Rectal Adenocarcinoma Patients Research Articles

Influence of the ligation sequence of the inferior mesenteric artery and vein on circulating tumor cells in laparoscopic rectal cancer surgery: a prospective pilot study

BackgroundThere is no regulation in the current guidelines on the sequence of ligation of the inferior mesenteric artery and vein during rectal cancer surgery owing to a lack of sufficient evidence. Circulating tumor cells (CTCs) in peripheral blood can be used as potential indicators for predicting prognosis in colorectal cancer patients. This study aims to explore the feasibility of different ligation sequences for the inferior mesenteric vessels and their potential influence on CTCs.MethodsThis pilot study involved 29 stage I-III rectal adenocarcinoma patients undergoing laparoscopic surgery. Patients were allocated into two groups based on the sequence of vascular ligation: vein-first (V-first) and artery-first (A-first). The primary objective was to assess the impact of the ligation sequence on peripheral blood CTC levels pre- and post-operatively. Secondary outcomes included intraoperative complications, surgical duration, blood loss, and number of lymph nodes harvested, and postoperative complications. The study was approved by the ethics committee of our hospital (SCCHEC-02-2024-102), and all patients provided informed consent.ResultsNo significant differences were found between the two groups regarding surgical duration, blood loss, lymph nodes harvested, or postoperative complications. A reduction in CTCs postoperatively was observed in 36% of patients in the V-first group, in comparison to 20% in the A-first group.ConclusionBoth A-first and V-first ligation sequences are viable and safe options in laparoscopic rectal cancer surgery. The V-first approach may be more effective in reducing levels of CTCs in peripheral blood. Further randomized studies are warranted to explore these findings comprehensively.

Neoadjuvant chemoradiation for down staging of locally-advanced rectal cancer, and assessment of clinical response with digital rectal examination, magnetic resonance imaging and colonoscopy

Background: In this era of total neoadjuvant treatment (TNT) followed by rectal preservation non-operative management (NOM) or wait and watch (WW) approach for non-metastatic locally-advanced rectal cancer (LARC), reliable and reproducible response evaluation to neoadjuvant therapies forms the cornerstone. Through this study, we try to evaluate clinical response of locally-advanced rectal cancer to neoadjuvant chemoradiation (CRT) in terms of downstaging and total mesorectal excision (TME), and the accuracy of digital rectal examination (DRE), magnetic resonance imaging (MRI) and colonoscopy in the assessment of clinical response to neoadjuvant CRT. Methods: Histologically proven locally advanced rectal adenocarcinoma patients, after pretreatment evaluation, were considered for neoadjuvant chemoradiation, i.e., intensity-modulated radiation therapy (IMRT) with 5-fluorouracil (5-FU) and leucovorin-based concurrent chemotherapy. Patients were evaluated 6-8 weeks after completion of CRT and clinical response assessed by means of DRE, colonoscopy and MRI of pelvis. Following surgery, pathological response was assessed on the final histopathological examination (HPE). Results: Twenty-two patients were accrued for this protocol, of which, 15 (68.2%) were male and 7 (31.8%) were female. Downstaging and TME was achieved in 90.9% of the patients. The sensitivity of DRE, colonoscopy and MRI to detect a complete response was 66.67% and specificity was 94.74%. There were no severe toxicities or deaths reported. Conclusions: Neoadjuvant concurrent chemoradiotherapy with bolus 5-FU and leucovorin is an accepted modality of treatment for locoregionally-advanced rectal cancer, which offers higher rates of downstaging and TME. Digital rectal examination, colonoscopy and MRI together can be reliably used to assess response following neoadjuvant CRT.

Is It Worth Performing Intersphincteric Resection in Patients Having Rectal Adenocarcinoma with Oligometastasis

AbstractIntersphincteric resection (ISR) is being increasingly performed in metastatic rectal adenocarcinoma (with oligometastasis) patients. There has been a trend towards worse prognosis in this group. This study compares the oncological and surgical outcomes of patients with and without pre-operative oligometastasis who underwent ISR. The outcomes compared include prognostic factors like margin positivity, recurrence rates, stoma reversal rate, and surgical failure rate (defined as a combination of one or more of the aforestated factors). The demographic pattern, American Society of Anaesthesia grade (ASA), treatment received, clinical and histopathological T and N stage, grade, type of minimally invasive surgery (MIS) approach, neoadjuvant therapy, and pathological high-risk features are also studied. Patients who underwent minimally invasive ISR over 10 years at a high-volume tertiary cancer center were selected for the study. Factors used for the assessment of oncological outcomes were margin positivity (circumferential resection and distal margin), recurrence (both local and systemic), and stoma reversal rate. A descriptive and comparative analyses were performed. Four hundred and eight patients underwent minimally invasive ISR of which 25 (6.12%) patients were oligometastatic. While R0 resection was similar in both groups, higher overall recurrence (24% versus 18.5%) and low stoma reversal rate (36.8% versus 67.3%) were observed in the oligometastatic group with statistically significant differences. No local recurrence was seen in the oligometastatic group, and the difference compared to non-metastatic group was not statistically different. This study indicates that oligometastatic patients who underwent ISR experienced lower stoma reversal rates, maintaining similar local control but facing higher rates of systemic recurrence.

The association of preoperative radiotherapy and surgery for AJCC stage I-III rectal adenocarcinoma: a population-based study

BackgroundWith the increasing application of neoadjuvant therapy in rectal adenocarcinoma, there remain many controversies in clinical practical applications. Preoperative radiotherapy (PR) can limit the surgical plane and potentially affect the quality of surgical treatment. This study aimed to investigate the potential impact of PR on the surgical quality of rectal adenocarcinoma.MethodsThis retrospective study analyzed the clinicopathological data from 6,585 AJCC stage I-III rectal adenocarcinoma in the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2015. Kaplan-Meier survival analysis and multivariate Cox proportional were used to assess the impact of PR on survival. Propensity score matching (PSM) was employed to balance the baseline covariates between the PR and non-PR groups and to compare postoperative pathological differences.ResultsAfter PSM, PR did not improve overall survival (OS) in stages I (p = 0.33), II (p = 0.37), and III (p = 0.14) patients. Multivariate Cox analysis indicated that PR was not an independent prognostic factor for patients. Restricted cubic spline (RCS) analysis demonstrated a nonlinear negative correlation between OS hazard ratios and both circumferential resection margin (CRM) and lymph node evaluation (LNE). Compared to the non-PR group, patients in the PR group had lower tumor deposits (TD) (p < 0.001), positive CRM (p = 0.191), and perineural invasion (PNI) (p = 0.001).ConclusionPR is not an independent prognostic factor for rectal adenocarcinoma patients. However, PR can reduce the likelihood of TD, CRM, and PNI, thereby potentially influencing the quality of surgery.

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

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

Lymphopenia Induced by Different Neoadjuvant Chemo-Radiotherapy Schedules in Patients with Rectal Cancer: Bone Marrow as an Organ at Risk.

Radiotherapy (RT)-induced lymphopenia may hinder the anti-tumor immune response. Preoperative RT or chemo-RT (CRT) for locally advanced rectal cancer is a standard therapeutic approach, while immunotherapy has been approved for mismatch repair-deficient rectal tumors. We retrospectively analyzed 98 rectal adenocarcinoma patients undergoing neoadjuvant CRT with VMAT (groups A, B, C) or IMRT (group D) techniques, with four different RT schemes: group A (n = 24): 25 Gy/5 Gy/fraction plus a 0.2 Gy/fraction rectal tumor boost; group B (n = 22): 34 Gy/3.4 Gy/fraction, with a 1-week treatment break after the first five RT fractions; group C (n = 20): 46 Gy/2 Gy/fraction plus a 0.2 Gy/fraction rectal tumor boost; group D (n = 32): 45 Gy/1.8 Gy/fraction followed by 5.4 Gy/1.8 Gy/fraction to the rectal tumor. We examined the effect of the time-corrected normalized total dose (NTD-T) to the BM on lymphopenia. Groups A and B (hypofractionated RT) had significantly higher lymphocyte counts (LCs) after RT than groups C and D (p < 0.03). An inverse association between the LCs after RT and NTD-T was demonstrated (p = 0.01). An NTD-T threshold of 30 Gy delivered to 30% of the BM volume emerged as a potential constraint for RT planning, which could be successfully integrated in the RT plan. Hypofractionated and accelerated RT schemes, and BM-sparing techniques may reduce lymphocytic damage and prove critical for immuno-RT clinical trials.

Organ preservation after neoadjuvant long-course chemoradiotherapy versus short-course radiotherapy

Potential differences in organ preservation between total neoadjuvant therapy (TNT) regimens integrating long-course chemoradiotherapy (LCCRT) and short-course radiotherapy (SCRT) in rectal cancer remain undefined. This natural experiment arose from a policy change in response to the COVID-19 pandemic during which our institution switched from uniformly treating patients with LCCRT to mandating that all patients be treated with SCRT. Our study includes 323 locally advanced rectal adenocarcinoma patients treated with LCCRT-based or SCRT-based TNT from January 2018 to January 2021. Patients who achieved clinical complete response were offered organ preservation with watch-and-wait (WW) management. The primary outcome was 2-year organ preservation. Additional outcomes included local regrowth, distant recurrence, disease-free survival (DFS), and overall survival (OS). Patient and tumor characteristics were similar between LCCRT (n= 247) and SCRT (n= 76) cohorts. Median follow-up was 31 months. Similar clinical complete response rates were observed following LCCRT and SCRT (44.5% versus 43.4%). Two-year organ preservation was 40% [95% confidence interval (CI) 34% to 46%] and 31% (95% CI 22% to 44%) among all patients treated with LCCRT and SCRT, respectively. In patients managed with WW, LCCRT resulted in higher 2-year organ preservation (89% LCCRT, 95% CI 83% to 95% versus 70% SCRT, 95% CI 55% to 90%; P= 0.005) and lower 2-year local regrowth (19% LCCRT, 95% CI 11% to 26% versus 36% SCRT, 95% CI 16% to 52%; P= 0.072) compared with SCRT. The 2-year distant recurrence (10% versus 6%), DFS (90% versus 90%), and OS (99% versus 100%) were similar between WW patients treated with LCCRT and SCRT, respectively. While WW eligibility was similar between cohorts, WW patients treated with LCCRT had higher 2-year organ preservation and lower local regrowth than those treated with SCRT, yet similar DFS and OS. These data support induction LCCRT followed by consolidation chemotherapy as the preferred TNT regimen for patients with locally advanced rectal cancer pursuing organ preservation.

Diagnostic performance of Node-RADS score for mesorectal lymph node metastasis in rectal cancer.

To explore the diagnostic performance of the Node-RADS scoring system on preoperative assessment of mesorectal lymph node metastasis (LNM) status in rectal cancer, in comparisonwith the ESGAR category and size of lymph node (LN). Preoperative clinical and MRI data of 154 rectal adenocarcinoma patients treated with radical resection surgery were retrospectively analyzed. The differences in the clinical, pathological and imaging characteristics between the pN- and pN + groups were surveyed. The correlations of Node-RADS score and ESGAR category to pN stage, LNM number and lymph node ratio (LNR) were investigated. The performances on assessing pathological LNM were compared among individual approaches. A nomogram combined the imaging and clinicalfeatures was also established and evaluated. Significant differences in CEA, tumor maximum diameter, tumor location, LN short-axis diameter, Node-RADS score and ESGAR category were found between the pN- and pN + groups. Node-RADS correlated significantly with pN stage, LNM number, and LNR (r = 0.665, 0.685, and 0.675, p < 0.001). Node-RADS had the highest AUC (0.862) for predicting pN + status, surpassing ESGAR (AUC = 0.797, p = 0.040) and LN size (AUC = 0.762, p = 0.015). The nomogram had the best diagnostic performance (AUC = 0.901), significantly outperforming Node-RADS alone (p = 0.037). The Node-RADS scoring system is comparable to the ESGAR category and surpasses short-axis diameter in preoperatively predicting LNM in rectal cancer. Integrating imaging and clinical features will lead to an enhancement in diagnostic performance. Moreover, a clear relationship was demonstrated between the Node-RADS score and the quantity-dependent pathological characteristics of LNM.

Measurement of the distance between tumor micro-foci and gross tumor in rectal cancer pathological specimens: implication on margin distance of clinical target volume treated with high-dose radiotherapy for rectal cancer.

To measure the micro-foci distance away from gross tumor and to provide reference to create the clinical target volume (CTV) margin for boost radiotherapy in rectal adenocarcinoma. Twenty-eight rectal cancer surgical specimens of only total mesorectal excision were collected. The pathological specimens were retrospectively measured, and the nearest distance between the tumor micro-foci and gross tumor was microscopically measured. The "in vivo-in vitro" retraction factor was calculated as the ratio of the deepest thickness laterally and the vertical height superior/inferiorly of the rectal tumor measured in MRI and those measured in immediate pathological specimens. The retraction factor during pathological specimen processing was calculated as the distance ratio before and after dehydration in the lateral, superior, and inferior sides by the "knot marking method." The distances of tumor micro-foci were individually corrected with these two retraction factors. The mean "in vivo-in vitro" tumor retraction factors were 0.913 peripherally and 0.920 superior/inferiorly. The mean tumor specimen processing retraction factors were 0.804 peripherally, 0.815 inferiorly, and 0.789 superiorly. Of 28 patients, 14 cases (50.0%) had 24 lateral micro-foci, 8 cases (28.6%) had 13 inferior micro-foci, and 7 cases (25.0%) had 19 superior micro-foci. The 95th percentiles of the micro-foci distance for 28 patients were 6.44mm (peripheral), 5.54mm (inferior), and 5.42mm (superior) after retraction correction. The micro-foci distances of 95% of rectal adenocarcinoma patients examined were within 6.44mm peripherally, 5.54mm inferiorly, and 5.42mm superiorly. These findings provide reference to set the boost radiotherapy CTV margin for rectal cancer.

Predictive value of circulating lymphocyte subsets and inflammatory indexes for neoadjuvant chemoradiotherapy response in rectal mucinous adenocarcinoma patients: A machine learning approach.

In this study, we aimed to evaluate the predictive value of circulating lymphocyte subsets and inflammatory indexes in response to neoadjuvant chemoradiotherapy (NCRT) in patients with rectal mucinous adenocarcinomas (MACs). Rectal MAC patients who underwent NCRT and curative resection at Fujian Medical University Union Hospital's Department of Colorectal Surgery between 2016 and 2020 were included in the study. Patients were categorized into good and poor response groups based on their pathological response to NCRT. An independent risk factor-based nomogram model was constructed by utilizing multivariate logistic regression analysis. Additionally, the extreme gradient boosting (XGB) algorithm was applied to build a machine learning (ML)-based predictive model. Feature importance was quantified using the Shapley additive explanations method. Out of the 283 participants involved in this research, 190 (67.1%) experienced an unfavorable outcome. To identify the independent risk factors, logistic regression analysis was performed, considering variables such as tumor length, pretreatment clinical T stage, PNI, and Th/Tc ratio. Subsequently, a nomogram model was constructed, achieving a C-index of 0.756. The ML model exhibited higher prediction accuracy than the nomogram model, achieving an AUROC of 0.824 in the training set and 0.762 in the tuning set. The top five important parameters of the ML model were identified as the Th/Tc ratio, neutrophil to lymphocyte, Th lymphocytes, Gross type, and T lymphocytes. Radiochemotherapy sensitivity is markedly influenced by systemic inflammation and lymphocyte-mediated immune responses in rectal MAC patients. Our ML model integrating clinical characteristics, circulating lymphocyte subsets, and inflammatory indexes is a potential assessment tool that can provide a reference for individualized treatment for rectal MAC patients.

The correlation between time-intensity curve parameters of transrectal contrast-enhanced ultrasound and pathological prognostic factors in rectal adenocarcinoma.

To investigate the correlation between time-intensity curve (TIC) parameters obtained from transrectal contrast-enhancedultrasound (TR-CEUS) and important pathological prognostic factors in rectal adenocarcinoma. We retrospectively included 477 patients with pathologically confirmed rectal adenocarcinoma. TIC parameters werederived from preoperative dynamic TR-CEUS images. These parameters included peak intensity (PI), time to peak (TTP),mean transit time (MTT), slope (S), and area under the curve (AREA). Pathological prognostic factors included TN stage,tumor diameter, lymphovascular invasion (LVI), perineural invasion, and tumor differentiation. Spearman's correlation analysisand binary logistic regression were used to analyze the association between TIC parameters and pathological prognosticfactors. pT1-2 stages rectal carcinomas exhibited higher PI-max, PI-min, S-max, S-min, AREA-max, and AREA-minthan pT3-4 stages (all p<0.05). pN0 stage rectal adenocarcinomas displayed higher PI-max, S-max, AREA-max, PI-ratio, Sratio,and AREA-ratio than pN1-2 stage (all p<0.05). PI-ratio and S-ratio were higher in the LVI-negative and tumor diameter≥4cm group compared to the LVI-positive and tumor diameter <4cm group, respectively (p<0.05). Well-differentiated rectaladenocarcinomas displayed higher PI-max, AREA-max, PI-ratio, S-ratio, and AREA-ratio than the moderate-poor differentiatedgroup (all p<0.05). PI-max, S-max, AREA-max, PI-ratio, S-ratio, and AREA-ratio were negatively correlated with pNstage (all p<0.05). PI-ratio and S-ratio were independent predictive factors for the pN stage (OR=0.774, OR=1.048). S-ratioand AREA-ratio were independent predictive factors for tumor differentiation (OR=1.071, OR=0.911). TIC parametersderived from TR-CEUS exhibit correlations with specific pathological prognostic factors in rectal adenocarcinomas.This non-invasive method may hold promise for preoperatively assessing the prognosis of rectal adenocarcinoma patients.

IFN-Type-I Response and Systemic Immunity in Rectal Adenocarcinoma Patients Treated with Conventional or Hypofractionated Neoadjuvant Radiotherapy.

The IFN-type-I pathway is involved in radiotherapy (RT)-mediated immune responses. Large RT fractions have been suggested to potently induce this pathway. Neoadjuvant hypofractionated short-course (scRT) and conventional long-course (lcRT) RT applied for the treatment of locally advanced rectal adenocarcinoma patients provides a unique model to address the immuno-stimulatory properties of RT on a systemic level. We prospectively analyzed the IFNβ plasma levels and lymphocyte counts (LCs) of rectal adenocarcinoma patients before and after treatment with scRT (n = 22) and lcRT (n = 40). Flow cytometry was conducted to assess the effects on lymphocytic subpopulations in a subset of 20 patients. A statistically significant increase in the post-RT IFNβ plasma levels was noted in patients undergoing scRT (p = 0.004). Improved pathological tumor regression was associated with elevated post-RT IFNβ levels (p = 0.003). Although all patients experienced substantial lymphopenia after treatment, the post-RT LC of patients treated with scRT were significantly higher compared to lcRT (p = 0.001). Patients undergoing scRT displayed significantly lower percentages of regulatory CD4+/CD25+ T-cells after therapy (p = 0.02). scRT enables effective stimulation of the IFN-type-I pathway on a systemic level and confers decreased lymphocytic cytotoxicity and limited regulatory T-cell activation compared to lcRT, supporting its increasing role in immuno-RT trials.

Construction and validation of a nomogram for predicting disease-free survival after radical resection of rectal cancer using perioperative inflammatory indicators.

Colorectal cancer is a common digestive tract malignancy that seriously affects patients' quality of life and survival time. Surgery is the main treatment modality, but postoperative prognosis varies greatly. This study sought to explore the impact of perioperative inflammatory indicators on disease-free survival (DFS) in patients after radical resection of rectal cancer and to construct a nomogram for clinical reference. A retrospective analysis was performed on 304 primary rectal adenocarcinoma patients who underwent laparoscopic radical resection of rectal cancer at the Affiliated Hospital of Xuzhou Medical University from May 1, 2018 to September 30, 2020. The patients were divided into a training set (n=213) and a validation set (n=91) at a ratio of 7:3. The cut-off values of each inflammatory indicator based on the receiver operating characteristic (ROC) curve were determined and each indicator was divided into high and low groups. The least absolute shrinkage and selection operator (LASSO)-Cox regression model was used to analyze the independent risk factors affecting DFS, and a nomogram was established. The model was internally validated using the validation set, and the discrimination, calibration, and clinical application value of the nomogram were evaluated using ROC curve, calibration curve, and clinical decision curve analysis (DCA). Tumor-node-metastasis (TNM) stage III, neural invasion, preoperative neutrophil-to-lymphocyte ratio (NLR) ≥1.995, postoperative systemic immune-inflammation index (SII) ≥451.05, and Δpan-immune-inflammation value (ΔPIV) ≥144.36 (P<0.05) were independent factors for predicting the 3-year DFS of patients after rectal cancer surgery. The area under the ROC curve (AUC) of the nomogram was 0.811 [95% confidence interval (CI): 0.778-0.889] in the training set and 0.808 (95% CI: 0.785-0.942) in the validation set. The nomogram showed good calibration, indicating good consistency between predicted and actual risks. DCA demonstrated the clinical utility of the nomogram. The nomogram constructed based on TNM stage III, neural invasion, preoperative NLR ≥1.995, postoperative SII ≥451.05, and ΔPIV ≥144.36 can predict the risk of 3-year DFS in patients undergoing curative surgery for rectal cancer, enabling strict postoperative follow-up and timely adjuvant treatment for high-risk patients.

Risk stratification of stage II rectal mucinous adenocarcinoma to predict the benefit of adjuvant chemotherapy following neoadjuvant chemoradiation and surgery.

The treatment strategy for stage II rectal mucinous adenocarcinoma (RMA) recommends neoadjuvant chemoradiotherapy (NCR) followed by total mesorectal excision (TME). However, the necessity of adjuvant chemotherapy (AC) remains controversial. Chi-square test was used to assess the relationship between pathological classification, AC and clinicopathological characteristics. Kaplan-Meier (KM) curves and the log-rank test were utilized to analyze differences in overall survival (OS) and cancer-specific survival (CSS) among different groups. Cox regression identified prognostic factors. Nomogram was established utilizing the independent prognostic factors. X-tile divided patients into three risk subgroups. Compared to RMA, rectal adenocarcinoma (RA) demonstrates longer OS and CSS in all and non-AC stage II patients, with no difference in OS and CSS for AC stage II patients. Propensity score matching analyses yielded similar results. Stratified analysis found that AC both improve OS of RA and RMA patients. Age, gender, pathologic T stage, regional nodes examined, and tumor size were identified as independent prognostic factors for RMA patients without AC. A nomogram was constructed to generate risk scores and categorize RMA patients into three subgroups based on these scores. KM curves revealed AC benefits for moderate and high-risk groups but not for the low-risk group. The external validation cohort yielded similar results. In summary, our study suggests that, compared to stage II RA patients, stage II RMA patients benefit more from AC after NCR. AC is recommended for moderate and high-risk stage II RMA patients after NCR, whereas low-risk patients do not require AC.

Outcomes of rectal cancer patients who refuse surgery after incomplete clinical response to neoadjuvant therapy.

Total mesorectal excision (TME) remains the standard of care for patients with rectal cancer who have an incomplete response to total neoadjuvant therapy (TNT). A minority of patients will refuse curative intent resection. The aim of this study is to examine the outcomes for these patients. A retrospective cohort study of stage 1-3 rectal adenocarcinoma patients who underwent neoadjuvant chemoradiation therapy or TNT at a single institution. Patients either underwent TME, watch-and-wait protocol, or if they refused TME, were counseled and watched (RCW). Clinical outcomes and resource utilization were examined in each group. One hundred seventy-onepatients (Male 59%) were included with a median surveillance of 43 months. Twenty-ninepatients (17%) refused TME and had shortened overall survival (OS). Twelvepatients who refused TME converted to a complete clinical response (cCR) on subsequent staging with a prolonged OS. 92% of these patients had a near cCR at initial staging endoscopy. Increased physician visits and testing was utilized in RCW and WW groups. A significant portion of patients convert to cCR and have prolonged OS. Lengthening the time to declare cCR may be considered in select patients, such as those with a near cCR at initial endoscopic staging.

Influence of High-Risk Pathological Factors and their Interaction on the Survival Benefit of Adjuvant Chemotherapy in Stage II Rectal Cancer: A Retrospective Study.

Objectives: We investigated the impact of high-risk factors in stage II (TNM stage) rectal cancer patients to determine whether they benefit from adjuvant chemotherapy after surgery. Additionally, we explored the interaction between high-risk factors and adjuvant chemotherapy. Our study provides refined guidance for postoperative treatment in patients with stage II rectal cancer. Methods: The retrospective study included 570 stage II rectal adenocarcinoma patients who underwent total mesorectal excision surgery at Tianjin Union Medical Center from August 2012 to July 2019. We employed Cox regression models to assess the collected pathological and clinical factors, identifying the risk factors for overall survival (OS) and disease-free survival (DFS). Additionally, we thoroughly examined the interaction between various high-risk pathological factors and postoperative chemotherapy (ACT), including multiplicative interaction (INTM) and additive interaction (RERI). Results: Among the 570 stage II rectal cancer patients in this study, the average age was 62 years, with 58.9% (N=336) of the population being older than 60. Males accounted for the majority at 64.9% (N=370). Age was found to have an impact on whether patients received adjuvant chemotherapy after surgery (P<=0.001).Furthermore, age (HR: 1.916, 95% CI: 1.158-3.173, P=0.011; HR: 1.881, 95% CI: 1.111-3.186, P=0.019), TNM stage (HR: 2.216, 95% CI: 1.003-4.897, P=0.029; HR: 2.276, 95% CI: 1.026-5.048, P=0.043), the number of lymph nodes cleared during surgery (HR: 1.968, 95% CI: 1.112-3.483, P=0.017; HR: 1.864, 95% CI: 0.995-3.493, P=0.045), and lymphovascular invasion (HR: 2.864, 95% CI: 1.567-5.232, P=0.001; HR: 3.161, 95% CI: 1.723-5.799, P<0.001) were identified as independent risk factors for patients' overall survival (OS) and disease-free survival (DFS). Moreover, the interaction analysis, both multiplicative and additive, revealed significant interactions between the number of lymph nodes cleared during surgery and the administration of adjuvant chemotherapy. For OS (HR for multiplicative interaction: 0.477, p=0.045; RERI: -0.531, 95% CI: -1.061, -0.002) and for DFS (HR for multiplicative interaction: 0.338, p=0.039; RERI: -1.097, 95% CI: -2.190, -0.005). Conclusions: This study provides insights into the complex relationship between adjuvant chemotherapy (ACT) and survival outcomes in stage II rectal cancer patients with high-risk pathological factors. The findings suggest that the number of cleared lymph nodes plays a significant role in the efficacy of ACT and underscores the need for individualized treatment decisions in this patient population.

Immunotherapy in rectal cancer patients-a propensity score matched analysis of the National Cancer Database.

Rectal cancer patients with microsatellite instability (MSI-H) are candidates for immunotherapy. However, there is little evidence on its effect on overall survival (OS). Retrospective analysis of stage II-IV rectal adenocarcinoma patients in the National Cancer Database (NCDB) between 2010 and 2019. Propensity score matching was adjusted for baseline and treatment confounders. The cohort was divided into patients who received immunotherapy and matched controls. The primary outcome was OS. 5175/206,615 (2.5%) patients withrectal adenocarcinoma underwent immunotherapy. These patients were younger (58 vs 62years; p < 0.001), more often male (64.4% vs 61.7%; p < 0.001),were more likely to haveprivate insurance (50.8% vs 43.4%; p < 0.001), more metastatic disease at presentation (clinical TNM stage IV-80.8% vs 23.3%; p < 0.001), presented with larger tumors (median: 5cm vs. 4.2cm; p < 0.001) and less often underwent surgery (33.7% vs. 69.9%; p < 0.001), radiation therapy (21.5% vs 57.4%; p < 0.001), and standard chemotherapy (38.1% vs 61%; p < 0.001) than controls. After matching, 488 patients were in each group. OS was significantly shorter in the immunotherapy group (mean survival: 56.4months (95% CI:-53.03-59.86)) compared to controls (mean survival: 70.5months (95%CI:-66.15-74.92) (p = 0.004)). Cox regression analysis of factors associated with OS demonstrated that immunotherapy was associated with increased mortality (HR 2.16; 95%CI: 2.09-2.24; p < 0.001). After clinical staging stratification, immunotherapy was associated with improved OS in stage IV (HR 0.91, 95%CI: 0.88-0.95; p < 0.001) but lower survival in stage II (HR 2.38; 95%CI: 2.05-2.77; p < 0.001) and stage III (HR 2.43; 95%CI: 2.18-2.7; p < 0.001) patients. Immunotherapy showed modest increase in OS in stage IV metastatic rectal cancer. OS was significantly lower in stage II-III disease treated with immunotherapy.

Comparison of preoperative CT- and MRI-based multiparametric radiomics in the prediction of lymph node metastasis in rectal cancer

ObjectiveTo compare computed tomography (CT)- and magnetic resonance imaging (MRI)-based multiparametric radiomics models and validate a multi-modality, multiparametric clinical-radiomics nomogram for individual preoperative prediction of lymph node metastasis (LNM) in rectal cancer (RC) patients.Methods234 rectal adenocarcinoma patients from our retrospective study cohort were randomly selected as the training (n = 164) and testing (n = 70) cohorts. The radiomics features of the primary tumor were extracted from the non-contrast enhanced computed tomography (NCE-CT), the enhanced computed tomography (CE-CT), the T2-weighted imaging (T2WI) and the gadolinium contrast-enhanced T1-weighted imaging (CE-TIWI) of each patient. Three kinds of models were constructed based on training cohort, including the Clinical model (based on the clinical features), the radiomics models (based on NCE-CT, CE-CT, T2WI, CE-T1WI, CT, MRI, CT combing with MRI) and the clinical-radiomics models (based on CT or MRI radiomics model combing with clinical data) and Clinical-IMG model (based on CT and MRI radiomics model combing with clinical data). The performances of the 11 models were evaluated via the area under the receiver operator characteristic curve (AUC), accuracy, sensitivity, and specificity in the training and validation cohort. Differences in the AUCs among the 11 models were compared using DeLong’s test. Finally, the optimal model (Clinical-IMG model) was selected to create a radiomics nomogram. The performance of the nomogram to evaluate clinical efficacy was verified by ROC curves and decision curve analysis (DCA).ResultsThe MRI radiomics model in the validation cohort significantly outperformed than CT radiomics model (AUC, 0.785 vs. 0.721, p&amp;lt;0.05). The Clinical-IMG nomogram had the highest prediction efficiency than all other predictive models (p&amp;lt;0.05), of which the AUC was 0.947, the sensitivity was 0.870 and the specificity was 0.884.ConclusionMRI radiomics model performed better than both CT radiomics model and Clinical model in predicting LNM of RC. The clinical-radiomics nomogram that combines the radiomics features obtained from both CT and MRI along with preoperative clinical characteristics exhibits the best diagnostic performance.

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

This study aimed to ascertain if the incorporation of intensity-modulated radiotherapy (IMRT) with chemotherapy (CTx) offered any advantages for patients diagnosed with stage pT3N0 rectal cancer located in the proximal (upper) region following a complete total mesorectum excision (TME). We retrospectively examined medical records of stage II/III rectal cancer patients who had undergone CTx or concurrent chemoradiation (CCRT) with IMRT after a successful TME. We juxtaposed a variety of survival outcomes across two patient cohorts. Each outcome was further classified according to Gunderson's risk stratification between proximal and distal (middle and low) rectal cancer patients, and we evaluated the factors associated with each outcome. The median follow-up duration was 4.9 years. Our research comprised 236 rectal adenocarcinoma patients treated at our institution between 2007 and 2019. They received either the CTx (n = 135) or the CCRT (n = 101) with 10-year locoregional recurrence-free survival (LRRFS) of 90.1% and 96.1%, respectively (p = 0.163). However, after performing multivariate adjustments, a pattern emerged hinting at a better LRRFS for the CCRT group (p = 0.052). Perforation had a strong correlation with locoregional recurrence. No significant differences were observed in other survival between the two treatment arms and their respective subgroups. The CCRT group witnessed significantly higher immediate and chronic complications with p = 0.007 and 0.009, respectively. The CCRT group had two secondary cancer-related fatalities (2%, one attributed to IMRT), and another reported by the CTx group (1%). The sole classified locoregional recurrence within the cohort of 37 individuals treated with CTx for proximal pT3N0 rectal cancer was, in fact, the development of sigmoid colon cancer. The results suggest that for patients with proximal pT3N0 rectal cancer post-TME, IMRT is better when not combined with CTx, except in highly perilous scenarios or those involving perforation.

Experience of a single academic institution with the National Accreditation Program for Rectal Cancer and the resulting improvement in care.

The American College of Surgeons Committee on Cancer developed the National Accreditation Program for Rectal Cancer (NAPRC) to reduce variations in rectal cancer care, standardize clinical practice and encourage multidisciplinary approaches. The aim of this study was to analyse if accreditation achieved a higher quality of care at one hospital. The University of California Davis Medical Center was accredited in 2019. A retrospective review of rectal adenocarcinoma patients was performed between the years 2013 and 2018. Patients presenting from 2013 to 2015 were discussed at a gastrointestinal tumour board while patients in 2018 had an accredited rectal cancer tumour board. Patients from 2016 to 2017 were excluded as the programme was still developing. Compliance to the NAPRC standards was compared between the cohorts. One hundred and thirty patients were evaluated, 88 (68%) in the prerectal tumour board cohort and 42 (32%) in the rectal tumour board cohort. The prerectal tumour board cohort often failed to meet attendance standards. All patients in the rectal tumour board cohort met all criteria. Similarly, clinical service compliance improved in the rectal tumour board cohort for 13 metrics, 10 of which were statistically significant. Although a high proportion of patients in both groups experienced quality surgery, i.e. complete total mesorectal excision and negative margins, the lack of complete pathological reporting in the prerectal tumour board cohort limited analysis. Multidisciplinary rectal cancer tumour boards are associated with improved compliance with recommended care by the NAPRC. Patients discussed at a rectal cancer tumour board were more likely to receive appropriate staging, coordinated care and have better clinical documentation.