Nomogram to predict ypN status after chemoradiation in patients with locally advanced rectal cancer. Br J Cancer. 2014;111:249-254. [PMID: 24967873 PMCID: PMC4102937 DOI: 10.1038/bjc.2014.256]

Development and validation of neoadjuvant rectal score-based signature nomograms to predict overall survival and disease-free survival in locally advanced rectal cancer: a retrospective, double center, cohort study

AIM

To evaluate the prognostic significance of the NAR score and develop nomograms for locally advanced rectal cancer (LARC) treated after neoadjuvant chemo-radiotherapy (nCRT) combined with total meso-rectal excision (TME) surgery to predict prognostic.

METHODS

Retrospective collection among LARC patients treated at Fujian Medical University Union Hospital (training cohort) and Fujian Medical University Affiliated Zhangzhou Hospital (external validation cohort) between Jan 10, 2011 and Dec 28, 2021. The NAR score was calculated by formula: [5pN-3(cT-pT) + 12]^2/9.61. NAR score low (< 8), intermediate (8-16), and high (> 16).

RESULTS

1665 patients in the training cohort and 256 patients in the external validation cohorts were enrolled. Lower NAR score was significantly associated with better cumulative incidence of OS, DFS, local recurrence (LR), and distant metastasis (DM) (all P < 0.001). Multivariate Cox regression analysis indicates that NAR score, distance to the anal verge, no.253 LN metastasis, post-CRT carbohydrate antigen 19-9, tumor regression grade, and surgery method are independent predictors of OS and DFS (all P < 0.001). Among these independent factors, the NAR score had the highest area under the curve (AUC) and the nomograms to predict OS and DFS were generated. The AUCs for the accuracy of the prediction OS were 1 year = 0.742, 3 years = 0.749, 5 years = 0.713; prediction DFS were 1 year = 0.727, 3 years = 0.739, 5 years = 0.718, the models have good accuracy.

CONCLUSIONS

The NAR score can effectively classify patients with LARC into groups with varying outcomes of OS, DFS, LR, and DM. Moreover, the novel nomograms comprising the NAR score were developed and validated to help predict OS and DFS.

Lymph node regression grading of locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

Neoadjuvant chemoradiotherapy (nCRT) and total rectal mesenteric excision are the main standards of treatment for locally advanced rectal cancer (LARC). Lymph node regression grade (LRG) is an indicator of prognosis and response to preoperative nCRT based on postsurgical metastatic lymph node pathology. Common histopathological findings in metastatic lymph nodes after nCRT include necrosis, hemorrhage, nodular fibrosis, foamy histiocytes, cystic cell reactions, areas of hyalinosis, residual cancer cells, and pools of mucin. A number of LRG systems designed to classify the amount of lymph node regression after nCRT is mainly concerned with the relationship between residual cancer cells and regressive fibrosis and with estimating the number of lymph nodes existing with residual cancer cells. LRG offers significant prognostic information, and in most cases, LRG after nCRT correlates with patient outcomes. In this review, we describe the systematic classification of LRG after nCRT, patient prognosis, the correlation with tumor regression grade, and the typical histopathological findings of lymph nodes. This work may serve as a reference to help predict the clinical complete response and determine lymph node regression in patients based on preservation strategies, allowing for the formulation of more accurate treatment strategies for LARC patients, which has important clinical significance and scientific value.

A nomogram for predicting good response after neoadjuvant chemoradiotherapy for locally advanced rectal cancer: a retrospective, double-center, cohort study

AIM

The purpose of this study was to explore the clinical factors associated with achieving good response after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer (LARC) and to develop and validate a nomogram.

METHODS

A total of 1724 consecutive LARC patients treated at Fujian Medical University Union Hospital from January 2010 to December 2021 were retrospectively evaluated as the training cohort; 267 consecutive LARC patients treated at Zhangzhou Affiliated Hospital of Fujian Medical University during the same period were evaluated as the external 2 cohorts. Based on the pathological results after radical surgery, treatment response was defined as follows: good response, stage ypT0∼2N0M0 and poor response, ypT3∼4N0M0 and/or N positive. Independent influencing factors were analyzed by logistic regression, a nomogram was developed and validated, and the model was evaluated using internal and external data cohorts for validation.

RESULTS

In the training cohort, 46.6% of patients achieved good response after nCRT combined with radical surgery. The rate of the retained anus was higher in the good response group (93.5% vs. 90.7%, P < 0.001). Cox regression analysis showed that the risk of overall survival and disease-free survival was significantly lower among good response patients than poor response patients, HR = 0.204 (95%CI: 0.146-0.287). Multivariate logistic regression analysis showed an independent association with 9 clinical factors, including histopathology, and a nomogram with an excellent predictive response was developed accordingly. The C-index of the predictive accuracy of the nomogram was 0.764 (95%CI: 0.742-0.786), the internal validation of the 200 bootstrap replication mean C-index was 0.764, and the external validation cohort showed an accuracy C-index of 0.789 (95%CI: 0.734-0.844), with good accuracy of the model.

CONCLUSION

We identified factors associated with achieving good response in LARC after treatment with nCRT and developed a nomogram to contribute to clinical decision-making.

Diagnostic Efficiency of Diffusion Sequences and a Clinical Nomogram for Detecting Lymph Node Metastases from Rectal Cancer

RATIONALE AND OBJECTIVES

First, to evaluate and compare three different diffusion sequences (i.e., standard DWI, IVIM, and DKI) for nodal staging. Second, to combine the DWI, and anatomic information to assess metastatic lymph node (LN).

MATERIALS AND METHODS

We retrospectively identified 136 patients of rectal adenocarcinoma who met the inclusion criteria. Three diffusion sequences (i.e., standard DWI, IVIM, and DKI) were performed, and quantitative parameters were evaluated. Univariate and multivariate analyses were used to assess the associations between the anatomic and DWI information and LN pathology. Multivariate logistic regression was used to identify independent risk factors. A nomogram model was established, and the model performance was evaluated by the concordance index (c-index) and calibration curve.

RESULTS

There was a statistical difference in variables (LN long diameter, LN short diameter, LN boundary, LN signal, peri-LN signal intensity, ADC_-1000, ADC_-1400, ADC_-2000, K_app and D) between metastatic and non-metastatic LN for training and validation cohorts (p < 0.05). The ADC value derived from b = 1000 mm/s (ADC_-1000) showed the relative higher AUC (AUC = 0.780) than the ADC value derived from b = 1400 mm/s (ADC_-1400) (AUC = 0.703). The predictive accuracy of the nomogram measured by the c-index was 0.854 and 0.812 in the training and validation cohort, respectively.

CONCLUSION

The IVIM and DKI model's diagnostic efficiency was not significantly improved compared to conventional DWI. The diagnostic accuracy of metastatic LN can be enhanced using the nomogram model, leading to a rational therapeutic choice.

Nomogram predicting cancer-specific mortality in early-onset rectal cancer: a competing risk analysis

BACKGROUND

The incidence of rectal cancer has meaningfully increased in young patients. However, quantitative evaluation for the competing data of early-onset rectal cancer is lacking. So, we performed a competing risk analysis to calculate the cumulative incidence of death for patients with early-onset rectal cancer and developed a nomogram to predict the probability of cancer-specific mortality for these patients.

METHODS

We abstracted data of patients with early-onset rectal cancer between 2004 and 2016 by using the Surveillance, Epidemiology, and End Results program database. The cumulative incidence function was used to calculate the crude cancer-specific mortality of early-onset rectal cancer. Fine and Gray's proportional sub-distribution hazard model was adopted to explore the risk factors of cancer-specific death. Then, we establish a nomogram to predict their 3-, 5-, and 10-year probabilities.

RESULTS

We identified 9917 patients with early-onset rectal cancer, and they were randomly divided into training (n = 6941) and validation (n = 2976) cohorts. In the training cohort, the 3-, 5-, and 10-year cumulative incidences of cancer-specific death after diagnosis for early-onset rectal cancer were 11.4%, 19.9%, and 28.8%, respectively. Fine and Gray's model showed that sex, race, marital status, histology, T stage, N stage, M stage, examined lymph nodes, and pretreatment carcinoembryonic antigen were independently associated with cancer-specific mortality. Such factors were selected to develop a prognostic nomogram.

CONCLUSION

The competing risk nomogram has an ideal performance for predictive cancer-specific mortality in early-onset rectal cancer.

Nomogram for prediction of pathologic complete remission using biomarker expression and endoscopic finding after preoperative chemoradiotherapy in rectal cancer

Objective

The aim of this study is to develop a nomogram for prediction of pathologic complete remission (pCR) after preoperative chemoradiotherapy (CRT) for rectal cancer.

Methods

mRNA expression levels of seven molecular markers [p53, p21, Ki-67, vascular endothelial growth factor (VEGF), CD133, CD24, CD44] were measured by reverse transcriptase polymerase chain reaction (RT-PCR) in 120 rectal cancers. Endoscopic findings of clinical complete remission (cCR) and biologic variables were used to construct nomogram in the training group (n=80), which was validated in the validation group (n=40).

Results

mRNA expression levels of four markers (p53, p21, Ki67, CD133) correlated with pCR (24/80, 30.0%) in the training group. Low expression of p53 and/or high expression of p21, Ki67 and CD133 showed greater pCR rate. pCR was shown in 18 (69.2%) of 26 cases showing endoscopic cCR in the training group. Higher pCR rate was demonstrated in lower tumor location than middle tumor (19/49, 38.8% vs. 5/31, 16.1%). A nomogram for prediction of pCR was developed from the multivariate prediction model using these six variables, which showed good discrimination ability in the training group [area under the curve (AUC)=0.945] and validation group (AUC=0.922). The calibration plot showed good agreement between actual and predicted pCR in both patient groups.

Conclusions

Nomogram for assessment of pCR can be useful for making treatment decisions after CRT according to predicted responses.

Prediction of tumor response of rectal cancer cells via 3D cell culture and in vitro cytotoxicity assay before initiating preoperative chemoradiotherapy

The aim of the present study was to investigate the utility of 3D cell culture and in vitro cytotoxicity assays, performed using cells derived from biopsies obtained prior to the initiation of preoperative chemoradiotherapy (preop-CRT), in predicting tumor response to chemoradiotherapy following preop-CRT in rectal cancer. Biopsies were obtained from 49 patients with locally advanced rectal cancer that underwent preop-CRT between August 2015 and March 2017. Tumor tissue was obtained before initiating preop-CRT. The response to chemoradiation was assessed by in vitro cytotoxicity assay following 3D cell culture and radiation treatment. The associations between the results from the cytotoxicity assay, and tumor regression grade (TRG) and yp node (ypN) positivity were investigated. Among 49 patients, 26 patients were available for analysis. Cytotoxicity ranged from 25.5-72.6% (median, 47.6%). There was no difference in cytotoxicity according to the TRGs 1-5 (P=0.940), or good tumor response (TRGs 1-2 vs. TRGs 3-5; P=0.729). However, there was a significant difference in cytotoxicity between the ypN-negative and -positive groups (53.2±14.1 and 38.7±10.1, respectively; P=0.021). Following dichotomization of patients with 45% cut-off value, the cytotoxicity assay was the only factor that predicted ypN positivity in multivariate analysis (odds ratio, 13; 95% confidence interval, 1.2-133.2; P=0.031). In conclusion, the cytotoxicity assay using the 3D cell culture method can be used to predict tumor response, particularly ypN positivity, in patients with rectal cancer who are scheduled for preop-CRT.

Clinical and molecular diagnosis of pathologic complete response in rectal cancer: an update

INTRODUCTION

The standard of care for locally advanced rectal cancer includes neoadjuvant chemoradiation with subsequent total mesorectal excision. This approach has shown various degrees of response to neoadjuvant chemoradiation (ranging from complete response to further tumor growth), which have substantial prognostic and therapeutic implications. A total regression of the tumor is a predictor of superior oncologic outcomes compared with partial responders and non-responders. Further, this concept has opened the possibility of nonoperative strategies for complete responders and explains the widespread research interest in finding clinical, radiographic, pathologic, and biochemical parameters that allow for identification of these patients. Areas covered: The present review evaluates the most recent efforts in the literature to identify predictors of patients likely to achieve a complete response following neoadjuvant treatment for the management of rectal cancer. This includes clinical predictors of pathologic complete response such as tumor location, size, and stage, molecular predictors such as tumor biology and microRNA, serum biomarkers such as carcinoembryogenic antigen and nomograms. Expert commentary: There has been significant progress in our ability to predict pathological complete response. However, more high-quality research is still needed to use this concept to confidently dictate clinical management.

Radiomics analysis of multiparametric MRI for prediction of pathological complete response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer

OBJECTIVES

To develop and validate a radiomics predictive model based on pre-treatment multiparameter magnetic resonance imaging (MRI) features and clinical features to predict a pathological complete response (pCR) in patients with locally advanced rectal cancer (LARC) after receiving neoadjuvant chemoradiotherapy (CRT).

METHODS

One hundred and eighty-six consecutive patients with LARC (training dataset, n = 131; validation dataset, n = 55) were enrolled in our retrospective study. A total of 1,188 imaging features were extracted from pre-CRT T2-weighted (T2-w), contrast-enhanced T1-weighted (cT1-w) and ADC images for each patient. Three steps including least absolute shrinkage and selection operator (LASSO) regression were performed to select key features and build a radiomics signature. Combining clinical risk factors, a radiomics nomogram was constructed. The predictive performance was evaluated by receiver operator characteristic (ROC) curve analysis, and then assessed with respect to its calibration, discrimination and clinical usefulness.

RESULTS

Thirty-one of 186 patients (16.7%) achieved pCR. The radiomics signature derived from joint T2-w, ADC, and cT1-w images, comprising 12 selected features, was significantly associated with pCR status and showed better predictive performance than signatures derived from either of them alone in both datasets. The radiomics nomogram, incorporating the radiomics signature and MR-reported T-stages, also showed good discrimination, with areas under the ROC curves (AUCs) of 0.948 (95% CI, 0.907-0.989) and 0.966 (95% CI, 0.924-1.000), as well as good calibration in both datasets. Decision curve analysis confirmed its clinical usefulness.

CONCLUSIONS

This study demonstrated that the pre-treatment radiomics nomogram can predict pCR in patients with LARC and potentially guide treatments to select patients for a "wait-and-see" policy.

KEY POINTS

• Radiomics analysis of pre-CRT multiparameter MR images could predict pCR in patients with LARC. • Proposed radiomics signature from joint T2-w, ADC and cT1-w images showed better predictive performance than individual signatures. • Most of the clinical characteristics were unable to predict pCR.

Can clinicopathological parameters predict for lymph node metastases in ypT0-2 rectal carcinoma? Results of the CAO/ARO/AIO-94 and CAO/ARO/AIO-04 phase 3 trials

BACKGROUND

The advent of less radical surgical approaches has generated concern about leaving locoregional lymph node metastases (LNM) unresected that could lead to adverse outcome. We examined the prognostic role of clinicopathological factors for ypN-positivity in patients with ypT0-2 rectal carcinoma treated within the CAO/ARO/AIO-94 and CAO/ARO/AIO-04 randomized phase 3 trials.

METHODS

The correlation of clinicopathological factors with ypN-status (ypN0 vs ypN1/2) was examined in n = 776 patients with ypT0-2 rectal carcinoma after preoperative CRT and total mesorectal excision surgery using Pearson's Chi-squared test for categorical variables and Kruskal-Wallis' test for continuous variables. Multivariable analysis was performed using binary logistic regression to identify independent prognosticators for ypN-positivity.

RESULTS

Residual LNM (ypN+) were found in 6%, 20.8% and 21.4% of patients with ypT0, ypT1 and ypT2 carcinomas, respectively. Independent prognosticators for LNM were advanced ypT category (p = 0.002) and lymphatic invasion (p = 0.020). In a separate multivariable analysis performed upon exclusion of ypT-category due to multicollinearity with residual tumor diameter (RTD), lymphatic invasion (p = 0.015) and RTD ≥10 mm (p = 0.005) demonstrated strong correlation with LNM.

CONCLUSION

Advanced ypT-stage, lymphatic invasion and RTD ≥10 mm were prognostic factors for LNM in patients ypT0-2 rectal carcinoma treated with CRT and surgery within both phase 3 trials. The high incidence of LNM in the ypT1-2 group needs to be taken into consideration in the context of oncological safety and indicate that LE should be advocated with great caution in this patient subgroup. The prognostic pathological factor identified here could help guide decision of LE vs TME after standard CRT.

Nomogram for predicting anastomotic leakage after low anterior resection for rectal cancer

PURPOSE

Anastomotic leakage after low anterior resection for rectal cancer is a critical problem. Many risk factors have been suggested and surgical techniques have improved, but anastomotic leakage remains a major postoperative challenge. This study sought to create a nomogram for precise prediction of anastomotic leakage after low anterior resection for rectal cancer.

METHODS

We used data of 936 patients that had been prospectively collected by the Japanese Society for Colon and Rectal Cancer between June 2010 and February 2013. Risk factors for anastomotic leakage were identified by multivariate logistic regression analysis and used to create a nomogram. The performance of the nomogram was evaluated by using a bootstrapped-concordance index and calibration plots.

RESULTS

Sex, preoperative serum albumin, tumor location and diameter, and simultaneous resection of other organs were identified as significantly associated factors that could be combined for accurate prediction of anastomotic leakage. We created a nomogram for anastomotic leakage by using these risk factors. The area under the curve was 0.72 (95% confidence interval 0.67-0.76). The nomogram had a bootstrapped-concordance index of 0.72 and was well calibrated.

CONCLUSIONS

Our nomogram was a useful tool for precise prediction of anastomotic leakage after low anterior resection for rectal cancer.

Total Mesorectal Excision Versus Local Excision After Preoperative Chemoradiotherapy in Rectal Cancer With Lymph Node Metastasis: A Propensity Score-Matched Analysis

PURPOSE

To determine whether local excision (LE) outcomes were comparable to total mesorectal excision (TME) outcomes in node-positive (cN+) rectal cancer patients who were good responders.

METHODS AND MATERIALS

This retrospective study included clinical T2-3 and cN+ low rectal cancer patient who received preoperative chemoradiotherapy (PCRT) followed by TME or LE. Clinical stage T1 or T4 tumors, upper-to-middle rectal tumors (>7 cm from anal verge), and synchronous distant metastases were excluded. Lymph nodes ≥5 mm in size were defined as tumor-positive, and patients with metastatic lymph nodes >20 mm in size were excluded. Preoperative chemoradiotherapy comprised radiation (50-50.4 Gy/25-28 fractions over 5 weeks) with 2 cycles of 5-fluorouracil or oral capecitabine. Propensity scores were computed from tumor and patient variables and used for 1-to-1 matched analysis. Local recurrence-free survival, disease-free survival, and overall survival were compared between the 2 matched groups.

RESULTS

Between January 2007 and December 2013, 563 and 55 patients underwent TME and LE, respectively. The median follow-up period was 54 months. In propensity score-matched analysis, 48 patients were included in each group. No statistical differences were observed in 3-year local recurrence-free survival (97.9% vs 97.9%, P = .994), 3-year disease-free survival (91.5% vs 91.4%, P = .968), or 3-year OS (93.7% vs 97.9%, P = .809) between the TME and LE groups.

CONCLUSIONS

In clinical N+ rectal cancer patients, oncologic outcomes of PCRT followed by LE were comparable to those of TME; this finding might be applicable only to those patients with good response in the primary tumor and small lymph node metastases.

A qualitative signature for predicting pathological response to neoadjuvant chemoradiation in locally advanced rectal cancers

BACKGROUND AND PURPOSE

The standard therapy for locally advanced rectal cancers (LARCs) is neoadjuvant chemoradiation (nCRT) followed by surgical resection. Pathological response to nCRT varies among patients, and it remains a challenge to predict pathological response to nCRT in LARCs.

MATERIAL AND METHODS

Using 42 samples as the training cohort, we searched a signature by screening the gene pairs whose within-sample relative expression orderings are significantly correlated with the pathological response. The signature was validated in both a public cohort of 46 samples and a cohort of 33 samples measured at our laboratory.

RESULTS

A signature consisting of 27 gene pairs was identified in the training cohort with an accuracy of 92.86% and an area under the receiver operating characteristic curve (AUC) of 0.95. The accuracy was 89.13% for the public test cohort and 90.91% for the private test cohort, with AUC being 0.95 and 0.91, respectively. Furthermore, the signature was used to predict disease-free survival benefits from 5Fu-based chemotherapy in 285 locally advanced colorectal cancers.

CONCLUSIONS

The signature consisting of 27 gene pairs can robustly predict clinical response of LARCs to nCRT.

Perineural Invasion Predicts for Distant Metastasis in Locally Advanced Rectal Cancer Treated With Neoadjuvant Chemoradiation and Surgery

OBJECTIVES

The benefit of adjuvant chemotherapy in patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (nCRT) and surgery is controversial. We examined the association of perineural invasion (PNI) with outcomes to determine whether PNI could be used to risk-stratify patients.

MATERIALS AND METHODS

We performed a retrospective study of 110 patients treated with nCRT and surgery for LARC at our institution from 2004 to 2011. Eighty-seven patients were identified in our final analysis. We evaluated the association of PNI with locoregional control, distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival, using log-rank and Cox proportional hazard modeling.

RESULTS

Fourteen patients (16%) were PNI+ and 73 patients (84%) were PNI-. The median follow-up was 27 months (range, 0.9 to 84 mo). The median DMFS was 13.5 months for PNI+ and median not reached (>40 mo) for PNI- (P<0.0001). The median DFS was 13.5 months for PNI+ and 39.8 months for PNI- (P<0.0001). In a multivariate model including 7 pathologic variables, type of surgery, time to surgery from end of nCRT, and use of adjuvant chemotherapy, PNI remained a significant independent predictor of DMFS (hazard ratio 9.79; 95% confidence interval, 3.48-27.53; P<0.0001) and DFS (hazard ratio 5.72; 95% confidence interval, 2.2-14.9; P=0.0001).

CONCLUSIONS

For patients with LARC treated with nCRT, PNI found at the time of surgery is significantly associated with worse DMFS and DFS. Our data support testing the role of adjuvant chemotherapy in patients with PNI and perhaps other high-risk features.

The effect of adjuvant chemotherapy on survival and recurrence after curative rectal cancer surgery in patients who are histologically node negative after neoadjuvant chemoradiotherapy

AIM

The aim of this study was to evaluate whether adjuvant chemotherapy will affect recurrence rate or disease-free and overall survival in patients with rectal adenocarcinoma who were staged with MRI node-positive disease (mrN+) preoperatively. These patients underwent neoadjuvant chemoradiotherapy with curative rectal cancer surgery and their pathological staging was negative for nodal disease (ypN0). There is no consensus on the role of adjuvant chemotherapy in such patients.

METHOD

Patients who received neoadjuvant chemoradiotherapy and underwent curative rectal cancer surgery for rectal adenocarcinoma staged as [mrTxN+M0] on MRI staging and who on pathological staging were found to be [ypTxN0M0] were retrospectively identified from January 2008 December 2012 from two tertiary referral centres (Royal Marsden Hospital, London and Saint-Andre Hospital, Bordeaux).

RESULTS

One hundred and sixty-three patients were recruited and, after propensity matching at a ratio of 2:1, n = 80 patients were divided to receive adjuvant (n = 28) or no adjuvant treatment (n = 52). A comparison of adjuvant chemotherapy vs no adjuvant therapy showed that the mean overall survival was 2.67 vs 3.60 years (P = 0.42) and disease-free survival was 2.27 vs 3.32 years (P = 0.14).

CONCLUSION

This study found no significant difference in survival or disease recurrence between patients who received adjuvant chemotherapy and patients who did not. There is no clear evidence to support or dismiss the use of adjuvant chemotherapy for patients who were node positive on preoperative MRI and node negative on histopathological staging. Further multicentre prospective randomized trials are needed to identify the appropriate treatment regime for this group of patients.

A nomogram predicting pathological complete response to neoadjuvant chemoradiotherapy for locally advanced rectal cancer: implications for organ preservation strategies

PURPOSE

To determine predictors of pathological complete response (pCR) in locally advanced rectal cancer patients treated with neoadjuvant chemoradiotherapy (nCRT), and develop a predictive nomogram.

METHODS

A total of 522 locally advanced rectal cancer patients undergoing nCRT and curative resection between 2008 and 2014 were included. Uni- and multivariate analysis was performed to identify predictors of pCR. A nomogram was developed and validated by internal (n=425) and external validation (n=97).

RESULTS

With a median follow-up of 55 months, pCR was associated with better 5-year overall and disease-free survival, distant control, but similar local control. Logistic regression showed that post-CRT distance from the anal verge (OR =0.840, P = 0.022), post-CRT tumor size (OR = 0.565, P = 0.003), post-CRT circumferential extent of tumor (OR = 0.021, P < 0.001), pre-CRT CEA level (OR = 2.004, P = 0.033), and post-CRT CEA level (OR = 3.767, P = 0.038) were independently associated with pCR. A nomogram was developed with a C-index of 0.81 and 0.75 on internal and external validation, respectively.

CONCLUSION

pCR was associated with better long-term outcome. A nomogram was successfully developed to predict pCR. It could support decision-making in organ preservation strategies.

Total Mesorectal Excision Versus Local Excision After Favorable Response to Preoperative Chemoradiotherapy in "Early" Clinical T3 Rectal Cancer: A Propensity Score Analysis

PURPOSE

To compare oncological outcomes of total mesorectal excision (TME) and local excision (LE) in patients with "early" clinical T3 rectal cancer who received preoperative chemoradiotherapy (PCRT).

METHODS AND MATERIALS

"Early" clinical T3 rectal cancer was radiologically defined as tumors with extramural extension of <5 mm without mesorectal fascia involvement and lateral lymph node metastasis. Patients with "early" clinical T3 rectal cancer who received PCRT followed by TME or LE between January 2007 and December 2013 were retrospectively analyzed. Propensity scores were generated using patient and tumor characteristics, and a one-to-one case-matched analysis was conducted. Local recurrence-free survival (LRFS), disease-free survival (DFS), and overall survival (OS) were compared between the TME and LE groups.

RESULTS

Of the 406 enrolled patients, 351 received TME and 55 received LE. The median follow-up period was 45 months. Following propensity score matching, each group contained 55 patients. Among 103 patients evaluable for pathologic tumor response, 82 patients (79.6%) showed complete response or near-complete response. No significant differences were observed between the TME and LE groups in LRFS (3-year LRFS 98.1% vs 94.4%, P=.312), DFS (3-year DFS 92.1% vs 90.8%, P=.683), and OS (3-year OS 98.2% vs 100.0%, P=.895).

CONCLUSIONS

In "early" clinical T3 rectal cancer, PCRT followed by LE showed comparable oncologic outcomes to TME. Because most of the matched cohort consisted of good responders to PCRT, the present results should be applied to a limited population.

Clinical utility of pretreatment prediction of chemoradiotherapy response in rectal cancer: a review

Approximately 20% of all patients with locally advanced rectal cancer experience pathologically complete responses following neoadjuvant chemoradiotherapy (CRT) and standard surgery. The utility of radical surgery for patients exhibiting good CRT responses has been challenged. Organ-sparing strategies for selected patients exhibiting complete clinical responses include local excision or no immediate surgery. The subjects of this tailored management are patients whose presenting disease corresponds to current indications of neoadjuvant CRT, and their post-CRT tumor response is assessed by clinical and radiological examinations. However, a model predictive of the CRT response, applied before any treatment commenced, would be valuable to facilitate such a personalized approach. This would increase organ preservation, particularly in patients for whom upfront CRT is not generally prescribed. Molecular biomarkers hold the greatest promise for development of a pretreatment predictive model of CRT response. A combination of clinicopathological, radiological, and molecular markers will be necessary to render the model robust. Molecular research will also contribute to the development of drugs that can overcome the radioresistance of rectal tumors. Current treatments for rectal cancer are based on the expected prognosis given the presenting disease extent. In the future, treatment schemes may be modified by including the predicted CRT response evaluated at presentation.

Long-Term Outcome of Rectal Cancer With Clinically (EUS/MRI) Metastatic Mesorectal Lymph Nodes Treated by Neoadjuvant Chemoradiation: Role of Organ Preservation Strategies in Relation to Pathologic Response

BACKGROUND

Organ preservation strategies are under investigation for patients with locally advanced rectal cancer (LARC) who achieve a complete pathologic response in the primary tumor (ypT0) after neoadjuvant chemoradiation therapy (CRT). This study explored the value of this approach for cN+ patients.

METHODS

Data were retrieved from our institutional prospective rectal cancer database. Tumors with mesorectal lymph nodes larger than 5 mm shown on endorectal ultrasonography, pelvic magnetic resonance imaging, or both were staged as cN+.

RESULTS

The study population comprised 226 patients (142 men and 84 women; median age, 64 years) with LARC who underwent CRT followed by surgery including total mesorectal excision (TME) (n = 179) and full-thickness local excision (LE) (n = 47) between 1996 and 2013. At staging, 123 patients (54.4 %) were cN+. In 65 cases (28.7 %), ypCR was observed. Metastatic mesorectal lymph nodes (ypN+) were detected in 41.6 % of the cN+ patients and in 2.8 % of the cN0 patients (P < 0.01). Among the cN+ patients, 16 % of the ypT0 cases were ypN+ compared with 51.8 % of the no-ypT0 cases (P < 0.01). Among the cN+ patients who underwent TME, the 5-year disease-specific survival (DSS) and disease-free survival (DFS) rates were respectively 100 and 91.6 % for the ypT0 patients compared with 71.2 and 58.0 % for the no-ypT0 patients (P = 0.01). Among the ypN+ patients, the 5-year DSS and DFS rates were both 100 % for the ypT0 cases compared with 59.1 and 43.3 % for the no-ypT0 patients. Among the cN+ and ypT0 patients, the 5-year DSS and DFS were respectively 100 and 85.7 % for the TME patients compared with 100 and 91.6 % for the LE patients. In the multivariate analysis, ypT0 was the only independent prognostic factor.

CONCLUSIONS

Protocols aimed at organ preservation in LARC that achieve ypT0 after CRT can be offered also to cN+ patients.

A Nomogram to Predict Lymph Node Positivity Following Neoadjuvant Chemoradiation in Locally Advanced Rectal Cancer

BACKGROUND

Patients with locally advanced rectal cancer typically receive neoadjuvant chemoradiation followed by total mesorectal excision. Other treatment approaches, including transanal techniques and close surveillance, are becoming increasingly common following positive responses to chemoradiation. Lack of pathologic lymph node staging is one major disadvantage of these novel strategies.

OBJECTIVE

The purposes of this study were to determine clinicopathologic factors associated with positive lymph nodes following neoadjuvant chemoradiation for rectal cancer and to create a nomogram using these factors to predict rates of lymph node positivity.

DESIGN

This is a retrospective cohort analysis.

SETTINGS

This study used the National Cancer Database.

PATIENTS

Patients aged 18 to 90 with clinical stage T3/T4, N0, M0 or Tany, N1-2, M0 adenocarcinoma of the rectum who underwent neoadjuvant chemoradiation before total mesorectal excision from 2010 to 2012 were identified.

MAIN OUTCOME MEASURES

The primary outcome measure was lymph node positivity after neoadjuvant chemoradiation for locally advanced rectal cancer. Bivariate and multivariate analyses were used to determine the associations of clinicopathologic variables with lymph node positivity.

RESULTS

Eight thousand nine hundred eighty-four patients were included. Young age, lower Charlson score, mucinous histology, poorly differentiated and undifferentiated tumors, the presence of lymphovascular invasion, elevated CEA level, and clinical lymph node positivity were significantly predictive of pathologic lymph node positivity following neoadjuvant chemoradiation. The predictive accuracy of the nomogram is 70.9%, with a c index of 0.71. There was minimal deviation between the predicted and observed outcomes.

LIMITATIONS

This study is retrospective, and it cannot be determined when in the course of treatment the data were collected.

CONCLUSIONS

We created a nomogram to predict lymph node positivity following neoadjuvant chemoradiation for locally advanced rectal cancer that can serve as a valuable complement to imaging to aid clinicians and patients in determining the best treatment strategy.

Nomograms for colorectal cancer: A systematic review

AIM

To assist in the selection of suitable nomograms for obtaining desired predictions in daily clinical practice.

METHODS

We conducted electronic searches for journal articles on colorectal cancer (CRC)-associated nomograms using the search terms colon/rectal/colorectal/nomogram. Of 174 articles initially found, we retrieved 28 studies in which a nomogram for CRC was developed.

RESULTS

We discuss the currently available CRC-associated nomograms, including those that predict the oncological prognosis, the short-term outcome of treatments, such as surgery or neoadjuvant chemoradiotherapy, and the future development of CRC. Developing nomograms always presents a dilemma. On the one hand, the desire to cover as wide a patient range as possible tends to produce nomograms that are too complex and yet have C-indexes that are not sufficiently high. Conversely, confining the target patients might impair the clinical applicability of constructed nomograms.

CONCLUSION

The information provided in this review should be of use in selecting a nomogram suitable for obtaining desired predictions in daily clinical practice.

New Perspectives on Predictive Biomarkers of Tumor Response and Their Clinical Application in Preoperative Chemoradiation Therapy for Rectal Cancer

Preoperative chemoradiation therapy (CRT) is the standard treatment for patients with locally advanced rectal cancer (LARC) and can improve local control and survival outcomes. However, the responses of individual tumors to CRT are not uniform and vary widely, from complete response to disease progression. Patients with resistant tumors can be exposed to irradiation and chemotherapy that are both expensive and at times toxic without benefit. In contrast, about 60% of tumors show tumor regression and T and N down-staging. Furthermore, a pathologic complete response (pCR), which is characterized by sterilization of all tumor cells, leads to an excellent prognosis and is observed in approximately 10-30% of cases. This variety in tumor response has lead to an increased need to develop a model predictive of responses to CRT in order to identify patients who will benefit from this multimodal treatment. Endoscopy, magnetic resonance imaging, positron emission tomography, serum carcinoembryonic antigen, and molecular biomarkers analyzed using immunohistochemistry and gene expression profiling are the most commonly used predictive models in preoperative CRT. Such modalities guide clinicians in choosing the best possible treatment options and the extent of surgery for each individual patient. However, there are still controversies regarding study outcomes, and a nomogram of combined models of future trends is needed to better predict patient response. The aim of this article was to review currently available tools for predicting tumor response after preoperative CRT in rectal cancer and to explore their applicability in clinical practice for tailored treatment.

Prognostic significance of pathological response to preoperative chemoradiotherapy in patients with locally advanced rectal cancer

BACKGROUND

Preoperative chemoradiotherapy (CRT) is widely used in the treatment of locally advanced rectal cancer (LARC). Pathological response to CRT has been shown to be a potential prognostic predictor in rectal cancer patients. The aim of this study was to determine the prognostic significance of pathological response to preoperative CRT in LARC patients.

METHODS

Thirty-two patients with LARC were retrospectively analyzed to determine the relationships of pathological response and clinicopathological characteristics to survival outcomes. Patients received CRT with tegafur/uracil and leucovorin. Radiotherapy was administered in fractions of 1.8 Gy/day and 5 days per week. The total dose of radiation delivered was 45 Gy.

RESULTS

All patients underwent total mesorectal excision with lymph node dissections after CRT, and resected specimens were examined pathologically. Four patients showed pathological complete response, 14 showed good response, and 14 showed poor response. Pathological complete or good response was associated with longer survival (P = 0.041). Clinicopathological factors excluding gender were not correlated with outcome. No factor was associated with recurrence.

CONCLUSION

Pathological response to preoperative CRT may be a useful prognostic predictor in patients with LARC.

Prognostic significance of pathological response to preoperative chemoradiotherapy in patients with locally advanced rectal cancer

BACKGROUND

Preoperative chemoradiotherapy (CRT) is widely used in the treatment of locally advanced rectal cancer (LARC). Pathological response to CRT has been shown to be a potential prognostic predictor in rectal cancer patients. The aim of this study was to determine the prognostic significance of pathological response to preoperative CRT in LARC patients.

METHODS

Thirty-two patients with LARC were retrospectively analyzed to determine the relationships of pathological response and clinicopathological characteristics to survival outcomes. Patients received CRT with tegafur/uracil and leucovorin. Radiotherapy was administered in fractions of 1.8 Gy/day and 5 days per week. The total dose of radiation delivered was 45 Gy.

RESULTS

All patients underwent total mesorectal excision with lymph node dissections after CRT, and resected specimens were examined pathologically. Four patients showed pathological complete response, 14 showed good response, and 14 showed poor response. Pathological complete or good response was associated with longer survival (P = 0.041). Clinicopathological factors excluding gender were not correlated with outcome. No factor was associated with recurrence.

CONCLUSION

Pathological response to preoperative CRT may be a useful prognostic predictor in patients with LARC.

Prognostic significance of clinical and pathological stages on locally advanced rectal carcinoma after neoadjuvant chemoradiotherapy

Objective

To investigate prognostic significance of clinical and pathological stages in patients with locally advanced rectal carcinoma treated with neoadjuvant chemoradiotherapy (neo-CRT) and total mesorectal excision.

Patients and methods

210 patients with locally advanced rectal carcinoma (cT3-4 or cN+) treated with neo-CRT followed by total mesorectal excision. Treatment outcomes were compared according to clinical and pathological stage. Overall survival (OS), disease free survival (DFS) among patients with different clinical stage and pathological stage after neo-CRT.

Results

The median follow-up time was 47 months (range, 14–98 months). Clinical T stage was associated with 5 year OS (p = 0.042) and 5 year DFS (p = 0.014) while clinical N stage was not associated with 5 year OS (p = 0.440), 5 year DFS (p = 0.711). Pathological T stage was associate with 5 year OS (p = 0.001) and 5 year DFS (p = 0.046); and N stage was associated with 5 year OS (p = 0.001), 5 year DFS (p = 0.002). The pathological stage was further classified into three groups: ypT0–2N0 in 91 patients (43.3 %), ypT3–4N0 in 69 patients (32.9 %) and ypT0–4N+ in 50 patients (23.8 %). While pathological stage (ypT0–2 vs ypT3–4N0 vs ypT0–4N+) was associated with 5 year OS (87.9 %, 75.5 %, 56.7 %, p = 0.000), 5 year DFS (74.5 %, 77.4 %, 50.5 %, p = 0.003). Multivariate analysis showed that ypN stage was an independent prognostic factor for patients 5 year DFS.

Conclusions

Pathological stage is strongly associated with treatment outcomes in patients with locally advanced rectal carcinoma treated with neo-CRT followed by total mesorectal excision, which may be used as guidance for further individualized treatment.