A Review of Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer

Development of a Joint Prediction Model Based on Both the Radiomics and Clinical Factors for Predicting the Tumor Response to Neoadjuvant Chemoradiotherapy in Patients with Locally Advanced Rectal Cancer

Purpose

Neoadjuvant chemoradiotherapy (nCRT) has become the standard treatment for locally advanced rectal cancer (LARC). However, the accuracy of traditional clinical indicators in predicting tumor response is poor. Recently, radiomics based on magnetic resonance imaging (MRI) has been regarded as a promising noninvasive assessment method. The present study was conducted to develop a model to predict the pathological response by analyzing the quantitative features of MRI and clinical risk factors, which might predict the therapeutic effects in patients with LARC as accurately as possible before treatment.

Patients and Methods

A total of 82 patients with LARC were enrolled as the training cohort and internal validation cohort. The pre-CRT MRI after pretreatment was acquired to extract texture features, which was finally selected through the minimum redundancy maximum relevance (mRMR) algorithm. A support vector machine (SVM) was used as a classifier to classify different tumor responses. A joint radiomics model combined with clinical risk factors was then developed and evaluated by receiver operating characteristic (ROC) curves. External validation was performed with 107 patients from another center to evaluate the applicability of the model.

Results

Twenty top image texture features were extracted from 6192 extracted-radiomic features. The radiomics model based on high-spatial-resolution T2-weighted imaging (HR-T2WI) and contrast-enhanced T1-weighted imaging (T1+C) demonstrated an area under the curve (AUC) of 0.8910 (0.8114–0.9706) and 0.8938 (0.8084–0.9792), respectively. The AUC value rose to 0.9371 (0.8751–0.9997) and 0.9113 (0.8449–0.9776), respectively, when the circumferential resection margin (CRM) and carbohydrate antigen 19-9 (CA19-9) levels were incorporated. Clinical usefulness was confirmed in an external validation cohort as well (AUC, 0.6413 and 0.6818).

Conclusion

Our study indicated that the joint radiomics prediction model combined with clinical risk factors showed good predictive ability regarding the treatment response of tumors as accurately as possible before treatment.

Reduced field-of-view versus full field-of-view diffusion-weighted imaging for the evaluation of complete response to neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer

PURPOSE

To determine whether reduced field-of-view (rFOV) DWI sequences can improve image quality and diagnostic performance compared with conventional full FOV (fFOV) DWI in the prediction of complete response (CR) to neoadjuvant chemoradiotherapy (CRT) in patients with locally advanced rectal cancers.

METHODS

Between September 2015 and December 2017, seventy-three patients with locally advanced rectal cancers (≥ T3 or lymph node positive) who underwent CRT and subsequent surgery were included in this retrospective study. All patients had tumor located no more than 10 cm from the anal verge, and underwent rectal MRI including fFOV b-1000 DWI and rFOV b-1000 DWI at 3 T before and after CRT. Image quality and diagnostic performance in predicting CR were compared between rFOV DWI and fFOV DWI sets by two reviewers.

RESULTS

Based on a 12-point scale, rFOV DWI provided better image quality scores than fFOV DWI (9.1 ± 1.7 vs. 8.4 ± 1.0, respectively, P < 0.001). Diagnostic accuracy (A_z) in evaluating CR was better with the rFOV DWI set than with the fFOV DWI set for both reviewers: reviewer 1, 0.78 vs. 0.57 (P = .004); reviewer 2, 0.72 vs. 0.61 (P = .031).

CONCLUSION

rFOV DWI of rectal cancer can provide better overall image quality, and its addition to conventional rectal MRI may provide better diagnostic accuracy than fFOV DWI in the evaluation of CR to neoadjuvant CRT in patients with locally advanced rectal cancer.

The Predictive Value of Baseline Volumetric PET/CT Parameters on Treatment Response and Prognosis in Locally Advanced Rectal Cancer Treated with Neoadjuvant Chemoradiotherapy

PURPOSE

To investigate the prognostic effects of baseline volumetric PET/CT parameters including the maximum standard uptake value (SUVmax), metabolic tumor volume (MTV), and tumor lesion glycolysis (TLG) on treatment response and prognosis in locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (NACRT).

METHODS

Between 2015 and 2018, 51 patients with LARC treated with NACRT followed by surgery were included in this retrospective study. Patients were divided into 2 groups by tumor regression grade (TRG) as follows: group I = TRG 1 (no detectable cancer cells) + TRG 2 (single cells and/or small groups of cancer cells) and group II = TRG3 (residual tumor outgrown by fibrosis) + TRG 4 (remarkable fibrosis outgrown by tumor cells) + TRG 5 (no fibrosis with extensive residual cancer).

RESULTS

Of the 51 patients, 34 (66.7%) were male. The median age was 55 (range, 37-78) years. According to TRG status, 14 (27.4%) patients were in group I and 37 (72.6%) patients were in group II. The area under the curve (95% CI) was 0.749 (0.593-0.905) in the ROC curve plotted for MTV. The cut-off value for MTV was 12, with 70% sensitivity and 65% specificity. MTV was ≥ 12 in 32 (62.8%) patients. MTV and TLG values were significantly different between groups I and II, whereas there was no significant difference between the groups in terms of SUVmax values (p = 0.006, p = 0.033, and p = 0.673, respectively). The disease-free survival was not reached in patients with MTV < 12 vs. 20 months in those with MTV ≥ 12 (p = 0.323). In multivariate analysis, MTV (OR, 95% Cl, 5.00 [1.17-21.383]) was found to be the factor that affected pathological complete response.

CONCLUSION

In LARC treated with NACRT, MTV prior to treatment can help predict the response to treatment.

Molecular mechanisms of astragaloside‑IV in cancer therapy (Review)

Radix Astragali (RA) is widely used in traditional Chinese medicine (TCM), and astragaloside IV (AS-IV) is the most critical component of RA. Previous studies have demonstrated that AS-IV exerts effects on the myocardium, nervous system and endocrine system, among others. In the present review article, data from studies conducted over the past 20 years were collated, which have evaluated the effects of AS-IV on tumors. The mechanisms of action of AS-IV on malignant cells both in vivo and in vitro were summarized and it was demonstrated that AS-IV plays a vital role, particularly in inhibiting tumor growth and metastasis, promoting the apoptosis of tumor cells, enhancing immune function and preventing drug resistance. Moreover, AS-IV controls several epithelial-mesenchymal transformation (EMT)-related and autophagy-related pathways, such as the phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT), Wnt/β-catenin, mitogen-activated protein kinase (MAPK)/extracellular regulated protein kinase (ERK) and transforming growth factor-β (TGF-β)/SMAD signaling pathways, which are commonly affected in the majority of tumors. The present review provides new perspectives on the functions of AS-IV and its role as an adjuvant treatment in cancer chemotherapy.

Transanal total mesorectal excision for stage II or III rectal cancer: pattern of local recurrence in a tertiary referral center

BACKGROUND

For mid and low rectal cancer, transanal total mesorectal excision (TaTME) has been established as an alternative approach to laparoscopic surgery. However, there are concerns about an unexpected pattern of local recurrence. This study aimed to analyze the pattern of local recurrence for patients treated with TaTME in a tertiary referral center.

METHODS

A retrospective single-center analysis was performed. Since 2011, all patients with rectal cancer undergoing TaTME with curative intent were prospectively included in a standardized database. Patients with tumors within 12 cm, clinical stage II or III were included. The primary endpoint of the study was the overall local recurrence rate, together with a critical analysis of the patterns of local failures.

RESULTS

Two hundred and five patients were included in this analysis. At the time of surgery, patients had a mean age of 67.1 years (SD 12.3), and 66.8% were male. Neoadjuvant therapy was administered in 73.7%. Mesorectal specimen quality was complete or near-complete in 98.5%, while circumferential resection margin was ≤ 1 mm (including T4 tumors) in 11.8%. After a median follow-up of 34.3 months (95% CI 30.1-38.5), 3.4% (n = 7) presented with local recurrent disease. Six out of the seven patients were also diagnosed with hematogenous metastases. Of the seven patients, three presented with at least one of the following risk factors: T4 tumor, N2 disease, incomplete mesorectal specimen, or positive CRM. Local failure was noted posteriorly (n = 3), laterally (n = 2), anteriorly (n = 1), and in the axial compartment (n = 1). Median time to relapse was 31.5 months (10.3-40.9). The median follow-up after local recurrence was 7.9 (95% CI 6.7-9.1) months, with an overall survival of 85.7%.

CONCLUSIONS

TaTME provided satisfactory local recurrence outcomes, and the most common patterns of failure were in the central pelvis.

Pro-protein convertase subtilisin/kexin type 9 promotes intestinal tumor development by activating Janus kinase 2/signal transducer and activator of transcription 3/SOCS3 signaling in ApcMin/+ mice

INTRODUCTION

Pro-protein convertase subtilisin/kexin type 9 (PCSK9) regulates lipoprotein homeostasis in humans. Evolocumab is a selective PCSK9 inhibitor that can reduce low-density lipoprotein cholesterol (LDLC) level and decrease hypercholesterolemia. The current study aimed to explore whether PCSK9 increases the risk of colorectal cancer.

METHODS

First, we utilized the classic intestinal tumor ApcMin/+ mouse model and PCSK9 knock-in (KI) mice to establish ApcMin/+PCSK9(KI) mice. Then, we investigated the effect of PCSK9 overexpression in ApcMin/+PCSK9(KI) mice and PCSK9 inhibition using evolocumab on the progression of intestinal tumors in vivo by hematoxylin and eosin (HE) staining, Western blot, and immunohistochemistry (IHC) assay.

RESULTS

ApcMin/+PCSK9(KI) mice had higher numbers and larger sizes of adenomas, with 83.3% of these mice developing adenocarcinoma (vs. 16.7% of ApcMin/+ mice). However, treatment with evolocumab reduced the number and size of adenomas and prevented the development of adenocarcinomas in ApcMin/+ mice. PCSK9 overexpression reduced tumor cell apoptosis, the Bax/bcl-2 ratio, and the levels of cytokine signaling 3 protein (SOCS3) suppressors, but activated Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling in intestinal tumors. In contrast, evolocumab treatment had the opposite effect on ApcMin/+mice.

CONCLUSION

PCSK9 might act as an oncogene or have an oncogenic role in the development and progression of colorectal cancer in vivo via activation of JAK2/STAT3/SOCS3 signaling.

Differences in and Prognostic Value of Quality of Life Data in Rectal Cancer Patients with and without Distant Metastases

(1) Background: Individualization of treatment is a major challenge in oncology and requires a variety of predictive and prognostic parameters. In addition to tumor biology analyses, baseline health-related quality of life might be a valid tool to predict overall survival. This study was conducted to evaluate the prognostic relevance of baseline quality of life data in patients with rectal cancer. In this context, differences between patients with and without distant metastases were of particular interest. (2) Methods: Our cohort included 258 patients with rectal cancer treated in the radiotherapy department of the University Hospital Erlangen. Patients completed the European Organisation for Research and Treatment of Cancer (EORTC) core quality of life questionnaire (QLQ C30) and colorectal cancer questionnaire (CR38). Clinical and survival data were provided by the Gießener Tumor Documentation System (GTDS) of the Comprehensive Cancer Center Erlangen-EMN (CCC, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany). Statistical analyses were performed using Kaplan–Meier analyses and univariate and multivariate Cox regression. (3) Results: A cohort of 258 patients with rectal adenocarcinoma was analyzed including 50 patients (19.4%) with metastatic disease. No differences were observed between patients with and without distant metastases in most areas of quality of life studied, with the exception of physical function, loss of appetite, chemotherapy side effects and weight loss. Gender, baseline physical function, sexual function, diarrhea, and weight loss over time had a prognostic value in the entire cohort. Appetite loss was an additional prognostic parameter in patients with distant metastases. (4) Conclusions: The quality of life of patients with metastatic disease differed only slightly from non-metastatic patients. Health-related quality of life data provide prognostic information for patients with rectal cancer.

Targeting Acid Ceramidase to Improve the Radiosensitivity of Rectal Cancer

Previous work utilizing proteomic and immunohistochemical analyses has identified that high levels of acid ceramidase (AC) expression confers a poorer response to neoadjuvant treatment in locally advanced rectal cancer. We aimed to assess the radiosensitising effect of biological and pharmacological manipulation of AC and elucidate the underlying mechanism. AC manipulation in three colorectal cancer cell lines (HT29, HCT116 and LIM1215) was achieved using siRNA and plasmid overexpression. Carmofur and a novel small molecular inhibitor (LCL521) were used as pharmacological AC inhibitors. Using clonogenic assays, we demonstrate that an siRNA knockdown of AC enhanced X-ray radiosensitivity across all colorectal cancer cell lines compared to a non-targeting control siRNA, and conversely, AC protein overexpression increased radioresistance. Using CRISPR gene editing, we also generated AC knockout HCT116 cells that were significantly more radiosensitive compared to AC-expressing cells. Similarly, two patient-derived organoid models containing relatively low AC expression were found to be comparatively more radiosensitive than three other models containing higher levels of AC. Additionally, AC inhibition using carmofur and LCL521 in three colorectal cancer cell lines increased cellular radiosensitivity. Decreased AC protein led to significant poly-ADP ribose polymerase-1 (PARP-1) cleavage and apoptosis post-irradiation, which was shown to be executed through a p53-dependent process. Our study demonstrates that expression of AC within colorectal cancer cell lines modulates the cellular response to radiation, and particularly that AC inhibition leads to significantly enhanced radiosensitivity through an elevation in apoptosis. This work further solidifies AC as a target for improving radiotherapy treatment of locally advanced rectal cancer.

Modular Peptide Probe for Pre/Intra/Postoperative Therapeutic to Reduce Recurrence in Ovarian Cancer

Even with optimal surgery, 80% of patients with ovarian cancer will have recurrence. Adjuvant therapy can reduce the recurrence of tumors; however, the therapeutic effect is still not prominent. Herein, we designed a modular peptide probe (T_CDTMP), which can be self-assembled into nanoparticles (NPs) by loading in miR-145-5p or VEGF-siRNA. In vivo, (1) preoperative administration of T_CDTMP/miR-145-5p ensured that NPs were adequately accumulated in tumors through active targeting and increased the expression of miR-145-5p in tumors, thereby inducing tumor cell apoptosis. (2) Intraoperatively, most of the tumors were removed, while the microscopic residual tumors were largely eliminated by T_CDTMP/miR-145-5p-mediated photodynamic therapy (PDT). (3) Postoperatively, T_CDTMP/VEGF-siRNA were given for antiangiogenesis therapy, thus delaying the recurrence of tumors. This treatment was named a preoperative (T_CDTMP/miR-145-5p)||intraoperative (surgery and PDT)||postoperative (T_CDTMP/VEGF-siRNA) therapeutic system and abbreviated as the PIP therapeutic system, which reduced the recurrence of ovarian cancer in subcutaneous tumor models, intraperitoneal metastasis models, and patient-derived tumor xenograft models. Our findings provide a therapeutic system based on modular peptide probes to reduce the recurrence of ovarian cancer after surgery, which provides a perspective for the surgical management of ovarian cancer.

A Convolutional Neural Network based system for Colorectal cancer segmentation on MRI images

The aim of the study is to present a new Convolutional Neural Network (CNN) based system for the automatic segmentation of the colorectal cancer. The algorithm implemented consists of several steps: a pre-processing to normalize and highlights the tumoral area, the classification based on CNNs, and a post-processing aimed at reducing false positive elements. The classification is performed using three CNNs: each of them classifies the same regions of interest acquired from three different MR sequences. The final segmentation mask is obtained by a majority voting. Performances were evaluated using a semi-automatic segmentation revised by an experienced radiologist as reference standard. The system obtained Dice Similarity Coefficient (DSC) of 0.60, Precision (Pr) of 0.76 and Recall (Re) of 0.55 on the testing set. After applying the leave-one-out validation, we obtained a median DSC=0.58, Pr=0.74, Re=0.54. The promising results obtained by this system, if validated on a larger dataset, could strongly improve personalized medicine.

Patterns of recurrence in patients with curative resected rectal cancer according to different chemoradiotherapy strategies: Does preoperative chemoradiotherapy lower the risk of peritoneal recurrence?

The present study aimed to compare the pattern of distant recurrence between patients with non-metastatic rectal cancer treated with pre-operative (OP) and those treated with post-operative (post-OP) chemoradiotherapy (CRT). A total of 631 patients with newly diagnosed non-metastatic rectal cancer who had received pre-OP or post-OP CRT with curative intent surgery between August 2008 and April 2015 were identified. Inverse probability of treatment weighting (IPTW) was performed to account for baseline differences between the two arms. Overall, 449 and 182 patients were treated with pre-OP and post-OP CRT, respectively. Sex, tumor location, clinical tumor stage, CRT regimen and adjuvant chemotherapy regimen were significantly different between the two arms. The median follow-up duration was 55.4 months (range, 53.7-57.1). The 5-year distant recurrence-free survival (RFS) rates and 5-year overall survival (OS) rates were not significantly different between the pre-OP and post-OP CRT arms (RFS, 67.5 vs. 71.6%, P=0.595 and OS, 81.9 vs. 77.0%, P=0.449), and no difference was observed in the distant recurrence patterns. Following IPTW, there was still no difference in distant RFS (pre-OP vs. post-OP CRT; hazard ratio (HR)=0.62; P=0.911), but pre-OP CRT was significantly associated with lower peritoneal recurrence (pre-OP vs. post-OP CRT; HR, 0.13; P=0.032). In addition, there was no significant difference in OS between the two arms (pre-OP vs. post-OP CRT; HR, 0.85; P=0.665). In conclusion, although distant RFS was not significantly different between the two arms, pre-OP CRT was significantly associated with a lower risk of peritoneal recurrence than post-OP CRT in patients non-metastatic rectal cancer.

Effect of synbiotic supplementation on matrix metalloproteinase enzymes, quality of life and dietary intake and weight changes in rectal cancer patients undergoing neoadjuvant chemoradiotherapy

BACKGROUND: Probiotic/synbiotic has the important role of in altering intestinal bacteria, reducing inflammation and improvement of intestinal diseases. OBJECTIVE: We aimed to investigate the effect of synbiotic supplementation on matrix metalloproteinase (MMP) enzymes, hs-CRP, quality of life, dietary intake and weight changes in rectal cancer patients undergoing neoadjuvant chemoradiotherapy (CRT). METHODS: In this study, 46 rectal cancer patients were recruited. Patients were allocated to the synbiotic (n = 23) group or placebo groups (n = 23) receiving 2 synbiotic or placebo capsules for six weeks. Anthropometric measurements, quality of life, dietary intakes, and serum levels of MMP-2, MMP-9, and hs-CRP were compared before and after intervention with the use of statistical tests. RESULTS: The mean energy, carbohydrate, and protein intake of patients increased in the synbiotic group, while in the placebo group, post intervention, significant reduction was noticed in these parameters (P < 0.05). Synbiotic supplementation caused improvement in global health status, symptom scale scores and scores of functional scale. At the end of intervention, the elevation in hs-CRP, MMP-2, and MMP-9 levels in the placebo group was approximately two and four times higher than the synbiotic group respectively. CONCLUSION: According to our results, synbiotic supplementation may be helpful in cancer patients undergoing CRT. However, further studies must consider synbiotic as a new complementary treatment.

Value of volumetric and textural analysis in predicting the treatment response in patients with locally advanced rectal cancer

OBJECTIVE

The aim of this study was to assess the value of baseline 18F-FDG PET/CT in predicting the response to neoadjuvant chemo-radiotherapy (NCRT) in patients with locally advanced rectal cancer (LARC) via the volumetric and texture data obtained from 18F-FDG PET/CT images.

METHODS

 In total, 110 patients who had undergone NCRT after initial PET/CT and followed by surgical resection were included in this study. Patients were divided into two groups randomly as a train set (n: 88) and test set (n: 22). Pathological response using three-point tumor regression grade (TRG) and metastatic lymph nodes in PET/CT images were determined. TRG1 were accepted as responders and TRG2-3 as non-responders. Region of interest for the primary tumors was drawn and volumetric features (metabolic tumor volume (MTV) and total lesion glycolysis (TLG)) and texture features were calculated. In train set, the relationship between these features and TRG was investigated with Mann-Whitney U test. Receiver operating curve analysis was performed for features with p < 0.05. Correlation between features were evaluated with Spearman correlation test, features with correlation coefficient < 0.8 were evaluated with the logistic regression analysis for creating a model. The model obtained was tested with a test set that has not been used in modeling before.

RESULTS

 In train set 32 (36.4%) patients were responders. The rate of visually detected metastatic lymph node at baseline PET/CT was higher in non-responders than responders (71.4% and 46.9%, respectively, p = 0.022). There was a statistically significant difference between TLG, MTV, SHAPE_compacity, NGLDMcoarseness, GLRLM_GLNU, GLRLM_RLNU, GLZLM_LZHGE and GLZLM_GLNU between responders and non-responders. MTV and NGLDMcoarseness demonstrated the most significance (p = 0.011). A multivariate logistic regression analysis that included MTV, coarseness, GLZLM_LZHGE and lymph node metastasis was performed. Multivariate analysis demonstrated MTV and lymph node metastasis were the most meaningful parameters. The model's AUC was calculated as 0.714 (p = 0.001,0.606-0.822, 95% CI). In test set, AUC was determined 0.838 (p = 0.008,0.671-1.000, 95% CI) in discriminating non-responders.

CONCLUSIONS

Although there were points where textural features were found to be significant, multivariate analysis revealed no diagnostic superiority over MTV in predicting treatment response. In this study, it was thought higher MTV value and metastatic lymph nodes in PET/CT images could be a predictor of low treatment response in patients with LARC.

Dual-energy CT parameters in correlation to MRI-based apparent diffusion coefficient: evaluation in rectal cancer after radiochemotherapy

Background

Rectal cancer (RC) is a frequent malignancy for which magnetic resonance imaging (MRI) is the most common and accurate imaging. Iodine concentration (IC) can be quantified with spectral dual-layer computed tomography CT (DL-CT), which could improve imaging of RC, especially for evaluation of response to radiochemotherapy (RCT).

Purpose

To compare a DL-CT system to MRI as the non-invasive imaging gold standard for imaging of RC to evaluate the possibility of a response evaluation with DL-CT.

Material and Methods

Eleven patients who received DL-CT as well as MRI before and after RCT of RC were retrospectively included into this study. For each examination, a region of interest (ROI) was placed within the tumor. For MRI, the mean apparent diffusion coefficient (ADC) was assessed. For DL-CT, IC, z-effective, and Hounsfield Units (HU) were measured. IC, z-effective, and HU were normalized to the aorta. ADC was correlated to absolute and relative normalized IC, z-effective, and HU with Spearman’s ρ. Differences before and after treatment were tested with Wilcoxon signed-rank test.

Results

HU, IC, and Z-effective values in DL-CT images decreased significantly after RCT (P<0.01 for each comparison). The mean ADC increased significantly after RCT. Spearman’s ρ of the absolute IC difference and the absolute ADC (both before and after RCT) is high and significant (ρ = 0.73; P = 0.01), whereas the ρ-value for z-effective (ρ = 0.56) or HU (ρ = 0.45) to ADC was lower and non-significant.

Conclusion

Response evaluation of RC after RCT could be possible with DL-CT via the measurement of IC.

Laparoscopic total mesorectal excision combined with en-bloc seminal vesicle and prostate resection for rectal cancer after chemoradiotherapy

BACKGROUND

This study aimed to explore the surgical outcomes of laparoscopic total mesorectal excision (TME) combined with en-bloc seminal vesicle resection (SVR) and partial prostate resection (PPR) for locally advanced rectal cancer (LARC) after chemoradiotherapy (CRT).

METHODS

Patients receiving TME combined with en-bloc SVR and PPR for LARC after CRT from 2014 to 2019 were enrolled retrospectively. Patients' characteristics and surgical outcomes were collected and analysed.

RESULTS

A total of six male patients were enrolled in this study. Among them, four patients proved to be T4b stage including three Denonvilliers fascia invasion and one seminal vesicle invasion. R0 resection was achieved in all patients. With a median follow-up time of 24 months, no local recurrence was observed.

CONCLUSION

It is safe and feasible to perform laparoscopic TME combined with en-bloc SVR and PPR in selected LARC patients after neoadjuvant CRT. It can provide a safe circumferential resection margin and R0 resection. More studies are warranted to improve the diagnostic accuracy for T4b stage after CRT and avoid unnecessary extended resection.

BMI1-KLF4 axis deficiency improves responses to neoadjuvant concurrent chemoradiotherapy in patients with rectal cancer

PURPOSE

Neoadjuvant concurrent chemoradiotherapy (CCRT) is a gold standard treatment for patients with stage II/III rectal cancer. B-cell-specific Moloney murine leukemia virus insertion site 1 (BMI1) is a member of the polycomb group of proteins that are involved in regulating gene expression. High levels of BMI1 have been demonstrated to contribute to the malignant phenotypes of several cancers; however, its relevance in rectal cancer treated with CCRT is largely unknown.

METHODS AND MATERIALS

We used two patient cohorts to address the clinical relevance of BMI1 in human cancers. In addition, HT-29 and HCT-116 cells were chosen as our in vitro models to verify the role of BMI1 in cell response to ionizing radiation. Stemness-related proteins were analyzed by western blotting and cell survival was determined using clonogenic assays.

RESULTS

BMI1 overexpression was found to significantly correlate with advanced pre-treatment nodal status (N1-N2; p < 0.001), post-treatment tumor stage (T1-T2; p = 0.015), inferior tumor regression grade (p = 0.001), and also an independent prognosis factor in 172 rectal cancer patients receiving CCRT. Serial cell-based functional examination indicated that BMI1 deficiency sensitized cells to radiation treatment by modulating the gene expression of Kruppel-like factor 4 (KLF4) and enhanced radiosensitivity in microsatellite stable (MSS) colorectal cancers. Overexpression of KLF4 partially overcame BMI1-deficiency-mediated γ-H2AX expression after ionizing radiation exposure. Consistent with in vitro data, an analysis of an additional 30 rectal cancer tissue specimens revealed a positive correlation between BMI1 and KLF4 (p = 0.02).

CONCLUSION

Higher levels of BMI1 are associated with poor therapeutic response and adverse outcomes in rectal cancer patients receiving CCRT.

Multiparametric MRI and Whole Slide Image-Based Pretreatment Prediction of Pathological Response to Neoadjuvant Chemoradiotherapy in Rectal Cancer: A Multicenter Radiopathomic Study

Background

The aim of this work is to combine radiological and pathological information of tumor to develop a signature for pretreatment prediction of discrepancies of pathological response at several centers and restage patients with locally advanced rectal cancer (LARC) for individualized treatment planning.

Patients and Methods

A total of 981 consecutive patients with evaluation of response according to tumor regression grade (TRG) who received nCRT were retrospectively recruited from four hospitals (primary cohort and external validation cohort 1–3); both pretreatment multiparametric MRI (mp-MRI) and whole slide image (WSI) of biopsy specimens were available for each patient. Quantitative image features were extracted from mp-MRI and WSI and used to construct a radiopathomics signature (RPS) powered by an artificial-intelligence model. Models based on mp-MRI or WSI alone were also constructed for comparison.

Results

The RPS showed overall accuracy of 79.66–87.66% in validation cohorts. The areas under the curve of RPS at specific response grades were 0.98 (TRG0), 0.93 (≤ TRG1), and 0.84 (≤ TRG2). RPS at each grade of pathological response revealed significant improvement compared with both signatures constructed without combining multiscale tumor information (P < 0.01). Moreover, RPS showed relevance to distinct probabilities of overall survival and disease-free survival in patients with LARC who underwent nCRT (P < 0.05).

Conclusions

The results of this study suggest that radiopathomics, combining both radiological information of the whole tumor and pathological information of local lesions from biopsy, could potentially predict discrepancies of pathological response prior to nCRT for better treatment planning.

Electronic supplementary material

The online version of this article (10.1245/s10434-020-08659-4) contains supplementary material, which is available to authorized users.

Pathological Predictors of Response to Neoadjuvant Treatment in Rectal Carcinoma

PURPOSE

Neoadjuvant chemoradiotherapy has now become a standard treatment for rectal cancer. Recently, attempts have been made to predict the response rate to this treatment to decide whether or not it must be performed. However, tissue factors for predicting the response rate is not cohesively reviewed.

METHODS

Eighty-three patients with rectal cancer, all under neoadjuvant chemoradiotherapy and subsequent surgery, were examined for tissue factors in the biopsy sample. The tissue factors examined include tumor differentiation grade, lymphovascular invasion, perineural invasion, pathological stage, and lymphocytic infiltration. Lymphocytic infiltration was investigated by immunohistochemistry for CD8 T lymphocyte in biopsy samples.

RESULTS

In this study, tissue factors were found to play a decisive role in predicting response to neoadjuvant treatment. The most important factor was the pathological stage, which has the highest correlation with response to treatment. There is a significant relationship between CD8 lymphocyte infiltration and response to treatment (P value = 0.018). Primary perineural invasion and lymphovascular invasion also have a significant meaningful relationship with response to treatment (P value = 0.021 and P value = 0.036).

CONCLUSION

In this study, it was determined that the investigated factors have a significant relationship with response to treatment and could be used to predict the response to treatment, and if a low possibility of positive response exists, prevention of the complications of neoadjuvant chemoradiotherapy for the patients could occur.

Plasma metabolites associated with colorectal cancer stage: Findings from an international consortium

Colorectal cancer is the second most common cause of cancer-related death globally, with marked differences in prognosis by disease stage at diagnosis. We studied circulating metabolites in relation to disease stage to improve the understanding of metabolic pathways related to colorectal cancer progression. We investigated plasma concentrations of 130 metabolites among 744 Stages I-IV colorectal cancer patients from ongoing cohort studies. Plasma samples, collected at diagnosis, were analyzed with liquid chromatography-mass spectrometry using the Biocrates AbsoluteIDQ™ p180 kit. We assessed associations between metabolite concentrations and stage using multinomial and multivariable logistic regression models. Analyses were adjusted for potential confounders as well as multiple testing using false discovery rate (FDR) correction. Patients presented with 23, 28, 39 and 10% of Stages I-IV disease, respectively. Concentrations of sphingomyelin C26:0 were lower in Stage III patients compared to Stage I patients (pFDR  < 0.05). Concentrations of sphingomyelin C18:0 and phosphatidylcholine (diacyl) C32:0 were statistically significantly higher, while citrulline, histidine, phosphatidylcholine (diacyl) C34:4, phosphatidylcholine (acyl-alkyl) C40:1 and lysophosphatidylcholines (acyl) C16:0 and C17:0 concentrations were lower in Stage IV compared to Stage I patients (pFDR  < 0.05). Our results suggest that metabolic pathways involving among others citrulline and histidine, implicated previously in colorectal cancer development, may also be linked to colorectal cancer progression.

Prognostic Significance of Neoadjuvant Rectal Score and Indication for Postoperative Adjuvant Therapy in Rectal Cancer Patients After Neoadjuvant Chemoradiotherapy

BACKGROUND/AIM

Neoadjuvant chemoradiotherapy (CRT) is a standard treatment for patients with clinical Stage II/III rectal cancer. However, the benefit of postoperative adjuvant chemotherapy for patients after neoadjuvant CRT is uncertain. Recently, neoadjuvant rectal (NAR) score was suggested as an independent prognostic factor for patients with rectal cancer after neoadjuvant CRT. The aim of this study was to examine the prognostic significance of NAR score in rectal cancer patients who underwent neoadjuvant CRT followed by surgery, and to investigate which patients may benefit from postoperative adjuvant therapy.

PATIENTS AND METHODS

A total of 72 patients who underwent neoadjuvant CRT followed by R0 resection for clinical stage II /III rectal cancer were evaluated. The correlation between NAR score, various clinicopathological factors and disease recurrence were evaluated.

RESULTS

Disease recurrence was significantly more often observed in patients with incomplete neoadjuvant CRT, tumor regression grade (TRG) 3-4, and high NAR score. Multivariate analysis revealed that NAR score was an independent predictor of disease recurrence.

CONCLUSION

NAR score may be one of the predictive markers for disease recurrence in patients who underwent neoadjuvant CRT followed by surgery for rectal cancer. Patients with a low NAR score may benefit form postoperative adjuvant chemotherapy.

Minimally invasive surgery in elderly patients with rectal cancer: An analysis of the Bi-National Colorectal Cancer Audit (BCCA)

BACKGROUND

Advanced age is associated with worse outcomes after open rectal cancer surgery. However, not much is known about outcomes of minimally invasive surgery (MIS) in the elderly. The aim of this study was to evaluate safety and efficacy of MIS in elderly rectal cancer patients using the Bi-national Colorectal Cancer Audit (BCCA) data from Australia and New Zealand (ANZ).

METHODS

3451 patients were included, divided into three groups: <50 years (n = 364), 50-74 years (n = 2157) and ≥75 years (n = 930). Propensity-score matching was performed for the elderly group analysis to correct for differences in baseline characteristics.

RESULTS

MIS was performed in 52.9% of elderly patients, slightly lower than rates in <50 year and 50-74 year old groups (61% and 55.5%, respectively, p = 0.022). Elderly patients had more postoperative complications (p < 0.0001) and had a longer length of hospital stay (LOS; median 11 vs. 8 days for both other groups; p < 0.0001). Elderly patients had higher (y)pT-stages compared to both other groups (p < 0.0001) and were less likely to receive adjuvant therapy (p < 0.0001). Propensity-score matched analysis of the elderly group showed a higher rate of superficial wound dehiscence and a longer LOS after open surgery compared to MIS (10.3% vs. 2.6%, p = 0.030; 12 days vs. 9.5 days, p = 0.001, respectively), with comparable short-term oncological outcomes.

CONCLUSIONS

MIS is performed in just over half of elderly rectal cancer patients who are selected for elective rectal resection surgery in ANZ. When performed in the elderly, MIS appears safe and is associated with fewer wound complications and a shorter LOS.

Risk factor analysis for inaccurate pre-operative MRI staging in rectal cancer

BACKGROUND

Various tumor characteristics might lead to inaccurate local MRI-defined stage of rectal cancer and the purpose of this study was to explore the clinicopathological factors that impact on the precision pre-treatment MRI-defined stage of rectal cancer.

METHODS

A retrospectively analysis was conducted in non-metastatic rectal cancer patients who received radical tumor resection without neoadjuvant treatment during 2007-2015 in the Sixth Affiliated Hospital of Sun Yat-sen University. Clinical T stage and N stage defined by pelvic enhanced MRI and pathological stage were compared and patients were subdivided into accurate-staging, over-staging and under-staging subgroups. Logistic regressions were used to explore risk factors for over-staging or under-staging.

RESULTS

Five hundred fifty-one cases of patients were collected. Among them, 109 cases (19.4%) of patients were over-T-staged and 50 cases (8.9%) were under-T-staged, while 78 cases (13.9%) were over-N-staged and 75 cases (13.3%) were under-N-staged. Logistic regression suggested that pre-operative bowel obstruction was risk factor for over-T-staging (OR = 3.120, 95%CI: 1.662-5.857, P < 0.001) as well as over-N-staging (OR = 3.494, 95%CI: 1.797-6.794, P < 0.001), while mucinous adenocarcinoma was a risk factor for under-N-staging (OR = 4.049, 95%CI: 1.876-8.772, P < 0.001). Patients with larger tumor size were at lower risk for over-T-staging (OR = 0.837, 95%CI: 0.717-0.976, P = 0.024) and higher risk for over-N-staging (OR = 1.434, 95%CI: 1.223-1.680, P < 0.001).

CONCLUSION

Bowel obstruction, mucinous adenocarcinoma and tumor size might have impact on the pre-operative MRI T staging or N staging of rectal cancer. Our results reminded clinicians to assess clinical stage individually in such rectal cancer patients.

Multidisciplinary Cancer Management of Colorectal Cancer in Tikur Anbessa Specialized Hospital, Ethiopia

PURPOSE

Multidisciplinary cancer care is currently considered worldwide as standard for the management of patients with cancer. It improves patient diagnostic and staging accuracy and provides patients the benefit of having physicians of various specialties participating in their treatment plan. The purpose of this study was to describe the profile of patients discussed in the Tikur Anbessa Multidisciplinary Tumor Board (MTB) and the potential benefits brought by multidisciplinary care.

METHODS

The study involved the retrospective assessment of all patient cases presented to the Tikur Anbessa Hospital colorectal cancers MTB between March 2016 and November 2017. The data were collected from the MTB medical summary documents and were analyzed using SPSS version 20 (SPSS, Chicago, IL).

RESULTS

Of 147 patients with colorectal cancer, 96 (65%) were men. The median age at presentation was 46 years (range, 17-78 years). The predominant cancer was rectal (n = 101; 69%), followed by colon (n = 24; 16%). Of these, 68 (45%) and 22 (15%) had stage III and IV disease, respectively, on presentation to the MTB. The oncology department presented the majority of the patients for discussion. Most patients had undergone surgery before the MTB discussion but had no proper preoperative clinical staging information. The majority of patients with rectal cancer treated before the MTB discussion had undergone surgery upfront; however, most of the patients who were treatment naive before MTB received neoadjuvant chemoradiotherapy before surgery.

CONCLUSION

Decisions made by tumor boards are more likely to conform to evidence-based guidelines than are those made by individual clinicians. Therefore, early referral of patients to MTB before any treatment should be encouraged. Finally, other hospitals in Ethiopia should take a lesson from the Tikur Anbessa Hospital colorectal cancers MTB and adopt multidisciplinary cancer management.

Neoadjuvant radiotherapy improves overall survival for T3/4N+M0 rectal cancer patients: a population-based study of 20300 patients

BACKGROUND

Neoadjuvant radiotherapy (RT) has been shown to improve local control; however, whether it can improve overall survival (OS) in locally advanced rectal cancer (LARC) patients remains controversial. We therefore aimed to examine the benefits of surgery alone, neoadjuvant radiotherapy (RT), adjuvant RT, and surgery plus chemotherapy in stage II (T3/4N0M0) and III (any T and N + M0) on the OS of rectal cancer patients.

METHODS

Date from the Surveillance, Epidemiology, and End Results (SEER) database diagnosed between 2004 and 2016 were used. Kaplan-Meier analyses were used to compare patient prognoses across different treatment modalities. Cox hazard regression analysis were used to identify independent predictors of OS.

RESULTS

For stage T3/4N0M0 patients, neoadjuvant RT, adjuvant RT, and surgery plus chemotherapy resulted in similar OS (all p > 0.05; mean survival, 115.89 months (M), 111.97 M, and 117.22 M, respectively), with better OS observed in these patients than in patients who underwent surgery alone (all p < 0.001, mean survival, 88.96 M). For stage T1/2N + M0 patients, neoadjuvant RT, adjuvant RT, and surgery plus chemotherapy resulted in similar OS (all p > 0.05; mean survival, 121.50 M, 124.25 M, and 121.20 M, respectively), with better OS observed in these patients than in patients who underwent surgery alone (all p < 0.001, mean survival 83.81 M). For stage T3/4N + M0 patients, neoadjuvant RT (HR = 0.436; 95% CI, 0.396~0.478; p < 0.001) resulted in significantly longer OS than adjuvant RT and surgery plus chemotherapy (mean survival, 104.47 M, 93.94 M, and 93.62 M, respectively), with better OS observed in these patients than in patients who underwent surgery alone (all p < 0.001, mean survival 54.87 M). Older age (> 60 years), black race, unmarried status, high tumour grade, and tumour size > 5 cm were all associated with a poor prognosis (all p < 0.05).

CONCLUSIONS

Neoadjuvant RT, adjuvant RT, and surgery plus chemotherapy results in better OS than surgery alone in LARC patients. Neoadjuvant RT has the potential to be highly recommended over adjuvant RT and surgery plus chemotherapy for T3/4N + M0 patients; however, it showed no OS advantage over adjuvant RT or surgery plus chemotherapy for T3/4N0M0 and T1/2N + M0 patients.

Transanal endoscopic operation for rectal lesion: a rapid initial experience

BACKGROUND

In recent decades, transanal surgery for rectal lesions has become a valid alternative treatment for the treatment of small lesions of the rectum. Significant benefits in terms of morbidity and mortality are confirmed. There are multiple platforms for transanal surgery but the TEO system® is one of the best known.

METHODS

Between November 2017 and July 2019, 25 patients with rectal lesions suitable to transanal treatment came to our observation. In all reported cases, full-thickness rectum resections were performed. Demographic, histopathological, surgical morbidity/mortality and clinical outcome in all patients who underwent TEO were retrospectively evaluated from a prospectively collected database.

RESULTS

For a period of less than 2 years, 25 rectal lesions were excised by TEO. Sixteen lesions (64%) were low (<4 cm), 7 (28%) were mid-rectal (4-8 cm) and 2 (8%) were in the proximal rectum (>8 cm). Postoperative complications included: 3 (12%) bleedings, and 8 (32%) post-polipectomy syndrome.

CONCLUSIONS

Our initial experience suggests TEO is safe and feasible. Full-thickness resection guarantees adequate deep margins. Moreover, the limited number of cases requires the development of adequate reference centers.

The impact of tumor regression grade on long-term survival in locally advanced rectal cancer treated with preoperative chemoradiotherapy

PURPOSE

The aim of this study is to investigate the prognostic effect of tumor regression grade (TRG) on long-term survival in locally advanced rectal cancer treated with preoperative chemoradiotherapy.

METHODS

Medical records of 182 patients with locally advanced rectal cancer, who were treated with preoperative chemoradiotherapy followed by surgery between 2002 and 2016, were retrospectively reviewed. TRG was classified into five categories based on the pathological response as follows - TRG1: no viable cancer cell, TRG2: single cancer cell or small groups of cancer cells, TRG3: residual tumor outgrown by fibrosis, TRG4: residual tumor outgrowing fibrosis, TRG5: diffuse residual tumor without regression. TRG1, (TRG2+TRG3), and (TRG4+TRG5) were grouped as complete response, intermediate response, and no response, respectively.

RESULTS

Of the 182 patients with locally advanced rectal cancer, 112 (61.5%) were male. The mean age was 54.4 (range, 25-87) years. The total number of patients in complete response, intermediate response, and no response group was 24 (13.2%), 105 (57.7%), and 53 (29.1%), respectively. The corresponding five-year relapse-free survival and overall survival rates were 79.8%-92.3%, 74.7%-79.4%, and 55.7%-55.8%, respectively (p < 0.05 for relapse-free survival, p < 0.05 for overall survival). According to ypTNM stage, there was no significant difference in relapse-free survival among TRG groups in ypStage I and II patients (p > 0.05). In ypStage III patients, relapse-free survival was 62 months in no response group vs. not reached in intermediate response group (p < 0.05). According to the ypTNM, there was no significant difference in overall survival among TRG groups in ypStage I, II, and III patients (p > 0.05). In the multivariate analysis, pathological complete response was found to be an independent variable for relapse-free survival and overall survival (hazard ratio (95% confidence interval), 0.34 (0.17-6.77), 0.39 (0.18-0.83), respectively).

CONCLUSION

This study showed that patients with pathological complete response to preoperative chemoradiotherapy had longer relapse-free survival and overall survival rates than those with residual disease.

Development of a long non-coding RNA signature for prediction of response to neoadjuvant chemoradiotherapy in locally advanced rectal adenocarcinoma

Standard treatment for locally advanced rectal adenocarcinoma (LARC) includes a combination of chemotherapy with pyrimidine analogues, such as capecitabine, and radiation therapy, followed by surgery. Currently no clinically useful genomic predictors of benefit from neoadjuvant chemoradiotherapy (nCRT) exist for LARC. In this study we assessed the expression of 8,127 long noncoding RNAs (lncRNAs), poorly studied in LARC, to infer their ability in classifying patients' pathological complete response (pCR). We collected and analyzed, using lncRNA-specific Agilent microarrays a consecutive series of 61 LARC cases undergoing nCRT. Potential lncRNA predictors in responders and non-responders to nCRT were identified with LASSO regression, and a model was optimized using k-fold cross-validation after selection of the three most informative lncRNA. 11 lncRNAs were differentially expressed with false discovery rate < 0.01 between responders and non-responders to NACT. We identified lnc-KLF7-1, lnc-MAB21L2-1, and LINC00324 as the most promising variable subset for classification building. Overall sensitivity and specificity were 0.91 and 0.94 respectively, with an AUC of our ROC curve = 0.93. Our study shows for the first time that lncRNAs can accurately predict response in LARC undergoing nCRT. Our three-lncRNA based signature must be independently validated and further analyses must be conducted to fully understand the biological role of the identified signature, but our results suggest lncRNAs may be an ideal biomarker for response prediction in the studied setting.

Changes in fatigue in rectal cancer patients before and after therapy: a systematic review and meta-analysis

PURPOSE

Fatigue is a common problem among rectal cancer patients and can affect their quality of life. This study conducted a systematic review to better understand changes in fatigue severity in rectal cancer patients before, during, and after they undergo therapy.

METHODS

We used preset keywords to search the Cochrane Library, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), PubMed, and ProQuest databases for relevant studies published between 2000 and 2018, and data analysis was performed using Comprehensive Meta-Analysis (CMA) software (version 2.2.048) and SPSS software (version 19.0). In total, nine articles with complete data were included in our meta-analysis.

RESULTS

Fatigue conditions were compared before the start of therapy (baseline) and at 1 month (time 1), 3 months (time 2), 6 months (time 3), and 12 months (time 4) after the start of therapy. The standardized mean differences (SMDs) of the pooling effects size were 1.013 (95% confidence interval (CI) 0.217-1.810), - 0.551 (95% CI - 0.647 to - 0.456), - 0.330 (95% CI - 0.427 to - 0.233), and - 0.149 (95% CI - 0.221 to - 0.078), respectively. Subsequent analysis with a linear mixed effect model revealed that the estimate of the time variable was - 0.226 (p = 0.047), which indicates that the severity of fatigue varies over time and over the course of treatment. The results reveal that fatigue affects rectal cancer patients even before they start therapy.

CONCLUSION

Although fatigue worsened during the first month after cancer therapy, it gradually improved thereafter.

Intraoperative radiotherapy as an immediate adjuvant treatment of rectal cancer due to limited access to external-beam radiotherapy

BACKGROUND

Neoadjuvant external-beam radiotherapy (EBRT) with concomitant chemotherapy is the current standard-of-care for locally-advanced rectal cancer. Intraoperative radiotherapy (IORT) is to date only recommended for pelvic recurrences or incompletely resectable tumors. We here report on patients with stage II/III rectal cancer that were treated with IORT in a regional Russian university center due to limited access to EBRT.

METHODS

We retrospectively analyzed data from patients that were diagnosed with locally-advanced rectal cancer and underwent surgery from December 2012 to October 2016 at a regional oncological center in Russia (Krasnodar). During this period, access to EBRT was limited due to a temporary lack of a sufficient number of EBRT facilities. Patients unable to travel to a distant radiotherapy site received IORT alone, those that could travel received neoadjuvant external beam (chemo-) radiotherapy. Factors of interest were tumor stage, tumor differentiation, resection status, surgery type and neoadjuvant or adjuvant chemotherapy. We assessed local progression-free survival (L-PFS), PFS and overall survival (OS).

RESULTS

A total of 172 patients were included in this analysis. Of those, 92 (53.5%) were treated with IORT alone (median dose: 15 Gy [8.4-17 Gy]) and 80 (46.5%) received both neoadjuvant EBRT (median dose: 50.4 Gy [40-50.4 Gy]) and IORT (median dose: 15 Gy [15-17 Gy]). The median age was 65 years [33-82]. The median follow-up was 23 months [0-63 months]. The incidence of toxicity was low in both groups with an overall complication rate of 5.4%. Local PFS at 4 years was comparable with 59.4% in the IORT group and 65.4% in the IORT/EBRT group (p = 0.70). Similarly, there was no difference in OS or PFS (p = 0.66, p = 0.51, respectively).

CONCLUSIONS

IORT is a valuable option for patients with locally-advanced rectal cancer in the absence of access to EBRT.

The clinical significance of simple endoscopic scoring of patients with rectal cancer after concurrent chemoradiotherapy

BACKGROUND

Neoadjuvant concurrent chemoradiotherapy (CCRT) is an effective treatment option for patients with rectal cancer. In this study, we investigated the clinical efficacy of simple endoscopic scoring of patients with rectal cancer after CCRT.

METHODS

Between July 2008 and October 2015, medical records including endoscopic imaging from 41 patients with rectal cancer who received CCRT were retrospectively reviewed. Two expert gastroenterologists reviewed the endoscopic images and assigned scores from 0-3 according to post-CCRT findings. The scoring criteria were as follows: 0= scar without marginal elevation; 1= clean-based ulcer without marginal elevation; 2= clean-based ulcer with marginal elevation; 3= non-clean-based ulcer. We evaluated image scores to predict long-term outcomes using Kaplan-Meier curves and Cox regression models.

RESULTS

The median follow-up duration was 55 months (interquartile range: 35-76 months). Patients with a low score (≤2) had a 17.2% recurrence rate, whereas patients with a high score [3] had a 50.0% recurrence rate. Patients with a low score had longer disease-free survival (DFS) than those with a high score in log-rank test (P=0.026). In multivariate Cox regression analysis, a high score was a significant predictor of poor DFS in patients with rectal cancer after CCRT treatment (hazard ratio =4.89, 95% confidence interval: 1.11-21.50, P=0.036).

CONCLUSIONS

This simple endoscopic scoring approach is helpful for predicting prognosis of patients with rectal cancer after treatment with CCRT.

Translational Potential of MicroRNAs for Preoperative Staging and Prediction of Chemoradiotherapy Response in Rectal Cancer

Colorectal cancer is the third most common cancer and the second cause of cancer-related deaths. Rectal cancer presents roughly one-third of all colorectal cancer cases and differs from it on both anatomical and molecular levels. While standard treatment of colon cancer patients is radical surgery, rectal cancer is usually treated with pre-operative chemoradiotherapy followed by total mesorectal excision, which requires precise estimation of TNM staging. Unfortunately, stage evaluation is based solely on imaging modalities, and they often do not correlate with postoperative pathological findings. Moreover, approximately half of rectal cancer patients do not respond to such pre-operative therapy, so they are exposed to its toxic effects without any clinical benefit. Thus, biomarkers that could precisely predict pre-operative TNM staging, and especially response to therapy, would significantly advance rectal cancer treatment—but till now, no such biomarker has been identified. In cancer research, microRNAs are emerging biomarkers due to their connection with carcinogenesis and exceptional stability. Circulating miRNAs are promising non-invasive biomarkers that could allow monitoring of a patient throughout the whole therapeutic process. This mini-review aims to summarize the current knowledge on miRNAs and circulating miRNAs involved in the prediction of response to treatment and pre-operative staging in rectal cancer patients.

Preoperative assessment of lymph node metastasis in clinically node-negative rectal cancer patients based on a nomogram consisting of five clinical factors

Background

Currently, reliable approaches for accurate assessment of lymph node metastases (LNM), which is an important indication of preoperative chemoradiotherapy (CRT), are not available for clinically node-negative rectal cancer patients. This study aims to identify clinical factors associated with LNM and to establish a nomogram for LNM prediction in clinically node-negative rectal cancer patients.

Methods

The least absolute shrinkage and selection operator (LASSO) aggression and multivariate logistic regression analyses were applied to identify clinical factors associated with LNM. A nomogram was established to predict the probability of LNM in clinically node-negative rectal cancer patients based on the multivariate logistic regression model.

Results

Six potential risk factors were selected on the basis of LASSO aggression analysis, and five of them were identified as independent risk factors for LNM based on multivariate analysis, including MRI-reported tumor location, clinical T classification, MRI-reported tumor diameter, white blood cell count (WBC), and preoperative elevated tumor markers. A nomogram consisting of the five clinical factors was established and showed good discrimination. Decision curve analysis demonstrated that the established nomogram was reliable and accurate for LNM prediction in clinically node-negative rectal cancer patients.

Conclusions

A nomogram based on five clinical factors, including MRI-reported tumor location, clinical T classification, MRI-reported tumor diameter, WBC, and preoperative elevated tumor markers, are useful for assessing LNM in clinically node-negative rectal cancer patients, which is important for preoperative CRT regimens.

Leptin and adiponectin dynamics at patients with rectal neoplasm - Gender differences

Background

Numerous studies associate adipokines with colorectal malignancy, but few data deal with patients suffering exclusively of rectal carcinoma (RC).

Aims

We evaluated leptin and adiponectin levels in RC patients compared to healthy population and their dynamics after surgery.

Material and methods

Serum leptin and adiponectin were evaluated before surgery in 59 RC consecutive patients (38 males and 21 females), and in age and weight matched healthy controls. Measurements were repeated at 24, 72 hours and 7 days after surgery.

Results

Adipokine levels were higher in women. Controls had higher leptin (32.±4.34 vs 9.51±1.73 ng/ml in women and 11±2.66 vs 2.54±0.39 ng/ml in men, p = 0.00048 and 0.0032) and lower adiponectin (9±0.64 vs 11.85±1.02 μg/ml in women and 7.39±0.51 vs 8.5±0.62 μg/ml in men, p = 0.017 and 0.019) than RC patients. Surgery caused an increase of leptin from 5.11±0.8 to 18.7±2.42 ng/ml, p = 6.85 x 10¨⁸, and a decrease of adiponectin from 9.71±0.58 to 7.87±0.47 μg/ml, p = 1.4 x 10¨¹⁰ for all RC patients and returned thereafter to the initial range at 7 days. Adipokines were correlated with body weight (BW). The significance of correlation persisted after surgery only in males, but disappeared in females. Adipokines were not modified by tumor position, presurgical chemoradiotherapy or surgical technique. Women with RC experiencing weight loss had higher adiponectin than women without weight modifications (p<0.05 at all time points).

Conclusions

Adipokine levels of patients with RC differ from the healthy population, possibly reflecting an adaptation to disease. Adipokine modifications after surgery may be related to acute surgical stress. Whether leptin and adiponectin directly interact is not clear. Women have higher adipokine levels, more so after significant weight loss, but the strength of their correlation with BW decreases after surgery. These data suggest gender differences in the adipokine profile of RC patients which may find clinical applications.

Anal squamous cell carcinoma with metastasis to duodenum causing duodenal stricture and gastric outlet obstruction

Squamous cell carcinoma (SCC) of the anal canal is a rare entity encompassing only 2-4 percent of all colon, rectal, and anal cancers. SCC of the anal canal tends to be loco-regional, and in the event of distant metastasis, a most common site of spread is to liver and lung. We report an unusual case of SCC of the anal canal with duodenal metastases in a 49-year-old female who had presented with symptoms of abdominal pain, nausea, and vomiting eight months after the primary diagnosis of SCC of the anal canal. Esophagogastroduodenoscopy (EGD) revealed duodenal stricture with subsequent biopsy revealing duodenal mucosa with scattered malignant cell clusters within lymphatic spaces, consistent with metastatic carcinoma. Immunohistological staining demonstrated malignant cells positive for CK7, p16, p63 favoring a metastatic SCC.

Molecular and Kinetic Analyses of Circulating Tumor Cells as Predictive Markers of Treatment Response in Locally Advanced Rectal Cancer Patients

Neoadjuvant chemoradiation (NCRT) followed by total mesorectal excision is the standard treatment for locally advanced rectal cancer (LARC). To justify a non-surgical approach, identification of pathologic complete response (pCR) is required. Analysis of circulating tumor cells (CTCs) can be used to evaluate pCR. We hypothesize that monitoring of thymidylate synthase (TYMS) and excision repair protein, RAD23 homolog B (RAD23B), can be used to predict resistance to chemotherapy/radiotherapy. Therefore, the aims of this study were to analyze CTCs from patients with LARC who underwent NCRT plus surgery for expression of TYMS/RAD23B and to evaluate their predictive value. Blood samples from 30 patients were collected prior to NCRT (S1) and prior to surgery (S2). CTCs were isolated and quantified by ISET^®, proteins were analyzed by immunocytochemistry, and TYMS mRNA was detected by chromogenic in situ hybridization. CTC counts decreased between S1 and S2 in patients exhibiting pCR (p = 0.02) or partial response (p = 0.01). Regarding protein expression, TYMS was absent in 100% of CTCs from patients with pCR (p = 0.001) yet was expressed in 83% of non-responders at S2 (p < 0.001). Meanwhile, RAD23B was expressed in CTCs from 75% of non-responders at S1 (p = 0.01) and in 100% of non-responders at S2 (p = 0.001). Surprisingly, 100% of non-responders expressed TYMS mRNA at both timepoints (p = 0.001). In addition, TYMS/RAD23B was not detected in the CTCs of patients exhibiting pCR (p = 0.001). We found 83.3% of sensitivity for TYMS mRNA at S1 (p = 0.001) and 100% for TYMS (p = 0.064) and RAD23B (p = 0.01) protein expression at S2. Thus, TYMS mRNA and/or TYMS/RAD23B expression in CTCs, as well as CTC kinetics, have the potential to predict non-response to NCRT and avoid unnecessary radical surgery for LARC patients with pCR.

Neoadjuvant Radiochemotherapy Significantly Alters the Phenotype of Plasmacytoid Dendritic Cells and 6-Sulfo LacNAc+ Monocytes in Rectal Cancer

Neoadjuvant radiochemotherapy (nRCT) can significantly influence the tumor immune architecture that plays a pivotal role in regulating tumor growth. Whereas, various studies have investigated the effect of nRCT on tumor-infiltrating T cells, little is known about its impact on the frequency and activation status of human dendritic cells (DCs). Plasmacytoid DCs (pDCs) essentially contribute to the regulation of innate and adaptive immunity and may profoundly influence tumor progression. Recent studies have revealed that higher pDC numbers are associated with poor prognosis in cancer patients. 6-sulfo LacNAc-expressing monocytes (slanMo) represent a particular proinflammatory subset of human non-classical blood monocytes that can differentiate into DCs. Recently, we have reported that activated slanMo produce various proinflammatory cytokines and efficiently stimulate natural killer cells and T lymphocytes. slanMo were also shown to accumulate in clear cell renal cell carcinoma (ccRCC) and in metastatic lymph nodes from cancer patients. Here, we investigated the influence of nRCT on the frequency of rectal cancer-infiltrating pDCs and slanMo. When evaluating rectal cancer tissues obtained from patients after nRCT, a significantly higher density of pDCs in comparison to pre-nRCT tissue samples was found. In contrast, the density of slanMo was not significantly altered by nRCT. Further studies revealed that nRCT significantly enhances the proportion of rectal cancer-infiltrating CD8⁺ T cells expressing the cytotoxic effector molecule granzyme B. When exploring the impact of nRCT on the phenotype of rectal cancer-infiltrating pDCs and slanMo, we observed that nRCT markedly enhances the percentage of inducible nitric oxide synthase (iNOS)- or tumor necrosis factor (TNF) alpha-producing slanMo. Furthermore, nRCT significantly increased the percentage of mature CD83⁺ pDCs in rectal cancer tissues. Moreover, the proportion of pDCs locally expressing interferon-alpha, which plays a major role in antitumor immunity, was significantly higher in post-nRCT tissues compared to pre-nRCT tumor specimens. These novel findings indicate that nRCT significantly influences the frequency and/or phenotype of pDCs, slanMo, and CD8⁺ T cells, which may influence the clinical response of rectal cancer patients to nRCT.

Photodynamic therapy as salvage therapy for residual microscopic cancer after ultra-low anterior resection: A case report

BACKGROUND

The rate of positive resection margins (R1) in patients with low rectal cancer is substantial. Recommended remedies such as extended resection or chemoradiotherapy have their own serious drawbacks. It has been reported that photodynamic therapy (PDT) as a remedial treatment for esophageal cancer. Colorectal cancer and esophageal cancer has many similarities, however, PDT as a salvage therapy for rectal cancer is rare.

CASE SUMMARY

Here, we describe a 56-year-old man who was admitted to the hospital due to a 6-mo history of hemafecia, which had been aggravated for 1 mo. Colonoscopy revealed a 3 × 4 cm ulcerated mass in the rectum 4 cm from the anus. Preoperative pathological examination showed villous adenoma, moderate-to-high-grade dysplasia, good differentiation, and invasion of the mucosal muscle. The patient had R1 after ultra-low anterior resection, but he refused extended resection and experienced severe liver function impairment after 3 cycles of chemotherapy. Ultimately, the patient underwent PDT to remove R1. After five years of follow-up, there was no liver function impairment, recurrence, metastasis, sexual dysfunction, or abnormal defecation function.

CONCLUSION

This is the first case worldwide in which R1 of rectal cancer were successfully treated by PDT.

Predicting locally advanced rectal cancer response to neoadjuvant therapy with 18F-FDG PET and MRI radiomics features

PURPOSE

Pathological complete response (pCR) following neoadjuvant chemoradiotherapy or radiotherapy in locally advanced rectal cancer (LARC) is reached in approximately 15-30% of cases, therefore it would be useful to assess if pretreatment of ¹⁸F-FDG PET/CT and/or MRI texture features can reliably predict response to neoadjuvant therapy in LARC.

METHODS

Fifty-two patients were dichotomized as responder (pR+) or non-responder (pR-) according to their pathological tumor regression grade (TRG) as follows: 22 as pR+ (nine with TRG = 1, 13 with TRG = 2) and 30 as pR- (16 with TRG = 3, 13 with TRG = 4 and 1 with TRG = 5). First-order parameters and 21 second-order texture parameters derived from the Gray-Level Co-Occurrence matrix were extracted from semi-automatically segmented tumors on T2w MRI, ADC maps, and PET/CT acquisitions. The role of each texture feature in predicting pR+ was assessed with monoparametric and multiparametric models.

RESULTS

In the mono-parametric approach, PET homogeneity reached the maximum AUC (0.77; sensitivity = 72.7% and specificity = 76.7%), while PET glycolytic volume and ADC dissimilarity reached the highest sensitivity (both 90.9%). In the multiparametric analysis, a logistic regression model containing six second-order texture features (five from PET and one from T2w MRI) yields the highest predictivity in distinguish between pR+ and pR- patients (AUC = 0.86; sensitivity = 86%, and specificity = 83% at the Youden index).

CONCLUSIONS

If preliminary results of this study are confirmed, pretreatment PET and MRI could be useful to personalize patient treatment, e.g., avoiding toxicity of neoadjuvant therapy in patients predicted pR-.

Identification of bioactive compounds in Lactobacillus paracasei subsp. paracasei NTU 101-fermented reconstituted skimmed milk and their anti-cancer effect in combination with 5-fluorouracil on colorectal cancer cells

Chemotherapy is currently used to treat colorectal cancer (CRC), the most common cancer worldwide.

Expression of the inhibitory B7 family molecule VISTA in human colorectal carcinoma tumors

Colorectal carcinoma (CRC) is one of the most common malignancies in the world. PD-1/PD-L1 inhibitors have benefited cancer patients with multiple tumor types. However, their efficacy for CRC is low and this treatment in melanoma patients results in adaptive resistance through upregulation of VISTA, another checkpoint inhibitory pathway. Thus, there is an urgent need to explore additional co-inhibitory molecular pathways such as VISTA for CRC treatment. In this study, C10orf54 (encoding VISTA) expression was analyzed by RNA-seq data from 367 CRC patients in human cancer datasets. Moreover, 28 clinical CRC specimens were used to assess VISTA protein expression. Human cancer datasets showed that CRC tumors expressed higher levels of C10orf54 than CD274 (encoding PD-L1). Moreover, C10orf54 mRNA expression was significantly correlated with genes responsible for tumor immune evasion. VISTA protein expression was high in tumors compared with para-tumors and normal tissues, which is similar to PD-L1 expression. However, in contrast to PD-L1, VISTA was mainly expressed by tumor-infiltrating lymphocytes. This study is the first investigation of VISTA expression in human resected CRC tumors, and the results justify the need for future studies on the role of VISTA in anti-CRC immunity in clinical samples.

Platelet and Neutrophil Counts as Predictive Markers of Neoadjuvant Therapy Efficacy in Rectal Cancer

AIMS

To investigate pretreatment platelet and neutrophil counts as well as a combined platelet-neutrophil (PN) index for prognostic information in patients with rectal adenocarcinoma that received neoadjuvant treatment.

PATIENTS AND METHODS

Charts from 164 patients with localized rectal adenocarcinoma were retrospectively reviewed, and 112 patients with complete data were included in the study. Patients were stratified in groups according to their neutrophil counts, platelet counts, and a combined platelet/neutrophil (PN) index. Baseline parameters of the groups were compared using the x² test. Pathologic responses on the surgical specimen of patients with lower platelet counts (≤ 350 × 10⁹/L), lower neutrophil counts (≤ 7.5 × 10⁹/L), and a lower PN index were compared with those of patients with higher platelet counts (> 350 × 10⁹/L), higher neutrophil counts (> 7.5 × 10⁹/L), and a higher PN index using the x² test. Kaplan-Meier curves of overall and progression free survival were constructed and compared with the log-rank test.

RESULTS

A total of 33 (29.5%) patients belonged to the high-PN index group, and 79 (70.9%) patients belonged to the low-PN index group. A significant difference was present between the two groups with regard to pathologic response. Patients with both high platelet and high neutrophil counts were less likely to have a complete pathologic response than those in the low-PN index group (P = 0.039). Additionally, tumor location and tumor stage were significantly associated with complete pathologic response to neoadjuvant treatment. Patients with a complete response were more likely to present with a low tumor (≤ 5 cm from the anal verge). Likewise, patients diagnosed with stage II disease were more likely to experience complete response than those diagnosed with stage III (x² test P = 0.016). There was no significant difference in overall and progression free survival between the two platelet groups (log-rank P = 0.73 and 0.40, respectively) and the two PN index groups (log-rank P = 0.92 and 0.43, respectively).

CONCLUSION

In this retrospective analysis, the combination of higher platelet and neutrophil counts at the time of diagnosis had predictive value with respect to complete pathologic response to neoadjuvant treatment in locally advanced rectal cancer.

Tertiary Care Multidisciplinary Teams Associated with Improved Survival in Rectal Cancer Patients: A Comparative Study

For stage II/III rectal cancer patients, comprehensive multidisciplinary care (MDC) affects outcomes. Randomized trials have shown the effectiveness of adjuvant and neoadjuvant therapy in treatment of these patients. However, the effectiveness of collaboration within MDC is undetermined. It is possible that regional variation in survival outcomes may be tied to treatment facility. We retrospectively reviewed a prospectively collected database of patients with stage II/III rectal cancer who received MDC at any location and underwent oncologic colorectal resection at a tertiary care center (TCC) between 2005 and 2011. Of the 571 rectal cancer patients, 391 had a stage II/III rectal cancer and received surgery at a TCC. After exclusion criteria, we observed that 120 patients received neoadjuvant therapy and 119 patients received adjuvant therapy. For neoadjuvant patients, no difference in overall survival was observed between treatment received at a TCC versus an outside facility. However, a significant improvement in survival was observed in patients who received adjuvant therapy at a TCC ( P = 0.01). Thus, the location of postoperative adjuvant therapy shows improvement in 10-year survival at a TCC versus elsewhere. Thus, standardization of care can impact outcomes for invasive rectal cancer patients. The limitations of this study are its retrospective nature and relatively small sample size.

'Watch and wait' in rectal cancer: summary of the current evidence

BACKGROUND

The management of rectal cancer has evolved considerably over the last few decades with increasing use of neoadjuvant chemoradiotherapy (nCRT). Complete clinical response (cCR) and even complete pathological response (pCR) have been noted in a proportion of patients who had surgery after nCRT. This raises the concern that we may have been 'over-treating' some of these patients and lead to an increasing interest in 'watch and wait' (W&W) approach for patients who had cCR to avoid the morbidity associated with rectal surgery.

METHODS

A review of the literature in English pertaining to rectal cancer in the context of W&W, organ preservation and active surveillance.

RESULTS

Evidence available to support W&W approach comes from non-randomised controlled trials (RCTs) with no current consensus on patients' selection criteria, lack of viable predictors of both cCR and pCR and lack of universal definitions of cCR and pCR. Also, there is no agreed protocol for disease surveillance.

CONCLUSION

Even though there has been increasing reports on the outcomes of W&W in rectal cancer, the current evidence cannot support its routine use in clinical practice. This approach should be used in clinical trials settings or after thorough counselling with the patient on the outcomes of various treatment options.

Prognostic value of tumour regression grade in locally advanced rectal cancer: a systematic review and meta-analysis

AIM

The current standard of care for locally advanced rectal cancer involves neoadjuvant chemoradiotherapy (CRT) followed by total mesorectal excision. There is a spectrum of response to neoadjuvant therapy; however, the prognostic value of tumour regression grade (TRG) in predicting disease-free survival (DFS) or overall survival (OS) is inconsistent in the literature.

METHOD

This study was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search was undertaken using Ovid MEDLINE, Embase and Google Scholar. Inclusion criteria were Stage II and III locally advanced rectal cancer treated with long-course CRT followed by radical surgery. The aim of the meta-analysis was to assess the prognostic implication of each TRG for rectal cancer following neoadjuvant CRT. Long-term prognosis was assessed. The main outcome measures were DFS and OS. A random effects model was performed to pool the hazard ratio (HR) from all included studies.

RESULTS

There were 4875 patients from 17 studies, with 775 (15.9%) attaining a pathological complete response (pCR) and 719 (29.9%) with no response. A significant association with OS was identified from a pooled-estimated HR for pCR (HR = 0.47, P = 0.002) and nonresponding tumours (HR = 2.97; P < 0.001). Previously known tumour characteristics, such as ypN, lymphovascular invasion and perineural invasion, were also significantly associated with DFS and OS, with estimated pooled HRs of 2.2, 1.4 and 2.3, respectively.

CONCLUSION

In conclusion, the degree of TRG was of prognostic value in predicting long-term outcomes. The current challenge is the development of a high-validity tests to predict pCR.

Potential of memory T cells in bridging preoperative chemoradiation and immunotherapy in rectal cancer

The management of locally advanced rectal cancer has passed a long way of developments, where total mesorectal excision and preoperative radiotherapy are crucial to secure clinical outcome. These and other aspects of multidisciplinary strategies are in-depth summarized in the literature, while our mini-review pursues a different goal. From an ethical and medical standpoint, we witness a delayed implementation of novel therapies given the cost/time consuming process of organizing randomized trials that would bridge an already excellent local control in cT3-4 node-positive disease with long-term survival. This unfortunate separation of clinical research and medical care provides a strong motivation to repurpose known pharmaceuticals that suit for treatment intensification with a focus on distant control. In the framework of on-going phase II-III IG/IMRT-SIB trials, we came across an intriguing translational observation that the ratio of circulating (protumor) myeloid-derived suppressor cells to (antitumor) central memory CD8+ T cells is drastically increased, a possible mechanism of tumor immuno-escape and spread. This finding prompts that restoring the CD45RO memory T-cell pool could be a part of integrated adjuvant interventions. Therefore, the immunocorrective potentials of modified IL-2 and the anti-diabetic drug metformin are thoroughly discussed in the context of tumor immunobiology, mTOR pathways and revised Warburg effect.