation of tumor cells to the anastomotic line; however, its risk factors and prognostic significance remain unclear.

OBJECTIVE

This study aimed to clarify the risk factors for anastomotic recurrence in colorectal cancer and assess the prognosis in comparison to nonanastomotic local recurrence.

DESIGN

A single-center retrospective observational study.

SETTINGS

The medical records of the study participants were retrospectively collected from the Department of Surgical Oncology at the University of Tokyo Hospital database.

PATIENTS

This study included 1584 patients with colorectal cancer who underwent surgical resection between January 2005 and December 2017. We focused on 15 patients who had an anastomotic recurrence.

MAIN OUTCOME MEASURES

The main outcome measures were the risk factors of anastomotic recurrence at the primary resection and prognosis data in comparison to that of nonanastomotic local recurrence.

RESULTS

There were 15 patients (0.95%) with anastomotic recurrence and 35 (2.21%) with nonanastomotic local recurrence. Univariate analysis revealed that lymph node metastasis and advanced T stage are the risk factors for anastomotic recurrence. The prognosis of patients with anastomotic recurrence was similar to that of those with nonanastomotic local recurrence who underwent resection.

LIMITATIONS

The small number of patients with anastomotic recurrence is a major limitation of this study. Additionally, the retrospective study design may have increased the risk of selection bias.

CONCLUSIONS

Lymph node metastasis and advanced T stage were associated with anastomotic recurrence. The prognosis of patients with anastomotic recurrence was similar to that with resected nonanastomotic local recurrence. Thus, surveillance should be carefully continued while considering the poor prognosis of patients with anastomotic recurrence. See Video Abstract at http://links.lww.com/DCR/C92 .

CARACTERSTICAS CLINICOPATOLGICAS DE LA RECURRENCIA ANASTOMTICA DESPUS DE LA RESECCIN CURATIVA DEL CNCER COLORRECTAL COMPARACIN CON LAS RECURRENCIAS LOCALES NO ANASTOMTICAS

ANTECEDENTES:Se cree que la recurrencia anastomótica es causada por la implantación de células tumorales en la línea anastomótica; sin embargo, los factores de riesgo asociados y el significado en cuanto a pronóstico siguen sin estar claros.OBJETIVO:Este estudio tuvo como objetivo aclarar los factores de riesgo para la recurrencia anastomótica en el cáncer colorrectal y evaluar el pronóstico en comparación con la recurrencia local no anastomótica.DISEÑO:Un estudio observacional retrospectivo de un solo centro.ESCENARIO:Los registros médicos de los participantes del estudio se recopilaron retrospectivamente de la base de datos del Departamento de Cirugía Oncológica del Hospital de la Universidad de Tokio.PACIENTES:Este estudio incluyó a 1584 pacientes con cáncer colorrectal que se sometieron a resección quirúrgica entre enero de 2005 y diciembre de 2017. Nos enfocamos en 15 pacientes que tuvieron recurrencia anastomótica.PRINCIPALES MEDIDAS DE RESULTADO:Las principales medidas de resultado fueron los factores de riesgo de recurrencia anastomótica en la resección primaria y los datos de pronóstico en comparación con la recurrencia local no anastomótica.RESULTADOS:Hubo 15 pacientes (0.95%) con recurrencia anastomótica y 35 (2.21%) con recurrencia local no anastomótica. El análisis univariable reveló que la metástasis en los ganglios linfáticos y el estadio T avanzado son los factores de riesgo para la recurrencia anastomótica. El pronóstico de los pacientes con recidiva anastomótica fue similar al de aquellos con recidiva local no anastomótica sometidos a resección.LIMITACIONES:El pequeño número de pacientes con recurrencia anastomótica es una limitación importante de este estudio. Además, el diseño retrospectivo del estudio puede haber aumentado el riesgo de sesgo de selección.CONCLUSIONES:La metástasis en los ganglios linfáticos y el estadio T avanzado se asociaron con recurrencia anastomótica. El pronóstico de los pacientes con recidiva anastomótica fue similar al de la recidiva local no anastomótica resecada. Por lo tanto, la vigilancia debe continuarse cuidadosamente considerando el mal pronóstico de los pacientes con recurrencia anastomótica. Consulte Video Resumen en http://links.lww.com/DCR/C92 . (Traducción-Dr. Jorge Silva Velazco ).

Investigating the spatial interaction of immune cells in colon cancer

The intricate network of interactions between cells and molecules in the tumor microenvironment creates a heterogeneous ecosystem. The proximity of the cells and molecules to their activators and inhibitors is essential in the progression of tumors. Here, we develop a system of partial differential equations coupled with linear elasticity to investigate the effects of spatial interactions on the tumor microenvironment. We observe interesting cell and cytokine distribution patterns, which are heavily affected by macrophages. We also see that cytotoxic T cells get recruited and suppressed at the site of macrophages. Moreover, we observe that anti-tumor macrophages reorganize the patterns in favor of a more spatially restricted cancer and necrotic core. Furthermore, the adjoint-based sensitivity analysis indicates that the most sensitive model's parameters are directly related to macrophages. The results emphasize the widely acknowledged effect of macrophages in controlling cancer cells population and spatially arranging cells in the tumor microenvironment.

High Expression of Tetraspanin 5 as a Prognostic Marker of Colorectal Cancer

Cancer is a major disease and the leading cause of death worldwide, with colorectal cancer (CRC) being the third-most common cancer in Korea. The survival rate associated with CRC reduces as the disease stage increases. Therefore, its early detection and treatment can greatly increase patient survival rates. In this study, we identified the tetraspanin 5 (TSPAN5) gene as an important biomarker for predicting the prognosis of patients with CRC. A TMA slide was used for statistical analysis. pN and clinical stage were found to be significant factors according to chi-square analysis, whereas pT, pN, metastasis, clinical stage, and TSPAN5 expression were significant according to Cox regression analysis. In order to prove the usefulness of TSPAN5, which is overexpressed in patients with metastatic CRC, as a biomarker, proliferation, migration, invasion, and tumorigenicity were examined using cell lines inhibited using small interfering RNA. The evaluations confirmed that TSPAN5 suppression, in turn, suppressed proliferation, migration, invasion, and tumorigenesis, which are characteristic of cancer cells. Therefore, the evaluation of TSPAN5 expression may help observe the prognosis of CRC and determine an appropriate treatment method for patients with CRC.

A bayesian approach to model the underlying predictors of early recurrence and postoperative death in patients with colorectal Cancer

Objective

This study aimed at utilizing a Bayesian approach semi-competing risks technique to model the underlying predictors of early recurrence and postoperative Death in patients with colorectal cancer (CRC).

Methods

In this prospective cohort study, 284 patients with colorectal cancer, who underwent surgery, referred to Imam Khomeini clinic in Hamadan from 2001 to 2017. The primary outcomes were the probability of recurrence, the probability of Mortality without recurrence, and the probability of Mortality after recurrence. The patients ‘recurrence status was determined from patients’ records. The Bayesian survival modeling was carried out by semi-competing risks illness-death models, with accelerated failure time (AFT) approach, in R 4.1 software. The best model was chosen according to the lowest deviance information criterion (DIC) and highest logarithm of the pseudo marginal likelihood (LPML).

Results

The log-normal model (DIC = 1633, LPML = -811), was the optimal model. The results showed that gender(Time Ratio = 0.764: 95% Confidence Interval = 0.456–0.855), age at diagnosis (0.764: 0.538–0.935 ), T₃ stage (0601: 0.530–0.713), N₂ stage (0.714: 0.577–0.935 ), tumor size (0.709: 0.610–0.929), grade of differentiation at poor (0.856: 0.733–0.988), and moderate (0.648: 0.503–0.955) levels, and the number of chemotherapies (1.583: 1.367–1.863) were significantly related to recurrence. Also, age at diagnosis (0.396: 0.313–0.532), metastasis to other sites (0.566: 0.490–0.835), T₃ stage (0.363: 0.592 − 0.301), T₄ stage (0.434: 0.347–0.545), grade of differentiation at moderate level (0.527: 0.387–0.674), tumor size (0.595: 0.500–0.679), and the number of chemotherapies (1.541: 1.332–2.243) were the significantly predicted the death. Also, age at diagnosis (0.659: 0.559–0.803), and the number of chemotherapies (2.029: 1.792–2.191) were significantly related to mortality after recurrence.

Conclusion

According to specific results obtained from the optimal Bayesian log-normal model for terminal and non-terminal events, appropriate screening strategies and the earlier detection of CRC leads to substantial improvements in the survival of patients.

PCR-based quantitative detection of intraperitoneal free cancer cells for predicting locoregional recurrence after rectal cancer resection

INTRODUCTION

Locoregional recurrence after curative resection remains an important issue in the treatment of colorectal cancer (CRC). The aim of the present study was to investigate the clinical significance of quantitative detection of intraperitoneal free cancer cells by a PCR-based method for predicting locoregional recurrence after CRC resection.

METHOD

A total of 114 patients with CRC were enrolled between March 2017 and December 2018, and 95 patients with Stage I-III CRC were analyzed. Peritoneal lavage fluid was collected before and after tumour resection and subjected to cytology and quantitative reverse transcription-PCR (qRT-PCR) with carcinoembryonic antigen (CEA) as a genetic marker.

RESULTS

2.1% of patients had positive cytology after resection, whereas 9.5% had positive CEA qRT-PCR (PCR+) after resection. Eight of nine PCR+ patients after resection had tumours in the rectum. Fifteen (15.8%) patients developed recurrence during the follow-up period, including three with locoregional recurrence. One of 86 (1.2%) PCR- patients and 2 of 9 (22.2%) PCR+ patients after resection developed locoregional recurrence. Overall and in rectal cancer patients, the 3-year cumulative risk of locoregional recurrence was 25.0% and 28.6% for PCR+ patients, which is significantly higher than PCR- patients (1.3% and 0%, P < 0.001 and P = 0.001, respectively).

CONCLUSION

Intraperitoneal free cancer cells can serve as a sensitive predictor of locoregional recurrence after rectal cancer resection. qRT-PCR for CEA can be a suitable method for detecting intraperitoneal free cancer cells in peritoneal lavage fluid.

Multifunctional Magnesium Anastomosis Staples for Wound Closure and Inhibition of Tumor Recurrence and Metastasis

Biodegradable magnesium (Mg) implants spontaneously releasing therapeutic agents against tumors are an intriguing therapeutic approach for both tissue repair and tumor treatment. Anastomotic staples are extensively used for wound closure after surgical resection in patients with colorectal tumors. However, the safety of Mg anastomosis implants for intestinal closure and the effect of tumor suppression remain elusive. Here, we used a high-purity Mg staple to study these issues. Based on the results, we found that it has the potential to heal wounds produced after colorectal tumor resection while inhibiting relapse of residual tumor cells in vitro and in vivo. After implantation of Mg staples for 7 weeks in rabbits, the intestinal wound gradually healed with no adverse effects such as leakage or inflammation. Furthermore, the implanted Mg staples inhibit the growth of colorectal tumor cells and block migration to normal organs because of the increased concentration of Mg ions and released hydrogen. Such an antitumor effect is further confirmed by the in vitro cell experiments. Mg significantly induces apoptosis of tumor cells as well as inhibits cell growth and migration. Our work presents a feasible therapeutic opinion to design Mg anastomotic staples to perform wound healing and simultaneously release tumor suppressor elements in vivo to decrease the risk of tumor recurrence and metastasis.

Lateral lymph node dissection in advanced low rectal cancer treatment

Lateral lymph node (LLN) metastasis is a determinant of local recurrence in advanced low rectal cancer. Lateral lymph node dissection (LLND) is effective in removing metastatic lymph nodes, and has been shown to have a decreased local recurrence rate. However, because of its complexity and complications it induces, there is still tremendous controversy about its usage. Neoadjuvant chemoradiotherapy (nCRT) and total mesorectal excision (TME) are recommended as a conventional treatment for advanced rectal cancer. However, LLN metastasis and local recurrence still occur despite nCRT with TME. In Japan, TME with LLND is the standard surgical treatment for Stage II/III of advanced low rectal cancer. Before surgery, a proper evaluation of LLN status should be performed. Laparoscopic LLND and robotic-assisted LLND are useful for this. More research is necessary to improve the oncological outcomes of LLND. In this review, we retrospectively examine previous reports about LLND, aiming to emphasize its application prospects to improve patient survival and life quality.

A novel amplification gene PCI domain containing 2 (PCID2) promotes colorectal cancer through directly degrading a tumor suppressor promyelocytic leukemia (PML)

Using whole genome sequencing, PCI Domain Containing 2 (PCID2) was identified to be amplified in colorectal cancer (CRC). In this study, we investigated the expression, biological function, molecular mechanism, and clinical implication of PCID2 in CRC. PCID2 mRNA and protein expression were higher in CRC cells and tumor tissues compared to healthy colonic tissues. The copy number of PCID2 was positively correlated with its mRNA expression. Multivariate analysis revealed that PCID2 is an independent prognostic factor for CRC recurrence. Functional studies showed that PCID2 promoted cell growth, cell cycle progression, and cell migration/invasion, while apoptosis was suppressed. Moreover, PCID2 promoted xenograft growth and lung metastasis in nude mice. Using co-immunoprecipitation and mass spectroscopy, we showed that PCID2 binds to promyelocytic leukemia (PML), a tumor suppressor involved in non-canonical β-catenin signaling. PCID2 promoted the degradation of PML via poly-ubiquitination, which in turn, induced Wnt/β-catenin signaling while simultaneously repressing ARF-p53 pathway. Thus, these results demonstrated that PCID2 functions as an oncogene in CRC by enhancing canonical Wnt/β-catenin signaling and inhibition of CTNNB1-ARF-p53 axis. PCID2 promoted canonical Wnt/β-catenin signaling in CRC via degradation of PML. PCID2 may serve as an independent prediction marker for CRC recurrence.

The Clinical Significance of Mesenteric Lymphocytes in Human Colorectal Cancer

Objective

The mesentery is a potential site of residual tumor in patients with colorectal cancer (CRC). However, the mesenteric immune microenvironment remains unclear. In this study, we investigated the immune landscape of the mesentery, particularly the role of lymphocytes and its association with the clinicopathological characteristics of CRC.

Methods

Flow cytometry was used to detect lymphocytes in the paired mesenteric tissue specimens adjacent to the colorectal tumors and normal mesenteric tissue specimens 10 cm away from the colorectal tumor edge and preoperative peripheral blood samples obtained from patients with CRC who underwent surgery. T-distributed stochastic neighbor embedding was utilized to analyze multiparameter flow cytometry data. Multiplex immunohistochemistry was performed to evaluate T cells subsets in the paired mesentery adjacent to the colorectal tumors and normal mesentery. The Fisher’s exact test and non-parametric Wilcoxon’s matched-pairs tests were used for statistical analysis. The non-parametric Mann-Whitney U test was used to determine associations between percentage data and clinical parameters of patients with CRC.

Results

We found that immune cells in the normal mesentery were mainly of lymphoid lineage. Compared with peripheral blood, the normal mesentery showed decreased NK cells and the CD4/CD8 ratio and increased CD3⁺ CD56⁺, memory CD4⁺ T, memory CD8⁺ T, CD4⁺ tissue-resident memory T (TRM), and CD8⁺ TRM cells. Compared with the normal mesentery, the mesentery adjacent to the colorectal tumor showed increased B and regulatory T cells and decreased NK, CD3⁺ CD56⁺, CD4⁺ TRM, and CD8⁺ TRM cells. Moreover, memory CD8⁺ T cells and plasmablasts are negatively correlated with the depth of invasion of CRC. Increased memory CD4⁺ T cells are associated with distant metastasis of CRC and high preoperative serum carcinoembryonic antigen levels.

Conclusion

The mesentery shows a specific immune microenvironment, which differs from that observed in peripheral blood. CRC can alter the mesenteric immune response to promote tumor progression.

Time-Programmed Delivery of Sorafenib and Anti-CD47 Antibody via a Double-Layer-Gel Matrix for Postsurgical Treatment of Breast Cancer

The highly immunosuppressive microenvironment after surgery has a crucial impact on the recurrence and metastasis in breast cancer patients. Programmable delivery of immunotherapy-involving combinations through a single drug delivery system is highly promising, yet greatly challenging, to reverse postoperative immunosuppression. Here, an injectable hierarchical gel matrix, composed of dual lipid gel (DLG) layers with different soybean phosphatidylcholine/glycerol dioleate mass ratios, was developed to achieve the time-programmed sequential delivery of combined cancer immunotherapy. The outer layer of the DLG matrix was thermally responsive and loaded with sorafenib-adsorbed graphene oxide (GO) nanoparticles. GO under manually controlled near-infrared irradiation generated mild heat and provoked the release of sorafenib first to reeducate tumor-associated macrophages (TAMs) and promote an immunogenic tumor microenvironment. The inner layer, loaded with anti-CD47 antibody (aCD47), could maintain the gel state for a much longer time, enabling the sustained release of aCD47 afterward to block the CD47-signal regulatory protein α (SIRPα) pathway for a long-term antitumor effect. In vivo studies on 4T1 tumor-bearing mouse model demonstrated that the DLG-based strategy efficiently prevented tumor recurrence and metastasis by locally reversing the immunosuppression and synergistically blocking the CD47-dependent immune escape, thereby boosting the systemic immune responses.

An MRI-based multi-objective radiomics model predicts lymph node status in patients with rectal cancer

PURPOSE

To apply a multi-objective radiomics model based on pre-operative magnetic resonance imaging (MRI) for improving diagnostic accuracy of LN metastasis in rectal cancer patients.

METHODS

This study consisted of 91 patients diagnosed with rectal cancer from April 2018 to March 2019. All patients underwent rectal MRI before surgery without any other treatment. Clinical data, subjective radiologist assessments, and radiomic features of LNs were obtained. A total of 1409 radiomic features were extracted from T2WI LN images. Multi-objective optimization with the iterative multi-objective immune algorithm (IMIA) was used to select radiomic features to build prediction models. Predictive performances of radiomic, radiologist, and combined radiomic and radiologist models were assessed for accuracy by receiver operating characteristics (ROC) curves.

RESULTS

For the radiologist analysis, heterogeneity was the only significant independent predictor of LN status. The sensitivity, specificity, and accuracy of the subjective radiologist analysis were 72.09%, 73.81%, and 78.12%, respectively. The sensitivity, specificity, and accuracy of the solitary radiomic model consisting of 10 features were 89.81%, 82.57%, and 87.77%, respectively. The sensitivity, specificity, and accuracy of the combined model, which consisted of 12 radiomic and radiologist features, were 92.23%, 84.69%, and 89.88%, respectively. The combined model had the best prediction performance with an AUC of 0.94.

CONCLUSIONS

The multi-objective radiomics model based on T2WI images was very useful in predicting pre-operative LN status in rectal cancer patients.

Sarcopenia is a strong predictive factor of clinical and oncological outcomes following curative colorectal cancer resection

BACKGROUND

Skeletal muscle depletion and subsequent functional loss is common in gastrointestinal malignancy. Usual markers of nutritional status may not be part of routine workup. The predictive value of sarcopenia was assessed and compared with clinically utilized factors. The aim of this was to assess the association between computed tomography assessed sarcopenia with outcomes in colorectal cancer resection.

METHODS

A total of 228 consecutive patients who underwent curative colorectal cancer resection were included. Skeletal muscle area was measured at L3, with pre-defined gender-specific cut-offs applied to a height standardized index. Albumin, body mass index and Subjective Global Assessment scores were recorded alongside measures of comorbidity. Predictors of complications, mortality, and recurrence were identified through multivariate logistic regression.

RESULTS

Computed tomography assessed sarcopenia was significantly associated with longer stays, complications, 30-day mortality, readmissions and recurrence at 1 year. Specific associations with major, respiratory and cardiac complications were seen. It independently predicted overall complications (odds ratio 2.96, confidence interval 1.19-7.35 P = 0.019), recurrence at 1 year (odds ratio 8.00, confidence interval 1.45-44.21, P = 0.017) and an increase in comprehensive complication index of 14 (P = 0.002). Subgroup analysis found sarcopenia predicted overall complications in rectal surgery and major complications in colonic surgery. American Society of Anesthesiologists predicted complications but not major complications while cancer stage also predicted recurrence rates.

CONCLUSIONS

Sarcopenia presents an objective, available predictive factor that may be superior to current biochemical and clinical measures of nutritional and functional status. This study found it to be predictive of complication rates and recurrence after curative in colorectal cancer resection.

Joint modelling of colorectal cancer recurrence and death after resection using multi-state model with cured fraction

Curing of colorectal cancer (CRC) occurs at the time of resection but it is not immediately observable. If the cancer is not completely eliminated, the patient will not be cured of cancer and will experience recurrence as the tumor has regrown to a detectable size. The main propose of the present study was to assess the effects of different covariates on the probability of being cured as well as the time-to-recurrence, and time-to-death in CRC patients by using multi-state cure model. The information of 283 patients with CRC, who underwent resection, from 2000 to 2015 in Imam Khomeini Hospital of Hamadan, Iran, were analyzed. The results of multi-state cure model reveal that females and who experience metastasis were more likely to be apparently cured. It has been shown that sex has a significant effect on the time-to-recurrence given patient was in the not cured group. The survival time of patients of the not cured group was affected by the stage of disease. However, the survival of the apparently cured patients were affected by age at diagnosis and metastasis status. The multi-state cure model provided a flexible framework to study the effects of prognostic factors simultaneously on the transition between different states and the probability of being apparently cured of CRC.

Distribution of Metastatic Cancer Cells in Colorectal Mesentery

BACKGROUND

To investigate the distribution of metastatic cancer cells in the mesentery (referred to as metastasis V) and enrich the understanding of the metastasis of colorectal cancer.

METHODS

A total of two hundred ninety-nine patients who received colorectal operations at the Department of Gastrointestinal Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology between April 2018 and December 2018 were included. Samples were acquired from the dissected mesentery after the operation, and hematoxylin-eosin staining or immunohistochemistry was used to detect metastatic cancer cells. Pathological factors, including tumor position, tumor size, invasion depth, tumor differentiation, lymph node involvement, local vessel invasion, and perineural invasion, were recorded.

RESULTS

Metastatic cancer cells in the colorectal mesentery (metastasis V) were detected in 62 of 299 patients. Metastasis V was closely correlated with tumor invasion depth, lymph node metastasis, tumor differentiation, and perineural and vessel invasion by cancer cells. Metastasis V occurred more frequently in patients with T3 stage (26.27%) and T4 stage (40.00%) than in patients with T1 and T2 stages (0% and 2%, respectively). Metastasis V was frequently detected in patients with N2a and N2b stage tumors (51.72% and 61.54%, respectively). Metastasis V was more frequently detected in patients with perineural metastasis and local vessel invasion. In addition, metastasis V incidences in colon and rectal cancer were similar.

CONCLUSION

The incidence rate of metastasis V is correlated with tumor staging factors and occurs more frequently in advanced-stage patients.

Injectable Liquid Crystal Formation System for Reshaping Tumor Immunosuppressive Microenvironment to Boost Antitumor Immunity: Postoperative Chemoimmunotherapy

Exploring optimal strategies to improve patient outcome postoperatively is still under challenge. Cancer immunotherapy has great potential to prevent the postoperative tumor recurrence and metastasis, which could be further strengthened by re-education of tumor microenvironment (TME). Herein, a local and sustained drug delivery system of liquid crystal formation system (LCFS) co-loaded with doxorubicin (DOX) and resiquimod (R848) (D/R@LCFS) is reported to confer effective chemoimmunotherapy with reduced systematic toxicity. After local administration, D/R@LCFS turns tumor into in situ vaccine via DOX-triggered immunogenic cell death effect accompanied with immunostimulatory effect of R848. Meanwhile, combination treatment of D/R@LCFS facilitates the recruitment of effector CD8⁺ T cells and the polarization of myeloid-derived suppressor cells and immunosuppressive type 2-polarized macrophages to tumoricidal antigen-presenting cells, favoring antigen-specific T cell immune response and inducing more immunogenic phenotypes in tumors. The generated in situ vaccine as well as reshaped TME by D/R@LCFS elicited systematic immune response and long term immune-memory effect in combination with immune checkpoint blockade to significantly prevent postoperative B16F10 or 4T1 tumor recurrence and metastasis. Therefore, this combination strategy of spatiotemporal TME modulation is expected to provide a clinical available option for effective postoperative chemoimmunotherapy.

Abdominal lymph node recurrence from colorectal cancer: Resection should be considered as a curative treatment in patients with controlled disease

BACKGROUND

Lymph node recurrences (LNR) from colorectal cancer (CRC) still represent a therapeutic challenge, as standardized recommendations have yet to be established. The aim of this study was to analyze short- and long-term oncological outcomes following resection of LNR from CRC.

METHODS

All patients with previously resected CRC who underwent histopathologically confirmed LNR resection in 3 tertiary referral centers between 2010 and 2017 were reviewed. Short- and long-term outcomes were analyzed, mainly recurrence-free and overall survival. Further recurrences following LNR resection were also analyzed.

RESULTS

Overall, 18 patients were included. Primary CRC was left-sided in 16 (89%) patients, staged T3-4 in 15 (83%), N+ in 14 (78%) and presented with synchronous metastases in 8 (43%). Median time interval between primary CRC and LNR resections was 31 months. Performed lymphadenectomies were aortocaval (n = 10), pelvic (n = 7), in hepatic pedicle (n = 3) and mesenteric (n = 1). Four patients had associated liver metastases resection. Three (17%) presented with postoperative complications, of which one Clavien-Dindo 3. Fourteen (78%) patients presented with further recurrences after a mean delay of 9 months, with 36% of patients presenting with early (<6 months) recurrence. Five (36%) patients could undergo secondary recurrence resection and 3 (21%) patients radiotherapy. Median overall survival following LNR resection reached 44 months.

CONCLUSIONS

Current results suggest that LNR resection is feasible and associated with improved survival, in selected patients. Longer time interval between primary CRC resection and LNR occurrence appeared to be a favorable prognostic factor whereas multisite recurrence appeared to be associated with impaired long-term survival.

Long-term Oncologic Outcomes of Laparoscopic Anterior Resections for Cancer with Natural Orifice Versus Conventional Specimen Extraction: A Case-Control Study

BACKGROUND

Although the short-term advantages of natural orifice specimen extraction are widely recognized, controversy exists concerning oncologic safety after laparoscopic surgery for colorectal cancer.

OBJECTIVE

This study aimed to investigate the impact of natural orifice specimen extraction on local recurrence and long-term survival of patients undergoing colorectal cancer surgery.

DESIGN

This is a propensity score-matched comparative study.

SETTING

This study presents a single-center experience.

PATIENTS

We retrospectively analyzed the records of patients who underwent curative laparoscopic anterior resection for American Joint Committee on Cancer stage I to III sigmoid or upper rectal cancer in 2011 to 2014, based on prospectively collected data.

INTERVENTIONS

Oncologic outcomes were compared between patients undergoing natural orifice or conventional specimen extraction by minilaparotomy. Patients were matched 1:1 according to propensity scores calculated by logistic regression analysis with the following covariates: American Joint Committee on Cancer stage, tumor diameter, age, sex, BMI, and T stage. Cox proportional hazards regression analysis was performed to determine the impact on oncologic outcome.

MAIN OUTCOME MEASURES

The primary outcomes measured were local recurrence and disease-free survival rates at 5 years.

RESULTS

Of 392 eligible patients, 188 were matched (94 undergoing natural orifice specimen extraction and 94 undergoing conventional extraction by minilaparotomy). Median follow-up was 50.3 months. The cumulative local recurrence risk at 5 years was 2.3% and 3.5% (p = 0.632), whereas 5-year disease-free survival for all tumor stages combined was 87.3% and 82.0% (p = 0.383) in laparoscopic anterior resection with natural orifice specimen extraction and conventional extraction groups. T3 and T4 stages were the only variables independently associated with disease-free survival.

LIMITATIONS

This study was limited because it focused on a single center, was a retrospective analysis, contained no long-term anorectal function testing, and had a small sample size.

CONCLUSION

Long-term oncologic outcomes of patients undergoing laparoscopic anterior resection with natural orifice specimen extraction for sigmoid and upper rectal cancer do not differ from those undergoing conventional extraction. Thus, natural orifice specimen extraction could be a viable alternative to reduce abdominal wall insult in laparoscopic colorectal operations for malignancy in selected patients. See Video Abstract at http://links.lww.com/DCR/B241. RESULTADOS ONCOLÓGICOS A LARGO PLAZO DE RESECCIONES ANTERIORES LAPAROSCÓPICAS PARA CÁNCER A TRAVÉS DE ORIFICIO NATURAL FRENTE A EXTRACCIÓN CONVENCIONAL DEL ESPÉCIMEN: UN ESTUDIO DE CASOS Y CONTROLES: Si bien las ventajas a corto plazo de la extracción de especímenes por orificio natural son ampliamente reconocidas, existe controversia con respecto a la seguridad oncológica después de la cirugía laparoscópica para el cáncer colorrectal.Investigar el impacto de la extracción de especímenes por orificio natural en la recurrencia local y la supervivencia a largo plazo de pacientes sometidos a cirugía de cáncer colorrectal.Estudio comparativo con emparejamiento por puntuación de propensión.Experiencia en un centro único.Analizamos retrospectivamente los registros de pacientes que se sometieron a resección anterior laparoscópica curativa para cáncer sigmoideo o rectal superior AJCC en estadio I-III en 2011-2014, con base en datos recolectados prospectivamente.Los resultados oncológicos se compararon entre pacientes sometidos a extracción por orificio natural o convencional mediante minilaparotomía de especímenes. Los pacientes fueron emparejados 1:1 de acuerdo con los puntajes de propensión calculados por análisis de regresión logística con las siguientes covariables: estadio AJCC, diámetro del tumor, edad, sexo, índice de masa corporal y estadio T. Se realizó un análisis de regresión de riesgos proporcionales de Cox para determinar el impacto en el resultado oncológico.Recurrencia local y tasas de supervivencia libre de enfermedad a los 5 años.De 392 pacientes elegibles, 188 fueron emparejados (94 sometidos a extracción de espécimen por orificio natural y 94 a extracción convencional por minilaparotomía). La mediana de seguimiento fue de 50.3 meses. El riesgo cumulativo de recurrencia local a 5 años fue de 2.3% y 3.5% (p = 0.632), mientras que la supervivencia libre de enfermedad a 5 años para todas las etapas tumorales combinadas fue de 87.3% y 82.0% (p = 0.383) en los grupos de resección anterior laparoscópica con extracción de espécimen por orificio natural y extracción convencional, respectivamente. Las etapas T3 y T4 fueron las únicas variables asociadas independientemente con la supervivencia libre de enfermedad.Centro único, análisis retrospectivo, ausencia de pruebas de función anorrectal a largo plazo y tamaño de muestra pequeño.Los resultados oncológicos a largo plazo de los pacientes sometidos a resección anterior laparoscópica con extracción de espécimen por orificio natural para cáncer sigmoideo y rectal superior no difieren de los de aquellos sometidos a extracción convencional. Por lo tanto, la extracción de especímenes por orificio natural podría ser una alternativa viable para reducir el insulto a la pared abdominal en operaciones colorrectales laparoscópicas por malignidad en pacientes selectos. Consulte Video Resumen en http://links.lww.com/DCR/B241.

Early recurrence after neoadjuvant chemoradiation therapy for locally advanced rectal cancer: Characteristics and risk factors

BACKGROUND/OBJECTIVE

Some locally advanced rectal cancer (LARC) patients treated with neoadjuvant chemoradiotherapy (CRT) prior to total mesorectal excision (TME) show early recurrence with a short disease-free interval. This is unacceptable for patients and their families, necessitating re-evaluation of the treatment process. We aimed to evaluate the risk factors and prognostic impact of early recurrence in patients who received preoperative CRT (pCRT) followed by TME for LARC.

METHODS

Of 714 patients who underwent curative resection after pCRT for LARC from January 2010 to December 2016, we included 139 who developed recurrence after resection. Patients were divided into an early recurrence group, diagnosed <12 months after primary surgery, and a late recurrence group, diagnosed ≥12 months after primary surgery.

RESULTS

Forty-nine patients experienced early recurrence and 90 experienced late recurrence. Multivariate analysis revealed that tumor regression grade (hazard ratio [HR] 2.962, 95% confidence interval [CI] 1.434-6.119, P = 0.003) and positive ypN stage (HR 2.110, 95% CI 1.144-3.892, P = 0.017) correlated with early recurrence. The 5-year overall survival rates for early and late recurrences were not significantly different (P = 0.121).

CONCLUSION

In patients with early recurrence after pCRT followed by TME, tumor regression grade and ypN stage positivity were independent predictors of the early recurrence.

Clinical study of colorectal cancer operation: Survival analysis

Purpose

Overall 5-year survival rates for colon and rectal cancer reported recently by the American Cancer Society were 89%, 90% for localized disease, 71%, 71% for regional disease, and 14%, 15% for distant disease. But the results of survival rate of colorectal cancer in a single institution were very rare. The aim of this study is to evaluate surgical results and survival rates of colorectal cancer.

Methods

We conducted a retrospective study with patients who underwent curative resection for a primary colorectal adenocarcinoma between 2009 and 2018.

Results

Five-year overall and disease-free survival were 79.5% and 69.9%, respectively. The overall 5-year survival by stages was 94.7% in stage I, 88.4% in stage II, 74.3% in stage III and 31.5% in stage IV. Five-year disease-free survival was 91% in stage I, 79.8% in stage II, 63.3% in stage III, and 18.9% in stage IV. The overall 5-year survival in rectal cancer was superior to colon cancer (P=0.014) while there was no difference in 5-year disease-free survival (P=0.338). Overall survival in female patients was better than male patient (P=0.029). Overall survival by age was worst in group of less than 40 years old (62.5%), and best in group between 41 and 65 years old (86.5%). Postoperative mortality within 30 days was 0.4%, and the recurrence rate was 19.2%.

Conclusion

With the development of surgical skills and various treatments, postoperative outcome of colorectal cancer is expected to improve. It may be helpful for surgeons to improve their surgical outcomes when they review their data and conduct active researches.

A Comprehensive Repertoire of Transfer RNA-Derived Fragments and Their Regulatory Networks in Colorectal Cancer

To provide systematic insight into the composition and expression of transfer RNA (tRNA) derivatives transcriptome in colorectal cancer (CRC). tRNA derivatives expression profiles in three pairs of CRC and adjacent normal colon tissues were performed by tRNA-derived small RNA fragments (tRFs) and tRNA halves (tiRNA) sequencing, and microarray data of transcriptomes from CRC and paired controls were retrieved from Gene Expression Omnibus database. The differentially expressed tRFs and tiRNAs and differentially expressed genes between CRC and paired normal samples were screened. The functional regulations between tRF and tiRNA and gene were identified. A total of 60 upregulated and 48 downregulated tRNA derivatives and 7373 upregulated and 12,138 downregulated messenger RNA (mRNA) were identified. The tRF and tiRNA-gene regulatory modules were constructed by analyzing computational tRF and tiRNA-target predictions and inverse expression relationships between tRF and tiRNAs and mRNA. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway annotation showed that the function of targets of tiRNA-Tyr-GTA was mainly enriched in negative regulation of epithelial cell apoptotic process and peroxisome proliferator activated-receptors (PPAR) signaling pathway. Cellular response to monoamine stimulus and inflammatory bowel disease was enriched in function of tiRNA-Val-CAC. Two functions, including negative regulation of c-Jun N-terminal kinase (JNK) cascade and choline metabolism in cancer, were enriched in tRF-Gln-CTG. The function of mesenchymal to epithelial transition was enriched in tRF-Leu-TAG. For the first time to our knowledge, our study provided a landscape of tRNA derivatives expression profiles in CRC. Further tRF and tiRNA-gene regulatory modules construction explored the potential functions related to these tRNA derivatives in the pathogenesis of CRC.

Humanized Anti-Tumor-Associated Glycoprotein-72 for Submillimeter Near-Infrared Detection of Colon Cancer in Metastatic Mouse Models

BACKGROUND

Tumor-associated glycoprotein (TAG)-72 is a pancarcinoma antigen that is overexpressed in greater than 80% of colorectal adenocarcinomas. CC49 is a TAG-72-specific antibody. The aim of the present study was to demonstrate selective imaging of colon tumors and metastases with the humanized TAG-72 antibody (anti-huCC49) conjugated to a near-infrared fluorophore in orthotopic mouse models.

METHODS

Anti-huCC49 was conjugated to near-infrared dye IR800CW. Mouse imaging was performed with the Pearl Trilogy Small Animal and FLARE Imaging Systems. Subcutaneous mouse models of colon cancer cell line LS174T were used to determine the optimal dose of administration and timing of imaging. Orthotopic mouse models of LS174T were established by surgical orthotopic implantation of LS174T tumors onto the serosa of the cecum. Peritoneal carcinomatosis models were established by injection of LS174T cells into the peritoneum of nude mice. Mice were administered anti-huCC49-IR800 via tail vein injection. Mice were euthanized 72 h later and imaged after laparotomy.

RESULTS

Subcutaneous LS174T xenografts demonstrated optimal tumor detection 72 h after administration with 50 μg anti-huCC49-IR800CW. Tumors were visualized with fluorescence imaging with a mean tumor-to-liver ratio of 7.39 (standard deviation: 2.76). In the orthotopic model, metastases smaller than 1 mm were fluorescently visualized that were invisible with bright light.

CONCLUSIONS

Anti-huCC49-IR800CW provides sensitive and specific imaging of colon cancer and metastases at a submillimeter resolution in metastatic nude mice models. This provides a promising near-infrared probe for the imaging of colon cancer and metastases for preoperative diagnosis and fluorescence-guided surgery.

Application of the Adaptive Validation Substudy Design to Colorectal Cancer Recurrence

Background

Among men and women diagnosed with colorectal cancer (CRC), 20-50% will develop a cancer recurrence. Cancer recurrences are not routinely captured by most population-based registries; however, linkage across Danish registries allows for the development of predictive models to detect recurrence. Successful application of such models in population-based settings requires validation against a gold standard to ensure the accuracy of recurrence identification.

Objective

We apply a recently developed validation study design for prospectively collected validation data to validate predicted CRC recurrences against gold standard diagnoses from medical records in an actively followed cohort of CRC patients in Denmark.

Methods

We use a Bayesian monitoring framework, traditionally used in clinical trials, to iteratively update classification parameters (positive and negative predictive values, and sensitivity and specificity) in an adaptive validation substudy design. This design allows determination of the sample size necessary to estimate the corresponding parameters and to identify when validation efforts can cease based on predefined criteria for parameter values and levels of precision.

Results

Among 355 men and women diagnosed with CRC in Denmark and actively followed semi-annually, there were 63 recurrences diagnosed by active follow-up and 70 recurrences identified by a predictive algorithm. The adaptive validation design met stopping criteria for the classification parameters after 120 patients had their recurrence information validated. This stopping point yielded parameter estimates for the classification parameters similar to those obtained when the entire cohort was validated, with 66% less patients needed for the validation study.

Conclusion

In this proof of concept application of the adaptive validation study design for outcome misclassification, we demonstrated the ability of the method to accurately determine when sufficient validation data have been collected. This method serves as a novel validation substudy design for prospectively collected data with simultaneous implementation of a validation study.

Plasma Lysyl-tRNA Synthetase 1 (KARS1) as a Novel Diagnostic and Monitoring Biomarker for Colorectal Cancer

Colorectal cancer (CRC) is one of the leading causes of world cancer deaths. To improve the survival rate of CRC, diagnosis and post-operative monitoring is necessary. Currently, biomarkers are used for CRC diagnosis and prognosis. However, these biomarkers have limitations of specificity and sensitivity. Levels of plasma lysyl-tRNA synthetase (KARS1), which was reported to be secreted from colon cancer cells by stimuli, along with other secreted aminoacyl-tRNA synthetases (ARSs), were analyzed in CRC and compared with the currently used biomarkers. The KARS1 levels of CRC patients (n = 164) plasma were shown to be higher than those of healthy volunteers (n = 32). The diagnostic values of plasma KARS1 were also evaluated by receiving operating characteristic (ROC) curve. Compared with other biomarkers and ARSs, KARS1 showed the best diagnostic value for CRC. The cancer specificity and burden correlation of plasma KARS1 level were validated using azoxymethane (AOM)/dextran sodium sulfate (DSS) model, and paired pre- and post-surgery CRC patient plasma. In the AOM/DSS model, the plasma level of KARS1 showed high correlation with number of polyps, but not for inflammation. Using paired pre- and post-surgery CRC plasma samples (n = 60), the plasma level of KARS1 was significantly decreased in post-surgery samples. Based on these evidence, KARS1, a surrogate biomarker reflecting CRC burden, can be used as a novel diagnostic and post-operative monitoring biomarker for CRC.

The Two Faces of Tumor-Associated Macrophages and Their Clinical Significance in Colorectal Cancer

Macrophages are one of the immune populations frequently found in colorectal tumors and high macrophage infiltration has been associated with both better and worst prognosis. Importantly, according to microenvironment stimuli, macrophages may adopt different polarization profiles, specifically the pro-inflammatory or M1 and the anti-inflammatory or M2, which display distinct functions. Therefore, concomitantly with the number of tumor-associated macrophages (TAMs), their characterization is fundamental to unravel their relevance in cancer. Here, we profiled macrophages in a series of 150 colorectal cancer (CRC) cases by immunohistochemistry, using CD68 as a macrophage lineage marker, CD80 as a marker of pro-inflammatory macrophages, and CD163 as a marker of anti-inflammatory macrophages. Quantifications were performed by computer-assisted analysis in the intratumoral region, tumor invasive front, and matched tumor adjacent normal mucosa (ANM). Macrophages, specifically the CD163+ ones, were predominantly found at the tumor invasive front, whereas CD80+ macrophages were almost exclusively located in the ANM, which suggests a predominant anti-inflammatory polarization of TAMs. Stratification according to tumor stage revealed that macrophages, specifically the CD163+ ones, are more prevalent in stage II tumors, whereas CD80+ macrophages are predominant in less invasive T1 tumors. Specifically in stage III tumors, higher CD68, and lower CD80/CD163 ratio associated with decreased overall survival. Importantly, despite the low infiltration of CD80+ cells in colorectal tumors, multivariate logistic regression revealed a protective role of these cells regarding the risk for relapse. Overall, this work supports the involvement of distinct microenvironments, present at the intra-tumor, invasive front and ANM regions, on macrophage modulation, and uncovers their prognostic value, further supporting the relevance of including macrophage profiling in clinical settings.

Antrodia cinnamomea Enhances Chemo-Sensitivity of 5-FU and Suppresses Colon Tumorigenesis and Cancer Stemness via Up-Regulation of Tumor Suppressor miR-142-3p

5-Fluorouracil (5-FU) regimen remains the backbone of the first-line agent to treat colon cancer, but often these patients develop resistance. Cancer stem cells (CSC's) are considered as one of the key contributors in the development of drug resistance and tumor recurrence. We aimed to provide preclinical evidence for Antrodia cinnamomea (AC), as a potential in suppressing colon cancer CSC's to overcome 5-FU drug-resistant. In-vitro assays including cell viability, colony formation, AC + 5-FU drug combination index and tumor sphere generation were applied to determine the inhibitory effect of AC. Mouse xenograft models also incorporated to evaluate in vivo effect of AC. AC treatment significantly inhibited the proliferation, colony formation and tumor sphere generation. AC also inhibited the expression of oncogenic markers (NF-κB, and C-myc), EMT/metastasis markers (vimentin and MMP3) and stemness associated markers (β-catenin, SOX-2 and Nanog). Sequential treatment of AC and 5-FU synergized and reduces colon cancer viability both in vivo and in vitro. Mechanistically, AC mediated anti-tumor effect was associated with an increased level of tumor suppressor microRNAs especially, miR142-3p. AC can be a potent synergistic adjuvant, down-regulates cancer stemness genes and enhances the antitumor ability of 5-FU by stimulating apoptosis-associated genes, suppressing inflammation and metastasis genes through miR142-3p in colon cancer.

Role of MRI and added value of diffusion-weighted and gadolinium-enhanced MRI for the diagnosis of local recurrence from rectal cancer

PURPOSE

To evaluate whether the addition of gadolinium-enhanced MRI and diffusion-weighted imaging (DWI) improves T2 sequence performance for the diagnosis of local recurrence (LR) from rectal cancer and to assess which approach is better at formulating this diagnosis among readers with different experience.

METHODS

Forty-three patients with suspected LR underwent pelvic MRI with T2 weighted (T2) sequences, gadolinium fat-suppressed T1 weighted sequences (post-contrast T1), and DWI sequences. Three readers (expert: G, intermediate: E, resident: V) scored the likelihood of LR on T2, T2 + post-contrast T1, T2 + DWI, and T2 + post-contrast T1 + DWI.

RESULTS

In total, 18/43 patients had LR; on T2 images, the expert reader achieved an area under the ROC curve (AUC) of 0.916, sensitivity of 88.9%, and specificity of 76%; the intermediate reader achieved values of 0.890, 88.9%, and 48%, respectively, and the resident achieved values of 0.852, 88.9%, and 48%, respectively. DWI significantly improved the AUC value for the expert radiologist by up to 0.999 (p = 0.04), while post-contrast T1 significantly improved the AUC for the resident by up to 0.950 (p = 0.04). For the intermediate reader, both the T2 + DWI AUC and T2 + post-contrast T1 AUC were better than the T2 AUC (0.976 and 0.980, respectively), but with no statistically significant difference. No statistically significant difference was achieved by any of the three readers by comparing either the T2 + DWI AUCs to the T2 + post-contrast T1 AUCs or the AUCs of the two pairs of sequences to those of the combined three sequences. Furthermore, using the T2 sequences alone, all of the readers achieved a fair number of "equivocal" cases: they decreased with the addition of either DWI or post-contrast T1 sequences and, for the two less experienced readers, they decreased even more with the three combined sequences.

CONCLUSIONS

Both DWI and T1 post-contrast MRI increased diagnostic performance for LR diagnosis compared to T2; however, no significant difference was observed by comparing the two different pairs of sequences with the three combined sequences.

Comparison of the diagnostic efficiency for local recurrence of rectal cancer using CT, MRI, PET and PET-CT: A systematic review protocol

BACKGROUND

The risk of local recurrence (LR) continues to threat patients with rectal cancer after surgery or chemoradiotherapy. The main reason is that there is frequently extensive scarring and reactive changes after radiotherapy and resection. Thus, the diagnosis of LR can be challenging. There are different imaging modalities that have been used in the follow-up of rectal cancer, including computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and positron emission tomography-computed tomography (PET-CT) in clinical practice.

METHODS

We will systematically search PubMed, EMBASE, the Cochrane Library, and Chinese Biomedical Literature Database for diagnostic trials using CT, MRI, PET, and PET-CT to detect LR of rectal cancer in April, 2018. Two review authors will independently screen titles and abstracts for relevance, assess full texts for inclusion, and carry out data extraction and methodological quality assessment using the QUADAS-2 tool. We will use bivariate meta-analysis to estimate summary sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio of CT, MRI, PET, and PET-CT, as well as different sequences of MRI. For each index test, estimates of sensitivity and specificity from each study will be plotted in summary receive operating curve space and forest plots will be constructed for visual examination of variation in test accuracy. We will perform meta-analyses using the hierarchical summary receiver-operating characteristic model to produce summary estimates of sensitivity and specificity. Then, head-to-head and indirect comparison meta-analyses will be carried out.

DISCUSSION

This review will help determine the diagnostic accuracy of CT, MRI, PET, and PET-CT for the diagnosis of patients with LR of rectal cancer.

ETHICS AND DISSEMINATION

Ethics approval and patient consent are not required, as this study is a systematic review.

PROSPERO REGISTRATION NUMBER

CRD42018104918.

Oncologic outcome and recurrence rate following anastomotic leakage after curative resection for colorectal cancer

INTRODUCTION

Anastomotic leakage is one of the most severe early complications after colorectal surgery, and it is associated with a high reoperation rate-, and increased in short-term morbidity and mortality rates. It remains unclear whether anastomotic leakage is associated with poor oncologic outcomes. The aim of this study was to determine the impacts of anastomotic leakage on long-term oncologic outcomes, disease-free survival and overall mortality in patients who underwent curative surgery for colorectal cancer.

METHODS

This single-centre, retrospective, observational cohort study included patients who underwent curative surgery for colorectal cancer between 2005 and 2015 and who had a primary anastomosis. Survival- and multivariate cox regression analyses were performed to adjust for confounding.

RESULTS

A total of 1984 patients had a primary anastomosis after surgery. The overall incidence of anastomotic leakage was 7.5%; 19 patients were excluded because they were lost to follow-up. Of the remaining 1965 patients, 41 (2.1%) developed local recurrence associated with anastomotic leakage [adjusted hazard ratio (HR) = 2.25; 95% confidence interval (CI) 1.14-5.29; P = 0.03]. Distant recurrence developed in 291(14.8%) patients with no association with anastomotic leakage [adjusted HR = 1.30 (95% CI: 0.85-1.97) P = 0.23]. Anastomotic leakage was associated with increased long-term mortality [adjusted HR = 1.69 (95% CI 1.32-2.18) P < 0.01]. Five year disease-free survival was significantly decreased in patients with anastomotic leakage, (log rank test P < 0.01).

CONCLUSION

Anastomotic leakage was significantly associated with increased rates of local recurrence, disease free-survival and overall mortality. Associations of anastomotic leakage with distant recurrence was not found.

Implantable Synthetic Immune Niche for Spatiotemporal Modulation of Tumor-Derived Immunosuppression and Systemic Antitumor Immunity: Postoperative Immunotherapy

The development of biomaterial-based immune niches that can modulate immunosuppressive factors in tumor microenvironment (TME) will be a key technology for improving current cancer immunotherapy. Here, implantable, engineered 3D porous scaffolds are designed to generate synergistic action between myeloid-derived suppressor cell (MDSC)-depleting agents, which can accommodate the establishment of a permissive immunogenic microenvironment to counteract tumor-induced immunosuppression, and cancer vaccines consisting of whole tumor lysates and nanogel-based adjuvants, which can generate tumor antigen-specific T cell responses. The local peritumoral implantation of the synthetic immune niche (termed immuneCare-DISC, iCD) as a postsurgical treatment in an advanced-stage primary 4T1 breast tumor model generates systemic antitumor immunity and prevents tumor recurrence at the surgical site as well as the migration of residual tumor cells into the lungs, resulting in 100% survival. These therapeutic outcomes are achieved through the inhibition of immunosuppressive MDSCs in tumors and spleens by releasing gemcitabine and recruitment/activation of dendritic cells, enhanced population of CD4⁺ and CD8⁺ T cells, and increased IFN-γ production by cancer vaccines from the iCD. This combined spatiotemporal modulation of tumor-derived immunosuppression and vaccine-induced immune stimulation through the iCD is expected to provide an immune niche for prevention of postoperative tumor recurrence and metastasis.

Precision Medicine for CRC Patients in the Veteran Population: State-of-the-Art, Challenges and Research Directions

Colorectal cancer (CRC) accounts for ~9% of all cancers in the Veteran population, a fact which has focused a great deal of the attention of the VA's research and development efforts. A field-based meeting of CRC experts was convened to discuss both challenges and opportunities in precision medicine for CRC. This group, designated as the VA Colorectal Cancer Cell-genomics Consortium (VA4C), discussed advances in CRC biology, biomarkers, and imaging for early detection and prevention. There was also a discussion of precision treatment involving fluorescence-guided surgery, targeted chemotherapies and immunotherapies, and personalized cancer treatment approaches. The overarching goal was to identify modalities that might ultimately lead to personalized cancer diagnosis and treatment. This review summarizes the findings of this VA field-based meeting, in which much of the current knowledge on CRC prescreening and treatment was discussed. It was concluded that there is a need and an opportunity to identify new targets for both the prevention of CRC and the development of effective therapies for advanced disease. Also, developing methods integrating genomic testing with tumoroid-based clinical drug response might lead to more accurate diagnosis and prognostication and more effective personalized treatment of CRC.

Local recurrences at the anastomotic area are clonally related to the primary tumor in sporadic colorectal carcinoma

PURPOSE

Anastomotic recurrences (AR) occur in 2-10% of colorectal carcinoma cases after resection of primary tumor (PT). Currently, there are no molecular data investigating their genetic profile and multiple theories exist about their pathogenesis. The aim of our study was to compare the genomic profile of AR to that of the patients' corresponding matched PT and, when available, to a distant metastasis (DM).

EXPERIMENTAL DESIGN

Thirty-six tumors from 14 patients were genotyped using a capture-based, next-generation assay to define the mutational status of 341 cancer-associated genes. All patients had R0 resection of their PT and AR occurred 1.1-7.0 years following PT resection. A DM or a second AR was analyzed in 8 patients. All tumors were microsatellite stable except in one patient with Lynch syndrome.

RESULTS

A total of 254 somatic mutations were detected including 138 mutations in the microsatellite stable (MSS) cases. The most commonly mutated genes were APC, KRAS, TP53, PIK3CA, ATM and PIK3R1. In all patients with MSS tumors the AR and PT shared between 50-100% of mutations, including mutations in key driver genes, consistent with these tumors being clonally related. Genetic events private to DM were not detected in AR and phylogenetic analysis showed that ARs were more closely related to PT than DM. In the Lynch syndrome patient the PT and AR showed distinct somatic mutations consistent with independent primaries.

CONCLUSIONS

ARs are clonally related to PT in sporadic colorectal carcinomas and do not appear to represent seeding of the anastomotic site by distant metastases.

Local recurrence after five years is associated with preoperative chemoradiotherapy treatment in patients diagnosed with stage II and III rectal cancer

AIM

To asses the moment of local recurrence and its influence on the appraisal of the results of neoadjuvant chemoradiotherapy (CRT).

METHODS

We evaluated 317 patients with a preoperative diagnosis of stage II or III rectal cancer who underwent rectal resection. Gender, age, neoadjuvant treatment, circumferencial resection margin, adjuvant treatment, pretreatment carcinoembryonic antigen level, tumor location, TNM stage, lymph node retrieval, abdominoperineal resection, and lymphatic or vascular infiltration were registered prospectively. Follow-up was performed to detect local or systemic recurrences. Timing of local recurrence (LR) in regard to analyzed variables was performed by using analysis of variance. To evaluate the influence of late local recurrence (LLR) on the results of neoadjuvant CRT, we performed a log-rank test censoring all observations at 60 and at 120 months.

RESULTS

After a mean follow-up of 73.6 months (range, 1-171), 68 patients developed a recurrence. Twenty-three patients developed LRs (6.9%), and 5 developed LLRs. The earliest relapse was diagnosed 4 months after rectal surgery, and the latest was diagnosed 120 months after surgery. Patients who underwent neoadjuvant CRT developed LR significantly later than patients without neoadjuvant CRT (51.8 vs 13.5 months; P = 0.002). LR rates in patients who underwent preoperative CRT and those who did not were 9.2% and 3.5% (difference, 5.7%), respectively, after censoring all observations at 60 months and 9.2% and 6.1% (difference, 3.1%) after censoring all observations at 120 months.

CONCLUSION

Local recurrence was diagnosed significantly later in patients treated with neoadjuvant CRT. Follow-up longer than 5 years is needed to evaluate definitive results in patients treated with neoadjuvant CRT.

Does circumferential tumor location affect the circumferential resection margin status in mid and low rectal cancer?

BACKGROUND/OBJECTIVE

The purpose of this study was to assess the impact of circumferential tumor location on circumferential resection margin (CRM) status and the depth of tumor invasion in mid and low rectal cancer.

METHODS

We retrospectively analyzed whole-mount slides of 58 patients who underwent total mesorectal excision for mid and low rectal cancer. The rate of tumor-positive CRM was compared according to the circumferential tumor location. In 31 patients, morphometric analyses of whole-mount specimens were performed to measure the depth of tumor invasion according to circumferential tumor location.

RESULTS

Among 58 patients, 50% of tumors were anterior tumor and 50% were nonanterior. A tumor-positive CRM was more observed frequently in anterior tumors than in nonanterior tumors (41.1% vs. 10.3%, p = 0.007). In a multivariate analysis, anterior tumor was the only independent risk factor for a positive CRM (odds ratio 4.725, 95% confidence interval 1.102-20.261, p = 0.037). In a morphometric analysis of 31 patients, the depth of tumor invasion from the muscularis mucosa was greater (11.9 mm vs. 6.6 mm, p = 0.028) in those with anterior tumors.

CONCLUSION

Anterior tumors are associated with a higher risk of tumor-positive CRM and tend to exhibit deeper invasion in mid and low rectal cancer.

Low acyl-CoA synthetase 5 expression in colorectal carcinomas is prognostic for early tumour recurrence

It has been shown that the metabolism of long chain fatty acids is involved in colorectal carcinogenesis. Acyl-CoA synthetases (ACSL) activate free fatty acids by synthesis of acyl-CoA thioesters. ACSL isoform 5 (ACSL5) is involved in enterocytic differentiation and maturation by regulating both pro-apoptotic and anti-proliferative effects. Whilst impaired expression of ACSL5 has been associated with sporadic colorectal carcinogenesis, little is known about ACSL5 as a prognostic factor. Aim of this retrospective study was to characterize the prognostic impact of ACSL5 expression levels in sporadic colorectal adenocarcinomas. A total of 72 patients with a median follow-up of 54 months was included. Using a standardized immunohistochemical approach, colorectal adenocarcinomas with low (n=41; group 1) or high (n=31; group 2) ACSL5 levels were identified. In a one-year follow-up, tumour recurrence was significantly increased in group 1 (p=0.0279). The finding was independent of the TNM- and UICC-stage in the surgical resections. Frequency of lymph node metastasis and mortality was not different between the groups. In a long-time follow-up no differences were found between the ACSL5 groups. The data indicate that ACSL5 could be an independent prognostic factor for early recurrence of sporadic colorectal adenocarcinoma.

Work Loss Duration and Predictors Following Rectal Cancer Treatment among Patients with and without Prediagnostic Work Loss

BACKGROUND

The number of working-age rectal cancer survivors is increasing due to early detection and improved treatment. However, work loss duration and predictors among them have not been studied thoroughly.

METHODS

We identified 3,438 patients with stage I-III rectal cancer, 18 to 61 years of age in the Swedish Colorectal Cancer Register 1996-2009. Information on work loss due to sick leave or disability pension was collected from 2 years before diagnosis to 5 years after (until December 31st, 2013). Incidence rate ratios (IRR) of work loss were estimated in a negative binominal model by clinical characteristics for the 1st and 2nd-5th years after diagnosis. Patients were stratified by prediagnostic work loss.

RESULTS

Patients without prediagnostic work loss (74%) experienced median 147 days (25th and 75th percentile: 55 and 281) of work loss during the 1st year after diagnosis. Work loss rates (2nd-5th years) were significantly increased among relapse-free patients diagnosed in stage III [IRR = 1.92; 95% confidence interval (CI), 1.52-2.43], operated with abdominoperineal resection (IRR = 1.26; 95% CI, 1.03-1.56), and treated with neoadjuvant (chemo)radiotherapy (IRR = 1.46; 95% CI, 1.06-2.02). Patients with prediagnostic work loss (26%) experienced median 336 days (25th and 75th percentile: 183 and 365) of work loss during the 1st year, and rates did not vary clinically till 5 years.

CONCLUSION

Without prediagnostic work loss, disease- and treatment-related factors could help identify rectal cancer patients in need of early interventions to facilitate return to work.

IMPACT

Clinical awareness around prediagnostic and postdiagnostic work loss and individualized cancer rehabilitation programs should be emphasized among cancer survivors. Cancer Epidemiol Biomarkers Prev; 25(6); 987-94. ©2016 AACR.

Anastomotic Leaks After Restorative Resections for Rectal Cancer Compromise Cancer Outcomes and Survival

BACKGROUND

Anastomotic leaks after restorative resections for rectal cancer may lead to worse long-term outcomes.

OBJECTIVE

The purpose of this study was to evaluate the best current evidence assessing anastomotic leaks in rectal cancer resections with curative intent and their impact on survival and cancer recurrence.

DATA SOURCES

A meta-analysis was performed using MEDLINE, EMBASE, and Cochrane search engines for relevant studies published between January 1982 and January 2015.

STUDY SELECTION

Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology was used to screen and select relevant studies for the review using key words "colorectal surgery; colorectal neoplasm; rectal neoplasm" and "anastomotic leak."

INTERVENTION

Anastomotic leak groups were compared with nonanastomotic leak groups.

MAIN OUTCOME MEASURES

ORs were calculated from binary data for local recurrence, distant recurrence, and cancer-specific mortality. A random-effects model was then used to calculate pooled ORs with 95% CIs.

RESULTS

Eleven studies with 13,655 patients met the inclusion criteria. This included 5 prospective cohort and 6 retrospective cohort studies. Median follow-up was 60 months. Higher cancer-specific mortality was noted in the leak group with an OR of 1.30 (95% CI, 1.04-1.62; p < 0.05). Local recurrences were more likely in rectal cancer resections complicated by anastomotic leaks (OR = 1.61 (95% CI, 1.25-2.09); p < 0.001). Distant recurrence was not more likely in the anastomotic leak group (OR = 1.07 (95% CI, 0.87-1.33); p = 0.52).

LIMITATIONS

All 11 studies are level 3 evidence cohort studies. Additional sensitivity analyses were performed to minimize cross-study heterogeneity.

CONCLUSIONS

Anastomotic leaks after restorative resections for rectal cancer adversely impact cancer-specific mortality and local recurrence.