Impact of T and N stage and treatment on survival and relapse in adjuvant rectal cancer: a pooled analysis

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

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

Serum inflammatory markers as prognostic marker for nasopharyngeal carcinoma with liver metastasis: a multi-center retrospective study

BACKGROUND

This retrospective study investigated the prognostic value of serum inflammatory markers in nasopharyngeal carcinoma (NPC) patients, focusing on their association with overall survival (OS) and liver metastasis-free survival (LMFS).

METHODS

The study included 314 NPC patients treated between 2010 and 2020. Clinical characteristics, treatment methods, and serum inflammatory markers were assessed. Patients were categorized into two groups of with and without liver metastasis. Univariate and multivariate Cox regression and Kaplan-Meier survival analyses were performed to investigate the prognostic value of serum inflammatory markers in NPC patients with and without liver metastasis.

RESULTS

In the whole cohort, univariate Cox regression analysis singled out tumor necrosis factor-α (TNF-α) (HR = 1.57, 95% CI 1.44-4.90, p = 0.004) and neutrophil-to-lymphocyte ratio (NLR) (HR = 2.13, 95% CI 1.33-3.99, p = 0.009), which were significantly associated with poorer OS. In patients with liver metastasis, TNF-α and NLR could not independently predict OS. However, high TNF-α levels were independently associated with worse OS in patients without liver metastasis (HR (95% CI) = 2.75 (1.67-8.68), p < 0.001). High NLR levels could independently predict poor OS in both groups with (HR (95% CI) = 1.94 (1.77-6.38), p = 0.010) and without liver metastasis (HR (95% CI) = 1.58 (1.19-7.54), p = 0.009). Ultimately, TNF-α and NLR could not significantly predict LMFS.

CONCLUSION

This study highlights the prognostic significance of TNF-α and NLR in NPC patients, especially in those with liver metastasis. These inflammatory markers could serve as valuable indicators for assessing the prognosis of NPC patients. Further research is warranted to validate their clinical utility and explore potential therapeutic implications.

Outcome of Patients with Locally Advanced Rectal Cancer Pursuing Non-Surgical Strategy in National Cancer Database

BACKGROUND

Survival data on patients with locally advanced rectal cancer (LARC) undergoing non-operative management (NOM) in a real-world setting are lacking.

METHODS

We analyzed LARC patients from the National Cancer Database with the following features: treated between 2010 and 2020, age 18-65 years, Charlson comorbidity index (CCI) ≤ 1, received neoadjuvant multiagent chemotherapy plus radiation ≥ 45 Gray, and underwent surgery or NOM. Patients were stratified into two groups: (A) clinical T1-3 tumors with positive nodes (cT1-3N+) and (B) clinical T4 tumors, N+/- (cT4N+/-). We performed a comparative analysis of overall survival (OS) with NOM versus surgery by the Kaplan-Meier method and propensity score matching. Additionally, a multivariable analysis explored the association between NOM and OS.

RESULTS

NOM exhibited significantly lower OS than surgery in both groups. In cT1-3N+ patients, NOM resulted in a 5-year OS of 73.9% (95% confidence interval [CI] = 69.7-77.6%) versus 84.5% (95% CI = 83.6-85.3%) with surgery (p < 0.001). In the cT4N+/- group, NOM yielded a 5-year OS of 44.5% (95% CI = 37.0-51.8%) versus 72.5% (95% CI = 69.9-74.8%) with surgery (p < 0.001). Propensity score matching and multivariable analyses revealed similar conclusions.

CONCLUSION

Patients with LARC undergoing NOM versus surgery in real-world settings appear to have inferior survival.

Neoadjuvant Short- Vs. Long-Course Radiation for Locally Advanced Rectal Cancer: How to Choose

OPINION STATEMENT

Over the past decades, the treatment of locally advanced rectal cancer has evolved dramatically due to improvements in diagnostic imaging, surgical technique, and the addition of radiotherapy and/or chemotherapy. Fractionation of neoadjuvant radiotherapy with or without concurrent chemotherapy remains the subject of discussion and the question multiple recent trials have aimed to answer. In light of recent data and concern for locoregional recurrence, our institution favors long-course chemoradiation in most cases, especially in low-lying primaries, threatened circumferential resection margin, consideration of non-operative management, or if the surgeon has concerns for resectability. Exceptions would include cases of oligometastatic disease planned for metastasectomy in which curative-intent treatment was pursued or if additional factors required a reduction in treatment time.

Frailty worsens long-term survival in patients with colorectal cancer: a systematic review and meta-analysis

Background

Colorectal cancer (CRC) is the 3rd most common cancer in men and 2nd most common malignancy in females across the globe leading to high mortality rates. Frailty is an age-related syndrome that has been associated with high morbidity and mortality. This systematic review aimed to examine if frailty can predict long-term (>1 year) outcomes of patients with CRC.

Methods

This PROSPERO registered review examined the databases of PubMed, Embase, and Web of Science till 4th September 2023 for cohort studies assessing the association between frailty and long-term outcomes of CRC.

Results

15 studies with 45288 patients were included. 6573 patients (14.5%) were frail. Meta-analysis demonstrated that frailty was associated with statistically significant poor overall survival (OS) (HR: 2.11 95% CI: 1.44, 3.08 I2 = 94%) (14 studies), cancer-specific survival (CSS) (HR: 4.59 95% CI: 2.75, 7.67 I2 = 38%) (2 studies), and disease-free survival (DFS) (HR: 1.46 95% CI: 1.28, 1.66 I2 = 0%) (5 studies) after CRC. Subgroup analysis for OS based on study type, location, sample size, stage of cancer, percentage with frailty, treatment, adjustment for CRC stage and comorbidities, and follow-up did not change the results. These results were not altered in significance on sensitivity analysis.

Conclusion

Our results show that frail CRC patients have poor OS and DFS as compared to non-frail patients. Variations in frailty measurement tools and high inter-study heterogeneity are major limitations of the review.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, PROSPERO, CRD42023450586.

An immune-related gene prognostic prediction risk model for neoadjuvant chemoradiotherapy in rectal cancer using artificial intelligence

Background

This study aimed to establish and validate a prognostic model based on immune-related genes (IRGPM) for predicting disease-free survival (DFS) in patients with locally advanced rectal cancer (LARC) undergoing neoadjuvant chemoradiotherapy, and to elucidate the immune profiles associated with different prognostic outcomes.

Methods

Transcriptomic and clinical data were sourced from the Gene Expression Omnibus (GEO) database and the West China Hospital database. We focused on genes from the RNA immune-oncology panel. The elastic net approach was employed to pinpoint immune-related genes significantly impacting DFS. We developed the IRGPM for rectal cancer using the random forest technique. Based on the IRGPM, we calculated prognostic risk scores to categorize patients into high-risk and low-risk groups. Comparative analysis of immune characteristics between these groups was conducted.

Results

In this study, 407 LARC samples were analyzed. The elastic net identified a signature of 20 immune-related genes, forming the basis of the IRGPM. Kaplan-Meier survival analysis revealed a lower 5-year DFS in the high-risk group compared to the low-risk group. The receiver operating characteristic (ROC) curve affirmed the model's robust predictive capability. Validation of the model was performed in the GSE190826 cohort and our institution's cohort. Gene expression differences between high-risk and low-risk groups predominantly related to cytokine-cytokine receptor interactions. Notably, the low-risk group exhibited higher immune scores. Further analysis indicated a greater presence of activated B cells, activated CD8 T cells, central memory CD8 T cells, macrophages, T follicular helper cells, and type 2 helper cells in the low-risk group. Additionally, immune checkpoint analysis revealed elevated PDCD1 expression in the low-risk group.

Conclusions

The IRGPM, developed through random forest and elastic net methodologies, demonstrates potential in distinguishing DFS among LARC patients receiving standard treatment. Notably, the low-risk group, as defined by the IRGPM, showed enhanced activation of adaptive immune responses within the tumor microenvironment.

The impact of intensity-modulated radiotherapy in conjunction with chemotherapy on proximal pT3N0 rectal cancer patients after total mesorectum excision

BACKGROUND

This study aimed to ascertain if the incorporation of intensity-modulated radiotherapy (IMRT) with chemotherapy (CTx) offered any advantages for patients diagnosed with stage pT3N0 rectal cancer located in the proximal (upper) region following a complete total mesorectum excision (TME).

METHODS

We retrospectively examined medical records of stage II/III rectal cancer patients who had undergone CTx or concurrent chemoradiation (CCRT) with IMRT after a successful TME. We juxtaposed a variety of survival outcomes across two patient cohorts. Each outcome was further classified according to Gunderson's risk stratification between proximal and distal (middle and low) rectal cancer patients, and we evaluated the factors associated with each outcome.

RESULTS

The median follow-up duration was 4.9 years. Our research comprised 236 rectal adenocarcinoma patients treated at our institution between 2007 and 2019. They received either the CTx (n = 135) or the CCRT (n = 101) with 10-year locoregional recurrence-free survival (LRRFS) of 90.1% and 96.1%, respectively (p = 0.163). However, after performing multivariate adjustments, a pattern emerged hinting at a better LRRFS for the CCRT group (p = 0.052). Perforation had a strong correlation with locoregional recurrence. No significant differences were observed in other survival between the two treatment arms and their respective subgroups. The CCRT group witnessed significantly higher immediate and chronic complications with p = 0.007 and 0.009, respectively. The CCRT group had two secondary cancer-related fatalities (2%, one attributed to IMRT), and another reported by the CTx group (1%). The sole classified locoregional recurrence within the cohort of 37 individuals treated with CTx for proximal pT3N0 rectal cancer was, in fact, the development of sigmoid colon cancer.

CONCLUSION

The results suggest that for patients with proximal pT3N0 rectal cancer post-TME, IMRT is better when not combined with CTx, except in highly perilous scenarios or those involving perforation.

Implication of MRI Risk Stratification System on the Survival Benefits of Adjuvant Chemotherapy After Neoadjuvant Chemoradiotherapy in Patients With Locally Advanced Rectal Cancer

RATIONALE AND OBJECTIVES

To investigate the implication of a Magnetic resonance imaging (MRI) risk stratification system on the selection of patients with locally advanced rectal cancer (LARC) who can benefit from adjuvant chemotherapy (ACT) after neoadjuvant chemoradiotherapy (NCRT).

MATERIALS AND METHODS

This retrospective study included 328 patients with LARC who underwent NCRT and surgery. The median follow-up duration was 79 months (Interquartile range, 66-94 months). Cox logistic regression analysis was used to identify MRI risk factors and develop a risk stratification system to stratify patients into groups with high and low risks. Kaplan-Meier curves of distant metastasis-free survival (DMFS) and overall survival (OS) were used to show the benefits of ACT and stratify results based on the MRI risk stratification system and postoperative pathological staging.

RESULTS

An MRI risk stratification system was built based on four MRI risk factors, including MRI-identified T3b-T4 stage, N1-N2 stage, extramural venous invasion, and tumor deposits. 74 (22.6%) patients with 3-4 MRI risk factors were classified into the MRI high-risk group. ACT could significantly improve 5-year DMFS (19.2% versus 52.1%; p < 0.001) and OS (34.6% versus 75.0%; p < 0.001) for patients in the MRI high-risk group, while ACT had no survival benefit for patients in the MRI low-risk group. The benefits of ACT were not observed in patients with any pathological staging subgroups (ypT0-2N0, ypT3-4N0, and ypN+).

CONCLUSION

Patients in the MRI high-risk group could benefit from ACT, regardless of postoperative pathological staging. Baseline MRI should be considered more in ACT decision-making.

Towards Response ADAptive Radiotherapy for organ preservation for intermediate-risk rectal cancer (preRADAR): protocol of a phase I dose-escalation trial

INTRODUCTION

Organ preservation is associated with superior functional outcome and quality of life (QoL) compared with total mesorectal excision (TME) for rectal cancer. Only 10% of patients are eligible for organ preservation following short-course radiotherapy (SCRT, 25 Gy in five fractions) and a prolonged interval (4-8 weeks) to response evaluation. The organ preservation rate could potentially be increased by dose-escalated radiotherapy. Online adaptive magnetic resonance-guided radiotherapy (MRgRT) is anticipated to reduce radiation-induced toxicity and enable radiotherapy dose escalation. This trial aims to establish the maximum tolerated dose (MTD) of dose-escalated SCRT using online adaptive MRgRT.

METHODS AND ANALYSIS

The preRADAR is a multicentre phase I trial with a 6+3 dose-escalation design. Patients with intermediate-risk rectal cancer (cT3c-d(MRF-)N1M0 or cT1-3(MRF-)N1M0) interested in organ preservation are eligible. Patients are treated with a radiotherapy boost of 2×5 Gy (level 0), 3×5 Gy (level 1), 4×5 Gy (level 2) or 5×5 Gy (level 3) on the gross tumour volume in the week following standard SCRT using online adaptive MRgRT. The trial starts on dose level 1. The primary endpoint is the MTD based on the incidence of dose-limiting toxicity (DLT) per dose level. DLT is a composite of maximum one in nine severe radiation-induced toxicities and maximum one in three severe postoperative complications, in patients treated with TME or local excision within 26 weeks following start of treatment. Secondary endpoints include the organ preservation rate, non-DLT, oncological outcomes, patient-reported QoL and functional outcomes up to 2 years following start of treatment. Imaging and laboratory biomarkers are explored for early response prediction.

ETHICS AND DISSEMINATION

The trial protocol has been approved by the Medical Ethics Committee of the University Medical Centre Utrecht. The primary and secondary trial results will be published in international peer-reviewed journals.

TRIAL REGISTRATION NUMBER

WHO International Clinical Trials Registry (NL8997; https://trialsearch.who.int).

Use of lymph node ratio to guide clinical decision-making concerning adjuvant radiotherapy in pT1-2N1 rectal cancer

PURPOSE

Lymph node metastases are uncommon in pT1-2 rectal cancer. pT1-2N1 are often characterized with low tumor burden and intermediate prognosis. Therefore, adjuvant radiotherapy (ART) is controversial in these patients. This study aimed to investigate the value of ART in pT1-2 rectal cancer and evaluate the guiding role of lymph node ratio (LNR) for utilization of ART.

METHODS

pT1-2N1 rectal cancer patients who received surgery without neoadjuvant radiotherapy between 2000 and 2018 with at least 12 lymph node harvest were extracted from the Surveillance, Epidemiology and End Results (SEER) database. We used time-dependent receiver operating characteristic (ROC) analysis to determine the optimal cutoff of LNR. Kaplan-Meier methods and Cox proportional hazards regression models were performed to determine the prognostic value of ART in pT1-2N1 rectal cancer patients and subgroups stratified by LNR.

RESULTS

A total of 674 and 1321 patients with pT1N1 and pT2N1 rectal cancer were eligible for analysis. There was no statistical cancer-specific survival (CSS) difference in pT1N1 rectal cancer patients between receiving and not receiving ART (P = 0.464). The 5-year CSS was 89.6% and 83.2% in pT2N1 rectal cancer patients between receiving and not receiving ART, respectively (P = 0.003). A total of 7.0% was identified as the optimal cutoff value of LNR. Survival improvement offered by ART was only found in LNR ≥ 7.0% subgroup (5-year CSS: 89.5% versus 79.6%, P = 0.003) instead of LNR < 7.0% subgroup (5-year CSS: 89.9% versus 86.3%, P = 0.208).

CONCLUSION

ART show substantial survival benefit in pT2N1 rectal cancer patients with LNR ≥ 7.0%, warranting the conventional adoption of ART in this subgroup.

Patterns of Care for Patients With Locally Advanced Rectal Cancer Treated with Total Neoadjuvant Therapy at Predominately Academic Centers between 2016-2020: An NCDB Analysis

Total neoadjuvant therapy (TNT) has emerged as the preferred approach for locally advanced rectal cancer (LARC), defined as T3/4 or any T with N+ disease. Our objective was to (1) determine the proportion of patients with LARC receiving TNT over time, (2) determine the most common method in which TNT is being delivered, and (3) determine what factors are associated with a greater likelihood of receiving TNT in the United States. Retrospective data was obtained from the National Cancer Database (NCDB) for patients diagnosed with rectal cancer between 2016 and 2020. Patients were excluded if they had M1 disease, T1-2 N0 disease, incomplete staging information, nonadenocarcinoma histology, received RT to a nonrectum site, or received a nondefinitive RT dose. Data were analyzed using linear regression, χ² test, and binary logistic regression. Of the 26,375 patients included, most patients were treated at an academic facility (94.6%). Five thousand three (19.0%) patients received TNT, and 21,372 (81.0%) patients did not receive TNT. The proportion of patients receiving TNT increased significantly over time, from 6.1% in 2016 to 34.6% in 2020 (slope = 7.36, 95% CI 4.58-10.15, R² = 0.96, P = .040). The most common TNT regimen was multiagent chemotherapy followed by long-course chemoradiation (73.2% of cases from 2016-2020). There was a significant increase in utilization of short-course RT as part of TNT from 2.8% in 2016 to 13.7% in 2020 (slope = 2.74, 95% CI 0.37-5.11, R² = 0.82, P = .035). Factors associated with a lower likelihood of TNT usage included age >65, female gender, Black race, and T3 N0 disease. TNT use in the United States has increased significantly from 2016-2020, with approximately 34.6% of patients with LARC receiving TNT in 2020. The observed trend appears to be in line with the recent National Comprehensive Cancer Network guidelines recommending TNT as the preferred approach.

A nomogram and risk classification system forecasting the cancer-specific survival of lymph- node- positive rectal cancer patient after radical proctectomy

Background

The aim of the study was to develop and validate a nomogram for predicting cancer-specific survival (CSS) in lymph- node- positive rectal cancer patients after radical proctectomy.

Methods

In this study, we analyzed data collected from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015. In addition, in a 7:3 randomized design, all patients were split into two groups (development and validation cohorts). CSS predictors were selected via univariate and multivariate Cox regressions. The nomogram was constructed by analyzing univariate and multivariate predictors. The effectiveness of this nomogram was evaluated by concordance index (C-index), calibration plots, and receiver operating characteristic (ROC) curve. Based on the total score of each patient in the development cohort in the nomogram, a risk stratification system was developed. In order to analyze the survival outcomes among different risk groups, Kaplan-Meier method was used.

Results

We selected 4,310 lymph- node- positive rectal cancer patients after radical proctectomy, including a development cohort (70%, 3,017) and a validation cohort (30%, 1,293). The nomogram correlation C-index for the development cohort and the validation cohort was 0.702 (95% CI, 0.687-0.717) and 0.690 (95% CI, 0.665-0.715), respectively. The calibration curves for 3- and 5-year CSS showed great concordance. The 3- and 5-year areas under the curve (AUC) of ROC curves in the development cohort were 0.758 and 0.740, respectively, and 0.735 and 0.730 in the validation cohort, respectively. Following the establishment of the nomogram, we also established a risk stratification system. According to their nomogram total points, patients were divided into three risk groups. There were significant differences between the low-, intermediate-, and high-risk groups (p< 0.05).

Conclusions

As a result of our research, we developed a highly discriminatory and accurate nomogram and associated risk classification system to predict CSS in lymph-node- positive rectal cancer patients after radical proctectomy. This model can help predict the prognosis of patients with lymph- node- positive rectal cancer.

Identification of patient subgroups with low risk of postoperative local recurrence for whom total mesorectal excision surgery alone is sufficient: a multicenter retrospective analysis

PURPOSE

For rectal cancer, a multimodality approach is mandatory including neoadjuvant chemoradiotherapy, neoadjuvant chemotherapy, and lateral pelvic lymph node (LPLN) dissection, in addition to the total mesorectal excision (TME). However, these treatments are associated with adverse events. It is important to select patients who do or do not need these treatments.

METHODS

We retrospectively analyzed patients with cStage II and III rectal cancer who underwent curative resection at three hospitals. Recurrence patterns were classified into three types; pelvic cavity, LPLN, and distant recurrences, and the risk factors for each pattern of recurrence were compared. We then analyzed the risk of recurrence in the patients who underwent TME alone.

RESULTS

In total, 506 patients were enrolled in this study. Pelvic cavity recurrence was significantly associated with clinical assumption of circumferential resection margin involvement (cCRM) (p < 0.001), distant recurrence was associated with cN positivity (p < 0.001), and LPLN recurrence was associated with pretreatment LPLN swelling ≥ 5 mm (p < 0.001), lower tumor location (p = 0.016), and serum CEA level > 5 ng/mL (p = 0.008). In patients without cCRM and swollen LPLN, the local recurrence rate was extremely low even if they underwent TME alone; the 5-year recurrence rates of pelvic cavity and LPLN were 2.2% and 1.9%, respectively.

CONCLUSION

Additional treatments to TME for rectal cancer need to be performed based on the risk factors for each recurrence pattern.

Multicenter validation of the PREDICT score for prediction of local recurrence after total mesorectal excision of rectal cancer

BACKGROUND

Total mesorectal excision (TME) is the gold standard treatment for rectal cancer. Although TME has managed to decrease the rates of local recurrence after rectal cancer resection, local recurrence is still recorded at varying rates. The present study aimed to validate the PREDICT score in the prediction of local recurrence of rectal cancer after TME with curative intent.

METHODS

This was a retrospective multicenter study on patients with nonmetastatic low or middle rectal cancer who underwent TME. The total PREDICT score was calculated for every patient and related to the onset of local recurrence. According to the final score, patients were allocated to one of three risk groups: low, moderate, and high, and the rates of local recurrence in each group were calculated and compared.

RESULTS

The present study included 262 patients (50.4% males) with a mean age of 47.1 years. The overall local recurrence rate was 12.6%. 29.4% of patients were in the low-risk group, 63.7% in the moderate-risk group, and 6.9% in the high-risk group. The local recurrence rate was 3.9% (95% confidence interval [CI]: 0.8-10.9) in the low-risk group, 13.2% (95% CI: 8.4-19.3) in the moderate risk group, and 44.4% (95% CI: 21.5-69.2) in the high-risk group (p < 0.0001). The sensitivity of the PREDICT score was 72.7%, the specificity was 88.1%, and the accuracy was 86.3%.

CONCLUSIONS

The PREDICT score had good diagnostic accuracy in the prediction of local recurrence after TME and a good discriminatory ability in the differentiation between patients at different risks to develop local recurrence.

The Multimodal Management of Locally Advanced Rectal Cancer: Making Sense of the New Data

In the past 40 years, the treatment of locally advanced rectal cancer has evolved with the addition of radiotherapy or chemoradiotherapy and providing (neo)adjuvant systemic chemotherapy to major surgery. However, recent trends have focused on improving our ability to risk-stratify patients and tailoring treatment to achieve the best oncologic outcome while limiting the impact on long-term quality of life. Therefore, there has been increasing interest in pursuing a watch-and-wait approach to achieve organ preservation. Several retro- and prospective studies suggest safety of the watch-and-wait approach, though it is still considered controversial due to limited clinical evidence, concerns about tumor regrowth, and subsequent distant progression. To further reduce treatment, MRI risk stratification, together with patient characteristics and patient preferences, can guide personalized treatment and reserve radiation and chemotherapy for a select patient population. Ultimately, improved options for reassessment during neoadjuvant treatment may allow for more adaptive therapy options based on treatment response. This article provides an overview of some major developments in the multimodal treatment of locally advanced rectal cancer. It reviews some relevant, controversial issues of the watch-and-wait approach and opportunities to personally tailor and reduce treatment. It also reviews the overall neoadjuvant treatment, including total neoadjuvant therapy trials, and how to best optimize for a potential complete response. Finally, it provides an algorithm as an example of how such a personalized, tailored, adaptive, and reduced treatment could look like in the future.

The number of cycles of adjuvant chemotherapy in stage III and high-risk stage II rectal cancer: a nomogram and recursive partitioning analysis

Objective

The prognostic role of the number of cycles of adjuvant chemotherapy (ACT) after total mesorectal excision in stage III and high-risk stage II rectal cancer is unknown. As a result of this, our study was designed to assess the effect of the number of cycles of ACT on the prediction of cancer-specific survival.

Methods

Four hundred patients that were diagnosed as stage III and high-risk stage II rectal cancer from January 2012 to January 2018 and who had received total mesorectal excision were enrolled in this study. A nomogram incorporating the number of cycles of ACT was also developed in this study. For internal validation, the bootstrap method was used and the consistency index was used to evaluate the accuracy of the model. The patients were stratified into risk groups according to their tumor characteristics by recursive partitioning analysis.

Results

We found that the risk of death was decreased by 26% (HR = 0.74, 95% CI: 0.61–0.89, P = 0.0016) with each increasing ACT cycle. The N stage, positive lymph node ratio (PLNR), carcinoembryonic antigen, neutrophil-to-lymphocyte ratio, and the number of cycles of ACT were chosen and entered into the nomogram model. Recursive partitioning analysis-based risk stratification revealed a significant difference in the prognosis in rectal cancer patients with high-risk, intermediate-risk, and low-risk (3-year cancer-specific survival: 0.246 vs. 0.795 vs. 0.968, P < 0.0001). Seven or more cycles of ACT yielded better survival in patients with PLNR ≥ 0.28 but not in patients with PLNR < 0.28.

Conclusion

In conclusion, the nomogram prognosis model based on the number of cycles of ACT predicted individual prognosis in rectal cancer patients who had undergone total mesorectal excision. These findings further showed that in patients with PLNR ≥ 0.28, no fewer than 7 cycles of ACT are needed to significantly reduce the patient’s risk of death.

SEOM-GEMCAD-TTD clinical guidelines for localized rectal cancer (2021)

The management of localized rectal cancer requires a multidisciplinary approach to optimize outcomes, reduce morbidity and prevent under or overtreatments. While early stages may obtain benefit of local resections without any additional therapies, locally advanced rectal cancer becomes a challenge defining the better sequential strategy of surgery, radiotherapy and chemotherapy. The latest results of international phase III studies have positioned the total neoadjuvant therapy as a potential new standard of care in high risk rectal cancers, however, the best schedule is still not well defined.

Radiomic analysis for predicting prognosis of colorectal cancer from preoperative 18F-FDG PET/CT

Background

To develop and validate a survival model with clinico-biological features and ¹⁸F- FDG PET/CT radiomic features via machine learning, and for predicting the prognosis from the primary tumor of colorectal cancer.

Methods

A total of 196 pathologically confirmed patients with colorectal cancer (stage I to stage IV) were included. Preoperative clinical factors, serum tumor markers, and PET/CT radiomic features were included for the recurrence-free survival analysis. For the modeling and validation, patients were randomly divided into the training (n = 137) and validation (n = 59) set, while the 78 stage III patients [training (n = 55), and validation (n = 23)] was divided for the further experiment. After selecting features by the log-rank test and variable-hunting methods, random survival forest (RSF) models were built on the training set to analyze the prognostic value of selected features. The performance of models was measured by C-index and was tested on the validation set with bootstrapping. Feature importance and the Pearson correlation were also analyzed.

Results

Radiomics signature (containing four PET/CT features and four clinical factors) achieved the best result for prognostic prediction of 196 patients (C-index 0.780, 95% CI 0.634–0.877). Moreover, four features (including two clinical features and two radiomics features) were selected for prognostic prediction of the 78 stage III patients (C-index was 0.820, 95% CI 0.676–0.900). K–M curves of both models significantly stratified low-risk and high-risk groups (P < 0.0001). Pearson correlation analysis demonstrated that selected radiomics features were correlated with tumor metabolic factors, such as SUVmean, SUVmax.

Conclusion

This study presents integrated clinico-biological-radiological models that can accurately predict the prognosis in colorectal cancer using the preoperative ¹⁸F-FDG PET/CT radiomics in colorectal cancer. It is of potential value in assisting the management and decision making for precision treatment in colorectal cancer.

Trial registration The retrospectively registered study was approved by the Ethics Committee of Fudan University Shanghai Cancer Center (No. 1909207-14-1910) and the data were analyzed anonymously.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03262-5.

Pathological Features and Prognostication in Colorectal Cancer

The prognostication of colorectal cancer (CRC) has traditionally relied on staging as defined by the Union for International Cancer Control (UICC) and American Joint Committee on Cancer (AJCC) TNM staging classifications. However, clinically, there appears to be differences in survival patterns independent of stage, suggesting a complex interaction of stage, pathological features, and biomarkers playing a role in guiding prognosis, risk stratification, and guiding neoadjuvant and adjuvant therapies. Histological features such as tumour budding, perineural invasion, apical lymph node involvement, lymph node yield, lymph node ratio, and molecular features such as MSI, KRAS, BRAF, and CDX2 may assist in prognostication and optimising adjuvant treatment. This study provides a comprehensive review of the pathological features and biomarkers that are important in the prognostication and treatment of CRC. We review the importance of pathological features and biomarkers that may be important in colorectal cancer based on the current evidence in the literature.

Re-evaluation of controversial issues in the treatment of cT3N0-2 rectal cancer: a 10-year cohort analysis using propensity-score matching

BACKGROUND

Although neoadjuvant treatment is thought to provide optimal local control for stage II and III rectal cancers, many patients have been reported cured by total mesorectal excision (TME), alone or with additional chemotherapy (CTX).

METHODS

This study retrospectively evaluated outcomes in 2643 patients with cT3N0-2 rectal cancers undergoing curative TME during 2005-2015. Recurrence and survival outcomes were measured in three propensity-score matched groups, consisting of patients who underwent preoperative chemoradiotherapy (CRT) with postoperative CTX (NAPOC), postoperative CRT (POCRT), and exclusively postoperative CTX (EPOCT).

RESULTS

Near-complete or complete TME was conducted in more than 95.9% of patients and 80% of scheduled dose of postoperative CTX was completed in 99%. Except for higher SR rate in the POCRT group than the NAPOC group (p = 0.008), 5-year cumulative local and systemic recurrence (LR and SR) rates were 4.9% and 15.2% for cT3N0, and 4.2% and 21% for cT3N1-2 patients (LR, p = 0.703; SR, 0.065), respectively, with no significant differences associated with treatment exposure (p = 0.11-1). The 5-year cumulative disease-free (75.6% vs 65.7%, p = 0.018) and overall survival (87.1% vs 79.4%, p = 0.018 each) rates were higher in the NAPOC group than the POCRT group with cT3N1-2. However, any significant survival differences were not identified between the NAPOC and EPOCT groups according to tumor sub-stages or locations (p = 0.395-0.971).

CONCLUSIONS

We found any treatment modalities including competent TME and postoperative adjuvant CTX efficiently reducing LR generating robust survival outcome in the propensity-matched cohorts, demanding further randomized controlled trials by clinical sub-stages II-III.

Combinatorial miRNA-34a replenishment and irinotecan delivery via auto-fluorescent polymeric hybrid micelles for synchronous colorectal cancer theranostics

The synergistic combination of microRNA (miRNA) modulation and chemotherapy has emerged as an effective strategy to combat cancer. Irinotecan (IRI) is a potent antitumor chemotherapeutic in clinical practice and has been used for treating various malignant tumors, including colorectal cancer (CRC). However, IRI is not effective for advanced CRC or metastatic behavior. Herein, novel polymeric hybrid micelles were engineered based on two different amphiphilic copolymers, polyethyleneimine-poly(d,l-lactide) (PEI-PLA) and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethyleneglycol) (DSPE-PEG), in which IRI and a tumor suppressive microRNA-34a (miR-34a) gene were efficiently co-loaded (MINPs) to achieve a chemo-miRNA combination therapy against CRC. MINPs were successfully constructed by two-step film dispersion and electrostatic interaction methods. IRI and miR-34a could be efficaciously encapsulated as MINPs and transferred to CRC cells. After encapsulation, MINPs would then upregulate miR-34a expression and regulate miR-34a-related downstream genes, which in turn led to enhanced cell cytotoxicity and apoptosis ratios. MINPs presented an excitation-dependent multi-wavelength emission feature due to the intrinstic fluorescence properties of PEI-PLA and could be utilized for in vitro/vivo imaging. According to the in vivo experimental results, MINPs possess the great characteristic of accumulating in situ in a tumor site and lightening it after intravenous administration. Furthermore, MINPs presented extraordinary antitumor efficacy owing to the combined therapy effects of IRI and miR-34a with good biocompability. Overall, our findings validated MINPs-mediated miR-34a replenishment and IRI co-delivery to serve as an effective theranostic platform and provided an innovative horizon for combining chemo-gene therapy against CRC.

MRI Staging in an Evolving Management Paradigm for Rectal Cancer, From the AJR Special Series on Cancer Staging

The treatment of rectal cancer centers around the distinct but related goals of management of distant metastases and management of local disease. Optimal local management requires attention to the primary tumor and its anatomic relationship to surrounding pelvic structures, with the goal of minimizing local recurrence (LR). High-resolution MRI is ideally suited for this purpose; application of MRI-based criteria in conjunction with optimized surgical and pathologic techniques have successfully reduced LR rates. This success has led to a shift away from using the TNM-based National Comprehensive Cancer Network (NCCN) guidelines as the sole determinant of whether a patient receives neoadjuvant chemoradiation. The new model uses a hybrid approach for assigning risk categories that combines elements of the TNM staging system with MRI-based anatomic features. These risk categories incorporate tumor proximity to the circumferential resection margin, T category, distance to the anal verge and presence of extramural venous invasion, to classify rectal tumors as low, intermediate, or high-risk. This approach has been validated by accumulated data from numerous multi-institutional studies. This review illustrates key anatomic concepts, depicts common interpretive errors and pitfalls, and discusses ongoing limitations; these insights should guide radiologists in optimal rectal MRI interpretation.

Relationship between Tertiary Lymphoid Structure and the Prognosis and Clinicopathologic Characteristics in Solid Tumors

Background: An increasing number of studies had shown that tertiary lymphoid structure (TLS) plays an important role in tumor progression. However, the prognostic role of TLS in various tumors remains controversial. This meta-analysis aims to investigate the clinicopathological and prognostic values of TLS in solid tumors. Methods: A systematic search was conducted in PubMed, EMBASE and Cochrane Library undated to November 2, 2020. Odds ratios of clinical parameters, hazard ratio (HR) of overall survival (OS), relapse-free survival (RFS), disease-free survival (DFS) and relapse rate were calculated in order to evaluate the relationship between TLS expression and clinicopathological or prognostic values in different tumors. Result: 27 eligible studies including 6647 patients with different types of tumors were analyzed. High TLS expression was associated with a longer OS (HR = 0.66, 95% CI: 0.50 - 0.86, P = 0.002) and RFS (HR = 0.61, 95% CI: 0.47 - 0.79, P = 0.0001). Moreover, high TLS levels in tumor were associated with a low risk of recurrence (HR = 0.43, 95% CI: 0.32 - 0.57, P < 0.0001). However, there was no relationship between TLS expression and DFS. Meanwhile, high TLS expression was associated with smaller tumor size (P < 0.00001) and higher tumor infiltrating lymphocytes (TILs). Furthermore, the subgroup analysis showed high TLS expression that may be associated with a lower clinical grading and N stage in breast cancer and colorectal cancer. Conclusion: High TLS expression is associated with the longer OS and RFS in solid tumors, and a lower risk of cancer relapse. Meanwhile, high TLS expression is also associated with a smaller tumor size, higher infiltration of TILs, lower clinical grading and N stage in the tumor. Therefore, high TLS expression in the tumor is a favorable prognostic biomarker for solid tumor patients.

Significance of Lymph Node Resection After Neoadjuvant Therapy in Pancreatic, Gastric, and Rectal Cancers

OBJECTIVE

Gastrointestinal cancers are increasingly being treated with NAT before surgical resection. Currently, quality metrics are linked to the number of LNs resected to determine subsequent treatment and prognosis. We hypothesize that NAT decreases LN metastasis, downstages patients, and decreases overall lymph node yields (LNY) compared to initial surgical resection. With increasing use of NAT, this brings into question the validity of quality metrics.

METHODS

Gastric (stage II/III), pancreatic (stage I/II/III), and rectal cancers (stage II/III) (2010-2015) treated with surgery with/without NAT were identified in National Cancer Database. We evaluated total LNY and LN metastasis with/without NAT and clinical and pathological stage to evaluate rates of downstaging.

RESULTS

A total of 7934 gastric, 15,908 pancreatic, and 21,354 rectal cancer patients were included of which 61.1%, 21.2%, and 85.7% received NAT, respectively. NAT patients were more likely to be downstaged (39.9% vs 11.1% gastric P< 0.001, 30.6% vs 3.2% pancreatic P< 0.001, 52.0% vs 16.3% rectal P< 0.001), have lower LNYs (18.8 vs 19.1 gastric P = 0.239, 18.4 vs 17.5 pancreatic P< 0.001, 15.7 vs 20.0 rectal P< 0.001) and have N0 pathologic disease (43.6% vs 26.7% gastric P< 0.001, 51.1% vs 30.9% pancreatic P< 0.001, 65.9% vs 49.4% rectal P< 0.001) when compared to initial surgical resection.

CONCLUSION

NAT for gastrointestinal cancers results in overall lower LN yields, lower LN metastases, and significant downstaging of tumors. As all patients undergoing NAT receive multimodality therapy, LN yield recommendations may not be true quality metric changing.

Total neoadjuvant therapy vs standard therapy of locally advanced rectal cancer with high-risk factors for failure

BACKGROUND

For locally advanced rectal cancer (LARC), standard therapy [consisting of neoadjuvant chemoradiotherapy (CRT), surgery, and adjuvant chemotherapy (ChT)] achieves excellent local control. Unfortunately, survival is still poor due to distant metastases, which remains the leading cause of death among these patients. In recent years, the concept of total neoadjuvant treatment (TNT) has been developed, whereby all systemic ChT-mainly affecting micrometastases-is applied prior to surgery.

AIM

To compare standard therapy and total neoadjuvant therapy for LARC patients with high-risk factors for failure.

METHODS

In a retrospective study, we compared LARC patients with high-risk factors for failure who were treated with standard therapy or with TNT. High-risk for failure was defined according to the presence of at least one of the following factors: T4 stage; N2 stage; positive mesorectal fascia; extramural vascular invasion; positive lateral lymph node. TNT consisted of 12 wk of induction ChT with capecitabine and oxaliplatin or folinic acid, fluorouracil and oxaliplatin, CRT with capecitabine, and 6-8 wk of consolidation ChT with capecitabine and oxaliplatin or folinic acid, fluorouracil and oxaliplatin prior to surgery. The primary endpoint was pathological complete response (pCR). In total, 72 patients treated with standard therapy and 89 patients treated with TNT were included in the analysis.

RESULTS

Compared to standard therapy, TNT showed a higher proportion of pCR (23% vs 7%; P = 0.01), a lower neoadjuvant rectal score (median: 8.43 vs 14.98; P < 0.05), higher T-and N-downstaging (70% and 94% vs 51% and 86%), equivalent R0 resection (95% vs 93%), shorter time to stoma closure (mean: 20 vs 33 wk; P < 0.05), higher compliance during systemic ChT (completed all cycles 87% vs 76%; P < 0.05), lower proportion of acute toxicity grade ≥ 3 during ChT (3% vs 14%, P < 0.05), and equivalent acute toxicity and compliance during CRT and in the postoperative period. The pCR rate in patients treated with TNT was significantly higher in patients irradiated with intensity-modulated radiotherapy/volumetric-modulated arc radiotherapy than with 3D conformal radiotherapy (32% vs 9%; P < 0.05).

CONCLUSION

Compared to standard therapy, TNT provides better outcome for LARC patients with high-risk factors for failure, in terms of pCR and neoadjuvant rectal score.

Recurrence Risk after Radical Colorectal Cancer Surgery-Less Than before, But How High Is It?

Simple Summary

Evidence indicates that recurrence risk after colon cancer today is less than it was when trials performed decades ago showed that adjuvant chemotherapy reduces the risk and prolong disease-free and overall survival. After rectal cancer surgery, local recurrence rates have decreased but it is unclear if systemic recurrences have. After a systematic review of available literature reporting recurrence risks after curative colorectal cancer surgery we report that the risks are lower today than they were in the past and that this risk reduction is not solely ascribed to the use of adjuvant therapy. Adjuvant therapy always means overtreatment of many patients, already cured by the surgery. Fewer recurrences mean that progress in the care of these patients has happened but also that the present guidelines giving recommendations based upon old data must be adjusted. The relative gains from adding chemotherapy are not altered, but the absolute number of patients gaining is less.

Abstract

Adjuvant chemotherapy aims at eradicating tumour cells sometimes present after radical surgery for a colorectal cancer (CRC) and thereby diminish the recurrence rate and prolong time to recurrence (TTR). Remaining tumour cells will lead to recurrent disease that is usually fatal. Adjuvant therapy is administered based upon the estimated recurrence risk, which in turn defines the need for this treatment. This systematic overview aims at describing whether the need has decreased since trials showing that adjuvant chemotherapy provides benefits in colon cancer were performed decades ago. Thanks to other improvements than the administration of adjuvant chemotherapy, such as better staging, improved surgery, the use of radiotherapy and more careful pathology, recurrence risks have decreased. Methodological difficulties including intertrial comparisons decades apart and the present selective use of adjuvant therapy prevent an accurate estimate of the magnitude of the decreased need. Furthermore, most trials do not report recurrence rates or TTR, only disease-free and overall survival (DFS/OS). Fewer colon cancer patients, particularly in stage II but also in stage III, today display a sufficient need for adjuvant treatment considering the burden of treatment, especially when oxaliplatin is added. In rectal cancer, neo-adjuvant treatment will be increasingly used, diminishing the need for adjuvant treatment.

Metachronous metastasis confined to isolated lymph node after curative treatment of colorectal cancer

BACKGROUND

The incidence of lymph node metastasis (LNM) in colorectal cancer is known to be 2-6%, but little data are available regarding metachronous metastasis confined to isolated LN. The aim of this study is to determine the distribution of isolated LNM and the risk factors for survival of isolated LNM in colorectal cancer.

METHODS

We retrospectively reviewed consecutive patients with colorectal adenocarcinoma between January 2008 and December 2015 at a tertiary referral center. A total of 5902 patients with biopsy-proven colorectal adenocarcinoma treated via surgery were included. Multivariate Cox proportional hazards analysis was used to identify prognostic factors for overall survival.

RESULTS

Of the 5902 patients, recurrent cases were 1326. Among the relapsed patients, 301 patients had isolated LNM (22.69%). Para-aortic (48.8%), pelvic (29.9%), and Lung hilum (10.0%) were the most common sites of isolated LNM; there were statistically significant differences in the distribution of isolated LNM between the colon and rectal cancer (p = 0.02). Approximately 80% of isolated LNM were diagnosed within 3 years. Multidisciplinary therapy for LNM, diagnosis time to LNM, the T-stage, and histological type of primary cancer were identified as independent prognostic factors for overall survival.

CONCLUSION

This study suggests that multidisciplinary management is a potentially effective treatment strategy for isolated LNM. Since time to LNM, the T-stage, and histological type are prognostic factors, an active follow-up program for colorectal cancer is required.

Post-Operative Morbidity and Mortality Following Total Neoadjuvant Therapy Versus Conventional Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer

BACKGROUND

Standard of care for locally advanced rectal cancer (LARC) (stage II/III) includes preoperative chemoradiation (CRT) followed by resection and adjuvant chemotherapy. Total neoadjuvant therapy (TNT) is a new treatment paradigm that delivers systemic therapy prior to CRT aimed at improving outcomes for high-risk patients. Here we analyzed the national cancer database (NCDB) comparing short-term post-operative outcomes between patients receiving TNT and CRT.

METHODS

The NCDB was queried to identify patients with LARC between the 2004 and 2014 treated with TNT or CRT. Primary outcomes included post-operative 30-day mortality and readmissions between TNT and CRT which were analyzed via logistic regression. Secondary outcomes included post-operative length of stay (LOS) and OS which were compared with two-tailed t-test and Kaplan-Meier with log rank testing, respectively.

RESULTS

A total of 9066 patients met inclusion criteria with a median age at diagnosis that was 57 years (IQR, 19-65); 62.3% were male and 87.8% white. Neoadjuvant therapy consisted of either standard CRT (97.2%) or TNT (2.8%). Patients treated at academic programs and those with N1 [p < 0.001, OR 2.34, 95%CI 1.71-3.19] or N2 [p < 0.001, OR 3.29, 95%CI 2.19-4.94] disease were associated with increased utilization of TNT. TNT was not significantly associated with either 30-day mortality (p = 1.0) or readmissions (p = 0.82). Further, there was no significant difference identified between CRT and TNT for hospital LOS or OS (p = 0.18).

CONCLUSION

This large-scale analysis of patients with LARC demonstrates increased utilization of TNT in patients harboring node-positive disease. Further, TNT does not appear to increase 30-day post-operative mortality, readmissions, or hospital LOS.

Advances in the treatment of locally advanced rectal cancer

Locally advanced rectal cancer requires multidisciplinary care. In the United States, most patients are treated with neoadjuvant chemoradiation delivered over 25‐28 days, total mesorectal excision, and 4 months of adjuvant chemotherapy. While effective, this trimodal approach is arduous. Alternative approaches have emerged to streamline treatment without sacrificing oncologic outcomes. These approaches include preoperative chemotherapy with selective use of radiation, short‐course radiotherapy delivered over 5 days, and total neoadjuvant therapy with attempted nonoperative organ‐preserving management (watch and wait). Ongoing trials are assessing the efficacies of these approaches in combination with various risk stratification strategies.

Do We Have to Treat All T3 Rectal Cancer the Same Way?

Chemoradiotherapy (CRT) followed by surgery is the recommended approach in the last years for stage II and III rectal cancer with the intention to decrease the risk of local recurrence. However, fewer patients benefit from this strategy in terms of overall survival and long-term adverse outcomes because T3 rectal cancer has a broad range of prognosis, as shown by recent publications. Many patients with cT3 rectal cancer have a substantial risk of overtreatment with long-term toxicity related to radiotherapy that could be avoided in a subset group of cT3 tumors with good prognosis. These findings raised the question of whether all cT3 rectal cancer should receive preoperative radiotherapy and if a selected cT3 subgroup could be treated by surgery alone. This review addresses the rationale of selecting good prognosis cT3 rectal cancer for surgery alone and analyzes the data to support this recommendation.

Development of the 'PREDICT' score through a systematic review and meta-analysis of the predictive parameters for locoregional recurrence after total mesorectal excision

BACKGROUND

Despite robust management techniques, locoregional recurrence rates of rectal cancer are still significant. Although offering intensive follow-up has been shown to be beneficial in the early detection, it can be resource consuming. Having a robust knowledge of risk factors of locoregional recurrence will help in identification of patients who actually need intensive follow-up programs. This review aimed to identify the factors that can predict locoregional recurrence after Total mesorectal excision (TME).

METHODS

We systematically reviewed PubMed, Scopus and Cochrane for relevant articles with no date restrictions while language was restricted to English. We only included articles that had either provided Hazards ratio (HR)/odds ratio (OR) or provided enough data that allowed calculation of HR/OR specifically for rectal cancer. Articles were deemed eligible if they included patients undergoing (TME).

RESULTS

Seventeen studies (18,605 patients) published between 2002 and 2019 were included. A total of 699 patients developed locoregional recurrence at a median time of 25.2 months after surgery. There were eight significant predictors evaluated by more than one study; T3-T4 stage, circumferential resection margin, lymphovascular invasion, mucinous histology, N1-N2 stage, positive distal resection margin, Tumor < 5 cm from anal verge, and lack of neoadjuvant radiotherapy. A scoring system was developed based on the weight and pooled OR/HR of each predictor.

CONCLUSION

Using predictive factors identified in our review in context of scoring system may help in the early detection of locoregional recurrence after TME. This may help in tailoring the application of intensive follow-up programs.

Postoperative radio-chemotherapy for rectal cancer: A retrospective analysis from a tertiary referral hospital

Aim

To report results of postoperative radio-chemotherapy (RT-CHT) for rectal cancer (RC).

Background

Total mesorectal excision (TME) is an essential treatment method in rectal cancer (RC). Perioperative radiotherapy in locally advanced RC improves loco-regional free survival (LRFS). Preoperative radiotherapy is a preferred option; however, some patients are not referred for it. In case of the risk of loco-regional failure postoperative radio-chemotherapy (RT-CHT) is indicated.

Material and methods

Between 2004 and 2010, 182 patients with pathological stage II-III RC (TME performed - 41%, resection R0 - 88%, circumferential resection margin evaluated - 55.5% and was above 2 mm in 66% of them) received postoperative RT-CHT in our institution. Overall survival (OS) and LRFS were estimated with the Kaplan-Meier method. Univariate and multivariate analysis were performed to compare the impact of prognostic factors on survival.

Results

Five-year OS and LRFS rates were 63% and 85%, respectively. Loco-regional recurrence and isolated distant metastases rates were 11.5% and 19%, respectively. Multivariate analysis showed stage (III vs. II), HR: 2.3 (95% confidence interval [CI]: 1.4-3.8), p = 0.0001; extent of resection (R1-2 vs. R0), HR: 2.14 (95%CI: 1.14-3.99), p = 0.017, and age (>65 vs. ≤65 years), HR: 1.66 (95%CI: 1.06-2.61), p = 0.027 as prognostic factors for OS. Extent of resection (R1-2 vs. R0), HR: 3.65 (95%CI: 1.41-9.43), p = 0.008 had significant impact on LRFS.

Conclusion

Despite a suboptimal quality of surgery and pathological reports, the outcome in our series is close to that reported in the literature. We confirm a strong impact of the extent of resection on patient's outcome, which confirms the pivotal role of surgery in the management of RC.

Association of T Stage and Serum CEA Levels in Determining Survival of Rectal Cancer

Purpose: To investigate the association of T stage and serum carcinoembryonic antigen (CEA) levels in determining oncologic outcomes of rectal cancer. Methods: Patients diagnosed with stage I-II rectal cancer patients were identified from the Surveillance, Epidemiology, and End Results database. Results: In stage T1N0M0 disease, elevated level of serum CEA (C1) was associated with 227.6% increased risk of mortality compared to normal level of serum CEA (C0; hazard ratio = 3.276, 95% confidence interval = 2.781-3.858, P < 0.001). Conclusions: Stage T1N0M0 rectal cancer, when involved in preoperative serum CEA elevation, may be a surrogate of biologically aggressive disease and correlate with unfavorable oncologic outcomes. Moreover, this subgroup of rectal cancer deserves more clinical attention of oncologists.

Report from the 20th annual Western Canadian Gastrointestinal Cancer Consensus Conference; Saskatoon, Saskatchewan; 28-29 September 2018

The 20th annual Western Canadian Gastrointestinal Cancer Consensus Conference was held in Saskatoon, Saskatchewan, 28-29 September 2018. This interactive multidisciplinary conference is attended by health care professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancers. In addition, invited speakers from other provinces participate. Surgical, medical, and radiation oncologists, and allied health care professionals participated in presentations and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses current issues in the management of colorectal cancers.

Locally recurrent rectal cancer: what the radiologist should know

Despite advances in surgical techniques and chemoradiation therapy, recurrent rectal cancer remains a cause of morbidity and mortality. After successful treatment of rectal cancer, patients are typically enrolled in a surveillance strategy that includes imaging as studies have shown improved prognosis when recurrent rectal cancer is detected during imaging surveillance versus based on development of symptoms. Additionally, patients who experience a complete clinical response with chemoradiation therapy may elect to enroll in a "watch-and-wait" strategy that includes imaging surveillance rather than surgical resection. Factors that increase the likelihood of recurrence, patterns of recurrence, and the imaging appearances of recurrent rectal cancer are reviewed with a focus on CT, PET CT, and MR imaging.

Construction of a nomogram to predict overall survival for patients with M1 stage of colorectal cancer: A retrospective cohort study

BACKGROUND

The M1 stage of colorectal cancer (CRC) has a poor prognosis. The aim of this study is to develop a reliable tool for the prediction for CRC patients with M1 stage, thus assisting the strategy of clinical diagnosis and treatment.

METHODS

CRC patient information collected in the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015 was extracted and evaluated. Multivariate analysis with Cox proportional hazards regression identified risk factors that predicted overall survival (OS) and the results were used to construct a nomogram to predict 3-, and 5-year OS in CRC patients with M1 stage. The Kaplan-Meier curve was plotted to evaluate OS differences.

RESULTS

A total of 19,796 patients from the SEER database were included for analysis. All patients were randomly allocated to 2 cohorts, the training cohort (n = 13,860) and the validation cohort (n = 5936). Patients' age at diagnosis; gender; race; tumor site; tumor grade; T and N stage; brain, lung, bone, and liver metastasis status; marital status; and therapy were associated with survival in the multivariate models. All these factors were incorporated to construct a nomogram. Additionally, we divide all 19,796 patients into high-risk group and low-risk group according to our nomogram, and plotted Kaplan-Meier curve. The result indicated that patients with higher risk had worse survival outcomes.

CONCLUSIONS

Our predictive model has the potential to provide an individualized risk estimate of survival in CRC patients with M1 stage.

Oncologic Outcomes of Postoperative Chemoradiotherapy Versus Chemotherapy Alone in Stage II and III Upper Rectal Cancer

PURPOSE

The aim of this study was to assess oncological outcomes of postoperative radiotherapy plus chemotherapy (CRT) versus chemotherapy alone (CTx) in stage II or III upper rectal cancer patients who underwent curative surgery.

METHODS

We retrospectively reviewed 263 consecutive patients with pathologic stage II or III upper rectal cancer who underwent primary curative resection with postoperative CRT or CTx from January 2008 to December 2014 at Chonnam National University Hwasun Hospital. Multivariate and propensity score matching analyses were used to reduce selection bias.

RESULTS

Median follow-up was 48.1 months for the entire cohort and 53.5 months for the matched cohort. In subgroup analysis of the propensity score matched cohort, the 3-year local recurrence-free survival was 94.1% (95% confidence interval [CI], 87.8%-100%) in the CRT group and 90.1% (95% CI, 82.8%-97.9%) in the CTx group (P = 0.370). No significant difference in disease-free survival was observed according to treatment type. On multivariate analysis, circumferential resection margin involvement (hazard ratio [HR], 2.386; 95% CI, 1.190-7.599; P = 0.032), N stage (HR, 6.262; 95% CI, 1.843-21.278, P = 0.003), and T stage (HR, 5.896, 95% CI, 1.298-6.780, P = 0.021) were identified as independent risk factors for local recurrence of tumors of the upper rectum.

CONCLUSION

Omission of radiotherapy in an adjuvant treatment setting may not jeopardize oncologic outcomes in stages II and III upper rectal cancer.

Laparoscopic and open resection of rectal cancer-is age an effect modifier for short- and long-term survival?

INTRODUCTION

Rectal cancer is a frequently diagnosed tumor worldwide. Various studies have shown the noninferiority or even slight superiority of laparoscopic resection. However, there is no clear recommendation on whether age should influence the choice of surgical approach.

MATERIALS AND METHODS

This study compared outcomes of laparoscopic and open surgery in rectal cancer patients. Perioperative mortality and 5-year overall, relative, and recurrence-free survival rates were analyzed separately for three age groups. Data originate from 30 regional German cancer registries that cover approximately one quarter of the German population. All primary nonmetastatic rectal adenocarcinoma cases with surgery between 2005 and 2014 were eligible for inclusion. To compare survival rates, Kaplan-Meier analysis, a relative survival model, and multivariable Cox regression were used; a sensitivity analysis assessed bias by exclusion.

RESULTS

Ten thousand seven hundred fifty-four patients were included in the analysis. The mean laparoscopy rate was 23.0% and increased over time. Analysis of 30-day postoperative mortality rates revealed advantages for laparoscopically treated patients, although the significance level was not reached in any age group. Regarding 5-year overall survival, laparoscopy generally seems to be the superior approach, whereas for recurrence-free survival, an age-dependent gradient in effect size was observed: with a hazard ratio (HR) of 0.703 for laparoscopy, patients under 60 years benefitted more from the minimally invasive approach than older patients (septuagenarians, HR 0.923).

CONCLUSION

Laparoscopy shows similar results to the open approach in terms of postoperative survival in all age groups. Concerning long-term outcomes, younger patients benefitted most from the minimally invasive approach.

The Effectiveness and Safety of Open Versus laparoscopic Surgery for Rectal Cancer after Preoperative Chemo-radiotherapy: A Meta-Analysis

BACKGROUND

Only a limited number of studies considered the combined chemo-radiation therapy after surgery for treating locally advanced rectal cancer. Comparative studies on laparoscopic and open procedures indicated that laparoscopy surgery may be associated with fewer postoperative complications. Despite encouraging results from rectal cancer patients who received neoadjuvant chemo-radiotherapy prior to laparoscopic surgery, the acceptance of this procedure remains controversial, and conflicting evidence exists only in the form of retrospective trials.

OBJECTIVES

Since laparoscopic surgery was introduced into clinical practice to treat rectal cancer after neoadjuvant chemo-radiotherapy, it has been discussed controversially whether laparoscopic surgery can be performed as effectively as an open procedure. To overcome the biases inherent in any nonrandomized comparison, we analyzed the propensity-matched analysis and randomized clinical trial. In this study, we set out to determine whether laparoscopic resection was non-inferior to open resection in treatment outcomes of rectal cancer after neoadjuvant chemo-radiotherapy.

METHODS

Publications on laparoscopic surgery in comparison with open thoracotomy in treatment outcomes of rectal cancer after neo-adjuvant chemo-radiotherapy to November 2017 were collected. Summary hazard ratios (HRs) of endpoints of interest such as 3-OS (overall survival), 3-DFS (disease-free survival), and individual postoperative complications were analyzed in all trials. By using fixed- or random-effects models according to the heterogeneity, meta-analysis Revman 5.3 software was applied to analyze combined pooled HRs.

RESULTS

A total of 6 trials met our inclusion criteria. The pooled analysis of 3-DFS showed that laparoscopic surgery did not improve disease -free survival, compared with open thoracotomy (OR =1.48, 95% CI 0.95 - 2.29; P = 0.08), as well with the 3-OS (OR=0.96, 95%CI=0.66-1.41, P=0.084). The pooled result of duration of surgery indicated that laparoscopic surgery had a tendency towards a longer surgery time (SMD= 43.96, 95% CI 34.04- 53.88; P < 0.00001) and a shorter hospital stay (SMD= -0.97, 95% CI -1.75- -0.18; P=0.02). However, no significant differences between laparoscopic surgery and open thoracotomy were observed in terms of the meta-analysis on the number of removed lymph nodes (SMD =-0.37, 95% CI -0.1.77 - 1.03; P = 0.60), blood loss (SMD =-21.30, 95% CI -0.48.36 - 5.77; P = 0.12), positive circumferential resection margin (OR =0.73, 95% CI 0.22- 2.48; P = 0.61) or postoperative complications (OR =0.89, 95% CI 0.67 - 1.17; P = 0.40) l.

CONCLUSION

The current data supported the concept that laparoscopic surgery had correlated with a longer operative time but a shorter hospital stay, without superior advantages in short-term survival rates or oncologic efficiency for locally treating advanced rectal cancer after neoadjuvant chemoradiotherapy. However, prospective investigation on long-term oncological results from laparoscopic surgery is required in the future to verify the benefits of laparoscopic surgery over open surgery after chemo-radiation therapy for treating locally advanced rectal cancer.

Surgeon-Level Variation in Utilization of Local Staging and Neoadjuvant Therapy for Stage II-III Rectal Adenocarcinoma

INTRODUCTION

Neoadjuvant therapy (NT) is the standard of care for clinical stage II-III rectal adenocarcinoma, but utilization remains suboptimal. We aimed to determine the underlying reasons for omission of local staging and NT.

METHODS

We conducted a retrospective study of patients with clinical stage II-III or undocumented clinical stage/pathologic stage II-III rectal adenocarcinoma who were treated in 2010-2016 in one of nine Intermountain Healthcare hospitals. The outcomes of omission of local staging and NT were examined with multivariable models. Risk- and reliability-adjusted rates of local staging and NT were calculated for surgeons who treated ≥ 3 patients. Pathologic and long-term outcomes were examined after excluding patients who were not resected or who underwent local excision (N = 11).

RESULTS

Local staging was omitted in 43/240 (17.9%) patients and NT was omitted in 41/240 (17.1%). The strongest risk factors for local staging and NT omission were upper rectal tumors and surgeons who treated ≤ 3 cases/year. Thirty-six of 41 (87.8%) cases of omitted NT had local staging omitted. Adjusted surgeon-specific local staging rates varied 1.6-fold (56.3-92.4%) and NT rates varied 2.8-fold (34.1-97.1%). Surgeon local staging and NT rates were strongly correlated (r = 0.92). NT was associated with lower rates of positive circumferential radial margins (7.9 vs. 20.0%; P = 0.02), node positivity (33.3 vs. 55.0%; P = 0.01), and local recurrences (7.6 vs. 14.9% at 5 years; P = 0.0176).

CONCLUSIONS

NT omission should be understood as a consequence of surgeon failure to perform local staging in most cases. Quality improvement efforts should focus on improving utilization of local staging.

18F-FDG PET/CT Is an Early Predictor of Pathologic Tumor Response and Survival After Preoperative Radiochemotherapy with Bevacizumab in High-Risk Locally Advanced Rectal Cancer

There is an unmet need for predictive biomarkers of the clinical benefit of antiangiogenic drugs. The aim of the present study was to prospectively evaluate the value of ¹⁸F-FDG PET/CT performed during and after preoperative chemoradiotherapy with bevacizumab for the prediction of complete pathologic tumor regression and survival in patients with MRI-defined high-risk locally advanced rectal cancer. Methods: Sixty-one patients treated in a nonrandomized phase II study (BRANCH) with concomitant or sequential (4 d before chemoradiotherapy) administration of bevacizumab with preoperative chemoradiotherapy were included. ¹⁸F-FDG PET/CT was performed at baseline, 11 d after the beginning of chemoradiotherapy (early), and before surgery (late). Metabolic changes were compared with pathologic complete tumor regression (TRG1) versus incomplete tumor regression (TRG2-TRG5), progression-free survival, cancer-specific survival, and overall survival. Receiver-operating-characteristic curves were calculated for those ¹⁸F-FDG PET/CT parameters that significantly correlated with TRG1. Results: Early total-lesion glycolysis and its percentage change compared with baseline (ΔTLG-early) could discriminate TRG1 from TRG2-TRG5. Only receiver-operating-characteristic analysis of ΔTLG-early showed an area under the curve greater than 0.7 (0.76), with an optimal cutoff at 59.5% (80% sensitivity, 71.4% specificity), for identifying TRG1. Late metabolic assessment could not discriminate between the 2 groups. After a median follow-up of 98 mo (range, 77-132 mo), metabolic responders (ΔTLG-early ≥ 59.5%) demonstrated a significantly higher 10-y progression-free survival (89.3% vs. 63.6%, P = 0.02) and cancer-specific survival (92.9% vs. 72.6%, P = 0.04) than incomplete metabolic responders. Conclusion: Our results suggest that early metabolic response can act as a surrogate marker of the benefit of antiangiogenic therapy. The findings provide further support for the use of early ¹⁸F-FDG PET/CT evaluation to predict pathologic response and survival in the preoperative treatment of patients with locally advanced rectal cancer. ΔTLG-early showed the best accuracy in predicting tumor regression and may be particularly useful in guiding treatment-modifying decisions during preoperative chemoradiotherapy based on expected response.

Role of postoperative radiotherapy in pT3N0 rectal cancer: A risk-stratification system based on population analyses

The impact of adjuvant radiotherapy in pT3N0 rectal cancer is controversial. We aimed to determine the risk factors for cancer-specific survival (CSS) among these patients and to develop a risk-stratification system to identify which of these patients would benefit from adjuvant radiotherapy. In this review of the Surveillance, Epidemiology, and End Results database (2010-2014), we analyzed the data of pT3N0 rectal cancer patients who had not undergone neoadjuvant radiotherapy. Prognostic factors were identified using the Cox proportional hazards model, and risk scores were derived according to the β regression coefficient. A total of 1021 patients were identified from the database search. The overall 5-year CSS was 86.31%. Multivariate analysis showed that age (P < 0.001), tumor differentiation (P = 0.044), number of nodes resected (P = 0.032), marital status (P = 0.005), and radiotherapy (P = 0.006) were independent prognostic factors for CSS. A risk-stratification system composed of age, tumor differentiation, and number of nodes resected was generated. Low-risk patients had better CSS than high-risk patients (92.13% vs 72.55%, P < 0.001). The addition of radiotherapy to surgery doubled the CSS among the high-risk patients (42.06% vs 91.26%, P = 0.001) but produced no survival benefit among the low-risk patients (93.36% vs 96.38%, P = 0.182). Our risk-stratification model based on age, tumor differentiation, and number of nodes resected predicted the outcomes of pT3N0 rectal cancer patients. This model could help identify patients who may benefit from adjuvant radiotherapy.

Tumor location as an indication for adjuvant radiotherapy in pT3N0 rectal cancer after surgery

Background

The optimal care for pT3N0 rectal cancer remains controversial. And whether tumor location can be used to guide the administration of adjuvant radiotherapy for pT3N0 rectal cancer is not fully confirmed. The current study was designed to identify the benefit of adjuvant radiotherapy for pT3N0 rectal cancer.

Methods

We performed a retrospective study of 265 pT3N0 rectal cancer patients who were treated by surgery and adjuvant therapy from Mar. 2005 to Sept. 2015. All patients were divided into two groups according to receiving adjuvant radiotherapy or not. Overall survival (OS), disease-free survival (DFS) were compare between patients who did and did not receive adjuvant radiotherapy. Multivariate analysis was performed to explore clinical factors significantly associated with DFS, local recurrence-free survival (LRFS) and distant metastasis-free survival (DMFS).

Results

For patients with lower tumor, DFS in adjuvant chemo-radiotherapy group was higher than that in adjuvant chemotherapy group. Besides, the rates of local recurrence and distant metastasis were found lower in patients who did receive adjuvant radiotherapy than those who did not. For patients with upper tumor, the 5-year OS and DFS were similar between groups of adjuvant chemotherapy and adjuvant chemo-radiotherapy. Multivariable analysis indicated both the CEA and tumor location were independent predictors of LRFS. And adjuvant radiotherapy predicted the DFS, LRFS and DMFS in lower rectal cancer patients.

Conclusion

Tumor location can serve as an indication for the administration of adjuvant radiotherapy in pT3N0 rectal cancer patients.

Pathologic Staging Inconsistency Between ypT4N0 (stage II) and ypT1-2N1 (stage III) After Preoperative Chemoradiotherapy and Total Mesorectal Excision in Rectal Cancer: A Multi-Institutional Study

BACKGROUND

In the Surveillance, Epidemiology, and End Results population-based data, the survival curves reversed between T4N0 (stages IIB or IIC) and T1-2N1 (stage IIIA) in rectal cancer. However, T4N0 had a higher stage than T1-2N1 in the current colorectal staging system.

PATIENTS AND METHODS

We analyzed 1804 patients with rectal cancer who were treated with preoperative chemoradiotherapy and curative surgery. We grouped patients by pathologic stage, and recurrence-free survival (RFS) and overall survival rates were calculated and compared for each stage. We evaluated prognostic factors that influenced recurrence and survival.

RESULTS

In the recurrence and survival analysis, 3-year RFS rates were 95.9% for ypStage 0, 94.0% for ypStage I, 78.9% for ypStage IIA, 55.8% for ypStage IIB/C, 80.2% for ypStage IIIA, 64.6% for ypStage IIIB, and 44.9% for ypStage IIIC. Patients with ypStage IIB/C showed significantly worse RFS (P = .004) than did those with ypStage IIIA. The ypStage IIB/C group showed significantly higher rates of both locoregional recurrence (24.3% vs. 5.5%; P = .02) and distant metastasis (31.6% vs. 17.1%; P = .048) than did the ypStage IIIA group. Compared with ypStage IIIA, ypStage IIB/C showed significantly higher pre-chemoradiotherapy carcinoembryonic antigen (P = .004), circumferential radial margin involvement (P = .001), and positive perineural invasion (P = .014).

CONCLUSION

Patients with rectal cancer staged ypT4N0 were associated with higher locoregional recurrence and distant metastasis rates than those staged ypT1-2N1 in the current staging system.

Surgical outcome after standard abdominoperineal resection: A 15-year cohort study from a single cancer centre

BACKGROUND

Abdominoperineal resection (APR) is associated with a poorer oncological outcome than anterior resection. This may be due to higher rates of intra-operative perforation and circumferential resection margin involvement. The aim of this study was to audit our short and long-term results of abdominoperineal resection performed using conventional techniques and to compare this with other published series.

MATERIALS AND METHODS

A retrospective review of all patients who had standard APR between January 2000 and December 2016 in a single institution, Cabrini Hospital, Melbourne, Australia. A total of 163 cases performed by nine different colorectal surgeons for primary rectal adenocarcinoma were identified, with their clinicopathological data analysed.

RESULTS

Using standard APR, only six patients (3.7%) were found to have a positive circumferential resection margin (CRM). There were two cases of intra-operative perforation (1.2%). Local recurrence rate was 5.6% of patients, with distant recurrence found in 24.9%. Disease-free survival at five years was 73.1%. Five-year overall survival was 66.7%, 67.9% of all deaths were cancer-related.

CONCLUSION

Short and long-term outcomes after standard APR in this study were comparable to previous published studies. The CRM rate of 3.7% compares favourably to published positive CRM rates for standard APR which ranged from 6 to 18%. Standard APR remains a viable technique for the treatment of rectal cancer. Patient selection and adequate training remain important factors.

Chemo-Radiation After Upfront Rectal Resections-a Clinical Dilemma

To compare the impact of adjuvant chemo-radiotherapy (ACRT) versus adjuvant chemotherapy (ACT) alone on recurrence and survival in patients with stage II and III rectal adenocarcinoma undergoing upfront curative resection. Prospective observational review of colorectal database at Tata Memorial Hospital from July 2010 to March 2015 identified 84 patients who underwent upfront curative resection for stage II or III rectal cancer. None of the patient received preoperative chemo-radiation. Of these, adjuvant chemo-radiotherapy was administered to 29 patients (ACRT group) and 55 patients received CAPEOX/FOLFOX-based adjuvant chemotherapy (ACT group) alone. At a median follow-up of 20 months, there were 10 recurrences (3 local recurrence) in the ACRT group and 15 (2 local recurrence) in ACT group. The estimated disease-free survival at 3 years in the ACRT group was 62.7% and in ACT group was 49.7% (p = 0.417) with an estimated 3-year overall survival of 74 and 78% in the ACRT and ACT group, respectively (p = 0.241). Subgroup analysis was performed after risk stratifying prognostic features (pT4, pN2, poor differentiation, involved resection margin). Our study does not show any benefit of ACRT over ACT on local control, disease-free and overall survival after upfront rectal cancer resection for low-risk stage II-III. In the subgroup analysis, local recurrence did not occur in patients who did not have poor prognostic features irrespective whether they received ACRT or ACT. Adjuvant chemo-radiation can be avoided in low-risk stage II-III rectal cancer after upfront resection.

Combination of carcinoembryonic antigen with the American Joint Committee on Cancer TNM staging system in rectal cancer: a real-world and large population-based study

AIM

This study assessed the combination of carcinoembryonic antigen (CEA) with the American Joint Committee on Cancer (AJCC) TNM staging system, aiming to improve the AJCC TNM staging system, in terms of prognostic accuracy and clinical management of rectal cancer.

METHODS

Eligible patients (N=22,132) were selected from the Surveillance, Epidemiology, and End Results database between January 1, 2004, and December 31, 2010. Patients with elevated CEA levels were designated as "C1 stage" and those with normal CEA amounts as "C0 stage". The outcome of interest was cancer-specific survival (CSS). Cox proportional hazards regression analyses and Kaplan-Meier curves were used to identify independent prognostic factors and analyze the odds of CSS in patients with rectal cancer in different C and TNM stages, respectively.

RESULTS

C1 stage was associated with a 61.0% risk increase in cancer-specific mortality (HR=1.610, 95% CI=1.219-1.705, P<0.001). In addition, C0-stage patients showed improved CSS compared with C1-stage counterparts. In addition, CSS was improved in stage IIB-C0 patients (HR=2.478, 95% CI=1.660-3.699) compared with stage IIIB-C1 patients (HR=2.431, 95% CI=2.021-2.924) or IIIA-C1 patients (HR=1.060, 95% CI=0.823-1.366, P=0.650) and stage IIC-C0 patients (HR=4.263, 95% CI=3.308-5.493) compared with stage IIIB-C1 or IIIA-C1 counterparts.

CONCLUSION

C stage is an independent prognostic factor of rectal cancer. The improved prognostic precision of the C-TNM staging system and, thus, more individualized risk-adaptive treatments support the incorporation of C stage into the AJCC TNM staging system in rectal cancer.