Suboptimal surgery and omission of neoadjuvant therapy for upper rectal cancer is associated with a high risk of local recurrence

Review of definition and treatment of upper rectal cancer

While the treatment of locally advanced lower and middle rectal cancer with total mesorectal excision (TME) after neoadjuvant therapy is now well defined, the treatment of locally advanced upper rectal cancer (LAURC) remains controversial. Although most teams and academic societies recommend upfront surgery (US) with partial mesorectal excision (PME), as this appears to be sufficient for these tumors, the literature remains conflicting regarding the additional use of neoadjuvant therapy and TME. Current recommendations for the treatment of LAURC do not reflect actual clinical practice. Notably, there is a paucity of published data specific to the treatment of LAURC since most of the data are from sub-analyses of different cohorts. Another important point responsible for the inconsistent data situation is the fact that the current definition of upper rectal cancer is based on anatomical criteria that are difficult to reproduce and therefore also differ between international professional societies. The aim of this review is to provide a deeper insight into the issues surrounding the treatment of LAURC based on an analysis of the current literature, including anatomic and embryologic data.

Comparing total mesorectal excision with partial mesorectal excision for proximal rectal cancer: evaluating postoperative and long-term oncological outcomes

The treatment role of Total Mesorectal Excision (TME) in proximal rectal cancers (PRC) is still debated. Partial Mesorectal Excision (PME) can reduce morbidity in PRC patients. The purpose of this study was to compare short-term clinical and long-term oncological outcomes between the two groups. A total of 157 PRC patients were enrolled in this study (114 performed with PME and 43 with TME). The two groups were compared in terms of perioperative and long-term oncological outcomes. The overall postoperative complications rate was higher in TME group (18.4% vs. 32.5%, p < 0.05). The incidence of diverting ileostomy was also significantly higher in TME group (86.0% vs. 2.6%, p < 0.001). Overall survival rates for 3, 5, and 7 years in PME and TME group accordingly were: 94.6%, 89.3%, 81.5% and 93.2%, 87.6%, 78.4% (p = 0.324). Disease-free survival rates for 3, 5, and 7 years in PME and TME group were: 90.2%, 84.5%, 78.6% and 88.7%, 81.2%, 75.3% (p = 0.297), respectively. Local recurrence rates for 3, 5, and 7 years in PME and TME group were: 2.6%, 6.1%, 8.8% and 4.6%, 9.3%, 11.2% (p = 0.061), respectively. PME is feasible and can be safely performed in PRC patients with favorable oncological outcomes. TME is associated with increasing risk of surgical complications and requires a two-step surgery for stoma takedown.

Current implications and challenges of artificial intelligence technologies in therapeutic intervention of colorectal cancer

Irrespective of men and women, colorectal cancer (CRC), is the third most common cancer in the population with more than 1.85 million cases annually. Fewer than 20% of patients only survive beyond five years from diagnosis. CRC is a highly preventable disease if diagnosed at the early stage of malignancy. Several screening methods like endoscopy (like colonoscopy; gold standard), imaging examination [computed tomographic colonography (CTC)], guaiac-based fecal occult blood (gFOBT), immunochemical test from faeces, and stool DNA test are available with different levels of sensitivity and specificity. The available screening methods are associated with certain drawbacks like invasiveness, cost, or sensitivity. In recent years, computer-aided systems-based screening, diagnosis, and treatment have been very promising in the early-stage detection and diagnosis of CRC cases. Artificial intelligence (AI) is an enormously in-demand, cost-effective technology, that uses various tools machine learning (ML), and deep learning (DL) to screen, diagnose, and stage, and has great potential to treat CRC. Moreover, different ML algorithms and neural networks [artificial neural network (ANN), k-nearest neighbors (KNN), and support vector machines (SVMs)] have been deployed to predict precise and personalized treatment options. This review examines and summarizes different ML and DL models used for therapeutic intervention in CRC cancer along with the gap and challenges for AI.

Tumour-specific mesorectal excision for rectal cancer: Systematic review and meta-analysis of oncological and functional outcomes

BACKGROUND

Tumour-specific mesorectal excision (TSME) practice for rectal cancer only relies on small retrospective studies. This study aimed to perform a systematic review and meta-analysis to assess the oncological and functional outcomes of TSME practice.

METHODS

A systematic review protocol was drawn to include all the studies that compared partial versus total mesorectal excision (PME vs TME) practised for rectal adenocarcinoma up to 16 cm from the anal verge. A systematic literature search was conducted on EMBASE-Medline, Pubmed and Cochrane Library. Reports were screened for the study's outcomes: oncological radicality, postoperative anastomotic leak risk and functional outcomes. Included studies were appraised for risk-of-bias and meta-analysed. Evidence was rated with the GRADE approach.

RESULTS

Twenty-seven studies were included, consisting of 12325 patients (PME n = 4460, 36.2%; TME n = 7865, 63.8%). PME was performed for tumours higher than 10 cm from the anal verge in 54.5% of patients. There was no difference between PME and TME in circumferential resection margin positivity (OR 1.31, 95%CI 0.43-3.95, p = 0.64; I2 = 38%), and local recurrence risk (HR 1.05, 95%CI 0.52-2.10, p = 0.90; I2 = 40%). The postoperative leak risk (OR 0.42, 95%CI 0.27-0.67, p < 0.001; I2 = 60%) and the major low anterior resection syndrome risk (OR 0.34, 95%CI 0.28-0.40, p < 0.001; I2 = 0%) were lower after PME surgery. No difference was found in urinary incontinence (OR 0.68, 95%CI 0.13-3.67, p = 0.66) and urinary retention after early catheter removal (OR 2.00, 95%CI 0.24-16.51, p = 0.52).

CONCLUSIONS

Evidence from this meta-analysis shows that TSME for rectal cancer has good oncological results and leads to the best-fitted functional results possible for the patient's condition.

Application of Artificial Intelligence in the Diagnosis, Treatment, and Prognostic Evaluation of Mediastinal Malignant Tumors

Artificial intelligence (AI), also known as machine intelligence, is widely utilized in the medical field, promoting medical advances. Malignant tumors are the critical focus of medical research and improvement of clinical diagnosis and treatment. Mediastinal malignancy is an important tumor that attracts increasing attention today due to the difficulties in treatment. Combined with artificial intelligence, challenges from drug discovery to survival improvement are constantly being overcome. This article reviews the progress of the use of AI in the diagnosis, treatment, and prognostic prospects of mediastinal malignant tumors based on current literature findings.

Required distal mesorectal resection margin in partial mesorectal excision: a systematic review on distal mesorectal spread

BACKGROUND

The required distal margin in partial mesorectal excision (PME) is controversial. The aim of this systematic review was to determine incidence and distance of distal mesorectal spread (DMS).

METHODS

A systematic search was performed using PubMed, Embase and Google Scholar databases. Articles eligible for inclusion were studies reporting on the presence of distal mesorectal spread in patients with rectal cancer who underwent radical resection.

RESULTS

Out of 2493 articles, 22 studies with a total of 1921 patients were included, of whom 340 underwent long-course neoadjuvant chemoradiotherapy (CRT). DMS was reported in 207 of 1921 (10.8%) specimens (1.2% in CRT group and 12.8% in non-CRT group), with specified distance of DMS relative to the tumor in 84 (40.6%) of the cases. Mean and median DMS were 20.2 and 20.0 mm, respectively. Distal margins of 40 mm and 30 mm would result in 10% and 32% residual tumor, respectively, which translates into 1% and 4% overall residual cancer risk given 11% incidence of DMS. The maximum reported DMS was 50 mm in 1 of 84 cases. In subgroup analysis, for T3, the mean DMS was 18.8 mm (range 8-40 mm) and 27.2 mm (range 10-40 mm) for T4 rectal cancer.

CONCLUSIONS

DMS occurred in 11% of cases, with a maximum of 50 mm in less than 1% of the DMS cases. For PME, substantial overtreatment is present if a distal margin of 5 cm is routinely utilized. Prospective studies evaluating more limited margins based on high-quality preoperative magnetic resonance imaging and pathological assessment are required.

Applications of Artificial Intelligence in Screening, Diagnosis, Treatment, and Prognosis of Colorectal Cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide. Accurate early detection and diagnosis, comprehensive assessment of treatment response, and precise prediction of prognosis are essential to improve the patients’ survival rate. In recent years, due to the explosion of clinical and omics data, and groundbreaking research in machine learning, artificial intelligence (AI) has shown a great application potential in clinical field of CRC, providing new auxiliary approaches for clinicians to identify high-risk patients, select precise and personalized treatment plans, as well as to predict prognoses. This review comprehensively analyzes and summarizes the research progress and clinical application value of AI technologies in CRC screening, diagnosis, treatment, and prognosis, demonstrating the current status of the AI in the main clinical stages. The limitations, challenges, and future perspectives in the clinical implementation of AI are also discussed.

Oncological outcome of wide anatomic resection with partial mesorectal excision in patients with upper and middle rectal cancer

AIM

The aim was to investigate the influence of distal resection margin and extent of mesorectal excision on long-term oncological outcomes.

METHOD

Consecutive patients with upper and middle third rectal cancer from June 2006 to February 2016 were reviewed. Patients were divided into four groups depending on the distal margin considered as a surrogate marker of the extension of mesorectal excision (Q1 ≤10 mm, Q2 11-20 mm, Q3 21-30 mm, Q4 ≥31 mm). Local-recurrence-free survival (LRFS), disease-free survival (DFS) and overall survival (OS) were estimated. Cox regression models were used to investigate the influence of surgical and clinicopathological variables on prognosis by adjusting for confounding factors.

RESULTS

Two hundred and eleven patients with mid (125) and upper (86) rectal cancer underwent wide mesorectal excision. The median follow-up was 48.64 months (interquartile range 28-63). 17.5% patients developed recurrence. The 5-year LRFS, DFS and OS for all patients were 93.20%, 83.89% and 80.1%, respectively, with no statistically significant differences between groups (LRFS, P = 0.601; DFS, P = 0.487; OS, P = 0.468). In the multivariable analysis the recurrences and survival were associated with the quality of the mesorectum (LRFS, hazard ratio 10.629, 95% CI 2.324-48.610, P = 0.002; DFS, hazard ratio 2.789, 95% CI 1.314-5.922, P = 0.008).

CONCLUSION

A wide anatomical resection with partial mesorectal excision and shorter distal resection margin does not jeopardize the oncological outcomes.

Prognostic importance of circumferential resection margin in the era of evolving surgical and multidisciplinary treatment of rectal cancer: A systematic review and meta-analysis

BACKGROUND

Circumferential resection margin is considered an important prognostic parameter after rectal cancer surgery, but its impact might have changed because of improved surgical quality and tailored multimodality treatment. The aim of this systematic review was to determine the prognostic importance of circumferential resection margin involvement based on the most recent literature.

METHODS

A systematic literature search of MEDLINE, Embase, and the Cochrane Library was performed for studies published between January 2006 and May 2019. Studies were included if 3- or 5-year oncological outcomes were reported depending on circumferential resection margin status. Outcome parameters were local recurrence, overall survival, disease-free survival, and distant metastasis rate. The Newcastle Ottawa Scale and Jadad score were used for quality assessment of the studies. Meta-analysis was performed using a random effects model and reported as a pooled odds ratio or hazard ratio with 95% confidence interval.

RESULTS

Seventy-five studies were included, comprising a total of 85,048 rectal cancer patients. Significant associations between circumferential resection margin involvement and all long-term outcome parameters were uniformly found, with varying odds ratios and hazard ratios depending on circumferential resection margin definition (<1 mm, ≤1 mm, otherwise), neoadjuvant treatment, study period, and geographical origin of the studies.

CONCLUSION

Circumferential resection margin involvement has remained an independent, poor prognostic factor for local recurrence and survival in most recent literature, indicating that circumferential resection margin status can still be used as a short-term surrogate endpoint.

Management of the adenocarcinoma of the upper rectum: a reappraisal

The present review attempts to assess whether upper rectal cancer (URC) should be treated either as colon cancer or as rectal one, namely to be managed with upfront surgery without neo-adjuvant treatment and partial mesorectal excision (PME), or with neo-adjuvant short course radiotherapy (SCRT) or chemoradiotherapy (CRT) as indicated, followed by surgery with total mesorectal excision. Reports from current evidence including studies, reviews and various guidelines are conflicting. Main reasons for inability to reach safe conclusions are (i) the various anatomical definitions of the rectum and its upper part, (ii) the inadequate preoperative local staging,(iii) the heterogeneity of selection criteria for the neo-adjuvant treatment,(iv) the different neo-adjuvant treatment regimens, and(v) the variety in the extent of surgical resection, among the studies. Although not adequately supported, locally advanced URC can be treated with neo-adjuvant CRT provided the lesion is within the radiation field of safety, and a PME if the lower border of the tumour is located above the anterior peritoneal reflection. There is evidence that adjuvant chemotherapy is of benefit in high-risk stage II and stage III lesions.

Neoadjuvant chemoradiation improves oncologic outcomes in low and mid clinical T3N0 rectal cancers

BACKGROUND

Controversial data exists in the current literature in regard to the use of neoadjuvant chemoradiation (nCRT) in patients with clinical T3N0 (cT3N0) rectal cancers, specifically based on location and relation to peritoneal reflection. We aimed to analyze the impact of nCRT on oncologic outcomes among cT3N0 rectal cancers, depending on the tumor height from anal verge (AV).

METHODS

A retrospective analysis of patients with cT3N0 rectal cancers was included from a query of a prospectively maintained rectal cancer database from 1980 to 2016. Patients were divided into 3 groups based on the tumor height: low (1-5 cm from AV), mid (6-10 cm from AV), and upper (11-15 cm from AV). Patients were stratified by use of nCRT.

MAIN OUTCOMES

5-year overall survival (OS), disease-free survival (DFS), cancer-specific survival (CSS), and local recurrence (LR) using Kaplan-Meier curves.

RESULTS

Five hundred ninety-two patients were included. Overall, 364 (61.4%) patients received nCRT and 228 (38.6%) patients did not. There were 251 (43%) patients with low, 302 (51%) with mid, and 39 (7%) with upper rectal cancer. Patients with low and mid rectal cancers received nCRT more frequently than those with upper rectal cancers (68.5% and 61.2% vs 43.6%, p = 0.007). The 5-year OS was 78% and 63%, DFS-88% and 73%, LR-1% and 8% in nCRT followed by resection vs. surgery alone (p < 0.001). In regard to cancer location after nCRT compared with surgery alone, low and mid cancers had better OS, DFS, and CSS, compared with upper ones.

CONCLUSION

nCRT prolongs survival among patients with rectal cancer below 10 cm from AV; however, it has no effect on 5-year oncologic survival of patients with upper rectal cancer located below peritoneal reflection.

Impact of a multidisciplinary training programme on outcome of upper rectal cancer by critical appraisal of the extent of mesorectal excision with postoperative MRI

BACKGROUND

Optimal management of patients with upper rectal cancer remains unclear. Partial mesorectal excision (PME) without neoadjuvant therapy is currently advocated for the majority of patients. Recent studies, however, reported a high risk of local recurrence and suboptimal surgery. The aim of this study was to evaluate the effects of a quality assurance initiative with postoperative MRI to improve outcomes in these patients.

METHODS

Patients who underwent mesorectal excision with curative intent for rectal cancer in 2007-2013 were included. Postoperative MRI of the pelvis was performed 1 year after surgery. In 2011, a multidisciplinary workshop with focus on extent and completeness of surgery was held for training surgeons, pathologists and radiologists involved in treatment planning. Images of residual mesorectum and histopathological reports were reviewed with regard to the distal resection margin. Local recurrence after a minimum of 3 years' follow-up was compared between two cohorts from 2007-2010 and 2011-2013.

RESULTS

A total of 627 patients were included; postoperative MRI of the pelvis was done in 381 patients. The 3-year actuarial local recurrence rate in patients with upper rectal cancer improved from 12·9 to 5·0 per cent (P = 0·012). After the workshop, fewer patients with cancer of the upper rectum were selected to have PME (90·8 per cent in 2007-2010 versus 80·2 per cent in 2011-2013; P = 0·023), and fewer patients who underwent PME had an insufficient distal resection margin (61·7 versus 31 per cent respectively; P < 0·001).

CONCLUSION

Quality assessment of surgical practice may have a major impact on oncological outcome after surgery for upper rectal cancer.

Distinct Prognosis of High Versus Mid/Low Rectal Cancer: a Propensity Score-Matched Cohort Study

BACKGROUND

Rectal cancers have long been treated as a single-entity disease; however, whether the prognosis of high rectal cancer (inferior margin located 10.1 to 15.0 cm from the anal verge) differs from that of mid/low rectal cancer (0 to 10.0 cm) remains disputed.

METHODS

Patients with stages I-III rectal adenocarcinomas undergoing curative-intent surgery were enrolled between 2007 and 2013 in this retrospective analysis. Exclusion criteria were neoadjuvant therapy or concurrent cancers. Propensity score matching and Cox regression analysis were performed to compare a 5-year overall and cancer-specific survival between patients with high and mid/low rectal cancer.

RESULTS

Of 613 patients who met the inclusion criteria, 199 (32.5%) and 414 (67.5%) had high and mid/low rectal cancer, respectively. After propensity score matching (187 cases for each group), the high group showed a better overall survival (70.9 vs. 56.9%, p = 0.042) and cancer-specific survival (77.4 vs. 60.3%, p = 0.028) at 5 years compared with the mid/low group with stage III disease. However, high rectal cancer did not demonstrate prognostic superiority in stages I-II disease. Multivariate analysis identified high tumor location as an independent prognostic factor for cancer-specific survival (hazards ratio = 0.422, 95% confidence interval 0.226-0.786, p = 0.007) and overall survival (hazards ratio = 0.613, 95% confidence interval 0.379-0.991, p = 0.046).

CONCLUSIONS

Patients with stage III high rectal adenocarcinoma demonstrated better overall and cancer-specific survival than those with mid/low type, and tumor location was an independent prognostic factor for patients with rectal carcinomas.

Local recurrence rate in a national Danish patient cohort after curative treatment for rectal cancer

AIM

Several trials have shown that preoperative (chemo)radiotherapy (CRT) reduces local recurrence rates (LRRs) in rectal cancer (RC). The use of CRT varies greatly between countries. It is unknown whether the restrictive use of CRT in Denmark results in a higher LRR relative to other countries. The aim was to evaluate the LRR in a national Danish consecutive cohort of patients with RC.

METHODS

All data from patients with RC in Denmark in 2009-2010 who were operated on with curative intent were retrieved from the Danish Colorectal Cancer Group database. Patients with metastases at the time of diagnosis, patients with synchronous colon cancer, and patients, in whom only local surgical procedures were performed, were excluded. In total, 1633 patients met the inclusion criteria. Clinical follow-up was at least five years with a cut-off date of 31 December 2015.

RESULTS

Clinical follow-up was 5.4 years (median) with an interquartile range of 4.5-6.1 years. Of all included patients, 479 (29%) were treated with preoperative long-course CRT. Local recurrence was found in 68 patients, resulting in an LRR of 4.2%, and 182 (11%) patients developed distant metastases. Five-year overall survival was 74% (95% CI: 71.64-75.91).

CONCLUSIONS

Five-year follow-up of curatively treated patients with RC in Denmark revealed a low LRR. This figure is identical to those reported in other Nordic countries, despite Denmark's considerably stricter guidelines for CRT. The obtained results justify the currently adopted restrictive use of preoperative CRT in Denmark.

Transanal total mesorectal excision: technical aspects of approaching the mesorectal plane from below

Standardization of transanal total mesorectal excision requires the delineation of the principal procedural components before implementation in practice. This technique is a bottom-up approach to a proctectomy with the goal of a complete mesorectal excision for optimal outcomes of oncologic treatment. A detailed stepwise description of the approach with technical pearls is provided to optimize one's understanding of this technique and contribute to reducing the inherent risk of beginning a new procedure. Surgeons should be trained according to standardized pathways including online preparation, observational or hands-on courses as well as the potential for proctorship of early cases experiences. Furthermore, technological pearls with access to the "video-in-photo" (VIP) function, allow surgeons to link some of the images in this article to operative demonstrations of certain aspects of this technique.

Follow-up after rectal cancer: developing and testing a novel patient-led follow-up program. Study protocol

BACKGROUND

The main treatment for non-metastatic rectal cancer (RC) is surgical resection. Late adverse effects that are highly prevalent and negatively impact patients' symptom burden and quality of life are: bowel-, urological and sexual dysfunctions; psychological distress; fear of recurrence. Patients and clinicians have requested a more patient-centred follow-up, balancing the focus on detection of recurrence, and physiological and psychological late adverse effects. The current follow-up program primarily focuses on detection of recurrence, with less attention on late adverse effects. As a consequence, the randomized controlled trial Follow-up after Rectal Cancer (FURCA) has been launched, testing the effect of a new patient-led, follow-up program. The aim of this paper is to describe the methodology used in the FURCA study and to report results from the development of the patient-led, follow-up program. Adult patients, treated with curative intent for primary adenocarcinoma in the rectum are included from four Danish centers.

MATERIAL AND METHODS

Patients are randomized into an intervention group, receiving standardized education and access to self-referral to an assigned project nurse, or a control group following the current follow-up program with routine medicals. The primary outcomes are symptom burden and quality of life, measured by the Functional Assessment of Cancer Therapy - Colorectal (FACT-C) questionnaire. Other outcome and demographic data are collected as patient-reported measures and register-based data. Results from developing the intervention: The education program is based on data from two focus group interviews and the feedback from experts. An algorithm is developed in order to qualify the research nurses' responses to patients' self-referral. Discussion and perspectives: The results of the FURCA study will strengthen the evidence base for RC follow-up, and qualify the ongoing transformation in cancer follow-up programs.