Advances and challenges in treatment of locally advanced rectal cancer

Pattern of colorectal surgery and long-term survival: 10-year experience from a single center

BACKGROUND

The incidence of colorectal cancer (CRC) has increased in recent decades, and ranks fourth among males and third among females in China. Surgical resection remains the most important treatment modality for curative intent in CRC. Several studies found that surgeon volumes and specialization appeared to be associated with improved overall survival (OS). Moreover, numerous reports have suggested that specialization and minimally invasive surgery have gained increased popularity in CRC surgery. However, few studies have specifically examined the role and long-term survival of all stage CRC in a real-world study.

AIM

To evaluate the effect of surgeon specialization on survival changes and minimally invasive surgery utilization in a real world study.

METHODS

A retrospective analysis on the association between surgeon specialization and OS between 2008 and 2013 in Zhongshan Hospital CRC database was performed. Standard demographic, clinicopathologic, surgical and follow-up data were obtained from the CRC database. Surgeon specialty was categorized as colorectal surgeon (CS) and general surgeon (GS). CRC patients who underwent primary surgical resection were enrolled.

RESULTS

A total of 5141 CRC patients who underwent primary surgical resection between 2008 and 2013 were evaluated, 1748 (34.0%) of these by CS. The percentage of minimally invasive procedures in the CS group showed an increasing trend. There was no benefit associated with surgeon specialization for stage I, II and IV patients. Surgeon specialization exhibited a significant association with OS solely among stage III patients, with 5-year OS rates of 76% and 67% for the CS and GS groups, respectively (P < 0.01). Further analyses found that surgeon specialization was significantly associated with survival only in stage III rectal patients, and the 5-year OS rate in the CS group and GS group was 80% and 67%, respectively (P < 0.01).

CONCLUSION

Surgeon specialization is associated with improved OS after primary surgery in stage III rectal patients. An appropriate surgical technique, perioperative program and adjuvant therapy may contribute to survival benefit in these patients.

Correlations between Apparent Diffusion Coefficient (ADC) and Prognosis in Patients with Locally Advanced Rectal Cancer

BACKGROUND

the aim of this study is to assess the performance of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) values in predicting the response to neoadjuvant chemoradiation therapy (CRT) and outcome in patients with locally advanced rectal cancer (LARC).

MATERIALS AND METHODS

ninety-four patients with magnetic resonance imaging (MRI) pre- and post-neoadjuvant treatment were retrospectively enrolled. Three regions of interest (ROIs) were manually drawn on three different slices of the tumor for every DWI sequence. ROIs were positioned to include only high signal areas and avoid artifacts or necrotic areas. ROIs were automatically copied onto the corresponding ADC maps and the system derived three different ADC values, distinguishing between mean, maximum, and minimum values, and the standard deviation (SD). Only mean ADC values were considered. After surgical intervention, pTNM and the Mandard tumor regression grade (TRG) were obtained. Patients with a TRG of 1-2 were classified as responders, while patients with a TRG from 3 to 5 were classified as non-responders.

RESULTS

no correlation was found between pre-ADC values and TRG classes, while post-ADC and ΔADC values showed a significant correlation with TRG classes (r = -0.285, p = 0.002 and r = -0.290, p = 0.019, respectively). Post-ADC values were statistically different between responders and non-responders (p = 0.019). When considering the relation between overall survival (OS) and ADC values, pre-ADC showed a negative correlation with OS (r = -0.381, p = 0.001), while a positive correlation was found between ΔADC values and OS (r = 0.323, p = 0.013). According to ΔADC values, the mean OS time between responders and non-responders showed a significant difference (p = 0.030). A statistical difference was found between TRG classes and OS (p = 0.038) and by dividing patients in responders and non-responders (p = 0.019).

CONCLUSIONS

the pre-ADC and ΔADC values could be used as useful predictors for patient prognosis, thus helping the treatment planning. On the other hand, the post-ADC values, thanks to their relationship with the TRG classes, could be the ideal tool to predict the histopathological response and plan a conservative approach to the treatment of rectal cancer.

Pathologic Complete Response, Total Neoadjuvant Therapy and the Survival Paradox in Locally Advanced Rectal Cancer

BACKGROUND

Pathologic complete response (pCR) after preoperative chemoradiation (nCRT) correlates with improved overall survival for patients with locally advanced rectal cancers (LARCs). Escalation protocols including total neoadjuvant therapy (TNT), which delivers multi-agent chemotherapy and chemoradiation before surgery, are associated with increased complete response rates. However, TNT is not associated with improved overall survival. The authors hypothesized that the route to pCR may be an important predictor of oncologic outcome.

METHODS

Adults with LARC between 2006 and 2017 were identified in the National Cancer Database. The cohort was limited to those who received neoadjuvant radiation (45-70 Gy) and underwent proctectomy.

RESULTS

Of 25,880 patients, 16 % received TNT and 84 % had nCRT followed by either multi-agent (27 %), single-agent (14 %), or no adjuvant chemotherapy (44 %). Overall, 18 % achieved pCR, with higher rates in the TNT cohort than in the nCRT (18 %) or multi-agent (14 %) chemotherapy cohorts. With control for covariates, the OS in the pCR cohort was similar for the patients that received single-agent therapy and those that received multi-agent adjuvant therapy, and superior to the TNT and no adjuvant therapy cohorts. Conversely, among the patients who did not achieve pCR, those who received single-agent chemotherapy had OS comparable with those who had multi-agent adjuvant therapy and TNT, which was better than no adjuvant therapy.

CONCLUSION

Patients achieving pCR after TNT had worse OS than those who had CRT alone, suggesting that the neoadjuvant route by which pCR is achieved is prognostically relevant. Therefore, in the era of neoadjuvant therapy escalation, pCR does not necessarily portend a uniformly favorable prognosis.

Omission of Chemoradiation in Locally Advanced Rectal Adenocarcinoma: Evaluation of PROSPECT in a National Database

BACKGROUND AND OBJECTIVES

The PROSPECT trial showed noninferiority of neoadjuvant chemotherapy (NAC) with selective chemoradiation (CRT) versus CRT alone. However, trial results are often difficult to reproduce with real-world data. Pathologic outcomes and overall survival (OS) were evaluated by neoadjuvant strategy in locally advanced rectal adenocarcinoma patients in a national database.

METHODS

The 2012-2020 National Cancer Database was queried for clinical T2N1 and T3N0-1 rectal adenocarcinoma patients with definitive resection. Patients were categorized by neoadjuvant treatment with CRT alone, NAC alone, and NAC with CRT. Outcomes included R0 resection, pathologic complete response (PCR), and OS.

RESULTS

Of 18 892 patients, 16 126 (85.4%) received CRT, 1018 (5.4%) NAC, and 1748 (9.3%) NAC with CRT. Patients with NAC alone or NAC with CRT were more likely to have stage-III disease, private insurance, and academic facility treatment (all p < 0.001). NAC alone had lower adjusted odds of an R0 resection (OR 0.72; 95%CI 0.54-0.95) and PCR (OR 0.77; 95%CI 0.64-0.93). NAC with CRT demonstrated improved OS (HR 0.71; 95%CI 0.61-0.82), with no difference between NAC and CRT alone. Among patients who received adjuvant chemotherapy, no differences in OS were seen.

CONCLUSIONS

Patients who received NAC alone had worse pathologic outcomes. NAC had similar OS to CRT and NAC with CRT showed improved OS.

Validation of a genome-based model for adjusting radiotherapy dose (GARD) in patients with locally advanced rectal cancer

Neoadjuvant radiotherapy is the standard care of locally advanced rectal cancer. Although a majority of patients received the same dose, the curative efficacy varies among individuals. In recent years, cancer treatment has entered the era of precise medical care, and how to identify patients for proper treatment by molecular signature is an important path of individualized therapy. This study aimed to establish and validate a genome-based model for adjusting radiation dose (GARD) for Chinese locally advanced rectal cancer through gene expression microarrays, and to evaluate the response of the GARD model in predicting the efficacy of neoadjuvant radiotherapy. Fresh-frozen primary tumor from 64 patients with locally advanced rectal cancer undergoing neoadjuvant radiotherapy from 2015 to 2018 were included. The gene expression profile was analyzed using Affymetrix 3000Dx gene-chip scanner. The radiosensitivity index (RSI) and GARD were calculated using the pGRT™ algorithm. Neoadjuvant rectal cancer score (NAR) was selected as efficacy evaluation indicators. Patients were divided into high and low NAR scoring groups, and two-sample t-test was used to analyze the differences in GARD values between different NAR subgroups. ROC curves were used to calculate the cut-off values and the area under the curve (AUC) for assessing the validity of the GARD models. The personalized radiation dose ( pGRT dose )can be computed using the formula nd = GARD / (α + βd). Among patients, 1.5% T2, 46.3% T3, and 52.2% T4. Wherein pCR (n = 10; 15.6%) and no pCR (n = 54; 84.4%). The median NAR is 8.43 (rang from 0 to 50.34, IQR 3.75-14.98). NAR > 8.43 (n = 27; 42.2%) and NAR ≤ 8.43 (n = 37; 57.8%), suggesting that there are significant individual differences in clinical efficacy of patients with similar tumor stages and under the same treatment conditions. The median RSI is 0.48 (rang from 0.22 to 0.92, IQR 0.41-0.55). Median GARD was 18.40 rang from (rang from 2.26 to 37.52, IQR 14.94-22.28) within tumor tissue, suggesting individual differences in the efficacy of radiation therapy. The RSI value was significantly lower in the NAR low group (NAR ≤ 8.43) than in NAR high group (NAR > 8.43) (0.44 vs. 0.54, p = 0.0003). The GARD value was significantly higher in the NAR low group (NAR ≤ 8.43) than in NAR high group (NAR > 8.43) (21.01 vs. 15.88, p = 0.0004). Using the Receiver Operating Characteristic (ROC) curve analysis, a GARD threshold of 17 was identified as optimal, covering 37.5% of the 64-patient sample, with an area under the curve (AUC) of 0.75. In the external validation cohort, the high GARD score group demonstrated superior DFS compared to the low GARD score group(p < 0.001). Only 17% of patients had pGRT dose within the guideline recommended dose (45-50 Gy). The differences in NAR values among LARC patients receiving standard neoadjuvant radiotherapy suggest significant individual differences in clinical outcomes among patients with similar tumor stage and the same treatment conditions. Patients with a GARD value exceeding 17 exhibit a more favorable prognosis. Our results suggest that the gene expression-based pGRT™ algorithm has good efficacy prediction performance in preoperative concurrent radiotherapy for locally advanced rectal cancer, suggesting the potential clinical application of this method to guide the designation of individualized radiotherapy doses.

The application of the golden-angle radial sparse parallel technique in T restaging of locally advanced rectal cancer after neoadjuvant chemoradiotherapy

PURPOSE

To evaluate the diagnostic performance of Golden-Angle Radial Sparse Parallel (GRASP) MRI in identifying pathological stage T0-1 (ypT0-1) after neoadjuvant chemoradiotherapy (nCRT) in patients with rectal cancer, compared to T2-weighted imaging (T2WI) combined with Diffusion Weighted Imaging (DWI).

METHODS

In this retrospective study, 168 patients were carefully selected based on inclusion criteria that targeted individuals with biopsy-confirmed primary rectal adenocarcinoma, identified via MRI as having locally advanced disease (≥ T3 and/or positive lymph node results) prior to nCRT. Post-nCRT, all MRI images obtained after nCRT were assessed by two observers independently. The area under the receiver operating characteristic curve (AUC), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for identifying ypT0-1 based on GRASP and T2 + DWI were calculated. Multivariable regression analysis was used to explore the factors independently associated with ypT0-1 tumor.

RESULTS

45 patients out of these cases were ypT0-1, and the accuracy, sensitivity, specificity, PPV, and NPV of GRASP were higher than the T2 + DWI (88% vs 74%, 93% vs 71%, 86% vs 75%, 71% vs 52% and 97% vs 88%), the AUC in identifying ypT0-1 tumor based on GRASP was 0.90 (95% CI:0.84, 0.94), which was better than the T2 + DWI (0.73; 95% CI: 0.66, 0.80). Multivariable logistic regression analysis showed that the yT stage on GRASP scans was the only factor independently associated with ypT0-1 tumor (P < 0.001).

CONCLUSION

The GRASP helped distinguish ypT0-1 tumor after nCRT and can select patients who may be suitable for local excision.

MRI Tumor Regression Response to Neoadjuvant Chemotherapy Alone without Radiation for Rectal Adenocarcinoma

Background Neoadjuvant chemotherapy (NCT) is gaining acceptance for the management of locally advanced rectal cancer (LARC) in patients without negative prognostic factors. However, the value of MRI in evaluating tumor response after NCT remains unclear. Purpose To investigate the accuracy of MRI in assessing pathologic complete response in participants with LARC who underwent surgery after NCT without radiation. Materials and Methods A retrospective imaging substudy was conducted within two consecutive prospective clinical trials: the expanded phase II trial (from December 2017 to May 2021) and the COPEC trial (comparison of tumor response to two or four cycles of neoadjuvant chemotherapy alone, ongoing from August 2021). All included participants received four cycles of capecitabine combined with oxaliplatin (or CAPOX) before surgery. Three radiologists who were blinded to the clinicopathologic data independently evaluated the tumor response using five methods, namely, MR tumor regression grade (MR-TRG) alone, diffusion-weighted imaging (DWI) alone, DWI-modified MR-TRG (DWImodMR-TRG), MRI complete response, and radiologic neoadjuvant response score. With pathologic assessment serving as the reference standard, the positive and negative predictive values, sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were determined to evaluate the accuracy and performance of these models. The AUCs of the models were compared using the DeLong test. Results A total of 224 participants were included, comprising 119 from the expanded phase II trial (median age, 61 years [IQR, 53-67]; 89 male) and 105 from the COPEC trial (median age, 59 years [IQR, 53-67]; 65 male). MR-TRG, DWI, DWImodMR-TRG, MRI complete response, and the radiologic neoadjuvant response score were associated with pathologic complete response. DWImodMR-TRG achieved the highest AUC of 0.90 (95% CI: 0.85, 0.95), with a specificity of 89% (162 of 182) and a negative predictive value of 93% (162 of 174). Conclusion MRI-based models were accurate for determining pathologic complete response in participants with LARC following NCT. DWI improved the predictive performance of MRI-based assessment. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Santiago and Shur in this issue.

Modified neoadjuvant rectal score as a novel prognostic model for rectal cancer patients who underwent chemoradiotherapy

BACKGROUND

The neoadjuvant rectal score (NAR score) has recently been proposed as a better prognostic model than the conventional TNM classification for rectal cancer patients that have undergone neoadjuvant chemoradiotherapy. We recently developed an apoptosis-detection technique for assessing the viability of residual tumors in resected specimens after chemoradiotherapy. This study aimed to establish an improved prognostic classification by combining the NAR score and the assessment of the apoptosis of residual cancer cells.

METHODS

We retrospectively enrolled 319 rectal cancer patients who underwent chemoradiotherapy followed by radical surgery. The recurrence-free survival and overall survival of the four models were compared: TNM stage, NAR score, modified TNM stage by re-staging according to cancer cell viability, and modified NAR score also by re-staging.

RESULTS

Downstaging of the ypT stage was observed in 15.5% of cases, whereas only 4.5% showed downstaging of ypN stage. C-index was highest for the modified NAR score (0.715), followed by the modified TNM, TNM, and NAR score. Similarly, Akaike's information criterion was smallest in the modified NAR score (926.2), followed by modified TNM, TNM, and NAR score, suggesting that the modified NAR score was the best among these four models. The overall survival results were similar: C-index was the highest (0.767) and Akaike's information criterion was the smallest (383.9) for the modified NAR score among the four models tested.

CONCLUSION

We established a novel prognostic model, for rectal cancer patients that have undergone neoadjuvant chemoradiotherapy, using a combination of apoptosis-detecting immunohistochemistry and neoadjuvant rectal scores.

High Rates of Organ Preservation in Rectal Cancer with Papillon Contact X-ray Radiotherapy: Results from a Swiss Cohort

Rectal cancer typically necessitates a combination of radiotherapy (RT), chemotherapy, and surgery. The associated functional disorders and reduction in quality of life have led to an increasing interest in organ preservation strategies. Response strongly correlates with RT dose, but dose escalation with external beam remains limited even with modern external beam RT techniques because of toxicity of the surrounding tissues. This study reports on the use of Papillon, an endocavitary Radiotherapy device, in the treatment of rectal cancer. The device delivers low energy X-rays, allowing for safe dose escalation and better complete response rate. Between January 2015 and February 2024, 24 rectal cancer patients were treated with the addition of a boost delivered by Papillon to standard RT, with or without chemotherapy, in an upfront organ preservation strategy. After a median follow-up (FU) of 43 months, the organ preservation rate was 96% (23/24), and the local relapse rate was 8% (2/24). None of our patients developed grade 3 or more toxicities. Our results demonstrate that the addition of Papillon contact RT provides a high rate of local remission with sustained long-term organ preservation, offering a promising alternative to traditional surgical approaches in patients with rectal cancer.

Treatment of Locally Advanced Rectal Cancer in the Era of Total Neoadjuvant Therapy: A Systematic Review and Network Meta-Analysis

Importance

Treatment of locally advanced rectal cancer (LARC) involves neoadjuvant chemoradiotherapy plus total mesorectal excision and adjuvant chemotherapy. However, total neoadjuvant therapy (TNT) protocols (ie, preoperative chemotherapy in addition to radiotherapy) may allow better adherence and early treatment of distant micrometastases and may increase pathological complete response (pCR) rates.

Objective

To assess the efficacy and tolerability of TNT protocols for LARC.

Data Sources

MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science Core Collection electronic databases and ClinicalTrials.gov for unpublished studies were searched from inception to March 2, 2024.

Study Selection

Randomized clinical trials including adults with LARC who underwent rectal resection as a final treatment were included. Studies including nonoperative treatment (watch-and-wait strategy), treatments other than rectal resection, immunotherapy, or antiangiogenic agents were excluded. Among the initially identified studies, 2.9% met the selection criteria.

Data Extraction and Synthesis

Two authors independently screened the records and extracted data. Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA)-compliant pairwise and network meta-analyses with a random-effects model were performed in a frequentist framework, and the certainty of evidence was assessed according to the confidence in network meta-analysis approach.

Main Outcomes and Measures

The primary outcome was pCR, defined as the absence of residual tumor at pathological assessment after surgery. Secondary outcomes included tolerability, toxic effects, perioperative outcomes, and long-term survival.

Results

Of 925 records identified, 27 randomized clinical trials, including 13 413 adults aged 18 years or older (median age, 60.0 years [range, 42.0-63.5 years]; 67.2% male) contributed to the primary network meta-analysis. With regard to pCR, long-course chemoradiotherapy (L-CRT) plus consolidation chemotherapy (relative risk [RR], 1.96; 95% CI, 1.25-3.06), short-course radiotherapy (S-RT) plus consolidation chemotherapy (RR, 1.76; 95% CI, 1.34-2.30), and induction chemotherapy plus L-CRT (RR, 1.57; 95% CI, 1.09-2.25) outperformed standard L-CRT with single-agent fluoropyrimidine-based chemotherapy. Considering 3-year disease-free survival, S-RT plus consolidation chemotherapy (RR, 1.08; 95% CI, 1.01-1.14) and induction chemotherapy plus L-CRT (RR, 1.12; 95% CI, 1.01-1.24) outperformed L-CRT, in spite of an increased 5-year locoregional recurrence rate of S-RT plus consolidation chemotherapy (RR, 1.65; 95% CI, 1.03-2.63).

Conclusions and Relevance

In this systematic review and network meta-analysis, 3 TNT protocols were identified to outperform the current standard of care in terms of pCR rates, with good tolerability and optimal postoperative outcomes, suggesting they should be recognized as first-line treatments.

Pretreatment MRI-detected extramural venous invasion as a prognostic and predictive biomarker for neoadjuvant chemoradiotherapy in non-metastatic rectal cancer: a propensity score matched analysis

OBJECTIVES

This study evaluated pretreatment magnetic resonance imaging (MRI)-detected extramural venous invasion (pmrEMVI) as a predictor of survival after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer (LARC).

MATERIALS AND METHODS

Medical records of 1184 patients with rectal adenocarcinoma who underwent TME between January 2011 and December 2016 were reviewed. MRI data were collected from a computerized radiologic database. Cox proportional hazards analysis was used to assess local, systemic recurrence, and disease-free survival risk based on pretreatment MRI-assessed tumor characteristics. After propensity score matching (PSM) for pretreatment MRI features, nCRT therapeutic outcomes according to pmrEMVI status were evaluated. Cox proportional hazards analysis was used to identify risk factors for early recurrence in patients receiving nCRT.

RESULTS

Median follow-up was 62.8 months. Among all patients, the presence of pmrEMVI was significantly associated with worse disease-free survival (DFS; HR 1.827, 95% CI 1.285-2.597, p = 0.001) and systemic recurrence (HR 2.080, 95% CI 1.400-3.090, p < 0.001) but not local recurrence. Among patients with pmrEMVI, nCRT provided no benefit for oncological outcomes before or after PSM. Furthermore, pmrEMVI( +) was the only factor associated with early recurrence on multivariate analysis in patients receiving nCRT.

CONCLUSIONS

pmrEMVI is a poor prognostic factor for DFS and SR in patients with non-metastatic rectal cancer and also serves as a predictive biomarker of poor DFS and SR following nCRT in LARC. Therefore, for patients who are positive for pmrEMVI, consideration of alternative treatment strategies may be warranted.

CLINICAL RELEVANCE STATEMENT

This study demonstrated the usefulness of pmrEMVI as a predictive biomarker for nCRT, which may assist in initial treatment decision-making in patients with non-metastatic rectal cancer.

KEY POINTS

• Pretreatment MRI-detected extramural venous invasion (pmrEMVI) was significantly associated with worse disease-free survival and systemic recurrence in patients with non-metastatic rectal cancer. • pmrEMVI is a predictive biomarker of poor DFS following nCRT in patients with LARC. • The presence of pmrEMVI was the only factor associated with early recurrence on multivariate analysis in patients receiving nCRT.

Assessing circulating tumour DNA (ctDNA) as a prognostic biomarker in locally advanced rectal cancer: a systematic review and meta-analysis

INTRODUCTION

Circulating tumour DNA (ctDNA) has emerged as a promising biomarker in various cancer types, including locally advanced rectal cancer (LARC), offering potential insights into disease progression, treatment response and recurrence. This review aims to comprehensively evaluate the utility of ctDNA as a prognostic biomarker in LARC.

METHODS

PubMed, EMBASE and Web of Science were searched as part of our review. Studies investigating the utility of ctDNA in locally advanced rectal cancer (LARC) were assessed for eligibility. Quality assessment of included studies was performed using the Newcastle Ottawa Scale (NOS) risk of bias tool. Outcomes extracted included basic participant characteristics, ctDNA details and survival data. A meta-analysis was performed on eligible studies to determine pooled recurrence-free survival (RFS).

RESULTS

Twenty-two studies involving 1676 participants were included in our analysis. Methodological quality categorised by the Newcastle Ottawa Scale was generally satisfactory across included studies. ctDNA detected at various time intervals was generally associated with poor outcomes across included studies. Meta-analysis demonstrated a pooled hazard ratio of 8.87 (95% CI 4.91-16.03) and 15.15 (95% CI 8.21-27.95), indicating an increased risk of recurrence with ctDNA positivity in the post-neoadjuvant and post-operative periods respectively.

CONCLUSION

Our systematic review provides evidence supporting the prognostic utility of ctDNA in patients with LARC, particularly in identifying patients at higher risk of disease recurrence in the post-neoadjuvant and post-operative periods.

Knockdown of BUB1B Inhibits the Proliferation, Migration, and Invasion of Colorectal Cancer by Regulating the JNK/c-Jun Signaling Pathway

Background: Colorectal cancer (CRC) ranks as the third most common cancer, accounting for a significant number of cancer-related deaths worldwide every year. Yet, the molecular mechanisms responsible for the progression of this malignancy are not fully understood. Numerous studies indicate that BUB1 mitotic checkpoint serine/threonine kinase B (BUB1B) plays a role in the progression of various malignant tumors. However, the specific biological functions and the detailed mechanisms of how BUB1B influences CRC are still not completely known. This study aimed to explore the expression and role of BUB1B in CRC. Materials and Methods: To achieve this, the expression levels of BUB1B in human CRC tissues and cell lines were examined using real-time polymerase chain reaction and Western blotting. The role and associated mechanisms of BUB1B in CRC cell progression were assessed both in vitro and in vivo using RNA interference. Results: The findings of this study revealed an elevated expression of BUB1B in both CRC tissues and cell lines. The silencing of BUB1B in CRC cell lines notably inhibited cell proliferation, migration, and invasion, leading to cell cycle arrest and apoptosis. In addition, the knockdown of BUB1B inhibited the JNK/c-Jun signaling pathway, increased the expression of proapoptotic proteins, and decreased the expression of antiapoptotic proteins. The effects of BUB1B knockdown on CRC cell progression were reversed by the JNK activator PAF(C-16). Conclusions: In summary, the suppression of BUB1B hindered malignant tumor progression and heightened apoptosis and cell cycle arrest in CRC cells via the JNK/c-Jun pathway. Importantly, the removal of BUB1B expression curtailed tumor growth in human CRC xenografts in nude mice, suggesting its potential as a promising therapeutic target for CRC patients. ClinicalTrials.gov ID: No.2019 K-C086.

Association of radiotherapy for prostate cancer and second primary colorectal cancer: a US population-based analysis

BACKGROUND

Radiotherapy (RT) is a common treatment for prostate cancer, yet the risk of second primary colorectal cancer (SPCRC) in patients with prostate cancer undergoing RT has not been adequately studied.

METHODS

This study employed a population-based cohort design using the US Surveillance, Epidemiology, and End Results (SEER) database to identify individuals diagnosed between January 1975 and December 2015. The cumulative incidence of SPCRC was estimated using Fine-Gray competing risk regression. Poisson regression analysis was used to estimate the risk associated with RT. Survival outcomes of patients with SPCRC were evaluated using the Kaplan-Meier method.

RESULTS

A total of 287,607 patients diagnosed with prostate cancer were identified. The cumulative incidences were higher in patients who did not receive RT (2.00%) compared to those who underwent RT (2.47%) after 25 years. After adjustment for multiple variables, RT was associated with an increased risk of developing combined SPCRC (adjusted HR 1.590). Additionally, the overall survival was significantly lower in patients who developed colorectal cancer after receiving RT as compared to those who did not receive RT.

CONCLUSION

These findings underscore the need for diligent long-term monitoring and effective management strategies to detect SPCRC in patients treated with RT for prostate cancer.

Radiogenomics: Contemporary Applications in the Management of Rectal Cancer

Radiogenomics, a sub-domain of radiomics, refers to the prediction of underlying tumour biology using non-invasive imaging markers. This novel technology intends to reduce the high costs, workload and invasiveness associated with traditional genetic testing via the development of 'imaging biomarkers' that have the potential to serve as an alternative 'liquid-biopsy' in the determination of tumour biological characteristics. Radiogenomics also harnesses the potential to unlock aspects of tumour biology which are not possible to assess by conventional biopsy-based methods, such as full tumour burden, intra-/inter-lesion heterogeneity and the possibility of providing the information of tumour biology longitudinally. Several studies have shown the feasibility of developing a radiogenomic-based signature to predict treatment outcomes and tumour characteristics; however, many lack prospective, external validation. We performed a systematic review of the current literature surrounding the use of radiogenomics in rectal cancer to predict underlying tumour biology.

A Review of Circulating Tumor DNA as a Biomarker Guide for Total Neoadjuvant Therapy in Patients with Locally Advanced Rectal Cancer

PURPOSE

Non-operative management of patients with locally advanced rectal cancer (LARC) is emerging as a popular approach for patients that have no evidence of disease following neoadjuvant therapy. However, high rates of local recurrence or distant metastases have highlighted the urgent need for robust biomarker strategies to aid clinical management of these patients.

METHODS

This review summarizes recent advances in the utility of cell-free (cf) and circulating tumor (ct) DNA as potential biomarkers to help guide individualized non-operative management strategies for LARC patients receiving neoadjuvant therapy.

RESULTS

Liquid biopsies and the detection of cfDNA/ctDNA is an emerging technology with the potential to provide a non-invasive approach to monitor disease response and improve the identification of patients with LARC that would best benefit from non-operative management.

CONCLUSIONS

Substantial work is still needed before cfDNA/ctDNA monitoring can be widely adopted in the clinical setting. Studies reviewed herein highlight several areas of opportunity for improving the effectiveness and utility of cfDNA/ctDNA for managing patients with LARC.

Survival outcomes of salvage surgery in the watch-and-wait approach for rectal cancer with clinical complete response after neoadjuvant chemoradiotherapy: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis compared the outcomes of the watch-and-wait (WW) approach versus radical surgery (RS) in rectal cancers with clinical complete response (cCR) after neoadjuvant chemoradiotherapy.

METHODS

This study followed the PRISMA guidelines. Major databases were searched to identify relevant articles. WW and RS were compared through meta-analyses of pooled proportions. Primary outcomes included overall survival (OS), disease-free survival (DFS), local recurrence, and distant metastasis rates. Pooled salvage surgery rates and outcomes were also collected. The Newcastle-Ottawa scale was employed to assess the risk of bias.

RESULTS

Eleven studies including 1,112 rectal cancer patients showing cCR after neoadjuvant chemoradiation were included. Of these patients, 378 were treated nonoperatively with WW, 663 underwent RS, and 71 underwent local excision. The 2-year OS (risk ratio [RR], 0.95; P = 0.94), 5-year OS (RR, 2.59; P = 0.25), and distant metastasis rates (RR, 1.05; P = 0.80) showed no significant differences between WW and RS. Local recurrence was more frequent in the WW group (RR, 6.93; P < 0.001), and 78.4% of patients later underwent salvage surgery (R0 resection rate, 97.5%). The 2-year DFS (RR, 1.58; P = 0.05) and 5-year DFS (RR, 2.07; P = 0.02) were higher among RS cases. However, after adjustment for R0 salvage surgery, DFS showed no significant between-group difference (RR, 0.82; P = 0.41).

CONCLUSION

Local recurrence rates are higher for WW than RS, but complete salvage surgery is often possible with similar long-term outcomes. WW is a viable strategy for rectal cancer with cCR after neoadjuvant chemoradiation, but further research is required to improve patient selection.

Development of a Diagnostic Artificial Intelligence Tool for Lateral Lymph Node Metastasis in Advanced Rectal Cancer

BACKGROUND

Metastatic lateral lymph node dissection can improve survival in patients with rectal adenocarcinoma, with or without chemoradiotherapy. However, the optimal imaging diagnostic criteria for lateral lymph node metastases remain undetermined.

OBJECTIVE

To develop a lateral lymph node metastasis diagnostic artificial intelligence tool using deep learning, for patients with rectal adenocarcinoma who underwent radical surgery and lateral lymph node dissection.

DESIGN

Retrospective study.

SETTINGS

Multicenter study.

PATIENTS

A total of 209 patients with rectal adenocarcinoma, who underwent radical surgery and lateral lymph node dissection at 15 participating hospitals, were enrolled in the study and allocated to training (n = 139), test (n = 17), or validation (n = 53) cohorts.

MAIN OUTCOME MEASURES

In the neoadjuvant treatment group, images taken before pretreatment were classified as baseline images and those taken after pretreatment as presurgery images. In the upfront surgery group, presurgery images were classified as both baseline and presurgery images. We constructed 2 types of artificial intelligence, using baseline and presurgery images, by inputting the patches from these images into ResNet-18, and we assessed their diagnostic accuracy.

RESULTS

Overall, 124 patients underwent surgery alone, 52 received neoadjuvant chemotherapy, and 33 received chemoradiotherapy. The number of resected lateral lymph nodes in the training, test, and validation cohorts was 2418, 279, and 850, respectively. The metastatic rates were 2.8%, 0.7%, and 3.7%, respectively. In the validation cohort, the precision-recall area under the curve was 0.870 and 0.963 for the baseline and presurgery images, respectively. Although both baseline and presurgery images provided good accuracy for diagnosing lateral lymph node metastases, the accuracy of presurgery images was better than that of baseline images.

LIMITATIONS

The number of cases is small.

CONCLUSIONS

An artificial intelligence tool is a promising tool for diagnosing lateral lymph node metastasis with high accuracy.

DESARROLLO DE UNA HERRAMIENTA DE INTELIGENCIA ARTIFICIAL PARA EL DIAGNSTICO DE METSTASIS EN GANGLIOS LINFTICOS LATERALES EN CNCER DE RECTO AVANZADO

ANTECEDENTES:Disección de nódulos linfáticos laterales metastásicos puede mejorar la supervivencia en pacientes con adenocarcinoma del recto, con o sin quimiorradioterapia. Sin embargo, aún no se han determinado los criterios óptimos de diagnóstico por imágenes de los nódulos linfáticos laterales metastásicos.OBJETIVO:Nuestro objetivo fue desarrollar una herramienta de inteligencia artificial para el diagnóstico de metástasis en nódulos linfáticos laterales mediante el aprendizaje profundo, para pacientes con adenocarcinoma del recto que se sometieron a cirugía radical y disección de nódulos linfáticos laterales.DISEÑO:Estudio retrospectivo.AJUSTES:Estudio multicéntrico.PACIENTES:Un total de 209 pacientes con adenocarcinoma del recto, que se sometieron a cirugía radical y disección de nódulos linfáticos laterales en 15 hospitales participantes, se inscribieron en el estudio y se asignaron a cohortes de entrenamiento (n = 139), prueba (n = 17) o validación (n = 53).PRINCIPALES MEDIDAS DE RESULTADO:En el grupo de tratamiento neoadyuvante, las imágenes tomadas antes del tratamiento se clasificaron como imágenes de referencia y las posteriores al tratamiento, como imágenes previas a la cirugía. En el grupo de cirugía inicial, las imágenes previas a la cirugía se clasificaron como imágenes de referencia y previas a la cirugía. Construimos dos tipos de inteligencia artificial, utilizando imágenes de referencia y previas a la cirugía, ingresando los parches de estas imágenes en ResNet-18. Evaluamos la precisión diagnóstica de los dos tipos de inteligencia artificial.RESULTADOS:En general, 124 pacientes se sometieron a cirugía solamente, 52 recibieron quimioterapia neoadyuvante y 33 recibieron quimiorradioterapia. El número de nódulos linfáticos laterales removidos en los cohortes de entrenamiento, prueba y validación fue de 2,418; 279 y 850, respectivamente. Las tasas metastásicas fueron 2.8%, 0.7%, y 3.7%, respectivamente. En el cohorte de validación, el área de recuperación de precisión bajo la curva fue de 0.870 y 0.963 para las imágenes de referencia y antes de la cirugía, respectivamente. Aunque tanto las imágenes previas a la cirugía como las iniciales proporcionaron una buena precisión para diagnosticar metástasis en los nódulos linfáticos laterales, la precisión de las imágenes previas a la cirugía fue mejor que la de las imágenes iniciales.LIMITACIONES:El número de casos es pequeño.CONCLUSIÓN:La inteligencia artificial es una herramienta prometedora para diagnosticar metástasis en los nódulos linfáticos laterales con alta precisión. (Traducción-Dr. Aurian Garcia Gonzalez ).

Characterization of the tumor microenvironment and identification of spatially predictive biomarkers associated with beneficial neoadjuvant chemoradiotherapy in locally advanced rectal cancer

Neoadjuvant chemoradiotherapy (nCRT) has become the standard treatment for patients with locally advanced rectal cancer (LARC). However, 20-40% of patients with LARC show little to no response to nCRT. Thus, comprehensively understanding the tumor microenvironment (TME), which might influence therapeutic efficacy, and identifying robust predictive biomarkers is urgently needed. Pre-treatment tumor biopsy specimens from patients with LARC were evaluated in detail through digital spatial profiling (DSP), public RNA sequencing datasets, and multiplex immunofluorescence (mIF). DSP analysis revealed distinct characteristics of the tumor stroma compared to the normal stroma and tumor compartments. We identified high levels of human leukocyte antigen-DR/major histocompatibility complex class II (HLA-DR/MHC-II) in the tumor compartment and B cells in the stroma as potential spatial predictors of nCRT efficacy in the Discovery cohort. Public datasets validated their predictive capacity for clinical outcomes. Using mIF in an independent nCRT cohort and/or the total cohort, we validated that a high density of HLA-DR/MHC-II+ cells in the tumor and CD20 + B cells in the stroma was associated with nCRT efficacy (all p ≤ 0.021). Spatial profiling successfully characterized the LARC TME and identified robust biomarkers with the potential to accurately predict nCRT response. These findings have important implications for individualized therapy.

Prognostic Impact of Lymphatic Invasion, Venous Invasion, Perineural Invasion, and Tumor Budding in Rectal Cancer Treated With Neoadjuvant Chemoradiotherapy Followed by Total Mesorectal Excision

BACKGROUND

The diagnostic implications of lymphatic invasion, venous invasion, perineural invasion, and tumor budding in rectal cancer treated with neoadjuvant chemoradiotherapy are unknown.

OBJECTIVE

This study aimed to identify the prognostic impact of lymphatic invasion, venous invasion, perineural invasion, and tumor budding in locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy.

DESIGN

This was a retrospective cohort study.

SETTINGS

This study was conducted at the Samsung Medical Center. Grouping was performed on the basis of lymphatic invasion, venous invasion, perineural invasion, and tumor budding status: no-risk group with 0 factor (n = 299), low-risk group with any 1 factor (n = 131), intermediate-risk group with any 2 factors (n = 75), and high-risk group with 3 or 4 risk factors (n = 32).

PATIENTS

Patients who underwent neoadjuvant chemoradiotherapy, followed by radical operation for locally advanced rectal cancer, from January 2010 to December 2015 were included.

MAIN OUTCOME MEASURES

The main outcome measures were disease-free and overall survival.

RESULTS

Disease-free and overall survival varied significantly between the groups in stage III ( p < 0.001 and p < 0.001). Disease-free survival in stage I differed between the no-risk group and the intermediate-risk group ( p = 0.026). In stage II, disease-free and overall survival differed between the no-risk group and the intermediate-risk group ( p = 0.010 and p = 0.045). In multivariable analysis, risk grouping was an independent prognostic factor for both disease-free (p <0.001) and overall survival ( p < 0.001).

LIMITATIONS

The inherent limitations are associated with the retrospective single-center study design.

CONCLUSIONS

Lymphatic invasion, venous invasion, perineural invasion, and tumor budding are strong prognostic factors for disease-free and overall survival in locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy. Therefore, adjuvant chemotherapy is strongly recommended in patients with positive lymphatic invasion, venous invasion, perineural invasion, and tumor budding. See Video Abstract at http://links.lww.com/DCR/B919 .

IMPACTO PRONSTICO DE LA INVASIN LINFTICA, LA INVASIN VENOSA, LA INVASIN PERINEURAL Y LA GEMACIN TUMORAL EN EL CNCER DE RECTO TRATADO CON QUIMIORRADIOTERAPIA NEOADYUVANTE SEGUIDA DE ESCISIN TOTAL DEL MESORRECTO

ANTECEDENTES:Se desconocen las implicaciones diagnósticas de la invasión linfática, la invasión venosa, la invasión perineural y el crecimiento tumoral en el cáncer de recto tratado con quimiorradioterapia neoadyuvante.OBJETIVO:Este estudio fue diseñado para identificar el impacto pronóstico de la invasión linfática, la invasión venosa, la invasión perineural y la gemación tumoral en el cáncer de recto localmente avanzado tratado con quimiorradioterapia neoadyuvante.DISEÑO:Este estudio fue un estudio de cohorte retrospectivo.AJUSTES:Este estudio se realizó en el Centro Médico Samsung. La agrupación se realizó en función de la invasión linfática, la invasión venosa, la invasión perineural y el estado de crecimiento del tumor: grupo sin riesgo con 0 factores (n = 299), grupo de bajo riesgo con cualquier factor 1 (n = 131), grupo de riesgo intermedio con 2 factores cualquiera (n = 75), y un grupo de alto riesgo con 3 o 4 factores de riesgo (n = 32).PACIENTES:Se incluyeron un total de 537 pacientes que se sometieron a quimiorradioterapia neoadyuvante seguida de operación radical por cáncer de recto localmente avanzado desde enero de 2010 hasta diciembre de 2015.PRINCIPALES MEDIDAS DE RESULTADO:Las principales medidas de resultado fueron la supervivencia libre de enfermedad y la supervivencia general.RESULTADOS:La mediana del período de seguimiento fue de 77 meses, y la supervivencia libre de enfermedad a los 5 años y la supervivencia general a los 5 años variaron significativamente entre los grupos en el estadio III (p < 0,001, p < 0,001). La supervivencia libre de enfermedad a los 5 años en el estadio I difirió entre el grupo sin riesgo y el grupo de riesgo intermedio (p = 0,026). En el estadio II, la supervivencia libre de enfermedad a 5 años y la supervivencia global a 5 años difirieron entre el grupo sin riesgo y el grupo de riesgo intermedio p = 0,010, p = 0,045). En el análisis multivariable, la agrupación de riesgo fue un factor pronóstico independiente tanto para la supervivencia libre de enfermedad (p < 0,001) como para la supervivencia global (p < 0,001).LIMITACIÓN:Las limitaciones inherentes están asociadas con el diseño de estudio retrospectivo de un solo centro..CONCLUSIÓN:La invasión linfática, la invasión venosa, la invasión perineural y la gemación tumoral son fuertes factores pronósticos para la supervivencia libre de enfermedad y la supervivencia general en el cáncer de recto localmente avanzado tratado con quimiorradioterapia neoadyuvante. Por lo tanto, se recomienda fuertemente la quimioterapia adyuvante en pacientes con invasión linfática positiva, invasión venosa, invasión perineural y tumor en en formacion. Consulte Video Resumen en http://links.lww.com/DCR/B919 . (Traducción-Dr Yolanda Colorado ).

Comparison of the pathological response to 2 or 4 cycles of neoadjuvant CAPOX in II/III rectal cancer patients with low/intermediate risks: study protocol for a prospective, non-inferior, randomized control trial (COPEC trial)

BACKGROUND

For patients with low- and intermediate-risk stage II/III rectal cancer, current studies have reached a consensus that preoperative radiotherapy may be dispensed with, and neoadjuvant chemotherapy (NCT) alone might achieve an accepted local control. Our previous phase II study has evidenced that the morphological response of NCT could be better judged at a relatively early stage. Low- and intermediate-risk stage II/III rectal cancer patients could achieve a high rate of tumor shrinkage and downgrade after only 4 cycles of NCT and obvious tumor morphological changes could be observed after 2 cycles of NCT. However, there is still a lack of more detailed stratification and evidence for pathological criteria. The aim of the present study (comparison of the pathological response to 2 or 4 cycles of neoadjuvant CAPOX in II/III rectal cancer patients with low/intermediate risks, COPEC trial) is to determine the pathological tumor regression grade (pTRG) rate of 2 or 4 cycles of NCT in low- and intermediate-risk stage II/III rectal cancer and verify the feasibility of early identification of chemotherapy-insensitive population.

METHODS/DESIGN

This is a multicenter, prospective, non-inferior, randomized controlled trial (RCT) initiated by West China Hospital of Sichuan University and designed to be conducted in fourteen hospitals around China. Eligible patients will be centrally randomized into 2 or 4 cycles of CAPOX in a 1:1 ratio using the central automated randomization system offered by the O-trial online system ( https://plus.o-trial.com/ ) and accept total mesorectal excision after 2 or 4 cycles of CAPOX (oxaliplatin 130 mg/m², once daily on day 1, every 21 days and capecitabine 1000 mg/m², twice daily on days 1 to 14, every 21 days). The primary endpoint is the proportion of patients with pathological no-tumor regression (pTRG 3), which is determined postoperatively by each sub-center and verified by the primary center.

DISCUSSION

COPEC trial is designed to verify that the preoperative CAPOX chemotherapy for low- and intermediate-risk stage II/III rectal cancer could achieve a good response judgment after 2 cycles and obtain the tumor pathological response rate after 2 cycles of CAPOX. We hope the COPEC trial could help in establishing a consensus standard of low- and intermediate-risk rectal cancer and the early identification of stage II/III rectal patients with low- and intermediate-risk who are poorly responding to NCT.

TRIAL REGISTRATION

Clinicaltrial.gov NCT04922853. Registered on June 4, 2021.

Total neoadjuvant therapy versus chemoradiotherapy for locally advanced rectal cancer: Bayesian network meta-analysis

BACKGROUND

Total neoadjuvant therapy is a promising treatment for locally advanced rectal cancer, utilizing either short-course radiotherapy or long-course chemoradiotherapy, but their relative efficacy remains unclear. The aim of this Bayesian network meta-analysis was to investigate clinical outcomes amongst patients receiving total neoadjuvant therapy with short-course radiotherapy or long-course chemoradiotherapy, and those receiving long-course chemoradiotherapy alone.

METHODS

A systematic literature search was performed. All studies that compared at least two of these three treatments for locally advanced rectal cancer were included. The primary endpoint was the pathological complete response rate, and survival outcomes were adopted as secondary outcomes.

RESULTS

Thirty cohorts were included. Compared with long-course chemoradiotherapy, both total neoadjuvant therapy with long-course chemoradiotherapy (OR 1.78, 95 per cent c.i. 1.43 to 2.26) and total neoadjuvant therapy with short-course radiotherapy (OR 1.75, 95 per cent c.i. 1.23 to 2.50) improved the pathological complete response rate. Similar benefits were observed in the sensitivity and subgroup analyses, except for short-course radiotherapy with one to two cycles of chemotherapy. No significant differences in survival outcomes were found amongst the three treatments. Long-course chemoradiotherapy with consolidation chemotherapy (HR 0.44, 95 per cent c.i. 0.20 to 0.99) exhibited higher disease-free survival than long-course chemoradiotherapy alone.

CONCLUSION

Compared with long-course chemoradiotherapy, both short-course radiotherapy with greater than or equal to three cycles of chemotherapy and total neoadjuvant therapy with long-course chemoradiotherapy can improve the pathological complete response rate, and long-course chemoradiotherapy with consolidation chemotherapy may lead to a marginal benefit in disease-free survival. The pathological complete response rate and survival outcomes are similar for total neoadjuvant therapy with short-course radiotherapy or long-course chemoradiotherapy.

The role of Lamin B2 in human diseases

Lamin B2 (LMNB2), on the inner side of the nuclear envelope, constitutes the nuclear skeleton by connecting with other nuclear proteins. LMNB2 is involved in a wide range of nuclear functions, including DNA replication and stability, regulation of chromatin, and nuclear stiffness. Moreover, LMNB2 regulates several cellular processes, such as tissue development, cell cycle, cellular proliferation and apoptosis, chromatin localization and stability, and DNA methylation. Besides, the influence of abnormal expression and mutations of LMNB2 has been gradually discovered in cancers and laminopathies. Therefore, this review summarizes the recent advances of LMNB2-associated biological roles in physiological or pathological conditions, with a particular emphasis on cancers and laminopathies, as well as the potential mechanism of LMNB2 in related cancers.

Neoadjuvant Chemotherapy With CAPOX Versus Chemoradiation for Locally Advanced Rectal Cancer With Uninvolved Mesorectal Fascia (CONVERT): Initial Results of a Phase III Trial

OBJECTIVE

To compare neoadjuvant chemotherapy (nCT) with CAPOX alone versus neoadjuvant chemoradiotherapy (nCRT) with capecitabine in locally advanced rectal cancer (LARC) with uninvolved mesorectal fascia (MRF).

BACKGROUND DATA

nCRT is associated with higher surgical complications, worse long-term functional outcomes, and questionable survival benefits. Comparatively, nCT alone seems a promising alternative treatment in lower-risk LARC patients with uninvolved MRF.

METHODS

Patients between June 2014 and October 2020 with LARC within 12 cm from the anal verge and uninvolved MRF were randomly assigned to nCT group with 4 cycles of CAPOX (Oxaliplatin 130 mg/m2 IV day 1 and Capecitabine 1000 mg/m2 twice daily for 14 d. Repeat every 3 wk) or nCRT group with Capecitabine 825 mg/m² twice daily administered orally and concurrently with radiation therapy (50 Gy/25 fractions) for 5 days per week. The primary end point is local-regional recurrence-free survival. Here we reported the results of secondary end points: histopathologic response, surgical events, and toxicity.

RESULTS

Of the 663 initially enrolled patients, 589 received the allocated treatment (nCT, n=300; nCRT, n=289). Pathologic complete response rate was 11.0% (95% CI, 7.8-15.3%) in the nCT arm and 13.8% (95% CI, 10.1-18.5%) in the nCRT arm ( P =0.33). The downstaging (ypStage 0 to 1) rate was 40.8% (95% CI, 35.1-46.7%) in the nCT arm and 45.6% (95% CI, 39.7-51.7%) in the nCRT arm ( P =0.27). nCT was associated with lower perioperative distant metastases rate (0.7% vs. 3.1%, P =0.03) and preventive ileostomy rate (52.2% vs. 63.6%, P =0.008) compared with nCRT. Four patients in the nCT arm received salvage nCRT because of local disease progression after nCT. Two patients in the nCT arm and 5 in the nCRT arm achieved complete clinical response and were treated with a nonsurgical approach. Similar results were observed in subgroup analysis.

CONCLUSIONS

nCT achieved similar pCR and downstaging rates with lower incidence of perioperative distant metastasis and preventive ileostomy compared with nCRT. CAPOX could be an effective alternative to neoadjuvant therapy in LARC with uninvolved MRF. Long-term follow-up is needed to confirm these results.

Nonoperative management of gastrointestinal malignancies in era of neoadjuvant treatment

Cancers derived from the gastrointestinal (GI) tract are often treated with radical surgery to achieve a cure. However, recent advances in the management of GI cancers involve the use of a combination of neoadjuvant radiation and chemotherapy followed by surgical intervention to achieve improved local control and cure. Interestingly, a small proportion of patients with highly sensitive tumors achieved a pathological complete response (pCR) (no residual tumor cells in the resected specimen) to neoadjuvant chemoradiation therapy (nCRT). The desire for organ preservation and avoidance of surgical morbidity brings the idea of a nonoperative management (NOM) strategy. Because of the different nature of tumor biology, GI cancers present diverse responses to nCRT, ranging from high sensitivity (anal cancer) to low sensitivity (gastric/esophageal cancer). There is an increasing attention to NOM of localized GI cancers; however, without the use of biomarkers/imaging parameters to select such patients, NOM will remain a challenge. Therefore, this review intends to summarize some of the recent updates from the aspect of current nCRT regimens, criteria for patient selection and active surveillance schedules. We also hope to review significant sequelae of radical surgery and the complications of nCRT to clarify the directions for optimization of nCRT and NOM for oncologic outcomes and quality of life.

The Position of Circulating Tumor DNA in the Clinical Management of Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer type worldwide, with over 1.9 million new cases and 935,000 related deaths in 2020. Within the next decade, the incidence of CRC is estimated to increase by 60% and the mortality by 80%. One of the underlying causes of poor prognosis is late detection, with 60 to 70% of the diagnoses occurring at advanced stages. Circulating cell-free DNA (ccfDNA) is probably the most promising tool for screening, diagnosis, prediction of therapeutic response, and prognosis. More specifically, the analysis of the tumor fraction within the ccfDNA (circulating tumor DNA, ctDNA) has great potential to improve the management of CRC. The present review provides an up-to-date and comprehensive overview of the various aspects related to ctDNA detection in CRC.

Gut microbiota-mediated nucleotide synthesis attenuates the response to neoadjuvant chemoradiotherapy in rectal cancer

Preoperative neoadjuvant chemoradiotherapy (nCRT) is a standard treatment for locally advanced rectal cancer (LARC) patients, yet little is known about the mediators underlying the heterogeneous patient response. In this longitudinal study, we performed 16S rRNA sequencing on 353 fecal specimens and find reduced microbial diversity after nCRT. Multi-omics data integration reveals that Bacteroides vulgatus-mediated nucleotide biosynthesis associates with nCRT resistance in LARC patients, and nonresponsive tumors are characterized by the upregulation of genes related to DNA repair and nucleoside transport. Nucleosides supplementation or B. vulgatus gavage protects cancer cells from the 5-fluorouracil or irradiation treatment. An analysis of 2,205 serum samples from 735 patients suggests that uric acid is a potential prognosis marker for LARC patients receiving nCRT. Our data unravel the role of intestinal microbiota-mediated nucleotide biosynthesis in the response of rectal tumors to nCRT, and highlight the importance of deciphering the cross-talk between cancer cells and gut microorganisms during cancer therapies.

Optimal diagnostic criteria for lateral lymph node dissection using magnetic resonance imaging: a multicenter prospective study

BACKGROUND

LLND in cases with suspected lateral lymph node (LLN) metastasis has been focused on as a novel treatment strategy in recent years. However, the optimal indication for LLND in rectal cancer patients has not been determined. This study aimed to establish the optimal indication for lateral lymph node dissection (LLND) in patients with rectal cancer using magnetic resonance imaging (MRI).

METHODS

A total of 209 patients with rectal adenocarcinoma who underwent total mesorectal excision and LLND in 13 hospitals were prospectively registered. By matching the sizes of the harvested LNs and those in magnetic resonance imaging (MRI), the pathological outcome of each LN was confirmed one-by-one. Using parameters of the LLNs in MRI, the optimal diagnostic criteria for LLND were established.

RESULTS

Of 3241 harvested LLNs, including 83 metastatic nodes, 1010 (31.1%) were visualized on MRI. Although all parameters assessed showed strong correlations with the presence of metastasis, none of these parameters could discriminate metastatic LLNs from non-metastatic nodes with sufficient sensitivity. However, by using the combination of long axis and short/long ratio in pretreatment MRI, we could establish optimal criteria for LLND. The sensitivity and specificity of the criteria for LLN metastasis were 94.3% and 40.2%, respectively.

CONCLUSIONS

In conclusion, we established novel criteria for LLND in rectal cancer patients using MRI. Our criteria will be of great clinical use in determining indications for LLND.

A Rectal Cancer Surgical Decision Aid Is Not Enough: A Qualitative Study

BACKGROUND

Rectal cancer patients often face complex surgical treatment decisions, but there are few available tools to aid in decision-making.

OBJECTIVE

We aimed to identify content and delivery preferences of rectal cancer patients and colorectal surgeons to guide future surgical decision aid creation.

DESIGN

Qualitative study: inductive thematic analysis of semi-structured interviews.

SETTING

In-person and phone interviews.

PATIENTS

We purposively sampled 15 rectal cancer survivors based on demographics and surgery type. Five caregivers also participated. We purposively selected 10 surgeons based on practice type and years of experience.

INTERVENTIONS

Semi-structured interviews.

MAIN OUTCOME MEASURES

Major and minor themes for survivors and surgeons with thematic saturation.

RESULTS

Interviews were a median of 61 minutes (41-93) for patients and 35 minutes (25-59) for surgeons. Nine survivors were younger than 65 years; 7 were female. Surgeons had been practicing for a mean of 10 years (SD 7.4), with 7 in academic and 3 in private settings. Participating survivors and surgeons wanted a comprehensive educational tool-not just a surgical decision aid. Survivors wanted more information on rectal cancer basics and lifestyle, care timelines, and resources during treatment. Surgeons thought patients mostly desired information about surgical options and bowel function. Both patients and surgeons wanted a tool that was personalized, simple, understandable, visually appealing, interactive, short, and in multiple formats.

LIMITATIONS

Results may not be generalizable due to selection bias of participants.

CONCLUSION

Rectal cancer survivors, their caregivers, and colorectal surgeons wanted an educational support tool that would address substantial educational needs through the continuum of disease rather than a surgical decision aid focusing on a discrete surgical choice only. See Video Abstract at http://links.lww.com/DCR/C20 .

UNA AYUDA PARA LA DECISIN QUIRRGICA DEL CNCER DE RECTO NO ES SUFICIENTE UN ESTUDIO CUALITATIVO

ANTECEDENTES:Los pacientes con cáncer de recto a menudo enfrentan decisiones de tratamiento quirúrgico complejas, pero hay pocas herramientas disponibles para ayudar en la toma de decisiones.OBJETIVO:Nuestro objetivo fue identificar el contenido y las preferencias de entrega de los pacientes con cáncer de recto y los cirujanos colorrectales para guiar la futura creación de ayuda para la toma de decisiones quirúrgicas.DISEÑO:Estudio cualitativo: análisis temático inductivo de entrevistas semiestructuradas.ESCENARIO:Entrevistas en persona y por teléfono.PACIENTES:Tomamos muestras intencionalmente de 15 sobrevivientes de cáncer de recto, según la demografía y el tipo de cirugía. También participaron cinco cuidadores. Seleccionamos intencionalmente a 10 cirujanos según el tipo de práctica y los años de experiencia.INTERVENCIONES:Entrevistas semiestructuradas.PRINCIPALES MEDIDAS DE RESULTADO:Temas principales y secundarios para sobrevivientes y cirujanos con saturación temática.RESULTADOS:Las entrevistas tuvieron una mediana de 61 minutos (41-93) para pacientes y 35 minutos (25-59) para cirujanos. Nueve sobrevivientes tenían menos de 65 años; siete eran mujeres. Los cirujanos habían estado ejerciendo una media de 10 años (DE 7,4), con siete en entornos académicos y 3 en entornos privados. Los sobrevivientes y cirujanos participantes querían una herramienta educativa comprensible, no solo una ayuda para la decisión quirúrgica. Los sobrevivientes querían más información sobre los conceptos básicos y el estilo de vida del cáncer de recto, los plazos de atención y los recursos durante el tratamiento. Los cirujanos pensaron que los pacientes en su mayoría deseaban información sobre las opciones quirúrgicas y la función intestinal. Tanto los pacientes como los cirujanos querían una herramienta que fuera personalizada, simple, comprensible, visualmente atractiva, interactiva, corta y en múltiples formatos.LIMITACIONES:Los resultados pueden no ser generalizables debido al sesgo de selección de los participantes.CONCLUSIÓN:Los sobrevivientes de cáncer rectal, sus cuidadores y los cirujanos colorrectales querían una herramienta de apoyo educativo que cubriera las necesidades educativas sustanciales a lo largo del tratamiento de la enfermedad en lugar de una ayuda para la decisión quirúrgica que se centre solo en una opción quirúrgica discreta. Consulte Video Resumen en http://links.lww.com/DCR/C20 . (Traducción-Dr. Yolanda Colorado ).

PRDM15 interacts with DNA-PK-Ku complex to promote radioresistance in rectal cancer by facilitating DNA damage repair

Neoadjuvant radiotherapy is a standard treatment for locally advanced rectal cancer, however, resistance to chemoradiotherapy is one of the main obstacles to improving treatment outcomes. The goal of this study was to explore the role of PRDM15 involved in the radioresistance of colorectal cancer and to clarify the underlying mechanism. In present study, we demonstrated that, after DNA damage, PRDM15 was upregulated and localized to DNA damage sites, co-localizing with γ-H2AX. Knockdown of PRDM15 inhibited DNA damage repair and increased radiosensitivity in colorectal cancer cells. Mechanistically, PRDM15 promoted DNA repair by interacting with DNA-PKcs and Ku70/Ku80 complex. In preclinical models of rectal cancer, knockdown of PRDM15 sensitized cell derived xenograft and patient derived xenograft to radiotherapy. In 80 rectal cancer patients treated with neoadjuvant chemoradiotherapy, higher PRDM15 expression was observed associated with weaker tumor regression and poorer prognosis. Our findings revealed that inhibiting PRDM15 was potent to overcome radioresistance through abrogating DNA repair in colorectal cancer cells. Additionally, the expression level of PRDM15 could be applied to predict radiotherapy responsiveness and the outcome of neoadjuvant radiotherapy in rectal cancer patients.

Supercritical fluid extract of Angelica sinensis promotes the anti-colorectal cancer effect of oxaliplatin

Oxaliplatin-based chemotherapy regimens are recommended for patients with advanced colorectal cancer (CRC). However, oxaliplatin (OXA) can cause toxic side effects at the recommended dosage. Therefore, it is necessary to find new drug candidates that can synergize with OXA and thereby lower the OXA dose while still maintaining its efficacy. Angelica sinensis is a common drug in traditional Chinese medicine and has demonstrated a significant anti-CRC effect in modern pharmacological studies. The active ingredients in Angelica sinensis can be effectively extracted by a supercritical fluid extract. In this study, the supercritical fluid extract of Angelica sinensis (A-SFE) was obtained by a stable extraction process and was chemically characterized by GC/MS. The anti-cancer effect of A-SFE when applied individually was explored in vitro through MTT, scratch, and Transwell assay. The effect of A-SFE on CRC cells under the influence of tumor-associated macrophages (TAMs) was explored by a co-culture model. The results showed that A-SFE could inhibit the viability, metastasis, and invasion of HCT116 cells, especially under the influence of TAMs. When 20–100 μg/ml of A-SFE and 8–64 μg/ml of OXA were used in combination in HCT116 cells, synergistic or additive effects were shown in different concentration combinations. The CT26 syngeneic mouse model was used to explore the anti-CRC effect of OXA combined with A-SFE in vivo. The tumor volume, expression levels of Ki67, MMP9, and CD206 in the OXA + A-SFE group were less than those in the OXA group. In conclusion, A-SFE has the potential to become an adjuvant drug for OXA in the treatment of CRC, which provides new strategies for anti-colorectal cancer research.

Current trends in nonoperative management for rectal adenocarcinoma: An unequal playing field?

BACKGROUND AND OBJECTIVES

Increasing evidence suggests patient-oriented benefits of nonoperative management (NOM) for rectal cancer. However, vigilant surveillance requires excellent access to care. We sought to examine patient, socioeconomic, and facility-level factors associated with NOM over time.

METHODS

Using the National Cancer Database (2006-2017), we examined patients with Stage II-III rectal adenocarcinoma, who received neoadjuvant chemoradiation and received NOM versus surgery. Factors associated with NOM were assessed using multivariable logistic regression with backward stepwise selection.

RESULTS

There were 59,196 surgical and 8520 NOM patients identified. NOM use increased from 12.9% to 15.9% between 2006 and 2017. Patients who were Black (adjusted odds ratio [aOR]: 1.36, 95% confidence interval [CI]: 1.26-1.47), treated at community cancer centers (aOR: 1.22, 95% CI: 1.12-1.30), without insurance (aOR: 1.87, 95% CI: 1.68-2.09), and with less education (aOR: 1.53, 95% CI: 1.42-1.65) exhibited higher odds of NOM. Patients treated at high-volume centers (aOR: 0.79, 95% CI: 0.74-0.84) and those who traveled >25.6 miles for care (aOR: 0.59, 95% CI: 0.55-0.64) had lower odds of NOM.

CONCLUSIONS

Vulnerable groups who traditionally have difficulty accessing comprehensive cancer care were more likely to receive NOM, suggesting that healthcare disparities may be driving utilization. More research is needed to understand NOM decision-making in rectal cancer treatment.

Nomogram to predict permanent stoma in rectal cancer patients after sphincter-saving surgery

BACKGROUND

Approximately 20 percent of patients with a tumour localized in the low rectum still encounter the possibility of requiring permanent stoma (PS), which can cause drastic changes in lifestyle and physical perceptions.

AIM

To determine the risk factors for PS and to develop a prediction model to predict the probability of PS in rectal cancer patients after sphincter-saving surgery.

METHODS

A retrospective cohort of 421 rectal cancer patients who underwent radical surgery at Taipei Medical University Hospital between January 2012 and December 2020 was included in this study. Univariate and multivariate analyses were performed to identify the independent risk factors for PS. A nomogram was developed according to the independent risk factors obtained in the multivariate analysis. The performance of the nomogram was assessed using a receiver operating characteristic curve and a calibration curve.

RESULTS

The PS rate after sphincter-saving surgery was 15.1% (59/391) in our study after a median follow-up of 47.3 mo (range 7–114 mo). Multivariate logistic regression analysis demonstrated that local recurrence, perirectal abscess, anastomosis site stenosis, perineural invasion, tumor size and operative time were independent risk factors for PS. These identified risk factors were incorporated into the nomogram, and the concordance index of this model was 0.903 (95%CI: 0.851-0.955). According to the calibration curves, the nomogram represents a perfect prediction model.

CONCLUSION

Several risk factors for PS after sphincter-saving surgery were identified. Our nomogram exhibited perfect predictive ability and will improve a physician’s ability to communicate the benefits and risks of various treatment options in shared decision making.

Multimodal Treatment of Rectal Cancer

BACKGROUND

Colorectal cancer is one of the three most common types of cancer in Germany. Approximately 30% of these cancers are located in the rectum, corresponding to about 18 000 new cases per year.

METHODS

This review is based on publications retrieved by a selective search in the PubMed database, including current guidelines and recommendations.

RESULTS

Specialized imaging, particularly magnetic resonance imaging, is essential for treatment planning. In very early stages of this disease, tumors without risk factors can be excised locally. Otherwise, radical surgical resection with lymphadenectomy remains the standard treatment, and can be performed either minimally invasive or open. At present, neoadjuvant treatment plans are evolving in the direction of total neoadjuvant therapy. In addition, recent studies investigate whether the improved efficacy of neoadjuvant therapy might now enable patients with a complete clinical remission to be spared from surgical resection (organ-preserving watch-and-wait strategy).

CONCLUSION

The treatment of rectal cancer is a prime example of an interdisciplinary, multimodal approach. In the past, the focus was mainly on improving oncologic outcomes; at present, increasing attention is being devoted to the patients' quality of life as well and the functional aspects of the various modes of treatment.

Risk factors and prognostic significance of postoperative complications following lateral pelvic lymph node dissection for rectal cancer: results of the multicenter lateral node study in China

OBJECTIVE

Total mesorectal excision (TME) plus lateral pelvic lymph node (LPN) dissection (LPND) is a technically complex and challenging procedure with higher morbidity than TME alone. We aimed to investigate the risk factors for postoperative complications after TME + LPND, and the impact of complications on patient prognosis.

METHODS

A total of 387 rectal cancer patients with clinical LPN metastasis (LPNM) who underwent TME + LPND at three institutions affiliated with the Chinese Lateral Node Collaborative Group were included. Logistic regression models were used to identify the risk factors for post-surgical complications, and the log-rank test was used to compare the prognosis. Severe complications were described as grade III-V.

RESULTS

The incidence rates of overall complications and severe complications after TME + LPND were 15.2% (59/387) and 7.8% (30/387), respectively. Multivariate analysis showed that a duration of operation ≥260 min was an independent risk factor for both overall (odds ratio [OR] = 3.03, 95% confidence interval [CI] = 1.57-5.85, P = 0.001) and severe postoperative complications (OR = 2.67, 95% CI = 1.06-6.73, P = 0.037). The development of overall postoperative complications (P = 0.114) and severe postoperative complications (P = 0.298) had no significant impact on the overall survival. However, patients with overall complications (P = 0.015) or severe complications (P = 0.031) with a postoperative hospital stay >30 days had significantly an overall worse survival.

CONCLUSION

A surgical duration of ≥260 min is a significant risk factor for both overall and severe postoperative complications after TME + LPND for middle-low rectal cancer. Furthermore, the development of overall complications or severe complications that require a postoperative hospital stay >30 days significantly worsens the prognosis.

Electrochemotherapy of Primary Colon Rectum Cancer and Local Recurrence: Case Report and Prospective Analysis

Purpose: Surgery, radiotherapy, and oncological treatment (chemotherapy and antineoplastic antibodies) are standard treatments of rectal cancer. ECT has shown its effectiveness and suitability in deep solid tumors conducted in both preclinical and clinical studies. We show here an update and preliminary results with locally advanced rectum cancer (LARC) treated with ECT. Methods: Two patients with major clinical response to restaging after neoadjuvant treatment for LARC were subjected to ECT 12 weeks after completing chemo-radiation therapy. One patient was subjected to ECT on a colorectal local recurrence formed after neoadjuvant treatment for LARC and surgery. Computed Tomography and Magnetic Resonance Imaging were used to assess ECT response. Results: The results showed stable disease in two of the three patients treated, while one patient achieved a complete response. The local control of disease is maintained in the patient follow-up. For each patient, a reduction in pain was observed and for the patient with local recurrence, a reduction in bleeding present before ECT was also achieved. Conclusion: Preliminary results showed that ECT is a safe and effective treatment in patients with a major clinical response or local recurrence after neoadjuvant therapy for LARC and allows a reduction in pain and bleeding with a consequent improvement to quality of life.

Application of tumoroids derived from advanced colorectal cancer patients to predict individual response to chemotherapy

Therapeutic approaches of advanced colorectal cancer are more complex, here we present a living biobank of patient-derived tumoroids from advanced colorectal cancer patients and show examples of how these tumoroids can be used to to simulate cancer behavior ex vivo and provide more evidence for tumoroids could be utilized as a predictive platform during chemotherapy treatment to identify the chemotherapy response. Morphological, histological and genomic characterization analysis of colorectal cancer tumoroids was conducted. Further, we treated colorectal cancer tumoroids with different drugs to detect cellular activities to evaluate drug sensitivity using CellTiter-Glo 3 D cell viability assay. Then the drug sensitivity of tumoroids was compared with clinical outcomes. Our results implied that tumoroids recapitulated the histological features of the original tumours and genotypic profiling of tumoroids showed a high-level of similarity to the matched primary tumours. Dose-response curves, area under the curve and tumour inhibitory rate of each therapeutic profiling calculations in tumoroids demonstrated a great diversity and we gained 88.24% match ratio between the sensitivity data of tumoroids with their paired patients' clinical outcomes. tumour inhibitory rate of each treatment parameters in tumoroids performed positive correlation with progression-free survival while area under the curve of each treatment parameters performed negative correlation with progression-free survival of the corresponding patients. In summary, We presented a living biobank of tumoroids from advanced colorectal cancer patients and show tumoroids got great potential for predicting clinical responses to chemotherapy treatment of advanced colorectal cancer.

Transanal versus Laparoscopic Total Mesorectal Excision in Male Patients with Low Tumor Location after Neoadjuvant Therapy: A Propensity Score-Matched Cohort Study

Background. Since Sylla and Lacy successfully reported the transanal total mesorectal excision in 2010, taTME was considered to have the potential to overcome some problematic laparoscopic cases in male, low advanced rectal cancer. However, the evidence is still lacking. This study compared the short and long outcomes of taTME with laTME in these “challenging” patients to explore the advantages of taTME among the patients. Method. After propensity score matching analysis, 106 patients were included in each group from 325 patients who met the including standard. Statistical analysis was used to compare the differences of perioperative outcomes, histopathological results, and survival results between taTME and laTME groups. Results. The mean time of pelvic operation in the taTME group was significantly shorter than in the laTME group ( $62.2\pm 14.2$ mins vs $81.1\pm 18.9$ mins, $P=0.003$ ). The complication incidence rate and the rate of protective loop ileostomy in the taTME group were significantly lower than those in the laTME group (19.8% vs 38.7%, $P=0.003$ and 70.8% vs 92.5%, $P<0.001$ ). In long-term result, there was no significant difference between the two groups for 3-year OS (87.3% vs 85.4%, $P=0.86$ ) or 3-year DFS (74.9% vs 70.1%, $P=0.92$ ). The 2-year cumulative local recurrence rate was similar between the two groups (1.1% vs 5.8%, $P=0.22$ ). Conclusion. This study demonstrated that taTME might reduce the incidence of postoperative complications, especially of anastomotic leakage in these “challenging” patients. taTME may be considered to have clear advantages for “challenging” patients.

Prognostic Significance of Lymphocyte-to-Monocyte and Platelet-to-Lymphocyte Ratio in Rectal Cancer: A Systematic Review, Meta-analysis, and Meta-regression

BACKGROUND

The low lymphocyte-to-monocyte ratio and high platelet-to-lymphocyte ratio have been reported to be poor prognostic indicators in various solid tumors, but the prognostic significance in rectal cancer remains controversial.

OBJECTIVES

We sought to determine the prognostic value of the lymphocyte-to-monocyte ratio and the platelet-to-lymphocyte ratio following curative-intent surgery for rectal cancer.

DATA SOURCES

Following PRISMA guidelines (PROSPERO, ID: CRD42020190880), PubMed and Embase databases were searched through January 2021 including 3 other registered medical databases.

STUDY SELECTION

Studies evaluating the impact of pretreatment lymphocyte-to-monocyte ratio and platelet-to-lymphocyte ratio on overall or disease-free survival in patients undergoing curative rectal cancer resection were selected.

MAIN OUTCOMES MEASURES

The main outcome measures were overall and disease-free survival.

RESULTS

A total of 23 studies (6683 patients) were included; lymphocyte-to-monocyte ratio and platelet-to-lymphocyte ratio were evaluated in 14 and 16 studies. A low lymphocyte-to-monocyte ratio was associated with poorer overall survival (HR, 1.57; 95% CI, 1.29-1.90; p < 0.001) and disease-free survival (HR, 1.29; 95% CI, 1.13-1.46; p < 0.001). However, when the analysis was limited to patients treated with surgery alone or to those with stage I to III tumors, lymphocyte-to-monocyte ratio was not a predictor of overall survival and disease-free survival. The platelet-to-lymphocyte ratio did not predict for overall or disease-free survival, regardless of the treatment modality, studied population, tumor stage, or cutoff value. Finally, a low lymphocyte-to-monocyte ratio, but not a high platelet-to-lymphocyte ratio, was inversely correlated with complete pathologic response rate.

LIMITATIONS

The retrospective nature of most included studies was a limitation.

CONCLUSIONS

Pretreatment lymphocyte-to-monocyte ratio, but not platelet-to-lymphocyte ratio, correlates with tumor response to neoadjuvant chemoradiotherapy and poorer prognosis after curative-intent surgery for rectal cancer, and it potentially represents a simple and reliable biomarker that could help optimize individualized clinical decision-making in high-risk patients.

REGISTRATION

https://www.crd.york.ac.uk/prospero/; ID: CRD42020190880.

Prognostic Impact of An Integrative Landscape of Clinical, Immune, and Molecular Features in Non-Metastatic Rectal Cancer

Rectal Cancer (RC) is a complex disease that involves highly variable treatment responses. Currently, there is a lack of reliable markers beyond TNM to deliver a personalized treatment in a cancer setting where the goal is a curative treatment. Here, we performed an integrated characterization of the predictive and prognostic role of clinical features, mismatch-repair deficiency markers, HER2, CDX2, PD-L1 expression, and CD3-CD8+ tumor-infiltrating lymphocytes (TILs) coupled with targeted DNA sequencing of 76 non-metastatic RC patients assigned to total mesorectal excision upfront (TME; n = 15) or neoadjuvant chemo-radiotherapy treatment (nCRT; n = 61) followed by TME. Eighty-two percent of RC cases displayed mutations affecting cancer driver genes such as TP53, APC, KRAS, ATM, and PIK3CA. Good response to nCRT treatment was observed in approximately 40% of the RC cases, and poor pathological tumor regression was significantly associated with worse disease-free survival (DFS, HR = 3.45; 95%CI = 1.14-10.4; p = 0.028). High neutrophils-platelets score (NPS) (OR = 10.52; 95%CI=1.34-82.6; p = 0.025) and KRAS mutated cases (OR = 5.49; 95%CI = 1.06-28.4; p = 0.042) were identified as independent predictive factors of poor response to nCRT treatment in a multivariate analysis. Furthermore, a Cox proportional-hazard model showed that the KRAS mutational status was an independent prognostic factor associated with higher risk of local recurrence (HR = 9.68; 95%CI = 1.01-93.2; p <0.05) and shorter DFS (HR = 2.55; 95%CI = 1.05-6.21; p <0.05), while high CEA serum levels were associated with poor DFS (HR = 2.63; 95%CI = 1.01-6.85; p <0.05). Integrated clinical and molecular-based unsupervised analysis allowed us to identify two RC prognostic groups (cluster 1 and cluster 2) associated with disease-specific OS (HR = 20.64; 95%CI = 2.63-162.2; p <0.0001), metastasis-free survival (HR = 3.67; 95%CI = 1.22-11; p = 0.012), local recurrence-free survival (HR = 3.34; 95%CI = 0.96-11.6; p = 0.043) and worse DFS (HR = 2.68; 95%CI = 1.18-6.06; p = 0.012). The worst prognosis cluster 2 was enriched by stage III high-risk clinical tumors, poor responders to nCRT, with low TILs density and high frequency of KRAS and TP53 mutated cases compared with the best prognosis cluster 1 (p <0.05). Overall, this study provides a comprehensive and integrated characterization of non-metastatic RC cases as a new insight to deliver a personalized therapeutic approach.

Elevated CXCL12 in the plasma membrane of locally advanced rectal cancer after neoadjuvant chemoradiotherapy: a potential prognostic marker

Background: Neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC) has been shown to improve sphincter preservation and local pelvic control, but the efficacy of nCRT plateaus due to metastasis. CXC chemokine ligand 12 (CXCL12) has a critical impact on cancer development and metastasis.

Methods: By investigating public databases containing LARC patient data, CXCL12, CXCR4 and FAPα expression was analyzed via the Tumor Immune Estimation Resource (TIMER) and GSEA. Immunohistochemistry was applied to a total of 121 surgically resected specimens consisting of 61 LARCs after nCRT and 60 LARCs with no nCRT and 16 cases with endoscopic resection of high-grade colorectal adenoma.

Results: By investigating public databases containing LARC patient data, CXCL12 expression is correlated with poor prognosis, immune cell infiltration, epithelial- mesenchymal transition, and angiogenesis in LARC. Furthermore, radiation selectively induced CXCL12, CXCR4 and FAPα expression in tumor tissues. Immunohistochemistry results showed that the levels of CXCL12, CXCR4, and FAPα in LARC cells after nCRT were higher than in LARC cells untreated with nCRT (p < 0.001 for each). Elevated levels of CXCL12 in the plasma membrane of LARC cells after nCRT demonstrated an association with the period of freedom from recurrence (FFR) in univariate and multivariate survival analyses (p = 0.005 and p = 0.031, respectively).

Conclusions: The expression of CXCL12 may influence the survival and invasive properties of LARC cells during nCRT and promote cancer recurrence. We suggest that CXCL12 expression in the plasma membrane of radioresistant LARC cells may be a predictive factor of recurrence and a viable therapeutic strategy to control radioresistant LARC recurrence.

Early age of onset is an independent predictor for worse disease-free survival in sporadic rectal cancer patients. A comparative analysis of 980 consecutive patients

BACKGROUND

while interest on early-onset colorectal cancer (age ≤49) is on the rise, studies on early-onset rectal cancer (EORC) are limited. The aim of this study was to compare predictors for disease progression/recurrence between sporadic EORC and late-onset RC patients (LORC).

METHODS

163 EORC and 830 LORC operated between January 1st^, 2010 and April 30th^, 2021 at a tertiary center were included. Demographics, tumor characteristics, microsatellite status, gene mutations (KRAS, BRAF, NRAS, PI3Kca) and oncologic outcomes were compared. A Cox proportional hazards regression analysis was performed to ascertain the effect of variables on recurrence/progression and death. Recurrence/Progression free survival (R/PFS) and cancer specific survival (CSS) were analyzed by the Kaplan-Meier estimator.

RESULTS

Mean age of EORC was 42.16, (46% aged 45-49). A majority of EORC patients had a family history for CRC (p = 0.01) and underwent total neoadjuvant treatment (p = 0.01). EORC patients showed a higher rate of low-grade tumor differentiation (p < 0.0001), stage III-IV (p = 0.001), microsatellite instability (p = 0.02), locoregional nodal (p = 0.001) and distant metastases (p < 0.0001). Accordingly, more EORC patients underwent adjuvant treatment (p < 0.0001). Mutations were mostly reported among LORC cases (p = 0.04), whereas EORC patients showed a worse R/PFS (p = 0.02), even at stage I (p = 0.04). CSS did not differ (p = 0.11) across groups. Multivariate analysis indicated age of onset (p = 0.04) was an independent predictor for progression/recurrence.

CONCLUSIONS

Age of onset was shown to be an independent unfavorable predictor. Delayed diagnosis could explain this effect in the more advanced stages, while the worse outcomes in stage I may suggest a more aggressive disease behavior.

Development of a Nomogram Combining Clinical Risk Factors and Dual-Energy Spectral CT Parameters for the Preoperative Prediction of Lymph Node Metastasis in Patients With Colorectal Cancer

Objective

This study aimed to develop a dual-energy spectral computed tomography (DESCT) nomogram that incorporated both clinical factors and DESCT parameters for individual preoperative prediction of lymph node metastasis (LNM) in patients with colorectal cancer (CRC).

Material and Methods

We retrospectively reviewed 167 pathologically confirmed patients with CRC who underwent enhanced DESCT preoperatively, and these patients were categorized into training (n = 117) and validation cohorts (n = 50). The monochromatic CT value, iodine concentration value (IC), and effective atomic number (Eff-Z) of the primary tumors were measured independently in the arterial phase (AP) and venous phase (VP) by two radiologists. DESCT parameters together with clinical factors were input into the prediction model for predicting LNM in patients with CRC. Logistic regression analyses were performed to screen for significant predictors of LNM, and these predictors were presented as an easy-to-use nomogram. The receiver operating characteristic curve and decision curve analysis (DCA) were used to evaluate the clinical usefulness of the nomogram.

Results

The logistic regression analysis showed that carcinoembryonic antigen, carbohydrate antigen 199, pericolorectal fat invasion, ICAP, ICVP, and Eff-ZVP were independent predictors in the predictive model. Based on these predictors, a quantitative nomogram was developed to predict individual LNM probability. The area under the curve (AUC) values of the nomogram were 0.876 in the training cohort and 0.852 in the validation cohort, respectively. DCA showed that our nomogram has outstanding clinical utility.

Conclusions

This study presents a clinical nomogram that incorporates clinical factors and DESCT parameters and can potentially be used as a clinical tool for individual preoperative prediction of LNM in patients with CRC.

Evaluation and Predictive Factors of Complete Response in Rectal Cancer after Neoadjuvant Chemoradiation Therapy

The response to neoadjuvant chemoradiation therapy is an important prognostic factor for locally advanced rectal cancer. Although the majority of the patients after neoadjuvant therapy are referred to following surgery, the clinical data show that complete clinical or pathological response is found in a significant proportion of the patients. Diagnostic accuracy of confirming the complete response has a crucial role in further management of a rectal cancer patient. As the rate of clinical complete response, unfortunately, is not always consistent with pathological complete response, accurate diagnostic parameters and predictive markers of tumor response may help to guide more personalized treatment strategies and identify potential candidates for nonoperative management more safely. The management of complete response demands interdisciplinary collaboration including oncologists, radiotherapists, radiologists, pathologists, endoscopists and surgeons, because the absence of a multidisciplinary approach may compromise the oncological outcome. Prediction and improvement of rectal cancer response to neoadjuvant therapy is still an active and challenging field of further research. This literature review is summarizing the main, currently known clinical information about the complete response that could be useful in case if encountering such condition in rectal cancer patients after neoadjuvant chemoradiation therapy, using as a source PubMed publications from 2010–2021 matching the search terms “rectal cancer”, “neoadjuvant therapy” and “response”.

Validation of Gene Expression-Based Predictive Biomarkers for Response to Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer

BACKGROUND

Neoadjuvant chemoradiotherapy (nCRT) followed by surgery is widely used for patients with locally advanced rectal cancer. However, response to nCRT varies substantially among patients, highlighting the need for predictive biomarkers that can distinguish non-responsive from responsive patients before nCRT. This study aimed to build novel multi-gene assays for predicting nCRT response, and to validate our signature and previously-reported signatures in multiple independent cohorts.

METHODS

Three microarray datasets of pre-therapeutic biopsies containing a total of 61 non-responders and 53 responders were used as the discovery cohorts to screen for genes that were consistently associated with nCRT response. The predictive values of signatures were tested in a meta-analysis using six independent datasets as the validation cohorts, consisted of a total of 176 non-responders and 99 responders.

RESULTS

We identified four genes, including BRCA1, GPR110, TNIK, and WDR4 in the discovery cohorts. Although our 4-gene signature and nine published signatures were evaluated, they were unable to predict nCRT response in the validation cohorts.

CONCLUSIONS

Although this is one of the largest studies addressing the validity of gene expression-based classifiers using pre-treatment biopsies from patients with rectal cancer, our findings do not support their clinically meaningful values to be predictive of nCRT response.

Outcomes of robotic partial excision of the levator ani muscle for locally advanced low rectal cancer invading the ipsilateral pelvic floor at the anorectal ring level

PURPOSE

The purpose of this study is to evaluate partial excision of the levator ani muscle (PELM) enables preservation of anal sphincter function although levator ani muscle (LAM) was invaded.

METHODS

Functional outcomes and oncologic outcomes of 23 consecutive patients who underwent robotic PELM for low rectal cancer at the anorectal ring level invading or abutting the ipsilateral LAM are analysed.

RESULTS

Secured resection margins were achieved, especially for the circumferential resection margin. During a median follow-up of 44 months, the 3-year local recurrence rate was 14.4%. Among patients who underwent diverting ileostomy closure, mean Memorial Sloan Kettering Cancer Center Bowel Function Instrument and Wexner scores were 68.3 ± 11.9 and 10.7 ± 5.3, respectively, at 1 year after closure.

CONCLUSION

PELM is a sphincter-preserving alternative to abdominoperineal resection (APR) or extralevator APR for low rectal cancer invading the ipsilateral LAM at the level of the anorectal ring.

Emerging applications of radiomics in rectal cancer: State of the art and future perspectives

Rectal cancer (RC) is the third most commonly diagnosed cancer and has a high risk of mortality, although overall survival rates have improved. Preoperative assessments and predictions, including risk stratification, responses to therapy, long-term clinical outcomes, and gene mutation status, are crucial to guide the optimization of personalized treatment strategies. Radiomics is a novel approach that enables the evaluation of the heterogeneity and biological behavior of tumors by quantitative extraction of features from medical imaging. As these extracted features cannot be captured by visual inspection, the field holds significant promise. Recent studies have proved the rapid development of radiomics and validated its diagnostic and predictive efficacy. Nonetheless, existing radiomics research on RC is highly heterogeneous due to challenges in workflow standardization and limitations of objective cohort conditions. Here, we present a summary of existing research based on computed tomography and magnetic resonance imaging. We highlight the most salient issues in the field of radiomics and analyze the most urgent problems that require resolution. Our review provides a cutting-edge view of the use of radiomics to detect and evaluate RC, and will benefit researchers dedicated to using this state-of-the-art technology in the era of precision medicine.

Organ Sparing for Locally Advanced Rectal Cancer after Neoadjuvant Treatment Followed by Electrochemotherapy

Simple Summary

This is a Phase II randomized controlled trial conducted with the aim of investigating whether the use of Electrochemotherapy after neoadjuvant therapy (ECT) and before surgery in patients with major clinical response allows for a more conservative surgical approach in patients with Locally Advanced Rectal Cancer (LARC) in comparison with the control group that will not receive ECT. The treatment response, in both the control arm and in the treatment arm, will be assessed using the histopathological tumor regression grade on tissue specimens after local excision.

Abstract

Background: Currently, 45–55% of rectal cancer patients receive preoperative chemo- radio-therapy for Locally Advanced Rectal Cancer (LARC). The idea of our study is to use Electrochemotherapy (ECT) before surgery, in patients with major clinical response after neoadjuvant therapy, to allow for a more conservative surgical approach. Objective: To evaluate the increase of the complete response rate after neoadjuvant treatment in LARC and to spare organ function due to total mesorectal excision (TME). Patients and Methods: This is a Phase II randomized controlled trial enrolling 70 patients that will be developed in two stages. In the first step, 28 patients will be enrolled: 14 of these will receive ECT for four weeks after neo-adjuvant treatment and then local excision (treatment group) and 14 patients will receive neo-adjuvant treatment and then local excision (control group). If an increase of response rate is observed in the first stage, and/or feasibility/safety is demonstrated, the second stage of the trial will be performed, enrolling an additional 42 patients. The treatment response. in both the control arm and the treatment arm, will be assessed using the histopathological tumor regression grade on tissue specimens after local excision.

The influence of predictive nursing on the emotions and self-management abilities of post-colostomy rectal cancer patients

OBJECTIVE

This study aimed to explore the influence of predictive nursing on the emotions and self-management abilities of post-colostomy rectal cancer patients.

METHODS

From March 2017 to October 2019, 130 patients with rectal cancer were recruited as the study cohort and placed into a predictive group (the PG) (n=80) that underwent predictive nursing or a normal group (the NG) (n=50) that underwent routine nursing. After the intervention, the operative indications, self-care abilities, nutritional indicators, mental health, postoperative recovery, complications, and nursing satisfaction of the two groups were compared.

RESULTS

After the intervention, compared with the NG, the average blood loss, operation times, gastrointestinal tract recovery times and durations of the hospital stays in the PG were shorter, and the self-care ability scores were higher, the nutritional conditions, namely the albumin (ALB), transferrin (TRF), and prealbumin (PAB) levels, were higher, the mental health, namely the self-rating anxiety scale (SAS) and self-rating depression scale (SDS) scores, was better, the total effective rate of the postoperative recovery and the nursing satisfaction were higher, and the incidence of complications was lower.

CONCLUSION

predictive nursing can improve the moods and self-management abilities of post-colostomy rectal cancer patients.