Chemoradiotherapy For Rectal Cancer Research Articles

Standard (8\u2009weeks) vs long (12\u2009weeks) timing to minimally-invasive surgery after NeoAdjuvant Chemoradiotherapy for rectal cancer: a multicenter randomized controlled parallel group trial (TiMiSNAR)

BackgroundThe optimal timing of surgery in relation to chemoradiation is still controversial. Retrospective analysis has demonstrated in the recent decades that the regression of adenocarcinoma can be slow and not complete until after several months. More recently, increasing pathologic Complete Response rates have been demonstrated to be correlated with longer time interval. The purpose of the trial is to demonstrate if delayed timing of surgery after neoadjuvant chemoradiotherapy actually affects pathologic Complete Response and reflects on disease-free survival and overall survival rather than standard timing.MethodsThe trial is a multicenter, prospective, randomized controlled, unblinded, parallel-group trial comparing standard and delayed surgery after neoadjuvant chemoradiotherapy for the curative treatment of rectal cancer. Three-hundred and forty patients will be randomized on an equal basis to either robotic-assisted/standard laparoscopic rectal cancer surgery after 8 weeks or robotic-assisted/standard laparoscopic rectal cancer surgery after 12 weeks.DiscussionTo date, it is well-know that pathologic Complete Response is associated with excellent prognosis and an overall survival of 90%. In the Lyon trial the rate of pCR or near pathologic Complete Response increased from 10.3 to 26% and in retrospective studies the increase rate was about 23–30%. These results may be explained on the relationship between radiation therapy and tumor regression: DNA damage occurs during irradiation, but cellular lysis occurs within the next weeks. Study results, whether confirmed that performing surgery after 12 weeks from neoadjuvant treatment is advantageous from a technical and oncological point of view, may change the current pathway of the treatment in those patient suffering from rectal cancer.Trial registrationClinicalTrials.gov NCT3465982.

Radiomics performs comparable to morphologic assessment by expert radiologists for prediction of response to neoadjuvant chemoradiotherapy on baseline staging MRI in rectal cancer.

To compare the performance of advanced radiomics analysis to morphological assessment by expert radiologists to predict a good or complete response to chemoradiotherapy in rectal cancer using baseline staging MRI. We retrospectively assessed the primary staging MRIs [prior to chemoradiotherapy (CRT)] of 133 rectal cancer patients from 2 centers. First, two expert radiologists subjectively estimated the likelihood of achieving a "complete response" (ypT0) and "good response" (TRG 1-2), using a 5-point score (based on TN-stage, MRF/EMVI-status, size/signal/shape). Next, tumor volumes were segmented on high b value DWI (semi-automated, corrected by 2 non-expert and 2-expert readers, resulting in 5 segmentations), copied to the remaining sequences after which a total of 2505 radiomic features were extracted from T2W, low and high b value DWI and ADC. Stability of features for noise due to inter-reader and inter-scanner and protocol variations was assessed using intraclass correlation (ICC) and the Kruskal-Wallis test. Using data from center 1 (n = 86; training set), top 9 features were selected using minimum Redundancy Maximum Relevance and combined in a logistic regression model. Finally, diagnostic performance of the fitted models was assessed on data from center 2 (n = 47; validation set) and compared to the performance of the radiologists. The Radiomic models resulted in AUCs of 0.69-0.79 (with similar results for the segmentations performed by expert/non-expert readers) to predict response, results similar to the morphologic prediction by the expert radiologists (AUC 0.67-0.83). Radiomics using semi-automatically generated segmentations (without manual input) did not result in significant predictive performance. Radiomics could predict response to therapy with comparable diagnostic performance as expert radiologists, regardless of whether image segmentation was performed by non-expert or expert readers, indicating that expert input is not required in order for the radiomics workflow to produce significant predictive performance.

Optimal interval to surgery after chemoradiotherapy in rectal cancer: A protocol for systematic review and network meta-analysis.

Rectal cancer is the second leading cause of cancer-related death in the Western world. Preoperative neoadjuvant chemoradiotherapy (nCRT) has been widely performed in the treatment of rectal cancer patients. However, there is no consensus on the length of waiting interval between the end of preoperative nCRT and surgery. Present network meta-analysis (NMA) aims to compare the differences of effect between all available interval to surgery after nCRT in rectal cancer in improving overall survival, disease-free survival and pathologic complete response (pCR) rate, and to rate the certainty of evidence from present NMA. We will systematically search PubMed, EMBASE, Chinese Biomedical Literature Database, and Cochrane Central Register of Controlled Trials (CENTRAL) databases to identify studies assessing the interval to surgery after CRT in rectal cancer. We will conduct this systematic review and meta-analysis using Bayesian method and report the full-text according to Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) Extension Vision statement (PRISMA-NMA). We will assess the risk of bias of individual study using the Newcastle-Ottawa Scale and Cochrane Handbook V.5.1.0. We will also use the advance of GRADE to rate the certainty of NMA. Data will be analyzed by using R software V.3.4.1. The results of this study will be published in a peer-reviewed journal. To the best of our knowledge, this systematic review and NMA will first use both direct and indirect evidence to compare the differences of all available interval to surgery after CRT in rectal cancer. This is a protocol of systematic review and meta-analysis, so the ethical approval and patient consent are not required.

Delayed Surgical Resection After Long-course Neoadjuvant Chemoradiotherapy in Rectal Cancer: Single Center Experience

Delayed Surgical Resection After Long-course Neoadjuvant Chemoradiotherapy in Rectal Cancer: Single Center Experience

A prospective clinical study assessing the presence of exfoliated cancer cells and rectal washout including tumors in patients who receive neoadjuvant chemoradiotherapy for rectal cancer.

Rectal washout is performed in rectal cancer surgery to eliminate exfoliated cancer cells. Before rectal washout, a cross-clamp should generally be placed distal to the tumor. In some patients with lower rectal cancer, however, the tumor cannot be adequately isolated. We, therefore, hypothesized that neoadjuvant chemoradiotherapy (nCRT) can decrease the number of exfoliated cancer cells even after the rectal washout including tumors. We prospectively studied 86 patients with rectal cancer who underwent proctectomy after nCRT. A cross-clamp was applied proximal to the tumor, and the rectum was washed with 2000mL of physiological saline solution. The initial 100mL used to wash the rectum was collected as a pre-washout sample. After the rectum was washed with the remaining 1900mL, the solution remaining in the rectum was collected as a post-washout sample. Cells classified as class IV or higher according to the papanicolaou classification were considered to indicate a positive diagnosis. The cytological diagnosis was positive in pre-washout samples in 21 patients (24%) and post-washout samples in two patients (2%). In patients with rectal cancer, nCRT may decrease the number of exfoliated cancer cells in the rectum, and rectal washout including the tumor may be oncologically acceptable.

Population-based study of morbidity risk associated with pathological complete response after chemoradiotherapy for rectal cancer.

Neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer may induce a pathological complete response (pCR) but increase surgical morbidity due to radiation-induced fibrosis. In this study the association between pCR and postoperative surgical morbidity was investigated. Patients in the Netherlands with rectal cancer who underwent nCRT followed by total mesorectal excision between 2009 and 2017 were included. Data were stratified into patients who underwent resection with creation of a primary anastomosis and those who had a permanent stoma procedure. The association between pCR and postoperative morbidity was investigated in univariable and multivariable logistic regression analyses. pCR was observed in 976 (12·2 per cent) of 8003 patients. In 3472 patients who had a primary anastomosis, the presence of pCR was significantly associated with surgical complications (122 of 443 (27·5 per cent) versus 598 of 3029 (19·7 per cent) in those without pCR) and anastomotic leak (35 of 443 (7·9 per cent) versus 173 of 3029 (5·7 per cent) respectively). Multivariable analysis also showed associations between pCR and surgical complications (adjusted odds ratio (OR) 1·53, 95 per cent c.i. 1·22 to 1·92) and pCR and anastomotic leak (adjusted OR 1·41, 1·03 to 2·05). Of 4531 patients with a permanent stoma, surgical complications were observed in 120 (22·5 per cent) of 533 patients with a pCR, compared with 798 (20·0 per cent) of 3998 patients with no pCR (adjusted OR 1·17, 0·94 to 1·46). Patients with a pCR in whom an anastomosis was created were at increased risk of developing an anastomotic leak.

Local excision following chemoradiotherapy in T2-T3 rectal cancer: current status and critical appraisal.

Local excision following chemoradiotherapy in rectal cancer is an organ-preserving procedure which aims at reducing morbidity and functional disorders associated with total mesorectal excision (TME) in selected patients. Although TME after chemoradiotherapy remains the gold standard for locally advanced mid and low rectal cancer, in the last years multicenter research trials have offered encouraging oncologic results which have allowed to preserve the rectum in patients with a pathologic complete response after chemoradiotherapy. A review of the available literature on this topic was conducted to define the state of the art of this conservative approach and to focus on the most controversial aspects concerning local excision performed after chemoradiotherapy, in particular tumor scatter and lymph node status, completion and salvage surgery, morbidity and quality of life. The analysis of these topics should be considered, in trial setting or in current practice, for their clinical implications. Oncologic outcomes of recent trials are encouraging for part of the patients presenting T2 rectal cancer; however, TME still remains the standard treatment in clinical practice. In such cases, local excision should include a surgical safety margin of at least 1 cm from the resection margin to achieve a true negative margin from residual tumor cells. The selection of the patients should be carefully performed and their consensus extremely detailed because TME is necessary in about 30% of cases. Failing that, morbidity and quality of life are negatively affected. However, about half of these patients refuse radical surgery (45%), thus undergoing only palliative care.

545P - Feasibility of chemoradiotherapy in rectal cancer patients with peritumoral abscesses and fistulas: A case-control non-inferiority trial

BackgroundNeoadjuvant chemoradiotherapy (CRT) is a standard treatment for patients with locally advanced rectal cancer and is effective as a palliative care in patients with nonresectable tumors. Unfortunately CRT is often being withheld for patients with tumor-associated complications due to safety concerns. Literature search reveals only case reports and neither supports nor declines additional risks of CRT in this patient group. The aim of this study was to determine feasibility of CRT in rectal cancer with peritumoral abscesses and fistulas. MethodsPatients with locally advanced or recurrent rectal cancer with peritumoral abscesses and fistulas were included in the study group. The control group consisted of T4 locally advanced or recurrent rectal cancer patients without complications, both groups received long-course neoadjuvant CRT. Groups were matched by age, previous treatment, treatment year. The primary endpoint was CRT toxicity. Secondary endpoints included postoperative morbidity (Clavien-Dindo), pathologic complete response (pCR) and 2year PFS. Results30 patients were included in each group. Patients in the main group had following tumor-associated complications: perianal fistula (n=11), abdominal wall fistula (n=1), rectovaginal fistula (n=9), rectovesical fistula (n=4), peritumoral abscess (n=17). Grade 3-4 toxicity was observed in 2 (6.66%) vs 3 (10%) patients, non-inferiority was confirmed (p=0.0326). Grade 3-4 postoperative complications were observed in 2 (7.14%) patients in the main group and in 3 (10.7%) patients in the control group (p=0.639) with no cases of mortality. pCR was achieved in 2 (7.14%) and 5 (17.8%) patients accordingly (p=0.225). Median follow-up was 25.2 months in the main group and 27.4 months in the control group. Two-year OS was 69% vs 100% (p=0.11), 2-year PFS was 65% vs 78% (p=0.434). ConclusionsPeritumoral abscesses and fistulas should not be considered as contraindication to neoadjuvant chemoradiotherapy. CRT is feasible and safe in patients with tumor-associated complications. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

"Watch and Wait" for complete clinical response after neoadjuvant chemoradiotherapy for rectal cancer.

The management of rectal cancer has evolved substantially over recent decades, becoming increasingly complex. This was once a disease associated with high mortality and limited treatment options that typically necessitated a permanent colostomy, has now become a model for multidisciplinary evaluation, treatment and surgical advancement. Despite advances in the rates of total mesorectal excision, decreased local recurrence and increased 5-year survival rates, the multimodal treatment of rectal cancer is associated with a significant impact on long-term functional and quality of life outcomes including risks of bowel, bladder and sexual dysfunction, and potential need for a permanent stoma. There is great interest in strategies to decrease the toxicity of treatment, including selective use of radiation, chemotherapy or even surgery. The modern concept of selective use of surgery for patients with rectal cancer are based on the observed pathological complete response in approximately 10-20% of patients following long-course chemoradiation therapy. While definitive surgical resection remains the standard of care for all patients with non-metastatic rectal cancer, a growing number of studies are providing supportive evidence for a watch-and-wait, organ preserving approach in highly selected patients with rectal cancer. However, questions regarding the heterogeneity of patient selection, optimal method for inducing pathological complete response, methods and intervals for assessing treatment response and adequacy of follow-up remain unanswered. The aim of this review is to provide an up-to-date summary of the current evidence for the watch-and-wait management of rectal cancer following a complete clinical response after neoadjuvant chemoradiation.

Mucin Pools Following Neoadjuvant Chemoradiotherapy for Rectal Cancer: A Marker of Response or Epiphenomenon?

Neoadjuvant chemoradiotherapy (CRT) is the standard of care for locally advanced rectal cancer. Morphologic changes such as fibrosis, inflammatory infiltrates, and the formation of extracellular mucin pools can be identified in the resection specimen after neoadjuvant CRT. The association of mucin pool formation with clinicopathologic variables and outcomes is unclear. The aim of this study was to meta-analyze all available evidence with regard to mucin pool formation and clinicopathologic outcomes following neoadjuvant CRT for rectal cancer. A comprehensive search for published studies analyzing outcomes between patients who formed mucin pools and patients who did not following neoadjuvant CRT for rectal cancer was performed. A random-effects model was used to combine the data. This study adhered to the recommendations of the MOOSE (Meta-analyses of Observational Studies in Epidemiology) guidelines. Data from 11 studies describing 1947 patients were included. Mucin pool formation was not associated with sex, T stage, N stage, tumor regression, pathologic complete response rate, lymphovascular invasion, perineural invasion, differentiation, margin status, local or distant recurrence, and disease-free or overall survival. Mucin pool formation is not associated with tumor response or downstaging; furthermore, on the basis of these data, it is not associated with local or systemic recurrence rate or survival.

Integrative Molecular Characterization of Resistance to Neoadjuvant Chemoradiation in Rectal Cancer.

Molecular properties associated with complete response or acquired resistance to concurrent chemotherapy and radiotherapy (CRT) are incompletely characterized.Experimental Design: We performed integrated whole-exome/transcriptome sequencing and immune infiltrate analysis on rectal adenocarcinoma tumors prior to neoadjuvant CRT (pre-CRT) and at time of resection (post-CRT) in 17 patients [8 complete/partial responders, 9 nonresponders (NR)]. CRT was not associated with increased tumor mutational burden or neoantigen load and did not alter the distribution of established somatic tumor mutations in rectal cancer. Concurrent KRAS/TP53 mutations (KP) associated with NR tumors and were enriched for an epithelial-mesenchymal transition transcriptional program. Furthermore, NR was associated with reduced CD4/CD8 T-cell infiltrates and a post-CRT M2 macrophage phenotype. Absence of any local tumor recurrences, KP/NR status predicted worse progression-free survival, suggesting that local immune escape during or after CRT with specific genomic features contributes to distant progression. Overall, while CRT did not impact genomic profiles, CRT impacted the tumor immune microenvironment, particularly in resistant cases.

NRF2 Metagene Expression Associated with Worse Response to Neoadjuvant Chemoradiotherapy in Rectal Cancer

NRF2 Metagene Expression Associated with Worse Response to Neoadjuvant Chemoradiotherapy in Rectal Cancer

FT3-L Dynamics in Blood Could be Predictive of Time of Occurrence Lymphocyte Nadir in Patients Undergoing Preoperative Chemoradiotherapy for Rectal Cancer.

The Fms-like tyrosine kinase 3 receptor (Flt-3) in conjunction with Flt-3 ligand (Flt-3L) participate in the growth and survival of bone marrow (BM) progenitor cells. To the best of our knowledge, correlation between concentration of Flt-3L in patients’ blood during 3-D planned chemoradiotherapy (CRT) and nadirs of lymphocytes (ALCnadir), neutrocytes (ANCnadir), platelets (PLTnadir), red blood cells (RBCnadir) has not been assessed yet. Available data comes from preclinical studies and small clinical studied without evaluation of dose-volume parameters of BM. Our pilot study aims to access clinical utility of Flt-3L concentration in patients’ blood during CRT. 33 patients qualified to preoperative CRT were enrolled. Blood samples for Flt-3L were collected at baseline, at 2nd, 4thand 5/6thweek; for ALC, ANC, PLT, and RBC every week. Flt-3L variability was assessed over time using Friedman’s ANOVA. The model for prediction of ALC, ANC, PLT, RBC nadir week was developed. The Flt-3L measured levels as well as relative changes between following weeks were used for decision tree induction using C4.5 algorithm. Resulting modelling method of prediction was assessed for overfitting in leave-one-out cross-validation. The concentration of Flt-3L was statistically significantly higher than the initial value from the second week of chemo-radiotherapy (in 2nd, 4thand 5/6thweek of CRT). Final model presented the accuracy of 84.8% and utilized the relative change of Flt-3L between baseline and 2ndweek, 2ndand 4thweek and the measurement at 5/6thweek. Weighted average area under the ROC curve in validation on training set for all weeks was 0.91. The accuracy in leave-one-out cross-validation was estimated as 69.7%. This pilot study presents the potential of Flt-3L in prediction of week of occurrence of lymphocyte nadir during preoperative CRT of rectal cancer. Further studies with larger number of participants could provide an overfitting-resistant and clinically applicable model for prediction of the expected week at which lymphocyte nadir occurs, hence enhance treatment monitoring. Additionally, in our complementary study ALC nadir was connected with dose-volume parameters of bone marrow, what may add clinical significance.

A Radiomics-Based Multi-Omics Integration Model to Predict the Therapeutic Response to Neoadjuvant Chemoradiotherapy of Rectal Cancer

A Radiomics-Based Multi-Omics Integration Model to Predict the Therapeutic Response to Neoadjuvant Chemoradiotherapy of Rectal Cancer

Cost Effectiveness of Watch-and-Wait or Total Mesorectal Excision after Complete Clinical Response to Chemoradiotherapy for Rectal Cancer

Cost Effectiveness of Watch-and-Wait or Total Mesorectal Excision after Complete Clinical Response to Chemoradiotherapy for Rectal Cancer

The clinical evaluation of clinical complete response to neoadjuvant chemoradiotherapy for rectal cancer

Neochemoradiotherapy has been implemented in the multidisciplinary therapy for advanced rectal cancer. The patients with complete response after neothemoradiation could avoid surgical resection and thereafter might be free of surgical complications, as well as functional impairment. However, the preoperative evaluated clinical complete response is not equally to the pathologic complete response after surgery. The accurate methods to evaluate the status of complete response remained controversy. Based on the digital rectal examination and endoscopic observation, rectal MRI and endorectal ultrasound could verify the integrity of mucosa and the structural changes in rectal wall. These preoperative staging methods, as well as PET-CT and needle biopsy, had been widely used, but with a low sensitivity. Key words: Rectal neoplasms; Rectal cancer; Neoadjuvant chemoradiotherapy; Clinical complete response; Magnetic resonance imaging, rectal; Ultrasound, rectal

Predicting the tumor response to chemoradiotherapy for rectal cancer: Model development and external validation using MRI radiomics

BackgroundIn well-responding patients to chemoradiotherapy for locally advanced rectal cancer (LARC), a watch-and-wait strategy can be considered. To implement organ-sparing strategies, accurate patient selection is needed. We investigate the use of MRI-based radiomics models to predict tumor response to improve patient selection. Materials and methodsModels were developed in a cohort of 70 patients and validated in an external cohort of 55 patients. Patients received chemoradiation followed by surgery and underwent T2-weighted and diffusion-weighted MRI (DW-MRI) before and after chemoradiation. The outcome measure was (near-)complete pathological tumor response (ypT0-1N0).Tumor segmentation was done on T2-images and transferred to b800-images and ADC maps, after which quantitative and four semantic features were extracted. We combined features using principal component analysis and built models using LASSO regression analysis. The best models based on precision and performance were selected for validation. Results21/70 patients (30%) achieved ypT0-1N0 in the development cohort versus 13/55 patients (24%) in the validation cohort. Three models (t2_dwi_pre_post, semantic_dwi_adc_pre, semantic_dwi_post) were identified with an area-under-the-curve (AUC) of 0.83 (95% CI 0.70–0.95), 0.86 (95% CI 0.75–0.98) and 0.84 (95% CI 0.75–0.94) respectively. Two models (t2_dwi_pre_post, semantic_dwi_post) validated well in the external cohort with AUCs of 0.83 (95% CI 0.70–0.95) and 0.86 (95% CI 0.76–0.97). These models however did not outperform a previously established four-feature semantic model. ConclusionPrediction models based on MRI radiomics non-invasively predict tumor response after chemoradiation for rectal cancer and can be used as an additional tool to identify patients eligible for an organ-preserving treatment.

Oncologic Risk of Rectal Preservation Against Medical Advice After Chemoradiotherapy for Rectal Cancer: A Multicenter Comparative Cross-Sectional Study with Rectal Preservation as Supported by Surgeon.

Rectal preservation against medical advice after neoadjuvant chemoradiotherapy for rectal cancer may increase oncologic uncertainty. This study aimed to compare the oncologic outcomes of patients undergoing rectal preservation as intended by the surgeon, and the outcomes of patients refusing rectal resection against medical advice. The study population consisted of patients in whom the rectum was preserved after neoadjuvant chemoradiotherapy for clinical stage I-III mid or low rectal cancer between May 2003 and August 2017 (n = 2883); these patients were divided into those in whom rectal preservation was intended by their surgeon (intended rectal preservation, group A, n = 41) and those in whom the rectum was not resected against medical advice (unintended rectal preservation, group B, n = 101), defined as non-operative management or local excision. The tumor distance, age, and performance status of patients were not significantly different between the groups, while the clinical T stage before chemoradiotherapy was lower in group A than in group B (P < 0.001). During the median follow-up period of 34months (interquartile range 18.0-72.0months), the 3-year overall survival in group B (59.7%) was worse than that in group A (90.1%; P < 0.001), and 80.2% of group B patients had residual or unknown disease status. This study showed that unintended rectal preservation increases oncologic risk after neoadjuvant chemoradiotherapy for rectal cancer regardless of short-term follow-up. Therefore, these findings could be shared with rectal cancer patients who choose to ignore medical advice after chemoradiotherapy to preserve their rectum.

A Multigene Model for Predicting Tumor Responsiveness After Preoperative Chemoradiotherapy for Rectal Cancer

Although preoperative chemoradiotherapy (PCRT) is regarded as a standard treatment for locally advanced rectal cancer, there is no reliable biomarker for predicting responsiveness to PCRT. We aimed to develop a biomarker model for predicting response to PCRT. We included 184 patients who received PCRT followed by surgical resection and categorized them as good responders (complete or near-complete regression) or poor responders (all other patients). Candidate gene mRNAs were isolated from formalin-fixed paraffin-embedded tumor specimens and analyzed using the NanoString nCounter gene expression assay. Stepwise logistic regression analysis was used to select genes in discovery and training phases. A quantitative radio-responsiveness prediction model was developed and validated using internal cross-validation groups, and the model's predictive value was assessed based on the area under the receiver operating characteristic curve (AUC). By comparing the gene expressions between good and poor responders, we created a multigene mRNA model using FZD9, HRAS, ITGA7, MECOM, MMP3, NKD1, PIK3CD, and PRKCB. This panel showed good ability to predict treatment response (AUC: 0.846 for the whole data set). Internal cross-validation was performed to evaluate the model's predictive stability among 3 cohorts, which provided AUC values of 0.808-0.909. The satisfactory diagnostic performance of the radio-response prediction index persisted regardless of other clinicopathologic features such as clinical T or N stage, interval between radiation and surgery, and pretreatment carcinoembryonic antigen levels (P = .001, 95% CI, 0.686-0.905). We developed a multigene mRNA-based biomarker model that allows prediction of rectal cancer response to PCRT, which may help identify patients who will benefit most from PCRT.

Timing of surgery following neoadjuvant chemoradiation in rectal cancer: a retrospective analysis from an academic medical center.

Neoadjuvant chemoradiotherapy (nCRT) has been shown to achieve decreased local recurrence (LR) with lower toxicity in rectal cancer patients, but data confirming the optimal timing of surgery following this therapy is less robust. The University of Iowa Cancer Registry was queried to identify all patients with stages II-III rectal cancer who received nCRT and surgery from 2000 through 2012. Primary endpoints were time interval to surgery (TI), and overall survival (OS). Secondary endpoints included pathologic outcomes, perioperative morbidities and postoperative complications. Patient characteristics and treatment regimens were compared. Univariate Cox proportional hazard models were used to study the association between TI and OS. Associations of TI with secondary endpoints were tested using Chi-square tests of association. Eighty-seven patients presented with stages II-III rectal cancer. Mean TI was 9.92 weeks. There was no significant association between TI and OS when comparing <8 to ≥8 weeks (P=0.23) or when considering the interval as a continuous variable (P=0.85). Increased LOS [median 7.00 days, P=0.05, HR 1.03 (1.00-1.06)] did correlate with worse survival outcomes. Delaying surgery beyond 8 weeks was associated with increased risk for wound infection (P=0.05). OS was not influenced by longer intervals between nCRT and surgery. Delaying surgery beyond 8 weeks was associated with increased risk for wound infection.