Rectal cancer surgery: A brief history

Navigating through novelties concerning mCRC treatment-the role of immunotherapy, chemotherapy, and targeted therapy in mCRC

Over the course of nearly six decades since the inception of initial trials involving 5-FU in the treatment of mCRC (metastatic colorectal cancer), our progressive comprehension of the pathophysiology, genetics, and surgical techniques related to mCRC has paved the way for the introduction of novel therapeutic modalities. These advancements not only have augmented the overall survival but have also positively impacted the quality of life (QoL) for affected individuals. Despite the remarkable progress made in the last two decades in the development of chemotherapy, immunotherapy, and target therapies, mCRC remains an incurable disease, with a 5-year survival rate of 14%. In this comprehensive review, our primary goal is to present an overview of mCRC treatment methods following the latest guidelines provided by the National Comprehensive Cancer Network (NCCN), the American Society of Clinical Oncology (ASCO), and the American Society of Colon and Rectal Surgeons (ASCRS). Emphasis has been placed on outlining treatment approaches encompassing chemotherapy, immunotherapy, targeted therapy, and surgery's role in managing mCRC. Furthermore, our review delves into prospective avenues for developing new therapies, offering a glimpse into the future of alternative pathways that hold potential for advancing the field.

Watch & wait - Post neoadjuvant imaging for rectal cancer

Rectal cancer management has evolved over the past decade with the emergence of total neoadjuvant therapy (TNT). For select patients who achieve a clinical complete response following TNT, organ preservation by means of the watch-and-wait (WW) strategy is an increasingly adopted alternative that preserves rectal function and quality of life without compromising oncologic outcomes. Recently, published 5-year results from the OPRA trial demonstrated that organ preservation can be achieved in approximately half of patients managed with the WW strategy, with most local regrowth events occurring within two years. Considering the potential for local regrowth, the implementation of the WW strategy mandates rigorous clinical and radiographic surveillance. Magnetic resonance imaging (MRI) serves as the conventional imaging modality for local staging and surveillance of rectal cancer given its excellent soft-tissue resolution. This review will discuss the current evidence for the WW strategy and the role of restaging rectal MRI in determining patient eligibility for this strategy. Restaging rectal MRI acquisition parameters and treatment response assessment, including important factors to assess, pitfalls, and classification systems, will be discussed in the context of the WW strategy.

A deep neural network predictor to predict the sensitivity of neoadjuvant chemoradiotherapy in locally advanced rectal cancer

Neoadjuvant chemoradiotherapy (NCRT) is widely used for locally advanced rectal cancer (LARC). This study aimed to conduct an effective model to predict NCRT sensitivity and provide guidance for clinical treatment. Biomarkers for NCRT sensitivity were identified by applying transcriptome profiles using logistic regression and subsequently screened out by Spearman correlation analysis and four machine learning algorithms. A deep neural network (DNN) predictor was constructed by using in-house dataset and validated in two independent datasets. Additionally, a web-based program was developed. Wnt/β-catenin signaling and linoleic acid metabolism (LA) pathways were associated with NCRT sensitivity and prognosis in LARC, antagonistically. A DNN predictor with an 18-gene signature was conducted within in-house datasets. In two validation cohorts, area under ROC curve (AUC) achieved 0.706 and 0.897. The DNN subtypes were significantly associated with NCRT sensitivity, survival status et al. Moreover, NK and cytotoxic T cells were observed contribution to NCRT sensitivity while regulatory T, myeloid-derived suppressor cells and dysfunction of CD4 T effector memory cells could impede NCRT response. A DNN predictor could predict NCRT sensitivity in LARC and stratify LARC patients with different clinical and immunity characteristic.

Contemporary management of rectal cancer

The management of rectal cancer has undergone significant changes over the past 50 years, and this has been associated with major improvements in overall outcomes and quality of life. From standardization of total mesorectal excision to refinements in radiation delivery and shifting of chemoradiotherapy treatment to favor a neoadjuvant approach, as well as the development of targeted chemotherapeutics, these management strategies have continually aimed to achieve locoregional and systemic control while limiting adverse effects and enhance overall survival. This article highlights evolving aspects of rectal cancer therapy including improved staging modalities, total neoadjuvant therapy, the role of short-course and more selective radiotherapy strategies, as well as organ preservation. We also discuss the evolving role of minimally invasive surgery and comment on lateral pelvic lymph node dissection.

Key message

Rectal cancer management is constantly evolving through refinements in radiation timing and delivery, modification of chemoradiotherapy treatment schedules, and increasing utilization of minimally invasive surgical techniques and organ preservation strategies. This manuscript aims to provide a synopsis of recent changes in the management of rectal cancer, highlighting contemporary modifications in neoadjuvant approaches and surgical management to enhance the knowledge of surgeons who care for this challenging population.

Watch-and-Wait Approach to Rectal Cancer: The Role of Imaging

The diagnosis and treatment of rectal cancer have evolved dramatically over the past several decades. At the same time, its incidence has increased in younger populations. This review will inform the reader of advances in both diagnosis and treatment. These advances have led to the watch-and-wait approach, otherwise known as nonsurgical management. This review briefly outlines changes in medical and surgical treatment, advances in MRI technology and interpretation, and landmark studies or trials that have led to this exciting juncture. Herein, the authors delve into current state-of-the-art methods to assess response to treatment with MRI and endoscopy. Currently, these methods for avoiding surgery can be used to detect a complete clinical response in as many as 50% of patients with rectal cancer. Finally, the limitations of imaging and endoscopy and future challenges will be discussed.

Gene-expression profiles of pretreatment biopsies predict complete response of rectal cancer patients to preoperative chemoradiotherapy

Purpose

Preoperative (neoadjuvant) chemoradiotherapy (CRT) and total mesorectal excision is the standard treatment for rectal cancer patients (UICC stage II/III). Up to one-third of patients treated with CRT achieve a pathological complete response (pCR). These patients could be spared from surgery and its associated morbidity and mortality, and assigned to a “watch and wait” strategy. However, reliably identifying pCR based on clinical or imaging parameters remains challenging.

Experimental design

We generated gene-expression profiles of 175 patients with locally advanced rectal cancer enrolled in the CAO/ARO/AIO-94 and -04 trials. One hundred and sixty-one samples were used for building, training and validating a predictor of pCR using a machine learning algorithm. The performance of the classifier was validated in three independent cohorts, comprising 76 patients from (i) the CAO/ARO/AIO-94 and -04 trials (n = 14), (ii) a publicly available dataset (n = 38) and (iii) in 24 prospectively collected samples from the TransValid A trial.

Results

A 21-transcript signature yielded the best classification of pCR in 161 patients (Sensitivity: 0.31; AUC: 0.81), when not allowing misclassification of non-complete-responders (False-positive rate = 0). The classifier remained robust when applied to three independent datasets (n = 76).

Conclusion

The classifier can identify >1/3 of rectal cancer patients with a pCR while never classifying patients with an incomplete response as having pCR. Importantly, we could validate this finding in three independent datasets, including a prospectively collected cohort. Therefore, this classifier could help select rectal cancer patients for a “watch and wait” strategy.

Translational relevance

Forgoing surgery with its associated side effects could be an option for rectal cancer patients if the prediction of a pathological complete response (pCR) after preoperative chemoradiotherapy would be possible. Based on gene-expression profiles of 161 patients a classifier was developed and validated in three independent datasets (n = 76), identifying over 1/3 of patients with pCR, while never misclassifying a non-complete-responder. Therefore, the classifier can identify patients suited for “watch and wait”.

A practical framework for the targeted use of total neoadjuvant therapy for rectal cancer

Total neoadjuvant therapy (TNT) for rectal cancer is the preoperative delivery of radiation or chemoradiotherapy as well as systemic chemotherapy for the purpose of improving treatment completion rates and decreasing toxicity, maximizing the primary tumor response, and improving survival for patients with rectal cancer. This review summarizes the data surrounding TNT, including several recent randomized controlled trials. Moreover, it reviews the literature regarding high-quality surgery and the role of radiation and chemotherapy in the treatment of rectal cancer in the modern era. Finally, it presents an evidence-based protocol for the selective use of TNT in the treatment of patients with rectal cancer.

Quality of Life after Rectal Cancer Resection Comparing Anterior Resection, Abdominoperineal Resection, and Complicated Cases

<b><i>Introduction:</i></b> Compared to abdominoperineal resection (APR), sphincter preservation using low anterior resection (AR) for rectal cancer (RC) implies the risk of impaired functional outcome and postoperative complications associated with a persistent or additionally required ostomy. The aim of our study was to compare quality of life (QoL) after AR and APR with a special separate analysis of AR patients with a stoma. <b><i>Methods:</i></b> QoL of 84 APR, 356 AR, and 29 AR patients with complications and an additional stoma, termed converted therapy (COT) patients, was compared with regard to groups and effect of radiotherapy (RT). All patients received rectal resection between 1998 and 2013, and 47% of the patients had RT. QoL was assessed using extended EORTC QLQ-C30 and -CR38 questionnaires. <b><i>Results:</i></b> Questionnaires from 57 APR, 165 AR, and 25 COT patients alive were evaluated after a median time of 4 years after surgery. Global health status was equally high in AR and APR patients (score: 67), whereas COT patients turned out with a significantly lower score of 50 (<i>p</i> = 0.007). Compared to APR and COT, AR patients revealed less symptoms and higher functionality, especially for physical, role, and social functioning (<i>p</i> &#x3c; 0.001). The reduction of QoL instances was significant in the COT group and in all patients treated by RT. <b><i>Conclusion:</i></b> QoL after RC resection may be further improved by avoiding additionally required ostomy after AR but also RT by a better individual selection of qualified patients. Qualification parameters urgently need to be defined by prospective studies.

Efficacy and safety of wait and see strategy versus radical surgery and local excision for rectal cancer with cCR response after neoadjuvant chemoradiotherapy: a meta-analysis

Background

Neoadjuvant therapy can shrink tumors, increase anus preservation rate, and protect anal function. Radical surgery need cut off the diseased bowel, clean up the lymph nodes, and then restore bowel function. It could bring traumatic effect and poor postoperative quality of life to the patient. Local resection requires removal of the diseased bowel with circular negative margin. The surgical trauma is small, and the postoperative quality of life is good. In this meta-analysis, we aimed to evaluate the efficacy and safety between wait and see strategy (WS), radical surgery (RS), and local excision (LE) of rectal cancer patients with clinical complete response (cCR) response after neoadjuvant chemoradiotherapy.

Methods

We searched PubMed, Cochrane Library, CNKI (China National Knowledge Infrastructure), and Wanfang databases to compare wait and see strategy with radical surgery and local excision for rectal cancer with cCR response after neoadjuvant chemoradiotherapy up to March 2020. We collected the data of local recurrence, distant metastasis, cancer-related death, overall survival, and disease-free survival and used RevMan 5.0 to carry out the meta-analysis. Continuous data were evaluated by the standardized mean differences (SMD) with 95% confidence intervals (95% CIs), and dichotomous data were evaluated by relative risks (ORs or RRs) with 95% CIs. We aimed to compare the advantages and disadvantages of the three groups.

Results

Eleven English studies with 1131 patients were included. There were 412 patients in WS group, 678 patients in RS group, and 41 patients in LE group. WS group had a higher local recurrence rate than RS group (OR 7.32, 95% CI 3.58 to 14.95, P < 0.001). There was no significant difference in the other data between the three groups.

Conclusion

Compared with the RS group, the WS group had an increased risk of local recurrence. However, the WS group had a similar DFS and OS compared with the RS group and the local excision group. Hence, we speculated that the WS group would have similar results as the surgery group for patients with cCR status.

Management of Rectal Cancer

Rectal cancer is often presented with a dizzying array of treatment recommendations. This article clarifies and simplifies this common clinical problem from the surgical perspective. Treatment of rectal cancer requires an understanding of presenting stage (early or advanced) and location (high or low) to provide oncologic sound treatment decisions. Surgical treatment requires a minimum of 1 cm distal margin, careful clearance of the mesorectum and radial margin using total mesorectal excision technique, and 12 or more regional lymph nodes harvested and analyzed. Appropriate and effective multimodality treatments exist and must be used based on sound guidelines as outlined.

[Intersphincteric resection for stage I-III low rectal cancer is an oncologically safe alternative to extralevator abdomino-perineal rectal resection]

AIM

To compare oncologic efficiency of intersphincteric resections and extralevator abdominoperineal excisions in surgical treatment of low rectal cancer.

METHODS

Between 2006 and 2015 in Department of colorectal and pelvic floor surgery (Russian scientific center of surgery n.a. acad. B.V. Petrovsky) and in Clinic of Colorectal and Minimally invasive surgery (Sechenov First Moscow State Medical University) 40 consecutive patients underwent intersphincteric resection (ISR) and 31 underwent extralevator abdominoperineal excision (EAPE). All patients had low rectal cancer staged I-III within 5 cm from the anal verge.

RESULTS

Circular resection margin >1 mm was achieved in 95% and 84% of patients after ISR and EAPR correspondingly (p=0.002), negative distal resection margin was achieved in 95% of ISR patients. In ISR group mean distance from the lower tumor edge to the distal resection margin was 1,17±0,78 cm. Colo-anal anastomosis leak rate was 17%. The 3-year disease-free survival in ISR group was 97%, 5-year disease-free survival was 93%. The 5-year disease-free survival in stage III for ISR group was 71,4%. In 98% of ISR patients complete restoration of bowel continuity was performed.

The evolution of pelvic dissection for rectal cancer from blunt dissection to total mesorectal excision

"Modern" rectal cancer treatment began in the 18th century. However, initial results of the pioneer surgeons were very poor. During the next several decades, significant progress was made towards the cure of rectal cancer. Improvements have included lowering mortality, reducing recurrence, and optimizing functional outcomes. This article reviews the individuals and their advancements in rectal cancer treatment. It describes the changes in the surgical approach for tumor resection, the study of the lymphatic spread of rectal cancer and the advances in sphincter preservation procedures from the era of blunt dissection until the paradigm changing revolution of total mesorectal excision.

Total Mesorectal Excision, an erroneous anatomical term for the gold standard in rectal cancer treatment

In 1986 Professor R J Heald published in The Lancet his new technique which he called Total Mesorectal Excision; today this is the gold standard for the surgical management of rectal cancer. In Total Mesorectal Excision (TME), the mesorectum is the term used to describe all the peri-rectal connective tissue including the posterior sheath of the endopelvic fascia containing the peri-rectal neurovascular structures. However, the mesenterium is a defined structure composed of a double layer of peritoneum which does not include the endopelvic fascia and the lateral rectal stalks, so these should not be included in the term 'mesorectum'. In our globalized medical culture it is important to use anatomic terms approved by the International Federation of Associations of Anatomists, as contained in the Terminologia Anatomica produced by the Federative International Programme for Anatomical Terminology (FIPAT). The term mesorectum is not listed in the Terminologia Anatomica.

Organ preservation in rectal cancer: current status and future perspectives

With the introduction of population screening initiatives, more patients may be amenable to local, transanal excision (LE) of early-stage rectal cancer. The most important drawback of LE is the risk of understaging node-positive disease. The most powerful predictors of node-positive disease are lymphatic invasion, submucosal invasion depth and width, tumor budding and poor differentiation. Therefore, LE should be reserved for low-risk T1 tumors in those reluctant or unable to undergo major surgery. Neoadjuvant chemoradiation followed by LE for T2 tumors allows adequate local control, and is currently being compared with anterior resection alone in randomized trials. A mere watchful waiting approach has been proposed in clinical complete responders to chemoradiation. However, given the very poor accuracy of current imaging modalities to predict a true pathological complete response, this strategy should not be offered outside of well-controlled trials.

Current concepts in rectal cancer

The history of rectal cancer management informs current therapy and points us in the direction of future improvements. Multidisciplinary team management of rectal cancer will move us to personalized treatment for individuals with rectal cancer in all stages.

Stimulation of the efferent limb before ileostomy closure: a randomized clinical trial

BACKGROUND

Postoperative ileus is the most common complication after ileostomy closure with an increase in morbidity, hospital stay, and health care costs.

OBJECTIVE

The aim of this study is to assess the utility of a new technique for reducing postoperative ileus after protective ileostomy closure.

DESIGN

This is a prospective randomized study registered at ClinicalTrials.gov (NCT01881594). Patients were randomly assigned to undergo either stimulation through the efferent limb of the ileostomy before surgery or nonstimulation before surgery.

SETTING

This study was conducted at the Department of Surgery of the Virgen de la Arrixaca Clinical University Hospital (Murcia).

PATIENTS

Seventy patients underwent surgery for ileostomy closure. In 35 patients, during the 2 weeks before surgery, daily stimulation of the defunctionalized stomal segment was performed by using a thick solution (500 mL of physiological saline associated with 30 g of thickening agent, Nestle Resource, Vevey, Switzerland). In the other 35 patients, stimulation was not performed before surgery.

MAIN OUTCOME MEASURES

The primary outcome was postoperative ileus. The secondary outcomes included time to tolerating a diet and postoperative stay.

RESULTS

Both groups of patients were homogenous for demographic data, characteristics of the first rectal cancer operation, and intersurgery periods. After ileostomy closure, the stimulated group of patients had an earlier return to oral tolerance (1.06 vs 2.57 days; p = 0.007) and passage of flatus or stool (1.14 vs 2.85 days; p <0.001) than the nonstimulated group of patients. The incidence of postoperative ileus (2.85% vs 20%; p = 0.024) and hospital stay (2.49 vs 4.61 days; p = 0.002) was also lower in the stimulated patients.

LIMITATIONS

Small numbers of patients means that no definitive statements can be made regarding the effectiveness of this technique.

CONCLUSIONS

Stimulation of the efferent limb of the ileostomy before closure is a safe technique that reduces postoperative ileus and fosters early intestinal transit and oral tolerance with a shorter postoperative hospital stay.

Progress in rectal cancer treatment

The dramatic improvement in local control of rectal cancer observed during the last decades is to be attributed to attention to surgical technique and to the introduction of neoadjuvant therapy regimens. Nevertheless, systemic relapse remains frequent and is currently insufficiently addressed. Intensification of neoadjuvant therapy by incorporating chemotherapy with or without targeted agents before the start of (chemo)radiation or during the waiting period to surgery may present an opportunity to improve overall survival. An increasing number of patients can nowadays undergo sphincter preserving surgery. In selected patients, local excision or even a "wait and see" approach may be feasible following active neoadjuvant therapy. Molecular and genetic biomarkers as well as innovative imaging techniques may in the future allow better selection of patients for this treatment option. Controversy persists concerning the selection of patients for adjuvant chemotherapy and/or targeted therapy after neoadjuvant regimens. The currently available evidence suggests that in complete pathological responders long-term outcome is excellent and adjuvant therapy may be omitted. The results of ongoing trials will help to establish the ideal tailored approach in resectable rectal cancer.