Outcomes Of Rectal Cancer Patients Research Articles

Impact of neoadjuvant immunotherapy on postoperative complications after surgery for rectal cancer.

Despite the increasing use of immunotherapy in treating various cancer types, there is still limited understanding of its impact on surgical complications. We used a national database to examine the difference in surgical outcomes for rectal cancer patients who received standard neoadjuvant chemoradiation plus neoadjuvant immunotherapy and patients who received neoadjuvant chemoradiation only. This retrospective cohort study used the National Cancer Database (NCDB). We selected patients aged 18-90 with T1-3, N1-2, and M0 rectal cancer who underwent curative-intent surgery between 2010 and 2020. We performed a 1:1 propensity match to control for patient age, sex, Charlson-Deyo comorbidity index, surgical approach, and tumor site. Our primary outcome was difference in surgical outcomes (hospital length of stay, unplanned 30-day readmission, 30-day mortality) between the two groups. Secondary outcomes included days from diagnosis to surgery and pathologic outcomes. Our study included 26 229 patients, of which 126 received immunotherapy in addition to chemoradiation and 26 103 received only chemoradiation. In our matched population of 125 pairs of patients, patients who received immunotherapy and chemoradiation underwent surgery later compared to patients who only received chemoradiation (median 245 vs. 144 days, p < 0.001). There were no significant differences in median length of stay (5 vs. 5 days, p = 0.202), unplanned 30-day readmission (7 vs. 9, p = 0.617), and 30-day mortality (0 vs. 1, p = 1.000) between the two groups. Neoadjuvant immunotherapy for rectal cancer is not associated with adverse surgical outcomes. This work can help clinicians optimize treatment protocols and move closer toward strategies tailored to specific patient profiles.

The association of preoperative hematologic parameters with short-term clinical outcomes in rectal cancer: A feature importance analysis.

Various hematologic parameters have been proposed as prognostic factors in rectal cancer management, but data are conflicting and unclear. This study is designed to investigate the prognostic factor capability of preoperative hematologic parameters with postoperative morbidities and mortality in rectal cancer patients undergoing curative resection. All 200 consecutive rectal cancer patients diagnosed at Ghaem University Hospital from 2017 to 2022 were retrospectively evaluated. The receiver operating characteristic (ROC) curves and machine learning (ML) algorithms of Random Forest, Recursive Feature Elimination, simulated annealing, Support Vector Machine, Decision Tree, and eXtreme Gradient Boosting were administered to investigate the role of preoperative hematologic parameters accompanied by baseline characteristics on three clinical outcomes including surgical infectious complications, recurrence, and death. The frequency of infectious complications was correlated with the surgical procedure, while tumor recurrence was significantly influenced by T stage and N stage. In terms of mortality, alongside T and N stage, the status of resection margin involvement was significantly correlated. Based on the ROC analysis, the NLR >2.69, MPV ≤9 fL, and PDW ≤10.5 fL were more classified patients to mortality status. Likewise, the PLT >220 109/L, MPV ≤9 fL, PDW ≤10.4 fL, and PLR >13.6 were correlated with recurrence. However, all factors examined in this study were not significant classifiers for the outcome of surgical infectious complications. The results of ML algorithms were also in line with ROC analysis. According to the results of both ROC analysis and ML models, preoperative hematologic parameters are considerable prognostic factors of postoperative outcomes in rectal cancer patients, and are recommended to be monitored by clinicians to prevent unfavorable outcomes.

Impact of mesorectal extranodal tumor deposits in magnetic resonance imaging on outcome of rectal cancer patients

AimMesorectal extranodal tumor deposits (TDs) are identified in many rectal cancers. Their radiological features differ from metastatic lymph nodes, and they can be detected with magnetic resonance imaging (MRI). The purpose of this study was to determine the prevalence of rectal cancer TDs detected with MRI and their impact on overall (OS), cancer-specific (CSS), and disease-free survival (DFS) and the local recurrence rate. MethodIn this retrospective cohort study, we screened all 525 consecutive rectal cancer patients who underwent surgery during 2017–2018 in a tertiary center. Patients with synchronous metastases or who had not undergone MRI were excluded. We analyzed the OS, CSS, and DFS as well as local recurrences. ResultsOf the 480 included patients, TDs were detected in the images of 81 (16.9 %). Extramural venous invasion (EMVI) and TDs were frequently found together (n = 50, 61.7 % of all cases with TDs). The presence of TDs alone [hazard ratio (HR) 1.66 (1.03–2.68)] or TDs and/or EMVI [HR 1.63 (1.01–2.62)] were risk factors for adverse DFS in multivariate Cox regression analysis. The OS and CSS rates were poorer among patients with TDs compared to those without, p = 0.009 and p < 0.001, respectively. TDs were also a risk factor for local recurrence in the univariate analysis. ConclusionsTDs detected with imaging are a risk factor for impaired DFS and associated with impaired CSS and OS of rectal cancer patients and should be taken into consideration in clinical decision-making.

The role of robotic-assisted surgery in the management of rectal cancer: a systematic review and meta-analysis.

Rectal cancer poses a significant global health burden. There is a lack of concrete evidence concerning the benefits of robotic-assisted surgery (RAS) for rectal cancer surgery as compared to laparoscopic and open techniques. To address this gap, we conducted a meta-analysis to assess the intraoperative, postoperative, and safety outcomes of robotic surgery in this context. MEDLINE, Scopus, and the Cochrane library were searched till May 2023 for randomized and non-randomized studies comparing robotic surgery with either laparoscopic or open approach for rectal cancers. The outcomes of interest were operative time, blood loss, harvested lymph nodes, conversion rate, postoperative hospital stay, survival to hospital discharge, urinary retention rate, and anastomotic leakage rate. A random-effects meta-analysis was performed to pool means and dichotomous data to derive weighted mean differences and odds ratios, respectively. A total of 56 studies were shortlisted after the study selection process with a total of 25,458 rectal cancer patients. From the intraoperative outcomes, RAS was significantly associated with an increased operative time (WMD: 41.04, P<0.00001), decreased blood loss (WMD: -24.56, P<0.00001), decreased conversion rates (OR: 0.39, P<0.00001), lesser stay at the hospital (WMD: -1.93, P<0.00001), and no difference was found in lymph nodes harvested. Similarly, RAS group had a significantly greater survival to hospital discharge (OR: 1.90, P=0.04), decreased urinary retention rate (OR: 0.59, P=0.002), and no difference was seen in anastomotic leakage rate. Robotic-assisted surgery (RAS) demonstrates favourable outcomes for rectal cancer patients, contributing to global prevention and control efforts, health promotion, and addressing non-communicable disease risk factors. Further research and public awareness are needed to optimize RAS utilization in this context.

Loss of psoas muscle during neoadjuvant treatment for rectal cancer is associated with poor oncological and surgical outcomes.

Sarcopenia has been associated with poor outcomes in rectal cancer patients. This study aims to assess the degree of muscle loss during neoadjuvant therapy in patients with rectal cancer, and its relationship with tumour response, post-operative complications and long-term disease recurrence. The change in the psoas muscle area was determined by measuring the psoas muscle area at L4 on initial staging PET CT scans and comparing this with the restaging scan 8-10 weeks after radiation treatment had been completed. The average change in the psoas muscle area was compared between patients who had residual disease versus complete clinical/pathological response, anastomotic leak vs. no leak, and distant recurrence vs. no recurrence on follow-up imaging. Ninety-two patients were included in the study. The mean loss of psoas muscle area was 5%. Patients who had a complete response to chemoradiotherapy showed a statistically significant difference in muscle mass loss (2.8%) compared to those with residual tumour present after therapy (6.2%), P = 0.02 on multivariable analysis. There was a statistically significant greater loss of muscle in patients who had an anastomotic leak versus those that did not (10.2% vs. 4.1%) and in those who developed metastatic disease versus those that did not (10.7% vs. 4.1%) (P < 0.05). Our study adds to the growing body of evidence that sarcopenia is a predictor of poor surgical and oncological outcomes in rectal cancer patients. We postulate that the loss of muscle is an indication of disease burden and worse tumour biology.

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.

Prospective results on functional outcome of rectal cancer patients under watch and wait

Prospective results on functional outcome of rectal cancer patients under watch and wait

Effect of adjuvant chemotherapy on the oncological outcome of rectal cancer patients with pathological complete response

BackgroundLocally advanced rectal cancer is typically treated using a combination of neoadjuvant chemoradiotherapy and total mesorectal resection. While achieving pathological complete response following neoadjuvant chemoradiotherapy has been recognized as a positive prognostic factor in oncology, the necessity of adjuvant chemotherapy for locally advanced rectal cancer patients with pathological complete response after surgery remains uncertain. The objective of this meta-analysis was to examine the impact of adjuvant chemotherapy on the oncological outcomes of rectal cancer patients who attain pathological complete response after neoadjuvant chemoradiotherapy.MethodsThis meta-analysis followed the guidelines outlined in the preferred reporting items for systematic review and meta-analysis (PRISMA). The Web of Science, PubMed, and Cochrane Library databases were systematically searched to identify relevant literature.ResultsA total of 34 retrospective studies, including 9 studies from the NCBD database, involving 31,558 patients with pathological complete response rectal cancer, were included in the meta-analysis. The included studies were published between 2008 and 2023. The pooled analysis demonstrated that adjuvant chemotherapy significantly improved overall survival (HR = 0.803, 95% CI 0.678–0.952, P = 0.011), and no heterogeneity was observed (I2 = 0%). Locally advanced rectal cancer patients with pathological complete response who underwent adjuvant chemotherapy exhibited a higher 5-year overall survival rate compared to those who did not receive adjuvant chemotherapy (OR = 1.605, 95% CI 1.183–2.177, P = 0.002). However, the analysis also revealed that postoperative ACT did not lead to improvements in disease-free survival and recurrence-free survival within the same patient population. Subgroup analysis indicated that pathological complete response patients with clinical stage T3/T4, lymph node positivity, and younger than 70 years of age may benefit from adjuvant chemotherapy in terms of overall survival.ConclusionsThe findings of this meta-analysis suggest that adjuvant chemotherapy has a beneficial effect on improving overall survival among rectal cancer patients with pathological complete response. However, no such association was observed in terms of disease-free survival and recurrence-free survival.

Presurgical mild anemia is a risk factor for severe postoperative complications of rectal cancer surgery: A Japanese nationwide retrospective cohort study.

Anemia has negative effects on long-term outcomes of rectal cancer patients; however, its status as a risk factor for severe complications is disputed. Perioperative risks may differ based on the severity of pre-surgical anemia; nonetheless, no previous study has investigated these differences. This study identified risks of severe postoperative complications in rectal cancer patients based on severity of their pre-surgical anemia. This study enrolled patients who underwent low anterior resection for rectal cancer and were registered in the Japanese National Clinical Database (NCD) between 2017 and 2019. Anemia severity was categorized into three levels: mild, moderate, and severe. A logistic regression model was applied to calculate the risk-adjusted odds ratio (OR) of severe complications after surgery. This study analyzed a cohort of 51 765 rectal cancer patients who underwent low anterior resection. Results showed that severe complications occurred in 10.9% of patients and were significantly more frequent in patients with anemia (13.6%) than those with normal hemoglobin levels (9.2%). Risk-adjusted ORs of severe complications in the severe, moderate, and mild anemia groups versus the normal group for males were 1.19 (95% confidence interval [CI]: 0.89-1.58), 1.47 (1.34-1.62), and 1.21 (1.12-1.31), respectively. Those for females were 1.39 (0.90-2.15), 1.64 (1.37-1.97), and 1.36 (1.16-1.58), respectively. According to this large cohort study, pre-surgical anemia significantly increases the risk of severe postoperative complications in rectal cancer patients. Even mild anemia presents a significant risk.

P21 as a Predictor and Prognostic Indicator of Clinical Outcome in Rectal Cancer Patients.

The cell cycle plays a key and complex role in the development of human cancers. p21 is a potent cyclin-dependent kinase inhibitor (CDKI) involved in the promotion of cell cycle arrest and the regulation of cellular senescence. Altered p21 expression in rectal cancer cells may affect tumor cells' behavior and resistance to neoadjuvant and adjuvant therapy. Our study aimed to ascertain the relationship between the differential expression of p21 in rectal cancer and patient survival outcomes. Using tissue microarrays, 266 rectal cancer specimens were immunohistochemically stained for p21. The expression patterns were scored separately in cancer cells retrieved from the center and the periphery of the tumor; compared with clinicopathological data, tumor regression grade (TRG), disease-free, and overall survival. Negative p21 expression in tumor periphery cells was significantly associated with longer overall survival upon the univariate (p = 0.001) and multivariable analysis (p = 0.003, HR = 2.068). Negative p21 expression in tumor periphery cells was also associated with longer disease-free survival in the multivariable analysis (p = 0.040, HR = 1.769). Longer overall survival times also correlated with lower tumor grades (p= 0.011), the absence of vascular and perineural invasion (p = 0.001; p < 0.005), the absence of metastases (p < 0.005), and adjuvant treatment (p = 0.009). p21 expression is a potential predictive and prognostic biomarker for clinical outcomes in rectal cancer patients. Negative p21 expression in tumor periphery cells demonstrated significant association with longer overall survival and disease-free survival. Larger prospective studies are warranted to investigate the ability of p21 to identify rectal cancer patients who will benefit from neoadjuvant and adjuvant therapy.

Quality of life and clinical outcomes in rectal cancer patients treated on a 1.5T MR-Linac within the MOMENTUM study

Background and purposeThis study assessed quality of life (QoL) and clinical outcomes in rectal cancer patients treated with magnetic resonance (MR) guided short-course radiation therapy (SCRT) on a 1.5 Tesla (T) MR-Linac during the first 12 months after treatment. Materials and methodsRectal cancer patients treated with 25 Gy SCRT in five fractions with curative intent in the Netherlands (2019–2022) were identified in MOMENTUM (NCT04075305). Toxicity (CTCAE v5) and QoL (EORTC QLQ-C30 and -CR29) was primarily analyzed in patients without metastatic disease (M0) and no other therapies after SCRT. Patients who underwent tumor resection were censored from surgery. A generalized linear mixed-model was used to investigate clinically meaningful (≥10) and significant (P < 0.05) QoL changes. Clinical and pathological complete response (cCR and pCR) rates were calculated in patients in whom response was documented. ResultsA total of 172 patients were included, of whom 112 patients were primarily analyzed. Acute and late radiation-induced high-grade toxicity were reported in one patient, respectively. CCR was observed in 8/64 patients (13 %), 14/37 patients (38 %) and 13/16 patients (91 %) at three, six and twelve months; pCR was observed in 3/69 (4 %) patients. After 12 months, diarrhea (mean difference [MD] −17.4 [95 % confidence interval [CI] −31.2 to −3.7]), blood and mucus in stool (MD −31.1 [95 % CI −46.4 to −15.8]), and anxiety (MD –22.4 [95 % CI −34.0 to −10.9]) were improved. ConclusionHigh-field MR-guided SCRT for the treatment of patients with rectal cancer is associated with improved disease-related symptom management and functioning one year after treatment.

Analysis of the impact of radiotherapy and surgical treatment regimens based on the SEER database on the survival outcomes of rectal cancer patients over 70 years.

This study evaluates the impact of different combinations of treatment regimens, such as additional radiation, chemotherapy, and surgical treatments, on the survival of elderly rectal cancer patients ≥ 70 years of age to support physicians' clinical decision-making. Data from a sample of elderly rectal cancer patients aged ≥ 70 years diagnosed from 2005-2015 from the US surveillance, epidemiology, and end results (SEER) database were retrospectively analyzed. The best cut-off point was selected using the x-tile software for the three continuity indices: age, tumor size, and number of regional lymph nodes. All patients were categorized into either the neoadjuvant radiotherapy and surgery group (R_S group), the surgical treatment group (S group), or the surgery and adjuvant radiotherapy group (S_R group). The propensity score allocation was used to match each included study subject in a 1:1 ratio, and the restricted mean survival time method (RMST) was used to predict the mean survival of rectal cancer patients within 5 and 10 years. The prognostic risk factors for rectal cancer patients were determined using univariate and multivariate Cox regression analyses, and nomograms were constructed. A subgroup stratification analysis of patients with different treatment combination regimens was performed using the Kaplan-Meier method, and log-rank tests were used for between-group comparisons. The model's predictive accuracy was assessed by receiver operating characteristic (ROC) curves, correction curves, and a clinical decision curve analysis (DCA). A total of 7556 cases of sample data from 2005 to 2015 were included, which were categorized into 6639 patients (87.86%) in the S group, 408 patients (5.4%) in the R_S group, and 509 patients (6.74%) in the S_R group, according to the relevant order of radiotherapy and surgery. After propensity score matching (PSM), the primary clinical characteristics of the groups were balanced and comparable. The difference in the mean survival time before and after PSM was not statistically significant in both R_S and S groups (P value > 0.05), and the difference in the mean survival time after PSM was statistically substantial in S_R and S groups (P value < 0.05). In the multifactorial Cox analysis, the M1 stage and Nodes ≥ 9 were independent risk factors. An age between 70-75 was an independent protective factor for patients with rectal cancer in the R_S and S groups. The Marital_status, T4 stage, N2 stage, M1 stage, and Nodes ≥ 9 were independent risk factors for patients with rectal cancer in the S_R and S groups, and an age between 70-81 was an independent protective factor. The ROC curve area, the model C index, and the survival calibration curve suggested good agreement between the actual and predicted values of the model. The DCA for 3-year, 5-year, and 10-year survival periods indicated that the model had some potential for application. The results of the study showed no significant difference in the overall survival (OS) between elderly patients who received neoadjuvant radiotherapy and surgery and those who received surgery alone; elderly patients who received surgery and adjuvant radiotherapy had some survival benefits compared with those who received surgery alone, though the benefit of adjuvant radiotherapy was not significant. Therefore, radiotherapy for rectal cancer patients older than 70 years old should be based on individual differences in condition, and a precise treatment plan should be developed.

Predictive Value of the Interaction between CEA and Hemoglobin in Neoadjuvant CCRT Outcomes in Rectal Cancer Patients.

The adoption of neoadjuvant concurrent chemoradiotherapy (CCRT) has reshaped the therapeutic landscape, but response prediction remains challenging. This study investigates the interaction between pre-CCRT carcinoembryonic antigen (CEA) and post-CCRT hemoglobin (Hb) levels in predicting the response of locally advanced rectal cancer (LARC) to CCRT. Retrospective data from 93 rectal cancer patients receiving neoadjuvant CCRT were analyzed. Univariate analyses assessed clinical factors associated with tumor regression grade (TRG) and T-stage outcomes. Machine learning identified predictive biomarkers. Interaction effects between CEA and Hb were explored through subgroup analyses. Post-CCRT Hb varied between pre-CCRT CEA groups. The interaction between pre-CCRT CEA and post-CCRT Hb influenced TRG. Males with normal pre-CCRT CEA and anemia showed better treatment responses. Females with elevated pre-CCRT CEA and post-CCRT anemia exhibited poorer responses. The interaction effect between them was significant, indicating that their relationship with TRG was not additive. Inflammatory biomarkers, WBC, neutrophil count, and post-CCRT platelet level correlated with CCRT response. Contrasting with previous findings, anemia was a predictor of better treatment response in males with normal pre-CCRT CEA. The interaction between pre-CCRT CEA and post-CCRT Hb levels predicts the response of LARC to CCRT. CEA, Hb, and sex should be considered when assessing treatment response. Inflammatory biomarkers contribute to response prediction. Understanding these complex relationships can enhance personalized treatment approaches in rectal cancer patients.

Association of microRNA-652 expression with radiation response of colorectal cancer: A study from rectal cancer patients in a Swedish trial of preoperative radiotherapy.

Radiotherapy is a standard adjuvant therapy in patients with progressive rectal cancer, but many patients are resistant to radiotherapy, leading to poor prognosis. Our study identified microRNA-652 (miR-652) value on radiotherapy response and outcome in rectal cancer patients. miR-652 expression was determined by qPCR in primary rectal cancer from 48 patients with and 53 patients without radiotherapy. The association of miR-652 with biological factors and the prognosis was examined. The biological function of miR-652 was identified through TCGA and GEPIA database searches. Two human colon cancer cell lines (HCT116 p53+/+ and p53-/-) were used for in vitro study. The molecular interactions of miR-652 and tumor suppressor genes were studied through a computational approach. In RT patients, miR-652 expression was significantly decreased in cancers when compared to non-radiotherapy cases (P=0.002). High miR-652 expression in non-RT patients was with increased apoptosis marker (P=0.036), ATM (P=0.010), and DNp73 expression (P=0.009). High miR-652 expression was related to worse disease-free survival of non-radiotherapy patients, independent of gender, age, tumor stage, and differentiation (P=0.028; HR=7.398, 95% CI 0.217-3.786). The biological functional analysis further identified the prognostic value and potential relationship of miR-652 with apoptosis in rectal cancer. miR-652 expression in cancers was negatively related to WRAP53 expression (P=0.022). After miR-652 inhibition, the estimation of reactive oxygen species, caspase activity, and apoptosis in HCT116 p53+/+ cells was significantly increased compared with HCT116 p53-/- cells after radiation. The results of the molecular docking analysis show that the miR652-CTNNBL1 and miR652-TP53 were highly stable. Our findings suggest the potential value of miR-652 expression as a marker for the prediction of radiation response and clinical outcome in rectal cancer patients.

Patient-Reported Outcomes of Rectal Cancer Patients Treated on a 1.5T MR-Linac within the MOMENTUM Study.

With the 1.5 MR-Linac, planning target volume (PTV) margins for the treatment of rectal cancer can be reduced by 1/3 compared to conventional radiotherapy techniques. This allows better sparing of surrounding tissues, potentially resulting in less toxicity and greater patient comfort. Patient-reported outcomes (PROs) after rectal cancer treatment on a 1.5T MR-Linac have not yet been reported. Through international collaboration, the 'Multi-OutcoMe EvaluatioN of radiation Therapy Using the MR-Linac (MOMENTUM)' registry provides the unique opportunity to study these outcomes in a relatively large patient cohort. The aim of this study is to assess PROs of rectal cancer patients treated on a 1.5T MR-Linac within MOMENTUM. An international, prospective, observational cohort study was performed, including all patients with rectal cancer who were treated with 25 Gy in five fractions on an MR-Linac in three institutions located in the Netherlands (2019-2022). Patient-reported outcomes were measured using the general EORTC QLQ-C30 and colorectal cancer-specific EORTC QLQ-CR29 questionnaires. Scores were calculated according to the EORTC QLQ-C30 scoring manual. A high score for a functional scale represents a high functioning level, while a high score for a symptom scale represents a high symptomatology level. Outcomes were measured at regular time points (i.e., at baseline and after three, 6 and 12 months follow-up). Patients who underwent tumor resection were censored at the date of surgery. In total, 152patients were included, with a median follow-up of 17 (interquartile range [IQR] 11-27) months. Of these, six patients (4%) had American Joint Committee on Cancer (AJCC) stage I disease, 11 patients (7%) stage II, 85 patients (56%) stage III, and 12 patients (8%) stage IV. A total of 87 patients (57%) reached three months follow-up without surgery, 60 patients (39%) six months, and 40 patients (26%) twelve months. At six months follow-up, 25/132 patients (19%) had received additional chemotherapy. The median global health score was 83 (interquartile range [IQR] 67-83) at baseline, 75 (IQR 58-83) at three months, 75 (IQR 58-83) at six months and 83 (IQR 83-100) at twelve months. In most QLQ-C30 domains, functional and symptom scores deteriorated during the first six months after treatment, but returned to or exceeded baseline scores at 12 months. Overall, treatment resulted in improved QLQ-CR29 scores after 12 months follow-up. Most frequently reported symptoms were blood and mucus in stool, urinary frequency, stool frequency and anxiety. This study presents patient-reported outcomes in the currently largest cohort of patients with rectal cancer who received treatment on a 1.5T MR-Linac. Overall, treatment resulted in improved symptom management, and stabilized or improved quality of life outcomes after twelve months of follow-up.

Molecular Subtypes and Outcomes in a Multi-Institutional Review of Rectal Cancer Patients

Colorectal cancer (CRC) is a heterogeneous malignancy associated with a variety of genetic mutations. More recent data indicates that CRC can be broken down into unique biologically distinct consensus molecular subtypes (CMS) based on different pathological and genetic signatures. The purpose of this study is to evaluate the outcomes of rectal cancer patients in a multi-institutional network based on tumor mutational assessment and CMS group. Patient exome and transcriptome sequencing data and clinical outcomes were collected under the Total Cancer Care Protocol and Avatar® project within the Oncology Research Information Exchange Network (ORIEN). A total of 101 patients with demographic and outcomes information had data for microsatellite instability (MSI), tumor mutation burden (TMB), transcriptome, and whole exome sequencing (WES). Molecular subclasses (CMS1, CMS2, CMS3, CMS4, CMS-Mixed) were assigned based on transcriptional signatures by the R package "CMS Caller." Survival analysis was performed with the R packages "Survival" and "Survminer." A total of 101 rectal cancer patients, with a median age of 56.8, had a median follow up of 3.5 years (range 0.26-23.5). 78 patients were treated with curative intent for clinically localized disease and 35% of these patients developed metastatic disease. The remaining 23 patients had synchronous metastatic disease at presentation. There were 5 (5%) CMS1, 29 (29%) CMS2, 13 (13%) CMS 3, 49 (49%) CMS 4, and 5 (5%) CMS-Mixed patients in our cohort respectively. The cohort included 5 (5%) BRAF, 51 (50%) KRAS, and 63 (62%) TP53 mutated patients and 5 (5%) MSI high patients. Median survival was 18.8, 117.2, 125.7 and 119 months for CMS1, CMS2, CMS3, and CMS4 patients respectively, with insufficient events in CMS-mixed for calculation (p = 0.15). CMS1 patients had a significantly shorter survival compared to the other cohorts (p = 0.02), with 2 of 5 of these patients having received immunotherapy. 40% (2,0) CMS1, 52% (7,8) of CMS2, 15% (1,1) of CMS3, 59% (13,15) of CMS4, and 40% (1,1) of CMS-Mixed presented with or developed metastatic disease respectively. When divided into mutation groups, median survival was 43 versus 119, 119 versus 117, and 126 versus 119 months for BRAF, KRAS, and TP53 mutated and wild type patients respectively (p = 0.18, p = 0.48, p = 0.93). Evaluation of TMB and MSI status did not reveal significant differences in outcomes (p = 0.54, p = 0.7), with median survival of 126 months versus 117 in TMB high versus low patients and unreached versus 119 months in MSI versus MSS patients respectively. Of note, 3 of the 5 MSI patients were also CMS1, with the other two coming from CMS4 and CMS-mixed cohorts. CMS classification and tumor mutation status are associated with differential outcomes for rectal cancer patients, with some groups having a large likelihood of developing metastatic disease. Further work on optimizing and personalizing treatments for these high-risk populations is necessary.

Long-Term Outcome of Rectal Cancer Patients Treated by High-Dose Radiotherapy and Concurrent Chemotherapy

To explore the therapeutic efficacy and adverse effects of high-dose radiotherapy concurrently with chemotherapy in treating patients with non-metastatic rectal cancer. Patients were enrolled if they were diagnosed with stage I-III rectal adenocarcinoma, refused surgery and received high-dose pelvic radiotherapy and concurrent chemotherapy instead. Their clinical data were retrospectively analyzed for calculating local control and survival rates. Treatment related toxicities was evaluated according to the Common Terminology Criteria for Adverse Events (version 5.0). Between April 2006 and February 2021, a total of 93 patients in our medical center were eligible for this study, with a median age of 61 (range, 21-84) years. Of those, 86 (92.5%) patients had tumors located within 5 cm of the anal verge. There were 8 (8.6%), 30 (32.3%) and 55 (59.1%) patients diagnosed with stage I, II and III, respectively. All patients received fluorouracil-based chemotherapy (single-agent fluorouracil or FOLFOX regimen). The irradiation techniques included three-dimensional conformal and intensity-modulated radiation therapy. The median total radiation dose for gross tumor volume (GTV) was 80 (range, 60-90) Gy. The 15 (16.1%) patients refusing surgery before treatment received one course of radiation (60-70 Gy/30-35 Fr). And a 2-course radiation (Course 1, 45-50 Gy/25 Fr; Course 2: 24-40 Gy/12-20 Fr) were given to the 78 (83.9%) patients who failed to achieve clinical complete remission (cCR) after neoadjuvant chemoradiotherapy but still refused surgery, with a median interval of 79 (range, 35-195) days. The median follow-up duration was 66 (range, 10-161) months. The 3- and 5-year overall survival (OS) rates for all patients were 90.5% and 72.7%, respectively. The clinical complete remission rate at the end of chemoradiotherapy was 69.9%. Colostomy was performed in the 14 patients whose rectal tumor did not attain cCR or progressed. There was no grade 4/5 severe acute toxicity. No patient suffered from intestinal perforation. Only one patient developed anal stenosis. Because of rectal bleeding, blood transfusion was performed in 7 patients, and one patient underwent an enterostomy. High-dose radiotherapy concurrent with chemotherapy brought encouraging survival outcomes, satisfactory organ preservation and acceptable short- and long-term side effects. It might be a safe and non-invasive alternative to abdominoperineal resection in rectal cancer patients refusing or unsuitable for surgery, especially for those with a low-position tumor.

Features and outcomes of rectal cancer patients treated in a hospital in Bogotá, Colombia: a retrospective cohort study

Rectal cancer is an increasing disease worldwide. The outcomes of its treatment are related to the preoperative characteristics of the patient. The objective of this study was to describe sociodemographic, clinical and surgical characteristics and outcomes of patients operated on for rectal cancer at Hospital Universitario Mayor Méderi (HUM) during the period within 2013–2017.A retrospective descriptive cohort-type study was carried out by consulting the clinical records of patients above the age of 18 years with a clinical/histopathological diagnosis of rectal cancer and an institutional follow-up in those who underwent surgery with laparoscopic anterior resection of the rectum carried out by the coloproctology service of the HUM between 2013 and 2017. For statistical analysis, the SPSS V22 program was used.Data from 133 patients were collected during the study period, most of them male, with more frequent involvement of the lower rectum. Complications occurred in 25% of the patients. Conversion rate to open surgery was 8.6%, in-hospital death was associated with cardiovascular comorbidity, corticosteroid uses and with the presence of complications. Sociodemographic characteristics of the patients were similar to the world population. The institution has a low prevalence of anastomotic dehiscence, global complications are comparable with international statistics.

Genomic-driven nutritional interventions for radiotherapy-resistant rectal cancer patient

Radiotherapy response of rectal cancer patients is dependent on a myriad of molecular mechanisms including response to stress, cell death, and cell metabolism. Modulation of lipid metabolism emerges as a unique strategy to improve radiotherapy outcomes due to its accessibility by bioactive molecules within foods. Even though a few radioresponse modulators have been identified using experimental techniques, trying to experimentally identify all potential modulators is intractable. Here we introduce a machine learning (ML) approach to interrogate the space of bioactive molecules within food for potential modulators of radiotherapy response and provide phytochemically-enriched recipes that encapsulate the benefits of discovered radiotherapy modulators. Potential radioresponse modulators were identified using a genomic-driven network ML approach, metric learning and domain knowledge. Then, recipes from the Recipe1M database were optimized to provide ingredient substitutions maximizing the number of predicted modulators whilst preserving the recipe’s culinary attributes. This work provides a pipeline for the design of genomic-driven nutritional interventions to improve outcomes of rectal cancer patients undergoing radiotherapy.

ThTP7.1 An audit of outcome of rectal cancer patients who were offered primary surgery. Are we following NICE guidelines for management of rectal cancer? –A retrospective cross sectional study at a District General Hospital

Abstract Aims The aim of this audit was to analyse whether we are following NICE guidelines regarding management of the rectal cancer. We also analysed the outcome of rectal cancer patients who were offered primary surgery. Methods It was a retrospective study in design. We evaluated 47 patients out of 266 patients who were registered as rectal cancer between 2017 to 2022. Only patients who were offered primary surgery were included. Patients with metastatic cancer, those unfit for chemoradiotherapy and those who were offered neoadjuvant therapy were excluded. Results We identified 47 patients with rectal cancer for evaluation. The mean age at presentation was 72 years. 65.95% (n=31/47) were men, 34.05 % (n=16/47) were women. After a median follow of 34 months, local recurrence rate was noted in 24% and distant metastasis in 32%. We also noted that 52% of the patients were disease free and total mortality of 12%. Conclusion Preoperative chemoradiotherapy comprises a vital part of the management part for rectal cancer patients. Evidence has showed that it decreases the local recurrence rate and increases the overall disease free survival. In our study, we found that compliance to the NICE guidelines was not satisfactory and outcome results were not at par with National Cancer Excellence centre's of the United Kingdom. The recommendation was to follow the updated NICE guidelines in order to standardize the treatment throughout the United Kingdom and for better outcome results.