Prognostic importance of Mandard tumour regression grade following pre-operative chemo/radiotherapy for locally advanced rectal cancer

Impact of consolidation chemotherapy in poor responders to neoadjuvant radiation therapy: magnetic resonance imaging-based clinical-radiological correlation in high-risk rectal cancers

PURPOSE

The current study was conducted to examine the role of consolidation chemotherapy after neoadjuvant radiation therapy (NART) in decreasing the involvement of the mesorectal fascia (MRF) in high-risk locally advanced rectal cancers (LARCs).

METHODS

In total, 46 patients who received consolidation chemotherapy after NART due to persistent MRF involvement were identified from a database. A team of 2 radiologists, blinded to the clinical data, studied sequential magnetic resonance imaging (MRI) scans to assess the tumor response and then predict a surgical plan. This prediction was then correlated with the actual procedure conducted as well as histopathological details to assess the impact of consolidation chemotherapy.

RESULTS

The comparison of MRI-based parameters of sequential images showed significant downstaging of T2 signal intensity, tumor height, MRF involvement, diffusion restriction, and N category between sequential MRIs (P < 0.05). However, clinically relevant downstaging (standardized mean difference, > 0.3) was observed for only T2 signal intensity and diffusion restriction on diffusion-weighted imaging. No clinically relevant changes occurred in the remaining parameters; thus, no change was noted in the extent of surgery predicted by MRI. Weak agreement (Cohen κ coefficient, 0.375) and correlation (Spearman rank coefficient, 0.231) were found between MRI-predicted surgery and the actual procedure performed. The comparison of MRI-based and pathological tumor response grading also showed a poor correlation.

CONCLUSION

Evidence is lacking regarding the use of consolidation chemotherapy in reducing MRF involvement in LARCs. The benefit of additional chemotherapy after NART in decreasing the extent of planned surgery by reducing margin involvement requires prospective research.

Expression Levels of GHRH-Receptor, pAkt and Hsp90 Predict 10-Year Overall Survival in Patients with Locally Advanced Rectal Cancer

Background: Rectal cancer constitutes nearly one-third of all colorectal cancer diagnoses, and certain clinical and molecular markers have been studied as potential prognosticators of patient survival. The main objective of our study was to investigate the relationship between the expression intensities of certain proteins, including growth-hormone-releasing hormone receptor (GHRH-R), Hsp90, Hsp16.2, p-Akt and SOUL, in specimens of locally advanced rectal cancer patients, as well as the time to metastasis and 10-year overall survival (OS) rates. We also investigated whether these outcome measures were associated with the presence of other clinical parameters. Methods: In total, 109 patients were investigated retrospectively. Samples of pretreatment tumors were stained for the proteins GHRH-R, Hsp90, Hsp16.2, p-Akt and SOUL using immunhistochemistry methods. Kaplan–Meier curves were used to show the relationships between the intensity of expression of biomarkers, clinical parameters, the time to metastasis and the 10-year OS rate. Results: High levels of p-Akt, GHRH-R and Hsp90 were associated with a significantly decreased 10-year OS rate (p = 0.001, p = 0.000, p = 0.004, respectively) and high expression levels of p-Akt and GHRH-R were correlated with a significantly shorter time to metastasis. Tumors localized in the lower third of the rectum were linked to both a significantly longer time to metastasis and an improved 10-year OS rate. Conclusions: Hsp 90, pAkt and GHRH-R as well as the lower-third localization of the tumor were predictive of the 10-year OS rate in locally advanced rectal cancer patients. The GHRH-R and Hsp90 expression levels were independent prognosticators of OS. Our results imply that GHRH-R could play a particularly important role both as a molecular biomarker and as a target for the anticancer treatment of advanced rectal cancer.

Plasma metabolomics, lipidomics and cytokinomics profiling predict disease recurrence in metastatic colorectal cancer patients undergoing liver resection

Purpose

In metastatic colorectal cancer (mCRC) patients (pts), treatment strategies integrating liver resection with induction chemotherapy offer better 5-year survival rates than chemotherapy alone. However, liver resection is a complex and costly procedure, and recurrence occurs in almost 2/3rds of pts, suggesting the need to identify those at higher risk. The aim of this work was to evaluate whether the integration of plasma metabolomics and lipidomics combined with the multiplex analysis of a large panel of plasma cytokines can be used to predict the risk of relapse and other patient outcomes after liver surgery, beyond or in combination with clinical morphovolumetric criteria.

Experimental design

Peripheral blood metabolomics and lipidomics were performed by 600 MHz NMR spectroscopy on plasma from 30 unresectable mCRC pts treated with bevacizumab plus oxaliplatin-based regimens within the Obelics trial (NCT01718873) and subdivided into responder (R) and non-R (NR) according to 1-year disease-free survival (DFS): ≥ 1-year (R, n = 12) and < 1-year (NR, n = 18). A large panel of cytokines, chemokines, and growth factors was evaluated on the same plasma using Luminex xMAP-based multiplex bead-based immunoassay technology. A multiple biomarkers model was built using a support vector machine (SVM) classifier.

Results

Sparse partial least squares discriminant analysis (sPLS-DA) and loading plots obtained by analyzing metabolomics profiles of samples collected at the time of response evaluation when resectability was established showed significantly different levels of metabolites between the two groups. Two metabolites, 3-hydroxybutyrate and histidine, significantly predicted DFS and overall survival. Lipidomics analysis confirmed clear differences between the R and NR pts, indicating a statistically significant increase in lipids (cholesterol, triglycerides and phospholipids) in NR pts, reflecting a nonspecific inflammatory response. Indeed, a significant increase in proinflammatory cytokines was demonstrated in NR pts plasma. Finally, a multiple biomarkers model based on the combination of presurgery plasma levels of 3-hydroxybutyrate, cholesterol, phospholipids, triglycerides and IL-6 was able to correctly classify patients by their DFS with good accuracy.

Conclusion

Overall, this exploratory study suggests the potential of these combined biomarker approaches to predict outcomes in mCRC patients who are candidates for liver metastasis resection after induction treatment for defining personalized management and treatment strategies.

Statins increase pathological response in locally advanced rectal cancer treated with chemoradiation: a multicenter experience

Aims: To investigate the influence of various concomitant medications on outcomes in patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiation. Materials & methods: The authors retrospectively identified 246 patients from 2003 to 2018, collecting demographic and clinicopathological data of interest. Odds ratio (OR) was used to assess the association between concomitant drugs and outcomes. Results: The authors found an association between statins and a Dworak regression grade of 3-4 (OR = 8.78; p = 0.01). Furthermore, statins were significantly associated with more frequent chemoradiation-related toxicity (OR = 2.39; p = 0.0098) and chemotherapy dose reduction or discontinuation (OR = 2.26; p = 0.03). Conclusion: Despite higher frequency of radiotherapy and chemotherapy interruption or dose reduction, the concomitant use of statins during neoadjuvant chemoradiation proved to be associated with better tumor regression.

Can Gastric Cancer Patients with High Mandard Score Benefit from Neoadjuvant Chemotherapy?

A high Mandard score may indicate the tumor is insensitive to chemotherapy. We analyzed tumor regression and lymph node response under different Mandard scores to assess the impact of Mandard score on prognosis. Methods. Mandard scores and ypN stage of postoperative pathological reports were recorded. The results were reviewed by a professional pathologist. The radiologist compared the tumor regression before and after chemotherapy by computed tomography (CT). The survival of all patients was obtained by telephone follow-up. Multivariate Cox regression was used to assess the relationship between overall risk of death and Mandard score, imaging evaluation, and ypN stage. Results. In the Mandard score (4-5) group, the median survival time for PR and ypN0 patients was 68.5 and 76.7 months. While in the Mandard score (1-2) group, the median survival time for PD and ypN3a patients was 15.6 and 14.5 months. Imaging evaluation of tumor regression (PR 68.5 months, SD 27.8 months, and PD 10.2 months) and lymph node remission (ypN0 76.7 months, ypN1 61.6 months, ypN2 18.0 months, ypN3a 18.7 months, and ypN3b 18.3 months) showed improved survival. Mandard score, imaging evaluation, and ypN stage are important prognostic factors affecting prognosis. Conclusion. A high Mandard score does not mean neoadjuvant chemotherapy is ineffective in gastric cancer. Patients with imaging evaluation of tumor regression and ypN stage reduction may benefit from neoadjuvant chemotherapy.

THUNDER 2: THeragnostic Utilities for Neoplastic DisEases of the Rectum by MRI guided radiotherapy

Background

Neoadjuvant chemoradiation therapy (nCRT) is the standard treatment modality in locally advanced rectal cancer (LARC). Since response to radiotherapy (RT) is dose dependent in rectal cancer, dose escalation may lead to higher complete response rates. The possibility to predict patients who will achieve complete response (CR) is fundamental. Recently, an early tumour regression index (ERI) was introduced to predict pathological CR (pCR) after nCRT in LARC patients.

The primary endpoints will be the increase of CR rate and the evaluation of feasibility of delta radiomics-based predictive MRI guided Radiotherapy (MRgRT) model.

Methods

Patients affected by LARC cT2-3, N0-2 or cT4 for anal sphincter involvement N0-2a, M0 without high risk features will be enrolled in the trial. Neoadjuvant CRT will be administered using MRgRT. The initial RT treatment will consist in delivering 55 Gy in 25 fractions on Gross Tumor Volume (GTV) plus the corresponding mesorectum and 45 Gy in 25 fractions on the drainage nodes. Chemotherapy with 5-fluoracil (5-FU) or oral capecitabine will be administered continuously.

A 0.35 Tesla MRI will be acquired at simulation and every day during MRgRT. At fraction 10, ERI will be calculated: if ERI will be inferior than 13.1, the patient will continue the original treatment; if ERI will be higher than 13.1 the treatment plan will be reoptimized, intensifying the dose to the residual tumor at the 11^th fraction to reach 60.1 Gy.

At the end of nCRT instrumental examinations are to be performed in order to restage patients. In case of stable disease or progression, the patient will undergo surgery. In case of major or complete clinical response, conservative approaches may be chosen. Patients will be followed up to evaluate toxicity and quality of life.

The number of cases to be enrolled will be 63: all the patients will be treated at Fondazione Policlinico Universitario A. Gemelli IRCCS in Rome.

Discussion

This clinical trial investigates the impact of RT dose escalation in poor responder LARC patients identified using ERI, with the aim of increasing the probability of CR and consequently an organ preservation benefit in this group of patients.

Trial registration

ClinicalTrials.gov Identifier: NCT04815694 (25/03/2021).

Biomarkers in Locally Advanced Rectal Cancer: A Review

Locally advanced rectal cancers (LARC) are the subject of a rapidly evolving treatment paradigm. The critical timepoints where management decisions are required during the care of the LARC patient are: prior to the institution of any treatment, post neoadjuvant therapy and post-surgery. This article reviews the clinical, imaging, blood-based, tissue-based, and molecular biomarkers that can assist clinicians at these timepoints in the patient's management, in prognosticating for their LARC patients or in predicting responses to therapy in the multi-modality neoadjuvant treatment era.

Tumor Regression Grade as a Prognostic Factor in Metastatic Colon Cancer Following Preoperative Chemotherapy

BACKGROUND

The prognostic value of tumor regression grade (TRG) in patients with locally advanced rectal cancer treated with neoadjuvant chemoradiation therapy has been explored extensively. However, whether TRG is predictive of outcome in colon cancer following preoperative chemotherapy has not been reported.

MATERIALS AND METHODS

A total of 276 colon cancer patients who had undergone preoperative chemotherapy and surgery in Fudan University Shanghai Cancer Center during the period March 2014 through November 2019 were recruited in this study. 113 (40.9%) and 163 (59.1%) patients were diagnosed with locally advanced colon cancer (LACC) and metastatic colon cancer (mCC) before preoperative chemotherapy, respectively. The TRG was divided into TRG0 (complete response), TRG1 (good response), TRG2 (moderate response), and TRG3 (poor response).

RESULTS

Of the 276 patients 4.0% were TRG0, 5.4% were TRG1, 29.3% were TRG2, 61.2% were TRG3. TRG0 and TRG1 or TRG0, TRG1 and TRG2 were combined to simplify analysis due to limited sample size. In entire cohort, the 3-year overall survival for TRG0-1, TRG2, and TRG3 groups were 80.0%, 68.8% and 43.3% (P = .003). In LACC cohort, TRG was not associated with patients' prognosis, which largely resulted from limited outcome events. In mCC cohort, the 3-year overall survival for TRG0-1, TRG2, and TRG3 groups were 74.3%, 62.8% to 28.1% (P<0.001). Multivariate analysis demonstrated that TRG was an independent prognostic factor for overall survival in both entire cohort and mCC cohort (TRG3 vs. TRG0-2).

CONCLUSION

TRG is a prognostic factor in predicting long-term outcomes of mCC patients treated with preoperative chemotherapy.

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.

Preoperative Fibrinogen-Albumin Ratio Index (FARI) is a Reliable Prognosis and Chemoradiotherapy Sensitivity Predictor in Locally Advanced Rectal Cancer Patients Undergoing Radical Surgery Following Neoadjuvant Chemoradiotherapy

Background

Inflammatory response and nutritional status are associated with cancer development and progression. The purpose of this study was to explore whether the preoperative fibrinogen-albumin ratio index (FARI) is related to prognosis and chemoradiotherapy outcome of radical surgery after neoadjuvant chemoradiotherapy (NCRT) in patients with locally advanced rectal cancer (LARC).

Methods

In total, 123 patients with LARC who underwent radical surgery after NCRT between June 2012 and December 2018 were collected in this study. Time-dependent receiver operating characteristic (ROC) curve analysis was made to evaluate the ability of the markers for forecasting prognosis. The correlation between FARI and clinicopathological parameters was analyzed. The Kaplan-Meier survival analysis, univariate and multivariate analysis based on Cox proportional hazards models, and subgroup analysis were performed to evaluate overall survival (OS) and disease-free survival (DFS). A nomogram was constructed to evaluate the predictive role of FARI in DFS.

Results

The ROC curve analysis showed that the ability of FARI on DFS prediction was superior to those of other inflammatory markers and carcinoembryonic antigen (CEA) (P<0.05). Based on the Youden's index, the optimal cut-off value of FARI was 8.8%. High FARI patients (>8.8%) showed a poor response to NCRT and a decreased DFS rate (P<0.05). In addition, multivariate analysis revealed that FARI (HR=3.098, P=0.033), neutrophil-to-lymphocyte ratio (NLR), and postoperative T stage were independent prognostic factors for DFS in TNM stage III LARC patients. However, FARI failed to distinguish patients with poor OS. Harrell's concordance index (C-index) of the nomogram containing FARI (0.807) was obviously higher than that without it (0.732) among LARC patients who underwent radical surgery after NCRT. Moreover, multivariate analysis revealed FARI (OR=3.044, P=0.012) as an independent predictor for response to NCRT.

Conclusion

Among LARC patients who underwent radical surgery after NCRT, preoperative FARI is an independent prognostic factor for DFS and an independent predictor for response to NCRT.

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.

Pathological Tumor Regression Grade Classifications in Gastrointestinal Cancers: Role on Patients' Prognosis

Preoperative chemotherapy or combined radiotherapy and chemotherapy (CRT), followed by surgery, represents the standard approach for locally advanced esophageal, gastric, and rectal carcinomas. To adequately evaluate the effects of neoadjuvant CRT in the resection specimens, several histopathologic tumor regression grade (TRG) scoring systems have been introduced into clinical practice. The primary goal of these TRG systems relies on a correct prognostic stratification of patients in the attempt to help clinical decision-making and influence surgical strategies, postoperative adjuvant therapies, and surveillance intensity. However, most TRG systems suffer from poor reproducibility and low interobserver concordance rates. Many efforts have been made in the identification of alternative, robust, simple, and universally accepted TRG scoring systems, which would help in the comparison of different treatment strategies and in the standardization of multimodal therapies. The aim of this review is to analyze the most commonly used TRG systems in gastrointestinal cancers highlighting their pitfalls and usefulness, depending on the tumor type.

ACRNaCT trial protocol: efficacy of adjuvant chemotherapy in patients with clinical T3b/T4, N+ rectal Cancer undergoing Neoadjuvant Chemoradiotherapy: a pathology-oriented, prospective, multicenter, randomized, open-label, parallel group clinical trial

BACKGROUND

The CAO/ARO/AIO-94 demonstrated that neoadjuvant chemoradiotherapy (CRT) could decrease the rate of local recurrence rather than distal metastases in advanced rectal cancer. Adjuvant chemotherapy (ACT) can eliminate micrometastasis, and render a better prognosis to rectal cancer. However, adoption of ACT mainly depends on the evidence from colon cancer. Neoadjuvant CRT can lead to tumor shrinkage in a number of patients with advanced rectal cancer. The administration of adjuvant therapy depending on pretreatment clinical stage or postoperative yield pathological (yp) stage remains controversial. At present, the clinical guidelines recommend ACT for patients with stage II/III (ypT3-4 N0 or ypTanyN1-2) rectal cancer following neoadjuvant CRT and surgery. However, the yp stage may influence the guidance of ACT.

METHODS

According to the postoperative pathological stage, the present study was divided into two parts with different study design procedures. Patients will undergo different therapeutic strategies after collecting data related to postoperative pathological stage. For patients with pathologic complete response or yp stage I, the study was designed as a non-inferiority trial to compare the patients' long-term outcomes in observational group and those in treatment group with 5-fluorouracil. For patients at yp stage II or III, the study was designed as a superiority trial to compare the oncological effect of oxaliplatin combined with 5-fluorouracil, in addition to 5-fluorouracil alone in ACT. The primary endpoint is 3-year disease-free survival (DFS). Secondary endpoints are 3-year, 5-year overall survival, 5-year DFS, and the rate of local recurrence and adverse events resulted from chemotherapy and the patients' quality of life postoperatively.

DISCUSSION

The ACRNaCT trial aims to investigate whether observation is not inferior than 5-fluorouracil for pathologic complete response or yp stage I, and indicate whether combined chemotherapy contains superior outcomes than 5-fluorouracil alone for yp stage II or III in patients receiving neoadjuvant CRT and surgery for locally advanced rectal cancer (LARC). This trial is expected to provide individualized adjuvant treatment strategies for LARC patients following neoadjuvant CRT and surgery.

TRIAL REGISTRATION

The trial has been registered in ClinicalTrials.gov on January 30, 2018 (Registration No. NCT03415763), and also, that was registered in Chinese Clinical Trial Registry on November 12, 2018 (Registration No. ChiCTR1800019445).

Standardized Pathology Report for Colorectal Cancer, 2nd Edition

The first edition of the 'Standardized Pathology Report for Colorectal Cancer,' which was developed by the Gastrointestinal Pathology Study Group (GIP) of the Korean Society of Pathologists, was published 13 years ago. Meanwhile, there have been many changes in the pathologic diagnosis of colorectal cancer (CRC), pathologic findings included in the pathology report, and immunohistochemical and molecular pathology required for the diagnosis and treatment of colorectal cancer. In order to reflect these changes, we (GIP) decided to make the second edition of the report. The purpose of this standardized pathology report is to provide a practical protocol for Korean pathologists, which could help diagnose and treat CRC patients. This report consists of "standard data elements" and "conditional data elements." Basic pathologic findings and parts necessary for prognostication of CRC patients are classified as "standard data elements," while other prognostic factors and factors related to adjuvant therapy are classified as "conditional data elements" so that each institution could select the contents according to the characteristics of the institution. The Korean version is also provided separately so that Korean pathologists can easily understand and use this report. We hope that this report will be helpful in the daily practice of CRC diagnosis.

Non-operative management of rectal cancer: understanding tumor biology

The management of locally-advanced rectal cancer involves a combination of chemotherapy, chemoradiation, and surgical resection to provide excellent local tumor control and overall survival. However, aspects of this multimodality approach are associated with significant morbidity and long-term sequelae. In addition, there is growing evidence that patients with a clinical complete response to chemotherapy and chemoradiation treatments may be safely offered initial non-operative management in a rigorous surveillance program. Weighed against the morbidity and significant sequelae of rectal resection, recognizing how to best optimize non-operative strategies without compromising oncologic outcomes is critical to our understanding and treatment of this disease.

ypTNM category combined with AJCC tumor regression grade for screening patients with the worst prognosis after neoadjuvant chemoradiation therapy for locally advanced rectal cancer

Background

The purpose of this study was to investigate the value of the postsurgical pathological T and N (ypTN) category combined with the American Joint Committee on Cancer-tumor regression grade (AJCC-TRG) in evaluating the prognosis of neoadjuvant chemoradiation therapy (NeoCRT) for locally advanced rectal cancer (LARC) to screen for a subgroup of patients with the worst prognosis.

Patients and methods

In total, 265 patients with LARC were enrolled in the trial. All patients received NeoCRT. Total mesorectal excision was performed 6-8 weeks after the completion of radiotherapy. The surgical specimens were re-evaluated based on the AJCC-TRG (seventh edition) and the AJCC-tumor-node-metastasis (TNM; seventh edition) systems. We followed up these patients and calculated their overall survival (OS), disease-free survival (DFS), local recurrence-free survival (RFS), and distant metastasis (DM)-free survival (MFS) rates through the Kaplan-Meier analysis. The logrank test was further applied to evaluate the predictive value of the ypTN stage combined with AJCC-TRG for several survival indexes.

Results

The median follow-up period was 65.1 months. The 5-year OS, DFS, RFS, and MFS rates were 79.4%, 68.8%, 94.4%, and 76.5%, respectively. There were significant differences in OS, DFS, and MFS rates among different ypT+AJCC-TRG and ypN+AJCC-TRG subgroups. The 5-year OS, DFS, and MFS rates for ypT3-4+TRG 1 and ypT3-4+TRG2-3 subgroups were 73.9% vs 65.3%, 61.2% vs 52.9%, and 65.0% vs 61.5%, respectively. The 5-year OS, DFS, and MFS rates for ypN1-2+TRG 0-1 and ypN1-2+TRG2-3 subgroups were 64.8% vs 54.1%, 44.9% vs 41.7%, and 61.4% vs 46.3%, respectively.

Conclusion

The ypTNM category combined with the AJCC-TRG can more accurately evaluate the prognosis of patients with LARC and identify the subgroup of patients with the worst prognosis and high risk of developing DM, thereby demonstrating clinical significance in guiding individualized postoperative adjuvant therapy and follow-up for LARC.

Identification of protein clusters predictive of tumor response in rectal cancer patients receiving neoadjuvant chemo-radiotherapy

Preoperative neoadjuvant chemoradiotherapy (nCRT) is the gold standard in locally advanced rectal cancer, only 10–30% of patients achieving benefits. Currently, there is a need of a reliable selection of markers for the identification of poor or non-responders prior to therapy. In this work, we compared protein profiles before therapy of patients differing in their responses to nCRT to find novel predictive markers of response to therapy. Patients were grouped into 3 groups according to their tumor regression grading (TRG) after surgery: 'TRG 1–2′, good responders, 'TRG 3′ and 'TRG 4′, poor responders. Paired surgical specimens of rectal cancer and healthy (histologically confirmed) rectal tissues from 15 patients were analysed before nCRT by two dimensional difference in gel electrophoresis followed by mass spectrometry. Thirty spots were found as differentially expressed (p < 0.05). Among them, 3 spots (spots 471, 683 and 684) showed an increased amount of protein in poor responders compared with good responders, and they were more tumor associated compared with healthy tissues. Proteins of these spots were identified as fibrinogen ß chain fragment D, actin isoforms, B9 and B5 serpins, cathepsin D isoforms and peroxiredoxin-4. In an independent validation set of 20 rectal carcinomas we validated the increased fibrinogen ß chain abundance before nCRT in poor responders by immunoblotting. In conclusion, we propose a risk-stratification tool in predicting the response to nCRT treatment in rectal cancer based on the quantity of these proteins.

Associations of tumor regression grade with outcomes in patients with locally advanced rectal cancer treated with preoperative two-week course of radiotherapy

Purpose

Studies concerning tumor regression grade (TRG) after two-week course of radiotherapy (RT) are limited. We tried to assess associations of TRG and outcomes in patients with locally advanced rectal cancer (LARC) treated with preoperative two-week course of RT.

Methods

356 consecutive LARC patients were retrospectively assessed. Patients with complete/intermediate (TRG1-3) and poor (TRG4-5) regressions were compared for overall survival (OS), disease-free survival (DFS) and metastasis-free survival (MFS).

Results

By univariate analysis, pretreatment and postoperative factors including TNM stages, ypT, ypN, surgical procedure, pathological grade, and TRG impacted survival outcomes. Complete/intermediate regressions (TRG1-3) had significantly improved survival outcomes compared with poor ones (TRG4-5) (5y-OS, 85.8% vs. 65.8%, P=0.001; 5y-DFS, 76.0% vs. 53.7%, P<0.001; 5y-MFS, 84.2% vs. 66.7%, P<0.001). Multivariate analysis showed that ypN (P<0.001) and pathological grade (P=0.018) were the most important independent prognostic factors for DFS. ypT (P=0.014) and ypN (P=0.001) were the independent prognostic factors for MFS. Meanwhile, ypT (P=0.009), ypN (P=0.001), surgical procedure (p=0.001), and TRG (p=0.019) were the independent prognostic factors for OS.

Conclusions

Complete/intermediate TRG regressions had a more favorable prognosis than the poor group. When treated with preoperative two-week course of RT; ypT, ypN, surgical procedure, and TRG seem to affect OS.

Modified 3-Point MRI-Based Tumor Regression Grade Incorporating DWI for Locally Advanced Rectal Cancer

OBJECTIVE

The purpose of this study was to evaluate the prognostic relevance of a modified 3-point MRI-based tumor regression grading system incorporating DWI for patients with locally advanced rectal cancer after preoperative chemoradiotherapy (CRT).

MATERIALS AND METHODS

Between March 2012 and September 2013, 118 consecutively registered patients with middle or lower locally advanced rectal cancer who underwent CRT followed by surgery were enrolled in this retrospective study. Two radiologists in consensus assessed MRI tumor regression grade (mrTRG) based on T2-weighted images and high b value DW images (0 and 1000 s/mm²) using the following grades: 0, complete regression (no obvious tumor); 1, intermediate regression (dominant fibrosis, regression > 50%); 2, poor regression (dominant tumor, regression ≤ 50%). Multivariate analysis with a Cox regression model was performed to evaluate the association between modified mrTRG and 3-year disease-free survival (DFS) rate. A Kaplan-Meier method with a log-rank test was used to compare the DFS rate between responder (grades 0 and 1) and nonresponder (grade 2) groups.

RESULTS

Both the accuracy (72.9% vs 38.1%; p < 0.001) and the interreader agreement (κ = 0.580 vs 0.338; p < 0.001) of modified 3-point mrTRG were improved over the established 5-point mrTRG. Modified mrTRG (adjusted hazard ratio, 2.505; 95% CI, 1.231-5.100) was independently associated with 3-year DFS rate (p = 0.011). There was also a significant difference in the 3-year DFS rate between responders (73.8%; 95% CI, 64.2-81.3%) and nonresponders (41.7%; 95% CI, 10.9-70.8%) (p = 0.028).

CONCLUSION

In patients with middle or lower locally advanced rectal cancer, the modified 3-point mrTRG incorporating DWI was independently associated with the 3-year DFS rate after CRT followed by surgery. The grading scale may be used as a surrogate for expected prognosis of preoperative CRT. Further prospective trials are warranted.

Tumor Regression Grade After Neoadjuvant Chemoradiation and Surgery for Low Rectal Cancer Evaluated by Multiple Correspondence Analysis: Ten Years as Minimum Follow-up

BACKGROUND

The role of Mandard's tumor regression grade (TRG) classification is still controversial in defining the prognostic role of patients who have undergone neoadjuvant chemoradiation (CRT) and total mesorectal excision. The present study evaluated multiple correspondence analysis (MCA) as a tool to better cluster variables, including TRG, for a homogeneous prognosis.

PATIENTS AND METHODS

A total of 174 patients with a minimum follow-up period of 10 years were stratified into 2 groups: group A (TRG 1-3) and group B (TRG 4-5) using Mandard's classification. Overall survival and disease-free survival were analyzed using univariate and multivariate analysis. Subsequently, MCA was used to analyze TRG plus the other prognostic variables.

RESULTS

The overall response to CRT was 55.7%, including 13.2% with a pathologic complete response. TRG group A correlated strictly with pN status (P = .0001) and had better overall and disease-free survival than group B (85.1% and 75.6% vs. 71.1% and 67.3%; P = .06 and P = .04, respectively). The TRG 3 subset (about one third of our series) showed prognostically heterogeneous behavior. In addition to multivariate analysis, MCA separated TRG 1 and TRG 2 versus TRG 4 and TRG 5 well and also allocated TRG 3 patients close to the unfavorable prognostic variables.

CONCLUSION

TRG classification should be used in all pathologic reports after neoadjuvant CRT and radical surgery to enrich the prognostic profile of patients with an intermediate risk of relapse and to identify patients eligible for more conservative treatment. Thus, MCA could provide added value.

Predictive clinical model of tumor response after chemoradiation in rectal cancer

Survival improvement in rectal cancer treated with neoadjuvant chemoradiotherapy (nCRT) is achieved only if pathological response occurs. Mandard tumor regression grade (TRG) proved to be a valid system to measure nCRT response. The ability to predict tumor response before treatment may significantly have impact the selection of patients for nCRT in rectal cancer. The aim is to identify potential predictive pretreatment factors for Mandard response and build a clinical predictive model design. 167 patients with locally advanced rectal cancer were treated with nCRT and curative surgery. Blood cell counts in peripheral blood were analyzed. Pretreatment biopsies expression of cyclin D1, epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) and protein 21 were assessed. A total of 61 single nucleotide polymorphisms were characterized using the Sequenom platform through multiplex amplification followed by mass-spectometric product separation. Surgical specimens were classified according to Mandard TRG. The patients were divided as: "good responders" (Mandard TRG1-2) and "poor responders" (Mandard TGR3-5). We examined predictive factors for Mandard response and performed statistical analysis. In univariate analysis, distance from anal verge, neutrophil lymphocyte ratio (NLR), cyclin D1, VEGF, EGFR, protein 21 and rs1810871 interleukin 10 (IL10) gene polymorphism are the pretreatment variables with predictive value for Mandard response. In multivariable analysis, NLR, cyclin D1, protein 21 and rs1800871 in IL10 gene maintain predictive value, allowing a clinical model design.

CONCLUSION

It seems possible to use pretreatment expression of blood and tissue biomarkers, and build a model of tumor response prediction to neoadjuvant chemoradiation in rectal cancer.

Potentiating the effects of radiotherapy in rectal cancer: the role of aspirin, statins and metformin as adjuncts to therapy

BACKGROUND

Complete tumour response (pCR) to neo-adjuvant chemo-radiotherapy for rectal cancer is associated with a reduction in local recurrence and improved disease-free and overall survival, but is achieved in only 20-30% of patients. Drug repurposing for anti-cancer treatments is gaining momentum, but the potential of such drugs as adjuncts, to increase tumour response to chemo-radiotherapy in rectal cancer, is only just beginning to be recognised.

METHODS

A systematic literature search was conducted and all studies investigating the use of drugs to enhance response to neo-adjuvant radiation in rectal cancer were included. 2137 studies were identified and following review 12 studies were extracted for full text review, 9 studies were included in the final analysis.

RESULTS

The use of statins or aspirin during neo-adjuvant therapy was associated with a significantly higher rate of tumour downstaging. Statins were identified as a significant predictor of pCR and aspirin users had a greater 5-year progression-free survival and overall survival. Metformin use was associated with a significantly higher overall and disease-free survival, in a subset of diabetic patients.

CONCLUSIONS

Aspirin, metformin and statins are associated with increased downstaging of rectal tumours and thus may have a role as adjuncts to neoadjuvant treatment, highlighting a clear need for prospective randomised controlled trials to determine their true impact on tumour response and overall survival.

High nodal positivity rates even in good clinical responders after chemoradiation of rectal cancer: is organ preservation feasible?

AIM

Local excision (LE) is emerging as a treatment option for rectal cancer responding well to chemoradiation. However, it does not address the mesorectal nodal burden. We aimed to identify the factors influencing nodal positivity and subsequently defined a low-risk group by including only patients at low risk.

METHOD

A single-centre, retrospective database analysis was carried out of patients with radically resected rectal cancer after neoadjuvant chemoradiation.

RESULTS

This study included 524 patients with predominantly low rectal tumours. Nodal positivity among ypT0, T1 and T2 groups was 14.7%, 28% and 30%, respectively. Multivariate analysis with stepwise logistic regression identified the following low-risk features: age ≥ 40 years, nonsignet ring cell carcinoma (SRCC) histology and pathological complete response (pCR). Sixty-nine patients fulfilling all three criteria were analysed and the nodal positivity was found to be 10.1%, which implies that, if these patients had been selected for LE, one in 10 would have had positive mesorectal nodes.

CONCLUSION

Even in patients with low-risk criteria (pCR, non-SRCC histology and age ≥ 40 years), the residual positive nodal disease burden is 10%. Whether this high incidence of residual nodal disease translates into a similar risk of locoregional recurrence if an organ-preservation strategy is adopted is unclear.

Correlation between tumor regression grade and rectal volume in neoadjuvant concurrent chemoradiotherapy for rectal cancer

PURPOSE

To determine whether large rectal volume on planning computed tomography (CT) results in lower tumor regression grade (TRG) after neoadjuvant concurrent chemoradiotherapy (CCRT) in rectal cancer patients.

MATERIALS AND METHODS

We reviewed medical records of 113 patients treated with surgery following neoadjuvant CCRT for rectal cancer between January and December 2012. Rectal volume was contoured on axial images in which gross tumor volume was included. Average axial rectal area (ARA) was defined as rectal volume divided by longitudinal tumor length. The impact of rectal volume and ARA on TRG was assessed.

RESULTS

Average rectal volume and ARA were 11.3 mL and 2.9 cm². After completion of neoadjuvant CCRT in 113 patients, pathologic results revealed total regression (TRG 4) in 28 patients (25%), good regression (TRG 3) in 25 patients (22%), moderate regression (TRG 2) in 34 patients (30%), minor regression (TRG 1) in 24 patients (21%), and no regression (TRG0) in 2 patients (2%). No difference of rectal volume and ARA was found between each TRG groups. Linear correlation existed between rectal volume and TRG (p = 0.036) but not between ARA and TRG (p = 0.058).

CONCLUSION

Rectal volume on planning CT has no significance on TRG in patients receiving neoadjuvant CCRT for rectal cancer. These results indicate that maintaining minimal rectal volume before each treatment may not be necessary.

Review of Neoadjuvant Chemotherapy Alone in Locally Advanced Rectal Cancer

BACKGROUND

Currently, the standard management of locally advanced rectal cancer (LARC) is neoadjuvant chemoradiotherapy followed by resection. Despite the significant improvement in local recurrence, survival benefits are not gained due to distant failure and radiotherapy-associated toxicity. Compliance to adjuvant chemotherapy after preoperative chemoradiotherapy is also poor. Neoadjuvant chemotherapy alone followed by surgery may be an alternative. The objective of this review is to determine the efficacy of neoadjuvant chemotherapy alone in operable LARC.

MATERIALS AND METHODS

Electronic databases searched (from database inception-December 2013) were Medline, PubMed, Embase, Scopus, Cochrane library, and the Clinical Trials Register. Specific journals were also hand searched. The selection criteria were studies published in English investigating stage II-III non-metastatic rectal cancer patients treated with neoadjuvant chemotherapy (oral, intravenous or rectal route) followed by curative resection. The primary outcome measure was tumour response. Secondary outcome measures included acute toxicity, operative morbidity, R0 resection, local recurrence, overall survival (OS) and disease-free survival (DFS).

RESULTS

One randomised phase III trial, six single-arm phase II trials and one retrospective case series study were eligible for inclusion. Six studies administered fluoropyrimidine-based multiple agent regimens and two studies administered fluorouracil-based monotherapy. The studies with multiple agents and stronger chemotherapy regimens (intravenous and/or oral) followed by delayed surgery showed better tumour response rates. The overall objective response rate was good and ranged from 62.5 to 93.7 %. Pathological complete response ranged from 3.8 to 33.3 %. The R0 resection and compliance rates were also high ranging from 90 to 100 % and 72 to 100 %, respectively. Grade 3-4 toxicities ranged from 2.3 to 39 %. Four- to 5-year OS and DFS ranged from 67.2 to 91 % and 60.5 to 84 %, respectively.

CONCLUSION

This review demonstrates that neoadjuvant chemotherapy could be affectively administered in LARC and could provide a good alternative to chemoradiotherapy in moderate-risk rectal cancers without compromising short- and long-term outcomes.

c-MET inhibition enhances the response of the colorectal cancer cells to irradiation in vitro and in vivo

The aim of the present study was to investigate the effect of hepatocyte growth factor receptor (c-MET) inhibition on the viability of colon cancer cells and xenografts exposed to irradiation using short hairpin (sh)RNA or the c-MET inhibitor PHA665752. The underlying mechanisms were also investigated. Human colorectal adenocarcinoma HT-29 cells were infected with a lentivirus expressing shRNAs against c-MET and were irradiated at 0, 2, 4, 6 and 8 Gy. The viability of the cells was assessed by alamarBlue® assays. Mice bearing human colon carcinoma SW620 xenografts were randomly selected to receive 2.5% dimethyl sulfoxide (DMSO), 25 mg/kg PHA665752 intraperitoneally once every 2 days for 3 weeks, irradiation at 10 Gy, or 25 mg/kg PHA665752 intraperitoneally once every 2 days for 3 weeks followed 24 h later by irradiation at 10 Gy. The mean tumor volume (MTV) was measured. The apoptotic rate of cells was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assays, and double stranded break marker antibody γ-H2AX and hypoxia inducible factor (HIF)-1α expression was examined by immunohistochemistry. alamarBlue assays revealed that c-MET downregulation by shRNA markedly accentuated the irradiation-induced reduction in the viability of HT-29 cells compared with HT-29 cells irradiated at the same doses (P<0.05). A combination of irradiation and PHA665752 caused an additional reduction in the MTV (382.8±42.4 mm3; P<0.01 vs. irradiation and PHA665752, 998.0±180.6 and 844.8±190.0 mm3, respectively). TUNEL assays revealed that irradiation and PHA665752 alone caused significant apoptosis of the SW620 cells in the tumor xenografts (P<0.01 vs. DMSO). The apoptotic index in the tumor xenografts of mice treated with a combination of irradiation and PHA665752 was significantly increased compared with mice treated with either agent alone (P<0.01). The combination of irradiation and PHA665752 was also associated with a marked increase in γ-H2AX levels and a significant decrease in HIF-1α expression in the xenografts (P<0.01). In conclusion, c-MET inhibition sensitizes colorectal cancer cells to irradiation by enhancing the formation of DNA double strand breaks and possibly alleviating tumor hypoxia.

Short-term Outcomes of an Extralevator Abdominoperineal Resection in the Prone Position Compared With a Conventional Abdominoperineal Resection for Advanced Low Rectal Cancer: The Early Experience at a Single Institution

Purpose

This study compared the perioperative and pathologic outcomes between an extralevator abdominoperineal resection (APR) in the prone position and a conventional APR.

Methods

Between September 2011 and March 2014, an extralevator APR in the prone position was performed on 13 patients with rectal cancer and a conventional APR on 26 such patients. Patients' demographics and perioperative and pathologic outcomes were obtained from the colorectal cancer database and electronic medical charts.

Results

Age and preoperative carcinoembryonic antigen (CEA) level were significantly different between the conventional and the extralevator APR in the prone position (median age, 65 years vs. 55 years [P = 0.001]; median preoperative CEA level, 4.94 ng/mL vs. 1.81 ng/mL [P = 0.011]). For perioperative outcomes, 1 (3.8%) intraoperative bowel perforation occurred in the conventional APR group and 2 (15.3%) in the extralevator APR group. In the conventional and extralevator APR groups, 12 (46.2%) and 6 patients (46.2%) had postoperative complications, and 8 (66.7%) and 2 patients (33.4%) had major complications (Clavien-Dindo III/IV), respectively. The circumferential resection margin involvement rate was higher in the extralevator APR group compared with the conventional APR group (3 of 13 [23.1%] vs. 3 of 26 [11.5%]).

Conclusion

The extralevator APR in the prone position for patients with advanced low rectal cancer has no advantages in perioperative and pathologic outcomes over a conventional APR for such patients. However, through early experience with a new surgical technique, we identified various reasons for the lack of favorable outcomes and expect sufficient experience to produce better peri- or postoperative outcomes.

Pathological Assessment of the AJCC Tumor Regression Grading System After Preoperative Chemoradiotherapy for Chinese Locally Advanced Rectal Cancer

We used American Joint Committee on Cancer (AJCC) Staging Manual system to assess the prognostic significance of tumor regression grading (TRG) for locally advanced rectal cancer (LARC) (T3/4 or N+) patients who were treated with preoperative chemoradiotherapy (CRT).The 4 AJCC-TRG classifications were evaluated on surgical specimens from 295 LARC patients receiving CRT. Overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were estimated using Kaplan-Meier method and Cox regression model.Classifications of TRG 0, 1, 2, and 3 were found in 27.5%, 19.3%, 45.7%, and 7.5% of the resected specimens, respectively. Three-year OS was 95.5% for TRG0, 91.5% for TRG1, 84.8% for TRG2, and 85.7% for TRG3 (P = 0.035). Three-year DFS was 89.0% for TRG0, 74.4% for TRG1, 70.9% for TRG2, and 62% for TRG3 (P = 0.018). By multivariate analysis, AJCC-TRG (P = 0.033), residual lymph node metastasis (ypN+) (P < 0.001) and pretreatment CA19-9 level (P = 0.035) were significant predictors of OS. Pathological T category (P = 0.006) and nodal status (P < 0.001) after CRT were the most important independent prognostic factors for DFS.AJCC-TRG is a prognostic factor for LARC patients receiving CRT, independent of pathological staging.

Therapy-Induced Cellular Senescence Induces Epithelial-to-Mesenchymal Transition and Increases Invasiveness in Rectal Cancer

INTRODUCTION

DNA damaging agents and ionizing radiation used in the therapy of human cancers can induce senescence of cancer cells. Senescent cells exhibit a secretory phenotype (senescence-associated secretome [SAS]) that can affect cancer cell behavior and, eventually, clinical prognosis. We assessed the effects of the SAS on the induction of epithelial-to-mesenchymal transition (EMT) in vitro and in clinical samples from patients with rectal cancer who had undergone neoadjuvant chemoradiotherapy (CRT).

MATERIALS AND METHODS

Colorectal cancer cells (HCT 116) were induced into senescence by exposure to either 5-fluorouracil (5-FU) or doxorubicin. The senescent state was confirmed by staining for senescence-associated β-galactosidase (SA-β-Gal). The paracrine effects of SASs were assessed on proliferating HCT 116 cells. The quantified parameters were cell proliferation, invasive capacity, and induction of EMT. Senescence and EMT in clinical samples were assessed by the expression levels (reverse transcriptase-quantitative polymerase chain reaction) of genes related to senescence and EMT after laser-assisted microdissection of cancer cell clusters that stained either positive or negative for SA-β-Gal.

RESULTS

We have shown that cultured colon cancer cells induced into senescence by exposure to 5-FU exhibit a SAS capable of paracrine induction of EMT in colon and rectal cancer cell lines and increased cell invasion in vitro. Using laser-assisted microdissection, we found that in rectal cancer samples from patients treated with neoadjuvant CRT, tumor cell niches enriched for senescent cells bookmark regions of increased mRNA expression levels of EMT-related proteins (Slug, Snail, vimentin) compared with the nearby senescent-null tumor cell niches.

CONCLUSION

We have provided, first-hand, strongly suggestive evidence that senescent cancer cells emerging in the context of neoadjuvant CRT for rectal cancer influenced the tumor microenvironment by promoting EMT by way of short-range interactions.

Response to chemoradiotherapy and lymph node involvement in locally advanced rectal cancer

AIM: To establish the association between lymph node involvement and the response to neoadjuvant therapy in locally advanced rectal cancer.

METHODS: Data of 130 patients with mid and low locally advanced rectal adenocarcinoma treated with neoadjuvant chemoradiation followed by radical surgery over a 5-year period were reviewed. Tumor staging was done by endorectal ultrasound and/or magnetic resonance imaging. Tumor response to neoadjuvant therapy was determined by T-downstaging and tumor regression grading (TRG). Pathologic complete response (pCR) is defined as the absence of tumor cells in the surgical specimen (ypT0N0). The varying degrees TRG were classified according to Mandard’s scoring system. The evaluation of the response is based on the comparison between previous clinico-radiological staging and the results of pathological evaluation. χ² and Spearman’s correlation tests were used for the comparison of variables.

RESULTS: Pathologic complete response (pCR, ypT0N0, TRG1) was observed in 19 cases (14.6%), and other 18 (13.8%) had only very few residual malignant cells in the rectal wall (TRG2). T-downstaging was found in 63 (48.5%). Mean lymph node retrieval was 9.4 (range 0-38). In 37 cases (28.5%) more than 12 nodes were identified in the surgical specimen. Preoperative lymph node involvement was seen in 77 patients (59.2%), 71 N1 and 6 N2. Postoperative lymph node involvement was observed in 41 patients (31.5%), 29 N1 and 12 N2, while the remaining 89 were N0 (68.5%). In relation to ypT stage, we found nodal involvement of 9.4% in ypT0-1, 22.2% in ypT2 and 43.7% in ypT3-4. Of the 37 patients considered “responders” to neoadjuvant therapy (TRG1 and 2), there were only 4 N+ (10.8%) and the remainder N0 (89.2%). In the “non responders” group (TRG 3, 4 and 5), 37 cases were N+ (39.8%) and 56 (60.2%) were N0 (P < 0.001).

CONCLUSION: Response to neoadjuvant chemoradiation in rectal cancer is associated with lymph node involvement.

Can perfusion MRI predict response to preoperative treatment in rectal cancer?

BACKGROUND AND PURPOSE

Dynamic contrast-enhanced MRI (DCE-MRI) provides information on perfusion and could identify good prognostic tumors. Aim of this study was to evaluate whether DCE-MRI using a novel blood pool contrast-agent can accurately predict the response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer.

MATERIALS AND METHODS

Thirty patients underwent DCE-MRI before and 7-10weeks after chemoradiotherapy. Regions of interest were drawn on DCE-MRI with T2W-images as reference. DCE-MRI-based kinetic parameters (initial slope, initial peak, late slope, and AUC at 60, 90, and 120s) determined pre- and post-CRT and their Δ were compared between good (TRG1-2) and poor (TRG3-5) responders. Optimal thresholds were determined and sensitivities, specificities, positive predictive values (PPV), and negative predictive values (NPV) were calculated.

RESULTS

Pre-therapy, the late slope was able to discriminate between good and poor responders (-0.05×10(-3) vs. 0.62×10(-3), p<0.001) with an AUC of 0.90, sensitivity 92%, specificity 82%, PPV 80%, and NPV 93%. Other pre-CRT parameters showed no significant differences, nor any post-CRT parameters or their Δ.

CONCLUSIONS

The kinetic parameter 'late slope' derived from DCE-MRI could potentially be helpful to predict before the onset of neoadjuvant chemoradiotherapy which tumors are likely going to respond. This could allow for personalized treatment-options in rectal cancer patients.

Comparison of tumor regression grade systems for locally advanced rectal cancer after multimodality treatment

BACKGROUND

Tumor regression grade (TRG) is a measure of histopathological response of rectal cancer to neoadjuvant chemoradiation and is associated with outcomes. Several TRG systems are used: Mandard (5,3-tier), Dowrak/Rödel (5,3-tier), Memorial Sloan Kettering Cancer Center (MSKCC), and American Joint Committee on Cancer (AJCC) Cancer Staging. A single measure of rectal cancer response would assist in comparing results across institutions, and in designing future rectal cancer studies. In this study, the predictive accuracies of the various published classification schemes are compared.

METHODS

Review of a prospective database identified 563 patients with locally advanced rectal cancer (T3/4 and/or N1) treated between 1998 and 2007 with long-course chemoradiation and total mesorectal excision. TRG was determined by measuring proportion of tumor mass replaced by fibrosis. Patients were classified into TRG schemes, which were compared by analyzing association with recurrence and survival using concordance index. Probabilities of recurrence-free survival were estimated using the Kaplan-Meier method. All statistical tests were two-sided.

RESULTS

All TRG systems were predictive of recurrence. Concordance indices of the three-tier Mandard, three-tier Dowrak/Rödel, three-tier MSKCC, and four-tier AJCC systems were: 0.665, 0.653, 0.683, and 0.694, respectively (higher number = better prediction). The AJCC system more accurately predicted recurrence than the three-tier Mandard (P = .002) or Dowrak/Rödel (P = .006) and had a higher concordance index than MSKCC, although this did not reach statistical significance (P = .068).

CONCLUSION

When classifying rectal cancer response to chemoradiation, the AJCC Staging Manual (7(th) edition) system is most accurate and should be adopted as the standard.

Long-term results of a randomized trial in locally advanced rectal cancer: no benefit from adding a brachytherapy boost

PURPOSE/OBJECTIVE(S)

Mature data on tumor control and survival are presented from a randomized trial of the addition of a brachytherapy boost to long-course neoadjuvant chemoradiation therapy (CRT) for locally advanced rectal cancer.

METHODS AND MATERIALS

Between March 2005 and November 2008, 248 patients with T3-4N0-2M0 rectal cancer were prospectively randomized to either long-course preoperative CRT (50.4 Gy in 28 fractions, per oral tegafur-uracil and L-leucovorin) alone or the same CRT schedule plus a brachytherapy boost (10 Gy in 2 fractions). The primary trial endpoint was pathologic complete response (pCR) at the time of surgery; secondary endpoints included overall survival (OS), progression-free survival (PFS), and freedom from locoregional failure.

RESULTS

Results for the primary endpoint have previously been reported. This analysis presents survival data for the 224 patients in the Danish part of the trial. In all, 221 patients (111 control arm, 110 brachytherapy boost arm) had data available for analysis, with a median follow-up time of 5.4 years. Despite a significant increase in tumor response at the time of surgery, no differences in 5-year OS (70.6% vs 63.6%, hazard ratio [HR] = 1.24, P=.34) and PFS (63.9% vs 52.0%, HR=1.22, P=.32) were observed. Freedom from locoregional failure at 5 years were 93.9% and 85.7% (HR=2.60, P=.06) in the standard and in the brachytherapy arms, respectively. There was no difference in the prevalence of stoma. Explorative analysis based on stratification for tumor regression grade and resection margin status indicated the presence of response migration.

CONCLUSIONS

Despite increased pathologic tumor regression at the time of surgery, we observed no benefit on late outcome. Improved tumor regression does not necessarily lead to a relevant clinical benefit when the neoadjuvant treatment is followed by high-quality surgery.

Integrated ¹⁸F-FDG PET/perfusion CT for the monitoring of neoadjuvant chemoradiotherapy in rectal carcinoma: correlation with histopathology

PURPOSE

The aim of this study was to prospectively monitor changes in the flow-metabolic phenotype (ΔFMP) of rectal carcinoma (RC) after neoadjuvant chemoradiotherapy (CRT) and to evaluate whether ΔFMP of RC correlate with histopathological prognostic factors including response to CRT.

METHODS

Sixteen patients with RC (12 men, mean age 60.7 ± 12.8 years) underwent integrated (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/perfusion CT (PET/PCT), followed by neoadjuvant CRT and surgery. In 13 patients, PET/PCT was repeated after CRT. Perfusion [blood flow (BF), blood volume (BV), mean transit time (MTT)] and metabolic [maximum and mean standardized uptake values (SUVmax, SUVmean)] parameters as well as the FMP (BF × SUVmax) were determined before and after CRT by two independent readers and correlated to histopathological prognostic factors of RC (microvessel density, necrosis index, regression index, vascular invasion) derived from resected specimens. The diagnostic performance of ΔFMP for prediction of treatment response was determined.

RESULTS

FMP significantly decreased after CRT (p < 0.001), exploiting higher changes after CRT as compared to changes of perfusion and metabolic parameters alone. Before CRT, no significant correlations were found between integrated PET/PCT and any of the histopathological parameters (all p > 0.05). After CRT, BV and SUVmax correlated positively with the necrosis index (r = 0.67/0.70), SUVmax with the invasion of blood vessels (r = 0.62) and ΔFMP with the regression index (r = 0.88; all p < 0.05). ΔFMP showed high accuracy for prediction of histopathological response to CRT (AUC 0.955, 95 % confidence interval 0.833-1.000, p < 0.01) using a cut-off value of -75%.

CONCLUSION

In RC, ΔFMP derived from integrated (18)F-FDG PET/PCT is useful for monitoring the effects of neoadjuvant CRT and allows prediction of histopathological response to CRT.

Prognostic value of mandard and dworak tumor regression grading in rectal cancer: study of a single tertiary center

Goal. To evaluate the prognostic value of Mandard and Dworak grading systems regarding neoadjuvant chemoradiotherapy (CRT) response on rectal cancer. Materials and Methods. We queried our center's database for patients with colo rectal cancer with locally advanced rectal cancer (LARC) who received neoadjuvant CRT followed by total mesorectum excision (TME) between 2003 and 2011. After excluding 18 patients from the initial query the remaining 139 were reassessed for disease recurrence and survival; the specimens' slides were reviewed and classified according to two tumor regression grading (TRG) systems: Mandard and Dworak. Based on these TRG scores, two patient groups were created: patients with good response versus patients with bad response (Mandard TRG1+2 versus Mandard TRG3+4+5 and Dworak TRG4+3 versus Dworak TRG2+1+0). Overall survival (OS), disease-free survival (DFS), and disease recurrence were then evaluated. Results. Mean age was 64.2 years and median follow up was 56 months. No significant survival difference was found when comparing patients with Dworak TRG 4+3 versus Dworak TRG2+1+0 (P = 0.10). Mandard TRG1+2 presented with significantly better OS and DFS than Mandard TRG3+4+5 (OS P = 0.013; DFS P = 0.007). Conclusions. Mandard system provides higher accuracy over Dworak system in predicting rectal cancer prognosis when neoadjuvant CRT is applied for tumor regression.

Mandard tumour regression grade, perineural invasion, circumferential resection margin and post-chemoradiation nodal status strongly predict outcome in locally advanced rectal cancer treated with preoperative chemoradiotherapy

AIMS

The pathology of tumours after chemo/radiotherapy for locally advanced rectal cancer can be difficult to interpret. The ypTNM staging does not accurately predict outcomes. Therefore, we developed a new prognostic index for this purpose.

MATERIALS AND METHODS

The Nottingham Rectal Cancer Prognostic Index (NRPI) is based on a study of 158 patients with locally advanced rectal cancer treated with preoperative chemo/radiotherapy at Nottingham University Hospital between April 2001 and December 2008. Patients were treated with radiotherapy to a dose of 50 Gy in 25 fractions over 5 weeks with/without concurrent capecitabine chemotherapy. Surgery was carried out after an interval of 6-10 weeks. Factors found to be significant on univariate analysis to predict for disease-free (DFS) and overall survival were further explored in multivariate analysis. The significant factors (Mandard tumour regression grade, perineural invasion, circumferential resection margin status and nodal status) were weighted to establish a score for the index. The median follow-up was 40 months (range 3-90 months).

RESULTS

On survival analysis, four distinct prognostic groups were found: Score 0 = excellent prognosis, 1-3 = good prognosis, 4-8 = moderate prognosis, 9-14 = poor prognosis. The NRPI significantly predicted both DFS and overall survival (P < 0.0001). DFS at 5 years was 95, 63, 25 and 0% for the four groups. On multivariate analysis the NRPI was found to be the strongest predictor of DFS including nodal and circumferential resection margin status (P < 0.0001). It was a stronger predictor of overall survival than the American Joint Committee on Cancer/Dukes staging (P < 0.0001).

CONCLUSIONS

The NRPI allocates patients into distinct prognostic categories. This seems to be a much stronger predictive factor than the American Joint Committee on Cancer/Dukes staging. This requires further validation, but seems to be a useful clinical index for future studies.

DNA content analysis of colorectal cancer defines a distinct 'microsatellite and chromosome stable' group but does not predict response to radiotherapy

Colorectal cancers (CRC) are thought to have genetic instability in the form of either microsatellite instability (MSI) or chromosomal instability (CIN). Recently, tumours have been described without either MSI or CIN, that is, microsatellite and chromosome stable (MACS) CRCs. We investigated the (i) frequency of the MACS-CRCs and (ii) whether this genotype predicted responsiveness to neoadjuvant chemoradiotherapy. To examine the frequency of MACS-CRCs, DNA content (ploidy) was examined in 89 sporadic microsatellite-stable CRCs using flow cytometry. The tumours were also screened for mutations in KRAS/BRAF/TP53/PIK3CA by QMC-PCR. To examine the value of tumour ploidy in predicting response to chemoradiotherapy, DNA content was tested in a separate group of 62 rectal cancers treated with neoadjuvant chemoradiotherapy. Fifty-one of 89 CRCs (57%) were aneuploid and 38 (43%) were diploid. There was no significant association between mutations in TP53/KRAS/BRAF/PIK3CA and ploidy. Testing of association between mutations revealed only mutual exclusivity of KRAS/BRAF mutation (P < 0.001). Of the 62 rectal cancers treated with neoadjuvant chemoradiotherapy, 22 had responded (Mandard tumour regression grade 1/2) and 40 failed to respond (Grade 3-5). Twenty-five of 62 (40%) tumours were diploid, but there was no association between ploidy and response to therapy. We conclude that MACS-CRCs form a significant proportion of microsatellite-stable CRCs with a mutation profile overlapping that of CRCs with CIN. A diploid genotype does not, however, predict the responsiveness to radiotherapy.

The prognostic value of tumour regression grade following neoadjuvant chemoradiation therapy for rectal cancer

AIM

To date, there is no uniform consensus on whether tumour regression grade (TRG) is predictive of outcome in rectal cancer. Furthermore, the lack of standardization of TRG grading is a major source of variability in published studies. The aim of this study was to evaluate the prognostic impact of TRG in a cohort of patients with locally advanced rectal cancer treated with neoadjuvant chemoradiation therapy (CRT). In addition to the Mandard TRG, we utilized four TRG systems modified from the Mandard TRG system and applied them to the cohort to assess which TRG system is most informative.

METHOD

One-hundred and fifty-three patients with a T3/T4 and/or a node-positive rectal cancer underwent neoadjuvant 5-fluorouracil-based CRT followed by surgical resection.

RESULTS

Thirty-six (23.5%) patients achieving complete pathological response (ypCR) had a 5-year disease-free survival (DFS) rate of 100% compared with a DFS rate of 74% for 117 (76.5%) patients without ypCR (P = 0.003). The Royal College of Pathologists (RCPath) TRG best condenses the Mandard five-point TRG by stratifying patients into three groups with distinct 5-year DFS rates of 100%, 86% and 67%, respectively (P = 0.001). In multivariate analysis, pathological nodal status and circumferential resection margin (CRM) status, but not TRG, remained significant predictors of DFS (P = 0.002, P = 0.035 and P = 0.310, respectively).

CONCLUSION

Our findings support the notion that ypCR status, nodal status after neoadjuvant CRT and CRM status, but not TRG, are predictors of long-term survival in patients with locally advanced rectal cancer.

Tumor regression grades: can they influence rectal cancer therapy decision tree?

Background. Evaluating impact of tumor regression grade in prognosis of patients with locally advanced rectal cancer (LARC). Materials and Methods. We identified from our colorectal cancer database 168 patients with LARC who received neoadjuvant therapy followed by complete mesorectum excision surgery between 2003 and 2011: 157 received 5-FU-based chemoradiation (CRT) and 11 short course RT. We excluded 29 patients, the remaining 139 were reassessed for disease recurrence and survival; the slides of surgical specimens were reviewed and classified according to Mandard tumor regression grades (TRG). We compared patients with good response (Mandard TRG1 or TRG2) versus patients with bad response (Mandard TRG3, TRG4, or TRG5). Outcomes evaluated were 5-year overall survival (OS), disease-free survival (DFS), local, distant and mixed recurrence. Results. Mean age was 64.2 years, and median followup was 56 months. No statistically significant survival difference was found when comparing patients with Mandard TRG1 versus Mandard TRG2 (p = .77). Mandard good responders (TRG1 + 2) have significantly better OS and DFS than Mandard bad responders (TRG3 + 4 + 5) (OS p = .013; DFS p = .007). Conclusions. Mandard good responders had a favorable prognosis. Tumor response (TRG) to neoadjuvant chemoradiation should be taken into account when defining the optimal adjuvant chemotherapy regimen for patients with LARC.

Lack of M30 expression correlates with factors reflecting tumor progression in rectal cancer with preoperative chemoradiotherapy

Preoperative chemoradiotherapy (CRT) is an effective tool for local control that functions by inducing cancer cell apoptosis and inhibiting cell growth. The aim of this study was to evaluate the expression of caspase-cleaved keratin 18 cytoskeletal protein, M30, which is known as an apoptotic marker in residual rectal cancer following preoperative CRT. A total of 72 patients with rectal cancer who had undergone preoperative CRT were enrolled in this study. Immunostaining with M30 cytodeath antibody was performed and the correlation between M30 staining and clinicopathological variables was analyzed. Furthermore, we examined the correlation of M30 staining with the expression of Bax, Bcl-2, Ki67 and PCNA using transcriptional and immunohistochemical analyses. The results showed that 34 (47%) patients were positive for M30 staining. Lack of M30 expression was significantly correlated with advanced T stage, postoperative stage and tumor recurrence (P<0.05). Patients with M30 staining had better recurrence-free survival (RFS) than those without it (P=0.0301). In the immunohistochemical analysis, residual cancer cells with M30 staining lacked Ki67 expression. No significant correlation was observed between M30 positivity and the gene expression of apoptotic and proliferative markers. In conclusion, findings of the present study suggested that the evaluation of M30 expression may be useful in the prediction of tumor recurrence in rectal cancer patients who have been treated with preoperative CRT.

Prognostic significance of partial tumor regression after preoperative chemoradiotherapy for rectal cancer: a meta-analysis

BACKGROUND

Complete tumor regression after preoperative chemoradiotherapy for rectal cancer has been associated with better disease-free and overall survival. The survival experience for patients with partial tumor regression is less clear.

OBJECTIVE

The aim of this meta-analysis was to evaluate the prognostic significance of partial response after preoperative chemotherapy on disease-free survival in rectal cancer patients.

DATA SOURCES

Relevant studies were identified by a search of MEDLINE and EMBASE databases with no restrictions to October 31, 2012.

STUDY SELECTION

We included long-course radiotherapy that reported the association between degree of tumor regression and disease-free survival of rectal cancer.

INTERVENTIONS

Direct, indirect, and graph methods were used to extract HRs.

MAIN OUTCOME MEASURES

Study-specific HRs on the disease-free survival were pooled using a random-effects model. Eleven articles in total were selected. Analysis was performed first among the 6 studies that separated partial response from the complete response and later among all 11 of the studies.

RESULTS

Pooled HR was 0.49 (95% CI, 0.28-0.85) for the 6 studies that compared partial response with poor response. It was 0.41 (95% CI, 0.25-0.67) when all 11 of the studies were analyzed together.

LIMITATIONS

The studies were limited by not being prospective, randomized trials, and the tumor regression grades were not uniform.

CONCLUSIONS

Partial tumor response is associated with a 50% improvement in disease-free survival and should be considered as a favorable prognostic factor.

Response of glutathione S-transferase Pi (GSTP1) to neoadjuvant therapy in rectal adenocarcinoma

AIM

The response of rectal adenocarcinoma to neoadjuvant therapy is variable. Accurate prediction of response would enable selective administration of therapy. The enzyme glutathione S-transferase Pi (GSTP1) has been shown to influence response to therapy in some solid tumours. Few data are available for rectal cancer.

METHOD

The GSTP1 levels in rectal adenocarcinoma and adjacent normal mucosa were quantified before and after exposure to neoadjuvant therapy. Venous blood samples and biopsies of normal rectal mucosa and tumour were prospectively obtained from patients with primary rectal cancer. Patients were stratified by exposure to neoadjuvant therapy or surgery alone. GSTP1 was quantitatively measured using an enzyme-linked immunosorbent assay.

RESULTS

Ninety-two patients (54 men; median age 68 years) were recruited. The median GSTP1 level was significantly higher in rectal adenocarcinoma than in matched normal mucosa [6.59 μg/mg vs 4.57 μg/mg; P < 0.001]. The median tumour GSTP1 level was significantly lower in the therapy group compared with unmatched samples from the no-therapy group [4.47 μg/mg vs 7.76 μg/mg; P < 0.001].

CONCLUSION

The GSTP1 level is increased in rectal adenocarcinoma compared with adjacent normal mucosa. It decreases following neoadjuvant therapy. Future studies correlating pre-therapy GSTP1 levels with pathological response would be of interest.

Treatment of locally advanced rectal cancer: Controversies and questions

Rectal cancers extending through the rectal wall, or involving locoregional lymph nodes (T3/4 or N1/2), have been more difficult to cure. The confines of the bony pelvis and the necessity of preserving the autonomic nerves makes surgical extirpation challenging, which accounts for the high rates of local and distant relapse in this setting. Combined multimodality treatment for rectal cancer stage II and III was recommended from National Institute of Health consensus. Neoadjuvant chemoradiation using fluoropyrimidine-based regimen prior to surgical resection has emerged as the standard of care in the United States. Optimal time of surgery after neoadjuvant treatment remained unclear and prospective randomized controlled trial is ongoing. Traditionally, 6-8 wk waiting period was commonly used. The accuracy of studies attempting to determine tumor complete response remains problematic. Currently, surgery remains the standard of care for rectal cancer patients following neoadjuvant chemoradiation, whereas observational management is still investigational. In this article, we outline trends and controversies associated with optimal pre-treatment staging, neoadjuvant therapies, surgery, and adjuvant therapy.

The utility of diagnostic biopsy specimens for predictive molecular testing in colorectal cancer

AIMS

If stratified medicine is to be applied in the neoadjuvant setting, predictive testing will have to be undertaken on preoperative diagnostic biopsy specimens. The aim of this study was to evaluate whether a diagnostic biopsy was adequately representative of the main tumour in colorectal cancer.

METHODS AND RESULTS

Thirty cases of paired biopsy and subsequent resection specimens were randomly selected. Samples were screened for mutation in KRAS (codons 12/13, 61, and 146), BRAF (codon 600 and exon 11), PIK3CA (exons 1, 9, and 20), TP53 (exons 5-8), and microsatellite instability, using the quick multiplex consensus or standard polymerase chain reaction (PCR) protocols followed by high-resolution melting analysis. A total of 570 paired PCR tests were performed for mutation detection, and identical results were obtained in both biopsy and resection specimens in 569 tests (>99% concordance). Four cases (13%) showed microsatellite instability, and, in all four cases, instability was seen at identical mononucleotide markers in both biopsy and matched resection specimens.

CONCLUSIONS

This is the first study to show that diagnostic biopsy specimens, even though they are a tiny sample of the tumour, are sufficiently representative for use in predictive testing for early driver mutations in colorectal cancer.