Nonoperative Management of Rectal Cancer

Incidental Findings and Their Significance in Rectal MRI: UK Experience

ABSTRACT

Rectal MRI studies used to stage and guide surgical or nonsurgical management of rectal cancer may harbor incidental findings (IFs) of varying significance. St George's Hospital uses a four-sequence MRI protocol which does not employ diffusion-weighted imaging (DW-MRI).

OBJECTIVES

To determine the frequency and significance of incidental findings identified when using a rectal MRI protocol which does not employ DW-MRI.

METHODS

Retrospective analysis of rectal MRI study reports for IFs and stratifying their significance. Medical records were reviewed to clarify IFs of interest.

RESULTS

One hundred thirty-four studies met the inclusion criteria for the study (75 men, mean age 65). 51/134 (38%) of studies had IFs. Fifteen percent (n = 7/46) of baseline studies for a new cancer had significant IFs. The commonest IF was diverticular disease (n = 10); however, a bladder malignancy was also identified.

CONCLUSION

Clinically significant IFs exist in 12% of patients undergoing rectal MRI, and any type of IFs exist in 38% of patients undergoing rectal MRI studies. The rate of significant IFs is comparable with other authors both in rectal and prostate MRI but with fewer overall IFs, possibly due to the lack of DW-MRI sequences in our local protocol. Our study is the first to assess IFs using a rectal MRI protocol which does not employ DW-MRI, and the results should be considered by centers when planning their rectal MRI protocol.

The Landmark Series: Organ Preservation in Rectal Cancer-The Watch and Wait Strategy

Radical treatment of rectal cancer has evolved quite significantly over the last few decades with the development of optimal local disease staging with magnetic resonance (MR), refined surgical techniques including total mesorectal excision (TME) with or without sphincter-preservation, and multimodality treatment with the use of chemotherapy and radiation. While oncological outcomes have shown some significant improvements in terms of local disease control and distant metastases rates, complication rates and functional sequelae remain quite significant for patients undergoing TME surgery. In this setting, organ-preserving alternatives, including transanal local excision (TAE) and Watch and Wait (WW), have become increasingly attractive to patients in an attempt to avoid major surgery (TME) as an alternative treatment strategy with no oncological compromise. In the present narrative review, the fundamentals of selection and outcomes of patients undergoing WW will be covered to provide updated information for colorectal surgeons and surgical oncologists interested in this treatment alternative in clinical practice.

Trends in resection rates and postoperative mortality for gastrointestinal cancers between 2005 and 2020 in the Netherlands

AIM

This study assesses trends in resection rates and postoperative mortality for oesophageal, gastric, colon, rectal, periampullary and pancreatic cancer in the Netherlands.

METHODS

This retrospective cohort study included all patients with gastrointestinal cancer diagnosed in the period 2005-2020 as registered in the Netherlands Cancer Registry. Cochran-Armitage trend tests were used to assess trends in resection rates. Multivariable logistic regression analyses were used to assess the association between time period and resection rates and postoperative mortality and were stratified for nonmetastatic versus metastatic disease at initial diagnosis.

RESULTS

A total of 226 925 patients with nonmetastatic and 92 343 with metastatic disease were included. A lower likelihood of undergoing resection was observed for patients diagnosed between 2017 and 2020 as compared to 2005-2008 for nonmetastatic colon (OR=0.73; 95 %CI:0.68-0.79) and rectal cancer (OR=0.44; 95 %CI:0.40-0.48). In contrast, higher resection rates were observed for nonmetastatic gastric (OR=1.17; 95 %CI:1.03-1.32), periampullary (OR=2.44;95 %CI:2.09-2.84) and pancreatic cancer (OR=2.81; 95 %CI:2.51-3.15 comparing the same time periods). Patients with nonmetastatic disease diagnosed in 2017-2020 had a lower likelihood of 90-day postoperative mortality compared to 2005-2008 for all cancer types with ORs ranging between 0.27 (95 %CI:0.22-0.33, rectal cancer) and 0.60 (95 %CI:0.43-0.84, periampullary cancer). In colon and rectal cancer patients presenting with metastatic disease, resection rates and postoperative mortality significantly decreased over time.

CONCLUSION

Resection rates decreased for some gastrointestinal cancer types possibly due to the introduction of treatment strategies without resection (e.g. watchful waiting). Postoperative mortality decreased for all patients, possibly as a result of increased quality of care, and improved patient selection.

Do Surgical Oncology Multidisciplinary Team Meetings Make a Difference?

BACKGROUND

Multidisciplinary team (MDT) meetings are important but resource-expensive components of surgical and oncologic care. This cohort study investigated the effectiveness of surgical MDT meetings by assessing the predictability of MDT meeting recommendations, the degree that patient management plans are changed by discussion, and the incidence of recommendation implementation.

METHODS

Multidisciplinary team meetings at The Queen Elizabeth Hospital in South Australia were audited for upper gastrointestinal (UGI) and colorectal (CR) surgical units from August 2021 to June 2022. All cases referred for MDT meeting discussion were included. Prospectively obtained pre-MDT meeting management plans were compared with formal MDT meeting recommendations to assess for concordance and degree of change. Patient records were assessed after 8 months for MDT meeting recommendation implementation. Multivariable analysis of patient factors was performed to identify associations between MDT meeting recommendation predictability and implementation.

RESULTS

In 438 patient cases, discussed during 30 MDT meetings, 317 (72.37%) were correctly predicted. Specifically, 226 (51.6%) were correct with no change, 28 (6.39%) were correct with minor changes, 40 (9.13%) were correct with moderate changes, and 23 (5.25%) were correct with major changes. The UGI and CR cohorts differed significantly in moderate changes (P = 0.0217). The female patients were 1.62 times more likely than the male patients to have pre-MDT meeting management plans predicted (P = 0.0201). Formal MDT meeting recommendations were implemented in 380 (89.62%) cases.

CONCLUSIONS

The MDT meetings changed management for almost 1 in 2 patients discussed. Other than female sex, no identifiable patient factors increased the likelihood of predictability, and no factors predicted recommendation implementation.

The Role of Frailty in the Treatment of Locally Advanced Rectal Cancer

Owing to the gradual aging of today's population, an increase in the prevalence of frailty syndrome has been noticed. This complex state of health, characterized by decreased resilience and tolerance with concurrent increased vulnerability to stressors and adverse health-related factors, has drawn researchers' attention in recent years. Rectal cancer, which constitutes ~30% of all colorectal cancers, is a disease noticeably related to the elderly. In its locally advanced form, it is conventionally treated with trimodal therapy-neoadjuvant chemoradiotherapy followed by total mesorectal excision and adjuvant chemotherapy. Despite its good clinical outcomes and improvement in rectal cancer local control, as evidenced by clinical trials, it remains unclear if all frail patients benefit from that approach since it may be associated with adverse side effects that cannot be handled by them. As old patients, and frail ones even more noticeably, are poorly represented in the clinical trials describing outcomes of the standard treatment, this article aims to review the current knowledge on the trimodal therapy of rectal cancer with an emphasis on novel approaches to rectal cancer that can be implemented for frail patients.

The Role of Predictive and Prognostic MRI-Based Biomarkers in the Era of Total Neoadjuvant Treatment in Rectal Cancer

The role of magnetic resonance imaging (MRI) in rectal cancer management has significantly increased over the last decade, in line with more personalized treatment approaches. Total neoadjuvant treatment (TNT) plays a pivotal role in the shift from traditional surgical approach to non-surgical approaches such as 'watch-and-wait'. MRI plays a central role in this evolving landscape, providing essential morphological and functional data that support clinical decision-making. Key MRI-based biomarkers, including circumferential resection margin (CRM), extramural venous invasion (EMVI), tumour deposits, diffusion-weighted imaging (DWI), and MRI tumour regression grade (mrTRG), have proven valuable for staging, response assessment, and patient prognosis. Functional imaging techniques, such as dynamic contrast-enhanced MRI (DCE-MRI), alongside emerging biomarkers derived from radiomics and artificial intelligence (AI) have the potential to transform rectal cancer management offering data that enhance T and N staging, histopathological characterization, prediction of treatment response, recurrence detection, and identification of genomic features. This review outlines validated morphological and functional MRI-derived biomarkers with both prognostic and predictive significance, while also exploring the potential of radiomics and artificial intelligence in rectal cancer management. Furthermore, we discuss the role of rectal MRI in the 'watch-and-wait' approach, highlighting important practical aspects in selecting patients for non-surgical management.

Chemoradiation, Consolidation Chemotherapy, and Watch and Wait for Early Rectal Cancer

As watch and wait has become an attractive management alternative among patients with rectal cancer who achieve a clinical complete response to neoadjuvant chemoradiation, the focus of organ preservation has now shifted toward the use of this approach in patients with early rectal cancer. These patients would otherwise be treated without the use of neoadjuvant therapy for oncological reasons. The sole purpose of any neoadjuvant treatment here would be the achievement of a complete clinical response in an attempt to avoid total mesorectal excision. This has become particularly interesting after the incorporation of total neoadjuvant therapy regimens. These regimens have resulted in significantly higher rates of complete tumor regression and therefore become an interesting alternative among early rectal cancer patients where organ preservation is desired. The present review provides an overview of the currently available evidence and the preliminary experience with this rather controversial approach.

Outcomes of rectal cancer patients who refuse surgery after incomplete clinical response to neoadjuvant therapy

BACKGROUND AND OBJECTIVES

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.

METHODS

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.

RESULTS

One hundred seventy-one patients (Male 59%) were included with a median surveillance of 43 months. Twenty-nine patients (17%) refused TME and had shortened overall survival (OS). Twelve patients 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.

CONCLUSION

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.

Lights and shadows in the early-onset colorectal cancer management and research: An integrative perspective - Physician scientist with patient advocates

Early-onset colorectal cancer (age under 50 years) (EOCRC) is an entity of undeniable importance, both because of its growing incidence, and the population it affects. Other current reviews emphasize the essential points regarding the clinical management and knowledge of its molecular bases. However, we intend to go one step further. With the increased significance of patient participation and disease experience in mind, we have integrated the voice of the patient to show the weaknesses and the needs, and next steps in the advancement of knowledge and management of EOCRC. This integrative review of the different perspectives, clinical, research and the patients themselves, can therefore be defined as an integrative needs assessment. Hence, this may be a first step in working towards an essential homogeneity of definitions and action.

MDT-How it is important in rectal cancer

The concept of multidisciplinary team discussion of patient's care has been a part of routine medical practice for several decades [Monson et al. in Bull Am Coll Surg 101:45-46, 2016; NHS. Improving outcomes in colorectal cancer-the manual. (Guidance on commissioning cancer services-improving outcomes). 1997.]. The idea of bringing multiple specialties and ancillary services together to help optimize patient outcomes has been implemented in several clinical arenas from burns to physical medicine and rehabilitation to oncology. In the oncology realm, multidisciplinary tumor boards (MDTs) originated as a broad-based meeting that would permit the review and discussion of cancer patients to optimize treatment strategies [Cancer Co. Optimal Resources for Cancer Care: 2020 Standards. Chicago, IL: 2019.]. Over time, as further specialization occurred and clinical treatment algorithms have become more complex, multidisciplinary tumor boards have become more disease site specific. In this article we will discuss the importance of MDTs, specifically focusing on rectal cancer MDTs including their impact on treatment planning as well as the unique interplay of clinical specialties that provide internal quality control and improvement. Additionally, we will discuss some of the potential benefits of MDTs beyond the direct impact on patient care and review some of the challenges of implementation.

Predicting Neoadjuvant Treatment Response in Rectal Cancer Using Machine Learning: Evaluation of MRI-Based Radiomic and Clinical Models

BACKGROUND

Radiomics is an approach to medical imaging that quantifies the features normally translated into visual display. While both radiomic and clinical markers have shown promise in predicting response to neoadjuvant chemoradiation therapy (nCRT) for rectal cancer, the interrelationship is not yet clear.

METHODS

A retrospective, single-institution study of patients treated with nCRT for locally advanced rectal cancer was performed. Clinical and radiomic features were extracted from electronic medical record and pre-treatment magnetic resonance imaging, respectively. Machine learning models were created and assessed for complete response and positive treatment effect using the area under the receiver operating curves.

RESULTS

Of 131 rectal cancer patients evaluated, 68 (51.9%) were identified to have a positive treatment effect and 35 (26.7%) had a complete response. On univariate analysis, clinical T-stage (OR 0.46, p = 0.02), lymphovascular/perineural invasion (OR 0.11, p = 0.03), and statin use (OR 2.45, p = 0.049) were associated with a complete response. Clinical T-stage (OR 0.37, p = 0.01), lymphovascular/perineural invasion (OR 0.16, p = 0.001), and abnormal carcinoembryonic antigen level (OR 0.28, p = 0.002) were significantly associated with a positive treatment effect. The clinical model was the strongest individual predictor of both positive treatment effect (AUC = 0.64) and complete response (AUC = 0.69). The predictive ability of a positive treatment effect increased by adding tumor and mesorectal radiomic features to the clinical model (AUC = 0.73).

CONCLUSIONS

The use of a combined model with both clinical and radiomic features resulted in the strongest predictive capability. With the eventual goal of tailoring treatment to the individual, both clinical and radiologic markers offer insight into identifying patients likely to respond favorably to nCRT.

Nonoperative Management Following Complete Response in Rectal Cancer After Short-course Radiation Therapy and Consolidation Chemotherapy: Clinical Outcomes and Quality of Life Measures

PURPOSE

The purpose of his study was to report on a cohort of patients managed with nonoperative management (NOM) with a watch-and-wait strategy after achieving complete response (CR) to sequential short-course radiation therapy (SCRT) and consolidation chemotherapy.

METHODS

This was a retrospective study of patients treated SCRT and chemotherapy who achieved a CR and were managed with NOM. Bowel function was assessed with European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30, EORTC Quality of Life Questionnaire-Colorectal Cancer 29, and the low anterior resection syndrome (LARS) questionnaires. Endpoints included overall survival (OS), freedom from local failure (FFLF), freedom from distant metastasis, and disease-free survival (DFS).

RESULTS

Twenty-six patients met inclusion criteria. Seven (26.9%) patients developed local failure at a median of 6.8 months following CR, of which 5 were successfully salvaged. Median FFLF was not reached, with 6-month, 1-, and 2-year FFLF rates of 100.0%, 82.3%, and 71.3%. Median OS was not reached, with 6-month, 1-, and 2-year OS rates of 100%. Median DFS was not reached, with 6-month, 1-, and 2-year DFS rates of 100%, 95.0%, and 89.4%. Questionnaire response rate was 83.3%. Median LARS score was 27. Major, minor, and no LARS occurred in 3 (20%), 6 (40%), and 6 (40%) patients, respectively. There were no differences in questionnaire scores between patients who had the majority of their anal sphincter complex irradiated and those who did not.

CONCLUSION

NOM with a watch-and-wait strategy is safe and feasible in patients with locally advanced rectal cancer who achieve CR after sequential SCRT and chemotherapy, with evidence for good anorectal function.