[Treatment of localized rectal cancer in 2024]. / Prise en charge du cancer du rectum localisé en 2024.

The management of localized rectal cancer has evolved significantly over the last two years. On one hand, intensification of treatments (radio-chemotherapy, chemotherapy, then surgery) for the most advanced tumors has shown an improvement in clinical results compared to less intense regiments. On the other hand, the possibility, as for prostate cancers, of opting for active surveillance without surgery in patients presenting a complete clinical response after a treatment phase, is now accepted. More recently, the Swiss recommendations for the surveillance of rectal cancer have been modified and now differ from those of colon cancers, by incorporating pelvic MRI and rectoscopy in addition, as well as special guidelines for tumors under active surveillance.

La prise en charge du cancer du rectum localisé a beaucoup évolué ces deux dernières années. D'un côté, l'intensification des traitements (radio-chimiothérapie, chimiothérapie, puis chirurgie) pour les tumeurs les plus avancées a montré une amélioration des résultats cliniques par rapport aux traitements moins intenses. De l'autre côté, la possibilité, comme pour les cancers de la prostate, d'opter pour une surveillance active sans chirurgie chez les patients présentant une réponse clinique complète après une phase de traitement est aujourd'hui acceptée. Plus récemment, les recommandations suisses pour la surveillance du cancer du rectum ont été modifiées et se différencient maintenant de celles des cancers du côlon, en incorporant IRM pelvienne et rectoscopie en sus, de même qu'un suivi spécial pour les tumeurs en surveillance active.

[Treatment strategies for recurrent rectal cancer]. / Therapiestrategien beim Rektumkarzinomrezidiv.

Multimodal treatment approaches with neoadjuvant radiotherapy and chemotherapy followed by oncological and total mesorectal excision (TME) have significantly reduced the recurrence rate even in locally advanced rectal cancer. Nevertheless, up to 10% of patients develop a local relapse. Surgical R0 resection is the only chance of a cure in the treatment of locally recurrent rectal cancer (LRRC). Due to the altered anatomy and physiology of the true pelvis as a result of the pretreatment and operations as well as the localization and extent of the recurrence, the treatment decision is individualized and remains a challenge for the interdisciplinary team. Even locally advanced tumors with involvement of adjacent structures can be treated in designated centers using multimodal treatment concepts with potentially curative intent.

Robotic transanal minimally invasive surgery (R-TAMIS): current evidence in the treatment of early rectal neoplasia.

INTRODUCTION: Robotic transanal minimally invasive surgery (R-TAMIS) was introduced in 2012 for the excision of benign rectal polyps and low grade rectal cancer. Ergonomic improvements over traditional laparoscopic TAMIS (L-TAMIS) include increased dexterity within a small operative field, with possibility of better surgical precision. We aim to collate the existing data surrounding the use of R-TAMIS to treat rectal neoplasms from cohort studies and larger case series, providing a foundation for future, large-scale, comparative studies. METHODS: Medline, EMBASE and Web of Science were searched as part of our review. Randomised controlled trials (RCTs), cohort studies or large case series (≥ 5 patients) investigating the use of R-TAMIS to resect rectal neoplasia (benign or malignant) were eligible for inclusion in our analysis. Quality assessment of included studies was performed via the Newcastle Ottawa Scale (NOS) risk of bias tool. Outcomes extracted included basic participant characteristics, operative details and histopathological/oncological outcomes. RESULTS: Eighteen studies on 317 participants were included in our analysis. The quality of studies was generally satisfactory. Overall complication rate from R-TAMIS was 9.7%. Clear margins (R0) were reported in 96.2% of patients. Local recurrence (benign or malignant) occurred in 2.2% of patients during the specified follow-up periods. CONCLUSION: Our review highlights the current evidence for R-TAMIS in the local excision of rectal lesions. While R-TAMIS appears to have complication, margin negativity and recurrence rates superior to those of published L-TAMIS series, comparative studies are needed.

PTEN and P-4E-BP1 might be associated with postoperative recurrence of rectal cancer patients undergoing concurrent radiochemotherapy.

BACKGROUND: Local recurrence after surgery and radiochemotherapy seriously affects the prognosis of locally advanced rectal cancer (LARC) patients. Studies on molecular markers related to the radiochemotherapy sensitivity of cancers have been widely carried out, which might provide valued information for clinicians to carry out individual treatment. AIM: To find potential biomarkers of tumors for predicting postoperative recurrence. METHODS: In this study, LARC patients undergoing surgery and concurrent radiochemotherapy were enrolled. We focused on clinicopathological factors and PTEN, SIRT1, p-4E-BP1, and pS6 protein expression assessed by immunohistochemistry in 73 rectal cancer patients with local recurrence and 76 patients without local recurrence. RESULTS: The expression of PTEN was higher, while the expression of p-4E-BP1 was lower in patients without local recurrence than in patients with local recurrence. Moreover, TNM stage, lymphatic vessel invasion (LVI), PTEN and p-4E-BP1 might be independent risk factors for local recurrence after LARC surgery combined with concurrent radiochemotherapy. CONCLUSIONS: This study suggests that PTEN and p-4E-BP1 might be potential biomarkers for prognostic prediction and therapeutic targets for LARC.

Risk factors of bleeding during rectal cancer surgery in obese patients in Japan.

BACKGROUND: According to several clinical trials for patients with rectal cancer, laparoscopic surgery significantly reduces intraoperative complications and bleeding compared with laparotomy and demonstrated comparable long-term results. However, obesity is considered one of the risk factors for increased surgical difficulty, including complication rate, prolonged operation time, and bleeding. METHODS: Patients with clinical pathological stage II/III rectal cancer and a body mass index of ≥25 kg/m2 who underwent laparotomy or laparoscopic surgery between January 2009 and December 2013 at 51 institutions participating in the Japan Society of Laparoscopic Colorectal Surgery were included. These patients were divided into major bleeding (>500 mL) group and minor bleeding (≤500 mL) group. The risk factors of major bleeding were evaluated by univariate and multivariate analyses. RESULTS: This study included 517 patients, of which 74 (19.9%) experienced major bleeding. Patient characteristics did not significantly differ between the two groups. The major bleeding group had a longer operative time (p < 0.001) and a larger tumor size than the minor bleeding group (p = 0.011). In the univariate analysis, age >65 years, laparotomy, operative time >300 min, and multivisceral resection were significantly associated with intraoperative massive bleeding. In the multivariate analysis, age >65 years (odds ratio [OR], 2.29; 95% confidence interval [CI], 1.13-4.82), laparotomy (OR, 20.82; 95% CI, 11.56-39.75), operative time >300 min (OR, 5.39; 95% CI, 1.67-132), and multivisceral resection (OR, 10.72; 95% CI, 2.47-64.0) showed to be risk factors for massive bleeding. CONCLUSION: Age >65 years, laparotomy, operative time >300 min, and multivisceral resection were risk factors for massive bleeding during rectal cancer surgery in patients with obesity.

Perfusion outcomes with near-infrared indocyanine green imaging system in laparoscopic total mesorectal excision for mid-rectal or low-rectal cancer (POSTER): a study protocol.

INTRODUCTION: Anastomotic leakage (AL) is defined as the failure of complete healing or disruption of the anastomosis subsequent to rectal cancer surgery, resulting in the extravasation of intestinal contents into the intra-abdominal or pelvic cavity. It is a serious complication of rectal cancer surgery, accounting for a considerable increase in morbidity and mortality. The use of fluorescence imaging technology in surgery allows surgeons to better evaluate blood perfusion. However, the conclusions of some existing studies are not consistent, so a consensus on whether the near-infrared indocyanine green (NIR-ICG) imaging system can reduce the incidence of AL is needed. METHODS: This POSTER trial is designed as a multicentre, prospective, randomised controlled clinical study adhering to the "population, interventions, comparisons, outcomes (PICO)" principles. It is scheduled to take place from August 2019 to December 2024 across eight esteemed hospitals in China. The target population consists of patients diagnosed with rectal cancer through pathological confirmation, with tumours located≤10 cm from the anal verge, eligible for laparoscopic surgery. Enrolled patients will be randomly assigned to either the intervention group or the control group. The intervention group will receive intravenous injections of ICG twice, with intraoperative assessment of anastomotic blood flow using the near-infrared NIR-ICG system during total mesorectal excision (TME) surgery. Conversely, the control group will undergo conventional TME surgery without the use of the NIR-ICG system. A 30-day follow-up period postoperation will be conducted to monitor and evaluate occurrences of AL. The primary endpoint of this study is the incidence of AL within 30 days postsurgery in both groups. The primary outcome investigators will be blinded to the application of ICG angiography. Based on prior literature, we hypothesise an AL rate of 10.3% in the control group and 3% in the experimental group for this study. With a planned ratio of 2:1 between the number of cases in the experimental and control groups, and an expected 20% lost-to-follow-up rate, the initial estimated sample size for this study is 712, comprising 474 in the experimental group and 238 in the control group. ETHICS AND DISSEMINATION: This study has been approved by Ethics committee of Beijing Friendship Hospital, Capital Medical University (approval number: 2019-P2-055-02). The results will be disseminated in major international conferences and peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04012645.

Analysis of risk characteristics for early progression and late progression in locally advanced rectal cancer patients: a large population-based and validated study.

BACKGROUND AND OBJECTIVE: The current study aimed to explore the factors influencing early progression (EP) and late progression (LP) in locally advanced rectal cancer (LARC) patients. METHODS: The patients were classified into EP and LP groups using one year as a cutoff. The random survival forest model was utilized to calculate the probability of time-to-progression. Besides, inverse probability of treatment weighting (IPTW) analysis and the Surveillance, Epidemiology, and End Results (SEER) were conducted to validate our results. RESULTS: Our study revealed that PNI, CEA level, and pathological stage were independent prognostic factors for PFS both in EP group and LP group. For EP group patients, Group 1 had the highest probability of progression at the 9th month of follow-up, while Group 2 exhibited the highest probability at the 6th month. Group 3, on the other hand, showed two peaks of progression at the 4th and 8th months of follow-up. As for LP group patients, Groups 4, 5, and 6 all exhibited peaks of progression between the 18th and 24th months of follow-up. Furthermore, our results suggested that PNI was also an independent prognostic factor affecting OS in both EP group and LP group. Finally, the analysis of IPTW and SEER database further confirmed our findings. CONCLUSIONS: Our results indicated a significant correlation between immune and nutritional status with PFS and OS in both EP and LP groups. These insights can aid healthcare professionals in effectively identifying and evaluating patients' nutritional status, enabling them to develop tailored nutrition plans and interventions.

An isolated vaginal metastasis from rectal cancer: a case report.

INTRODUCTION: Vaginal metastasis from colorectal cancer is a rare occurrence, typically associated with other metastatic lesions. Isolated metastasis is exceedingly uncommon, with only a few cases documented in the literature. Vaginal involvement in colorectal cancer primarily results from direct contiguous spread from the primary tumor. CASE PRESENTATION: We present the case of a 70-year-old African woman diagnosed with adenocarcinoma of the middle rectum. She underwent chemotherapy, radiotherapy, and subsequent anterior resection. After 2 months, an isolated metastasis of rectal cancer was identified in the lower third of the left vaginal wall, confirmed by biopsy. Colonoscopy ruled out colorectal recurrence. Thoraco-abdominal computed tomography scan showed no distant metastases. The patient underwent abdominoperineal resection, removing the lateral and posterior vaginal wall with free macroscopic margins and a definitive colostomy. The final histopathological analysis confirmed the diagnosis of moderately differentiated adenocarcinoma of the vagina, measuring 5 × 4.5 cm. The rectal wall was extrinsically invaded by the tumor down to the muscularis propria while respecting the rectal mucosa. Resection margins were negative. The patient was discharged 1 week postoperation with no complications. Adjuvant chemotherapy was indicated, and the patient is currently tolerating the treatment well. CONCLUSION: Vaginal metastases from colorectal cancer are extremely rare. A vigilant gynecological examination is recommended during the follow-up of colorectal cancer patients. Diagnosis can be challenging, especially if the metastatic lesion is small and asymptomatic, even after standard radiological examination. Surgical resection followed by chemotherapy is a valid option for patients with early isolated metastases.

Impact of tumor size on overall survival and cancer-specific survival of early-onset colon and rectal cancer: a retrospective cohort study.

PURPOSE: This study aimed to investigate the impact of tumor size on survival in early-onset colon and rectal cancer. METHODS: Early-onset colon and rectal cancer patients were identified from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015. Tumor size was analyzed as both continuous and categorical variables. Several statistical techniques, including restricted cubic spline (RCS), Cox proportional hazard model, subgroup analysis, propensity score matching (PSM), and Kaplan-Meier survival analysis, were employed to demonstrate the association between tumor size and overall survival (OS) and cancer-specific survival (CSS) of early-onset colon and rectal cancer. RESULTS: Seventeen thousand five hundred fifty-one (76.7%) early-onset colon and 5323 (23.3%) rectal cancer patients were included. RCS analysis confirmed a linear association between tumor size and survival. Patients with a tumor size > 5 cm had worse OS and CSS, compared to those with a tumor size ≤ 5 cm for both early-onset colon and rectal cancer. Notably, subgroup analysis showed that a smaller tumor size (≤ 50 mm) was associated with worse survival in stage II early-onset colon cancer, although not statistically significant. After PSM, Kaplan-Meier survival curves showed that the survival of patients with tumor size ≤ 50 mm was better than that of patients with tumor size > 50 mm. CONCLUSION: Patients with tumors larger than 5 cm were associated with worse survival in early-onset colon and rectal cancer. However, smaller tumor size may indicate a more biologically aggressive phenotype, correlating with poorer survival in stage II early-onset colon cancer.

Short-term and long-term outcomes after robotic radical surgery for rectal gastrointestinal stromal tumor.

BACKGROUND: The optimal approach for ensuring both complete resection and preservation of anal function in rectal gastrointestinal stromal tumor (GIST) remains unknown. The aim of this study was to clarify short-term and long-term outcomes after robotic radical surgery for rectal GIST. METHODS: A total of 13 patients who underwent robotic radical surgery for rectal GIST between December 2011 and April 2022 were included. All robotic procedures were performed using a systematic approach. A supplemental video of robotic radical surgery for rectal GIST is attached. The short-term outcome was the incidence of postoperative complications during the first 30 days after surgery. Surgical outcomes were retrieved from a prospective database. Long-term outcomes, including overall survival and recurrence-free survival, were determined in all patients. RESULTS: Median distance from the tumor to the anal verge was 4.0 cm. Surgical margins were negative in all patients. Two patients underwent neoadjuvant imatinib therapy. All patients underwent sphincter-preserving surgery. None underwent conversion to open or laparoscopic surgery. The incidence of postoperative Clavien-Dindo grade II and grade ≥ III complications was 7.7% and 0%, respectively. The median postoperative hospital stay was 7 days. Twelve patients (92.3%) underwent stoma closure within 5 months of the initial surgery. Median follow-up time was 76 months. The 5-year overall survival and recurrence-free survival rates were both 100%. None of the patients had recurrence. CONCLUSION: Short-term and long-term outcomes after radical robotic surgery for rectal GIST were favorable. Robotic surgery might be a useful surgical approach for rectal GIST.

Meta-analysis: loop ileostomy versus colostomy to prevent complications of anterior resection for rectal cancer.

PURPOSE: Anastomotic leakage is a serious complication of colorectal cancer surgery, prolonging hospital stays and impacting patient prognosis. Preventive colostomy is required in patients at risk of anastomotic fistulas. However, it remains unclear whether the commonly used loop colostomy(LC) or loop ileostomy(LI) can reduce the complications of colorectal surgery. This study aims to compare perioperative morbidities associated with LC and LI following anterior rectal cancer resection, including LC and LI reversal. METHODS: In this meta-analysis, the Embase, Web of Science, Scopus, PubMed, and Cochrane Library databases were searched for prospective cohort studies, retrospective cohort studies, and randomized controlled trials (RCTs) on perioperative morbidity during stoma development and reversal up to July 2023, The meta-analysis included 10 trials with 2036 individuals (2 RCTs and 8 cohorts). RESULTS: No significant differences in morbidity, mortality, or stoma-related issues were found between the LI and LC groups after anterior resection surgery. However, patients in the LC group exhibited higher rates of stoma prolapse (RR: 0.39; 95%CI: 0.19-0.82; P = 0.01), retraction (RR: 0.45; 95%CI: 0.29-0.71; P < 0.01), surgical site infection (RR: 0.52; 95%CI: 0.27-1.00; P = 0.05) and incisional hernias (RR: 0.53; 95%CI: 0.32-0.89; P = 0.02) after stoma closure compared to those in the LI group. Conversely, the LI group showed higher rates of dehydration or electrolyte imbalances(RR: 2.98; 95%CI: 1.51-5.89; P < 0.01), high-output(RR: 6.17; 95%CI: 1.24-30.64; P = 0.03), and renal insufficiency post-surgery(RR: 2.51; 95%CI: 1.01-6.27; P = 0.05). CONCLUSION: Our study strongly recommends a preventive LI for anterior resection due to rectal cancer. However, ileostomy is more likely to result in dehydration, renal insufficiency, and intestinal obstruction. More multicenter RCTs are needed to corroborate this.

A novel perineal exposure method in laparoscopic abdominal perineal resection of rectal cancer: a case series study.

BACKGROUND: Abdominal perineal resection (APR) of rectal cancer, also known as Mile's procedure, is a classic procedure for the treatment of rectal cancer. Through the improvement of surgical skills and neoadjuvant therapy, the sphincter-preserving rate in rectal cancer patients has improved, even in patients with ultralow rectal cancer who underwent APR in the past. However, APR cannot be completely replaced by low anterior resection (LAR) in reality. APR still has its indications, when the tumor affects the external sphincter, etc. Good perineal exposure in APR is difficult and can seriously affect surgical safety and the long-term prognosis. METHODS: We reviewed the records of 16 consecutive patients with rectal cancer who underwent APR at Anqing Municipal Hospital from January 2022 to April 2023, including 11 males and 5 females, with an average age of 64.8 ± 10.3 years. The perineal operation was completed with the Lone-Star® retractor-assisted (LSRA) exposure method. After incising the skin and subcutaneous tissue, a Lone-Star® retractor was placed, and the incision was retracted in surrounding directions with 8 small retractors, which facilitated the freeing of deep tissues. We dynamically adjusted the retractor according to the plane to fully expose the surgical field. RESULTS: All 16 patients underwent laparoscopic-assisted APR successfully. Thirteen procedures were performed independently by a single person, and the others were completed by two persons due to intraoperative arterial hemostasis. All specimens were free of perforation and had a negative circumferential resection margin (CRM). Postoperative complications occurred in 4 patients, including urinary retention in 1 patient, pulmonary infection in 1 patient, intestinal adhesion in 1 patient and peristomal dermatitis in 1 patient, and were graded as ClavienDindo grade 3 or lower and cured. No distant metastasis or local recurrence was found for any of the patients in the postoperative follow-up. CONCLUSIONS: The application of the LSRA exposure method might be helpful for perineal exposure during APR for rectal cancer, which could improve intraoperative safety and surgical efficiency, achieve one-person operation, and increase the comfort of operators.

Predictive role of preoperative sarcopenia for long-term survival in rectal cancer patients: A meta-analysis.

PURPOSE: To identify the predictive role of sarcopenia in long-term survival among rectal cancer patients who underwent surgery based on available evidence. METHODS: The Medline, EMBASE and Web of Science databases were searched up to October 20, 2023, for relevant studies. Overall survival (OS), disease-free survival (DFS) and cancer-specific survival (CSS) were the endpoints. Hazard ratios (HRs) and 95% confidence intervals (CIs) were combined to evaluate the association between sarcopenia and survival. RESULTS: Fifteen studies with 4283 patients were included. The pooled results demonstrated that preoperative sarcopenia significantly predicted poorer OS (HR = 2.07, 95% CI = 1.67-2.57, P<0.001), DFS (HR = 1.85, 95% CI = 1.39-2.48, P<0.001) and CSS (HR = 1.83, 95% CI = 1.31-2.56, P<0.001). Furthermore, subgroup analysis based on neoadjuvant therapy indicated that sarcopenia was a risk factor for worse OS and DFS in patients who received (OS: HR = 2.44, P<0.001; DFS: HR = 2.16, P<0.001) but not in those who did not receive (OS: HR = 2.44, P<0.001; DDFS: HR = 1.86, P = 0.002) neoadjuvant chemoradiotherapy. In addition, subgroup analysis based on sample size and ethnicity showed similar results. CONCLUSION: Preoperative sarcopenia is significantly related to poor survival in surgical rectal cancer patients and could serve as a novel and valuable predictor of long-term prognosis in these patients.

Which Treatment for Which Patient: Rectal Cancer Management After PROSPECT Trial.

Determining treatment options for patients with locally advanced rectal cancer after the PROSPECT trial data readout adds an important level to the decision-making process.

Comparison of early and late removal of the urinary catheter after rectal cancer surgery.

OBJECTIVE: This study is aiming to compare the results of early and late removal of urinary catheters after rectal cancer surgery. MATERIALS AND METHODS: Patients who undergone rectal cancer surgery in a single center were included in this prospective randomized study. The timing of the urinary catheter removal was randomized by a computer-assisted program and divided into 2 groups, which are early (first 48 h) and late (after 48 h). The primary outcome of this study was to compare the urinary retention and re-catheterization rates between patients with early and those with late catheter removal. RESULTS: Sixty-six patients were included in this study. The median age was 60 (31-88 years), and the patient group was predominantly male (n: 40, 60.9%). Urinary retention after catheter removal developed in 8 (12%) of 66 patients. There was no difference between the two groups in terms of the need for re-catheterization (14% vs. 10%, p: 0.63). All the patients who required re-catheterization (n: 8) and were discharged with a urinary catheter (n: 4) were male. When the male and female patients were evaluated separately, there was no difference in urinary retention in the early or late groups. CONCLUSIONS: Early or late removal of the catheter does not play a role in the development of urinary retention in patients undergoing rectal cancer surgery.

OBJETIVO: Comparar los resultados de la retirada precoz y tardía de la sonda urinaria tras la cirugía de cáncer rectal. MÉTODO: Estudio prospectivo aleatorizado que incluyó pacientes sometidos a cirugía de cáncer rectal en un único centro. El momento de la retirada de la sonda urinaria se aleatorizó y se dividió en dos grupos: primeras 48 horas y después de 48 horas. Se compararon las tasas de retención urinaria y de nueva cateterización entre los pacientes con retirada precoz y tardía de la sonda. RESULTADOS: Se incluyeron 66 pacientes, con una mediana de edad de 60 años (31-88 años) y predominio del sexo masculino (n = 40, 60.9%). Se produjo retención urinaria tras la retirada de la sonda en 8 (12%). No hubo diferencias entre los dos grupos en cuanto a necesidad de nueva cateterización (14% frente a 10%, p = 0.63). Todos los pacientes que precisaron un nuevo cateterismo (n = 8) y fueron dados de alta con una sonda urinaria (n = 4) eran varones. CONCLUSIONES: La retirada precoz o tardía de la sonda no influye en la aparición de retención urinaria en pacientes intervenidos de cáncer de recto.

Necrotizing fasciitis of the thigh secondary to perforated rectal cancer: the sciatic foramen as a route for infective spread.

Necrotizing fasciitis (NF) is a potentially life-threatening surgical emergency. It is a rapidly progressive infection of soft tissues, and mortality is related to the degree of sepsis and the general condition of the patient. It is a rare condition that requires a rapid diagnosis and surgical treatment is aggressive debridement. There are a small number of reported cases of perforation of a rectal malignancy leading to NF of the thigh. We present a case with rectal cancer in which the sciatic foramen had provided a channel for the spread of pelvic infection into the thigh.

La fascitis necrotizante es una emergencia quirúrgica potencialmente mortal. Es una infección de tejidos blandos rápidamente progresiva y la mortalidad está relacionada con el grado de sepsis y el estado general del paciente. Es una condición poco común que requiere un diagnóstico rápido, y el tratamiento quirúrgico consiste en un desbridamiento agresivo. Existe un pequeño número de casos notificados de perforación de neoplasia maligna de recto que conduce a fascitis necrotizante del muslo. Presentamos un caso de cáncer de recto en el cual el foramen ciático fue el canal para la propagación de la infección pélvica al muslo.

A combinatorial MRI sequence-based radiomics model for preoperative prediction of microsatellite instability status in rectal cancer.

This study aimed to develop an optimal radiomics model for preoperatively predicting microsatellite instability (MSI) in patients with rectal cancer (RC) based on multiparametric magnetic resonance imaging. The retrospective study included 308 RC patients who did not receive preoperative antitumor therapy, among whom 51 had MSI. Radiomics features were extracted and dimensionally reduced from T2-weighted imaging (T2WI), T1-weighted imaging (T1WI), diffusion-weighted imaging (DWI), and T1-weighted contrast enhanced (T1CE) images for each patient, and the features of each sequence were combined. Multifactor logistic regression was used to screen the optimal feature set for each combination. Different machine learning methods were applied to construct predictive MSI status models. Relative standard deviation values were determined to evaluate model performance and select the optimal model. Receiver operating characteristic (ROC) curve, calibration curve, and decision curve analyses were performed to evaluate model performance. The model constructed using the k-nearest neighbor (KNN) method combined with T2WI and T1CE images performed best. The area under the curve values for prediction of MSI with this model were 0.849 (0.804-0.887), with a sensitivity of 0.784 and specificity of 0.805. The Delong test showed no significant difference in diagnostic efficacy between the KNN-derived model and the traditional logistic regression model constructed using T1WI + DWI + T1CE and T2WI + T1WI + DWI + T1CE data (P > 0.05) and the diagnostic efficiency of the KNN-derived model was slightly better than that of the traditional model. From ROC curve analysis, the KNN-derived model significantly distinguished patients at low- and high-risk of MSI with the optimal threshold of 0.2, supporting the clinical applicability of the model. The model constructed using the KNN method can be applied to noninvasively predict MSI status in RC patients before surgery based on radiomics features from T2WI and T1CE images. Thus, this method may provide a convenient and practical tool for formulating treatment strategies and optimizing individual clinical decision-making for patients with RC.

Diagnostic value of one-stop CT energy spectrum and perfusion for angiogenesis in colon and rectum cancer.

OBJECTIVE: Evaluation of the predictive value of one-stop energy spectrum and perfusion CT parameters for microvessel density (MVD) in colorectal cancer cancer foci. METHODS: Clinical and CT data of 82 patients with colorectal cancer confirmed by preoperative colonoscopy or surgical pathology in our hospital from September 2019 to November 2022 were collected and analyzed retrospectively. Energy spectrum CT images were measured using the Protocols general module of the GSI Viewer software of the GE AW 4.7 post-processing workstation to measure the CT values of the arterial and venous phase lesions and the neighboring normal intestinal wall in a single energy range of 40 kev∼140 kev, and the slopes of the energy spectrum curves (λ) were calculated between 40 kev-90 kev; Iodine concentration (IC), Water concentration (WC), Effective-Z (Eff-Z) and Normalized iodine concentration (NIC) were measured by placing a region of interest (ROI) on the iodine concentration map and water concentration map at the lesion and adjacent to the normal intestinal wall.Perfusion CT images were scanned continuously and dynamically using GSI Perfusion software and analyzed by applying CT Perfusion 4.0 software.Blood volume (BV), blood flow (BF), surface permeability (PS), time to peak (TTP), and mean transit time (MTT) were measured respectively in the lesion and adjacent normal colorectal wall. Based on the pathological findings, the tumors were divided into a low MVD group (MVD < 35/field of view, n = 52 cases) and a high MVD group (MVD ≥ 35/field of view, n = 30 cases) using a median of 35/field of view as the MVD grouping criterion. The collected data were statistically analyzed, the subjects' operating characteristic curve (ROC) was plotted, and the area under curve (AUC), sensitivity, specificity, and Yoden index were calculated for the predicted efficacy of each parameter of the energy spectrum and perfusion CT and the combined parameters. RESULTS: The CT values, IC, NIC, λ, Eff-Z of 40kev∼140kev single energy in the arterial and venous phase of colorectal cancer in the high MVD group were higher than those in the low MVD group, and the differences were all statistically significant (p < 0.05). The AUC of each single-energy CT value in the arterial phase from 40 kev to 120 kev for determining the high or low MVD of colorectal cancer was greater than 0.8, indicating that arterial stage has a good predictive value for high or low MVD in colorectal cancer; AUC for arterial IC, NIC and IC + NIC were all greater than 0.9, indicating that in arterial colorectal cancer, both single and combined parameters of spectral CT are highly effective in predicting the level of MVD. The AUC of 40 kev to 90 kev single-energy CT values in the intravenous phase was greater than 0.9, and its diagnostic efficacy was more representative; The AUC of IC and NIC in venous stage were greater than 0.8, which indicating that the IC and NIC energy spectrum parameters in venous stage colorectal cancer have a very good predictive value for the difference between high and low MVDs, with the greatest diagnostic efficacy in IC.The values of BV and BF in the high MVD group were higher than those in the low MVD group, and the differences were statistically significant (P < 0.05), and the AUC of BF, BV, and BV + BF were 0.991, 0.733, and 0.997, respectively, with the highest diagnostic efficacy for determining the level of MVD in colorectal cancer by BV + BF. CONCLUSION: One-stop CT energy spectrum and perfusion imaging technology can accurately reflect the MVD in living tumor tissues, which in turn reflects the tumor angiogenesis, and to a certain extent helps to determine the malignancy, invasion and metastasis of living colorectal cancer tumor tissues based on CT energy spectrum and perfusion parameters.

Preoperative chemoradiotherapy in older patients with rectal cancer guided by comprehensive geriatric assessment within a multidisciplinary team-a multicenter phase II trial.

BACKGROUND: The purpose of this study was to evaluate the safety and efficacy of preoperative concurrent chemoradiotherapy (preCRT) for locally advanced rectal cancer in older people who were classified as "fit" by comprehensive geriatric assessment (CGA). METHODS: A single-arm, multicenter, phase II trial was designed. Patients were eligible for this study if they were aged 70 years or above and met the standards of "fit" (SIOG1) as evaluated by CGA and of the locally advanced risk category. The primary endpoint was 2-year disease-free survival (DFS). Patients were scheduled to receive preCRT (50 Gy) with raltitrexed (3 mg/m2 on days 1 and 22). RESULTS: One hundred and nine patients were evaluated by CGA, of whom eighty-six, eleven and twelve were classified into the fit, intermediate and frail category. Sixty-eight fit patients with a median age of 74 years were enrolled. Sixty-four patients (94.1%) finished radiotherapy without dose reduction. Fifty-four (79.3%) patients finished the prescribed raltitrexed therapy as planned. Serious toxicity (grade 3 or above) was observed in twenty-four patients (35.3%), and fourteen patients (20.6%) experienced non-hematological side effects. Within a median follow-up time of 36.0 months (range: 5.9-63.1 months), the 2-year overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS) rates were 89.6% (95% CI: 82.3-96.9), 92.4% (95% CI: 85.9-98.9) and 75.6% (95% CI: 65.2-86.0), respectively. Forty-eight patients (70.6%) underwent surgery (R0 resection 95.8%, R1 resection 4.2%), the corresponding R0 resection rate among the patients with positive mesorectal fascia status was 76.6% (36/47). CONCLUSION: This phase II trial suggests that preCRT is efficient with tolerable toxicities in older rectal cancer patients who were evaluated as fit based on CGA. TRIAL REGISTRATION: The registration number on ClinicalTrials.gov was NCT02992886 (14/12/2016).