New Frontiers in Management of Early and Advanced Rectal Cancer

Early Rectal Cancer: Advances in Diagnosis and Management Strategies

Colorectal cancer (CRC) is the second most prevalent cause of cancer-related death and the third most common cancer globally. Early-stage rectal cancer is defined by lesions confined to the bowel wall, without extension beyond the submucosa in T1 or the muscularis propria in T2, with no indication of lymph node involvement or distant metastasis. The gold standard for managing rectal cancer is total mesorectal excision (TME); however, it is linked to considerable morbidities and impaired quality of life. There is a growing interest in local resection and non-operative treatment of early RC for organ preservation. Local resection options include three types of transanal endoscopic surgery (TES): transanal endoscopic microsurgery (TEM), transanal endoscopic operations (TEO), and transanal minimally invasive surgery (TAMIS), while endoscopic resection includes endoscopic mucosal resection (EMR), underwater endoscopic mucosal resection (UEMR), and endoscopic submucosal dissection (ESD). Although the oncological outcome of local resection of early rectal cancer is debated in the current literature, some studies have shown comparable outcomes with radical surgery in selected patients. The use of adjuvant and neoadjuvant chemoradiotherapy in early rectal cancer management is also controversial in the literature, but a number of studies have reported promising outcomes. This review focuses on the available literature regarding diagnosis, staging, and management strategies of early rectal cancer and provides possible recommendations.

Evaluating the impact of adjuvant chemotherapy on survival outcomes in stage II rectal cancer: a retrospective cohort study

Background Rectal cancer, accounting for a significant proportion of colorectal malignancies, presents unique challenges in treatment. Surgery remains the primary curative approach, but recurrence rates post-surgery poses challenges. While neoadjuvant chemoradiation has improved outcomes, the role of adjuvant chemotherapy is still debated. Herein, we aimed to clarify the efficacy of adjuvant chemotherapy in patients with confirmed pathological stage II rectal cancer. Methods In this retrospective single-center study, we investigated the role of adjuvant chemotherapy in 173 patients with biopsy-proven stage II rectal adenocarcinoma. Participants received neoadjuvant chemoradiation followed by open TME surgery, with or without adjuvant chemotherapy. The study was conducted at Sina Hospital between January 2014 and 2019, and analyzed overall survival (OS) and disease-free survival (DFS) outcomes. Propensity score matching (PSM) was used to adjust for potential confounders. Survival outcomes were assessed using Cox proportional hazards models, and sensitivity analysis was conducted using doubly robust estimation. Results Before matching, 173 patients showed significantly improved overall survival (HR:0.33, 95%C:0.22-0.50, p < 0.001) and disease-free survival (HR:0.41, 95%CI:0.28-0.61, p < 0.001) with adjuvant chemotherapy. Age ≥ 70 years was associated with poorer overall survival (HR:1.76, 95%CI:1.08-2.88, p = 0.02). After matching, in 100 patients (50 with chemotherapy, 50 without), adjuvant chemotherapy remained significantly beneficial for both overall and disease-free survival (p < 0.001), while age ≥ 70 years continued to negatively impact overall survival. Conclusion Our findings suggest that adjuvant chemotherapy provides benefits in terms of OS and DFS in stage II rectal cancer following neoadjuvant chemoradiation and TME surgery. Further prospective studies are warranted to confirm these results and optimize treatment strategies.

MRI-based radiomics for preoperative prediction of recurrence and metastasis in rectal cancer

OBJECTIVES

To explore the value of multi-parametric MRI (mp-MRI) radiomic model for preoperative prediction of recurrence and/or metastasis (RM) as well as survival benefits in patients with rectal cancer.

METHODS

A retrospective analysis of 234 patients from two centers with histologically confirmed rectal adenocarcinoma was conducted. All patients were divided into three groups: training, internal validation (in-vad) and external validation (ex-vad) sets. In the training set, radiomic features were extracted from T2WI, DWI, and contrast enhancement T1WI (CE-T1) sequence. Radiomic signature (RS) score was then calculated for feature screening to construct a rad-score model. Subsequently, preoperative clinical features with statistical significance were selected to construct a clinical model. Independent predictors from clinical and RS related to RM were selected to build the combined model and nomogram.

RESULTS

After feature extraction, 26 features were selected to construct the rad-score model. RS (OR = 0.007, p < 0.01), MR-detected T stage (mrT) (OR = 2.92, p = 0.03) and MR-detected circumferential resection margin (mrCRM) (OR = 4.70, p = 0.01) were identified as independent predictors of RM. Then, clinical model and combined model were constructed. ROC curve showed that the AUC, accuracy, sensitivity and specificity of the combined model were higher than that of the other two models in three sets. Kaplan-Meier curves showed that poorer disease-free survival (DFS) time was observed for patients in pT3-4 stages with low RS score (p < 0.001), similar results were also found in pCRM-positive patients (p < 0.05).

CONCLUSION

The mp-MRI radiomics model can be served as a noninvasive and accurate predictors of RM in rectal cancer that may support clinical decision-making.

A modified method for precise anastomosis during laparoscopic low anterior resection for rectal cancer: the first clinical experience and application

BACKGROUND

There is no criterion to guide and evaluate the anastomosis of laparoscopic low anterior resection (LAR). We developed a new technique for precise anastomosis. This study endeavored to evaluate the effectiveness and safety of this new technology.

METHODS

Patients with mid-low rectal cancer who underwent laparoscopic LAR in our department were enrolled retrospectively between January 1, 2021 and July 1, 2023. During the LAR, the distance between the sacral promontory and the rectal stump was measured and used to determine the length of the sigmoid colon, which was preserved for anastomose. The demographic characteristics and short-term outcomes were analyzed.

RESULTS

Forty-nine patients (26 men, 23 women) with low and middle rectal cancer were retrospectively enrolled in the study. The distance of the tumor from the anal verge was 6.4 ± 2.7 cm. The operative time was 193 ± 42 min. All patients underwent precise anastomosis, among which 12 patients underwent freeing of the splenic flexure of the colon. According to our criteria, there was no redundant or tense state of the colon anterior to the sacrum after the anastomosis. Only one patient had a postoperative anastomotic leak (Grade B). All 15 patients receiving neoadjuvant chemoradiotherapy underwent terminal ileostomy. No postoperative death occurred within 30 days of the surgery. The median follow-up time in our study was 12 months. One patient developed a single metastasis in the right lobe of the liver in the eighth month after surgery and underwent microwave radiofrequency ablation, which did not recur in the four months of postoperative follow-up, and the rest of the patients survived disease-free without recurrence of metastasis.

CONCLUSIONS

Precise measurement of the proximal colon of the anastomosis can ensure accurate and convenient colorectal anastomosis and this may be a technique worthy of clinical application. However, its effectiveness needs to be further verified in a multicenter clinical trial.

Special Issue "Current Management of Early and Advanced Rectal Cancer"

As expected, surgery for low or ultralow disease remains a challenging issue in rectal cancer treatment [...].

Current Surgical Methods in Local Rectal Excision

Background

The treatment of rectal cancer has evolved with the advancement of surgical techniques. Less invasive approaches are becoming more accepted as the primary treatment method.

Summary

Such methods as transanal excision, transanal endoscopic microsurgery, and transanal minimally invasive surgery can reduce morbidity and mortality rates. However, not all patients are suitable candidates for these procedures, and proper diagnostics are necessary to establish indications. Compared to total mesorectal excision, transanal excision techniques have been shown to have fewer complications and comorbidities while still being able to remove cancerous tissue entirely. Transanal excision is the simplest method, where the operator removes visible rectal lesions. The basic principle of transanal endoscopic microsurgery is to dilate the rectum mechanically and by air insufflation and then use special surgical instruments to remove suspicious lesions under the vision of a telescope. Transanal minimally invasive surgery combines transanal endoscopic microsurgery and single-incision laparoscopic surgery, making the hard-to-reach proximal rectum accessible to classic laparoscopic instruments.

Key Message

Local excision techniques, when used as a monotherapy for treating patients with rectal cancer, have established themselves as a curative and less radical treatment for strictly selected patients with early rectal carcinoma, leading to improved quality of life. When combined with other modalities such as neoadjuvant chemoradiotherapy, total neoadjuvant therapy, and immunotherapy, transanal surgery can be offered to patients with locally advanced rectal cancer as part of the organ preservation strategy. This review will discuss the patient selection and technical aspects of transanal surgery, showcasing its current role in treating rectal carcinoma.