EURECCA consensus conference highlights about colon & rectal cancer multidisciplinary management: The radiology experts review

Diagnostic Accuracy of CT for Local Staging of Colon Cancer: A Systematic Review and Meta-Analysis

OBJECTIVE

The purpose of this article is to determine the accuracy of CT in the detection of tumor invasion beyond the bowel wall and nodal involvement of colon carcinomas. A literature search was performed to identify studies describing the accuracy of CT in the staging of colon carcinomas. Studies including rectal carcinomas that were inseparable from colon carcinomas were excluded. Publication bias was explored by using a Deeks funnel plot asymmetry test. A hierarchic summary ROC model was used to construct a summary ROC curve and to calculate summary estimates of sensitivity, specificity, and diagnostic odds ratios (ORs).

CONCLUSION

On the basis of a total of 13 studies, pooled sensitivity, specificity, and diagnostic ORs for detection of tumor invasion beyond the bowel wall (T3-T4) were 90% (95% CI, 83-95%), 69% (95% CI, 62-75%), and 20.6 (95% CI, 10.2-41.5), respectively. For detection of tumor invasion depth of 5 mm or greater (T3cd-T4), estimates from four studies were 77% (95% CI, 66-85%), 70% (95% CI, 53-83%), and 7.8 (95% CI, 4.2-14.2), respectively. For nodal involvement (N+), 16 studies were included with values of 71% (95% CI, 59-81%), 67% (95% CI, 46-83%), and 4.8 (95% CI, 2.5-9.4), respectively. Two studies using CT colonography were included with sensitivity and specificity of 97% (95% CI, 90-99%) and 81% (95% CI, 65-91%), respectively, for detecting T3-T4 tumors. CT has good sensitivity for the detection of T3-T4 tumors, and evidence suggests that CT colonography increases its accuracy. Discriminating between T1-T3ab and T3cd-T4 cancer is challenging, but data were limited. CT has a low accuracy in detecting nodal involvement.

Role of Magnetic Resonance Imaging in Primary Rectal Cancer-Standard Protocol and Beyond

New-generation magnetic resonance imaging (MRI) scanners with optimal phased-array body coils have contributed to obtainment of high-resolution T2-weighted turbo spin echo images in which visualization of anatomical details such as the mesorectal fascia and the bowel wall layers is feasible. Preoperative, locoregional staging of rectal cancer with MRI, considered standard of care nowadays, relies on these images for stratification of high-risk patients for local recurrence, patients most likely to benefit from neoadjuvant therapy, as well as patients who exhibit imaging features indicative of a high risk of metastatic disease. Functional imaging, including optimized for rectal cancer diffusion-weighted imaging and more recently use of dynamic contrast-enhanced MRI, combined with radiologists׳ rising level of familiarity regarding the assessment of reactive changes postchemoradiation treatment, have shown to increase MRI staging accuracy after neoadjuvant treatment. Our intention is to review already established standard protocols for primary rectal cancer and go through potential additional promising imaging tools.

Complications and risk prediction in treatment of elderly patients with rectal cancer

PURPOSE

The primary aim of this study was to characterise complications, identify predictors of postoperative morbidity and mortality and to evaluate existing risk prediction models in elderly rectal cancer patients.

METHODS

An observational single-centre study of 330 consecutive patients >75 years treated in 1994-2006. Analyses were performed by age group: 75-79 years, 80-85 years and >85 years.

RESULTS

Total observed in-hospital morbidity was 48.7 %. In multivariate analysis, age (OR 1.04, 95 % CI 1.01-1.08, p = 0.04), ASA grade ≥ 3 (p = 0.01), acute presentation (OR 1.67, 95 % CI 1.2-13.2, p = 0.02) and major surgery (APR OR 3.72, 95 % CI 1.37-10.15, p = 0.01, LAR OR 2.98, 95 % CI 1.14-7.79, p = 0.03, Hartmann OR 5.46, 95 % CI 1.60-19.28, p = 0.02) were independent risk factors for postoperative morbidity. The 30-day mortality was 6.3, 6.4 and 14.3 % (p = 0.146) in the three age groups, and the 100-day mortality was 8.7, 10.1 and 22.2 % (p = 0.03), respectively. ASA group 3 (OR 6.21, 95 % CI 4.39-27.69, p = 0.017), ASA group 4 (OR 32.6, 95 % CI 5.12-207.75, p < 0.001) and acute presentation (OR 6.48, 95 % CI 1.62-25.99, p = 0.008) increased the risk of 100-day mortality. The Physiological and Operative Severity Score for enUmeration of Mortality and Morbidity (POSSUM) observed/estimated (O/E) ratio for morbidity was 1.05. For 30-day mortality, the colorectal POSSUM (Cr-POSSUM) O/E ratio was 0.74, Surgical Risk Scale 0.61 and the Association of Coloproctology of Great Britain and Ireland (ACPGBI) mortality model 0.63, and for 100-day mortality, ratios were 1.12, 0.91 and 0.95, respectively.

CONCLUSION

In this series, age increased the risk of in-hospital morbidity and 100-day mortality. Cr-POSSUM, SRS and ACPGBI overestimated 30-day mortality but predicted 100-day mortality with a high degree of accuracy. POSSUM correctly predicted in-hospital morbidity.

Targeting BRAF aberrations in advanced colorectal carcinoma: from bench to bedside

Colorectal cancer (CRC) is a global health problem with profound mortality and morbidity effects particularly in the advanced/metastatic setting. Because of the recent understanding of the biology of this disease, many candidate targets have come into light for therapeutic evaluation. The current review is about evaluating the preclinical and clinical aspects of BRAF as a therapeutic target in this disease. The available clinical results suggest that while the use of unselective RAF inhibitors (e.g., sorafenib) has been ineffective in the management of advanced CRC patients with KRAS mutation, combination of selective BRAF inhibitors plus EGFR inhibitors may represent a good therapeutic strategy in BRAF-mutant CRC.

Rectal Cancer Magnetic Resonance Imaging: Imaging Beyond Morphology

Magnetic resonance imaging (MRI) has in recent years progressively established itself as one of the most valuable modalities for the diagnosis, staging and response assessment of rectal cancer and its use has largely focused on accurate morphological assessment. The potential of MRI, however, extends beyond detailed anatomical depiction: aspects of tissue physiology, such as perfusion, oxygenation and water molecule diffusivity, can be assessed indirectly. Functional MRI is rapidly evolving as a promising non-invasive assessment tool for tumour phenotyping and assessment of response to new therapeutic agents. In spite of promising experimental data, the evidence base for the application of functional MRI techniques in rectal cancer remains modest, reflecting the relatively poor agreement on technical protocols, image processing techniques and quantitative methodology to date, hampering routine integration into clinical management. This overview outlines the established strengths and the critical limitations of anatomical MRI in rectal cancer; it then introduces some of the functional MRI techniques and quantitative analysis methods that are currently available, describing their applicability in rectal cancer and reviewing the relevant literature; finally, it introduces the concept of a multi-parametric quantitative approach to rectal cancer.

Colorectal cancer

Colorectal cancer had a low incidence several decades ago. However, it has become a predominant cancer and now accounts for approximately 10% of cancer-related mortality in western countries. The 'rise' of colorectal cancer in developed countries can be attributed to the increasingly ageing population, unfavourable modern dietary habits and an increase in risk factors, such as smoking, low physical exercise and obesity. New treatments for primary and metastatic colorectal cancer have emerged, providing additional options for patients; these treatments include laparoscopic surgery for primary disease, more-aggressive resection of metastatic disease (such as liver and pulmonary metastases), radiotherapy for rectal cancer, and neoadjuvant and palliative chemotherapies. However, these new treatment options have had limited impact on cure rates and long-term survival. For these reasons, and the recognition that colorectal cancer is long preceded by a polypoid precursor, screening programmes have gained momentum. This Primer provides an overview of the current state of the art of knowledge on the epidemiology and mechanisms of colorectal cancer, as well as on diagnosis and treatment.

New hope on the horizon for patients with metastatic colorectal cancer

Colorectal cancer is the second leading cause of cancer death in the USA. It is estimated that approximately 132,700 patients are diagnosed with, and more than 49,700 are expected to die of colorectal cancer each year. For many years, 5-fluorouracil was the only treatment option for patients with metastatic colorectal cancer but, over the last decade, the introduction and the US FDA approval of irinotecan, oxaliplatin and several monoclonal antibodies that target the VEGF and EGF receptor have markedly changed the therapeutic landscape. Most recently, regorafenib, ramucirumab and the novel orally active TAS-102 have also become available, presenting even more therapeutic options. In this review, we focus on emerging systemic therapy options for the management of advanced/metastatic colorectal cancer, particularly in the second-line/salvage settings, highlighting existing scientific evidence for the activity of, as well as future perspectives on, these more novel treatments.

Rectal and colon cancer: Not just a different anatomic site

Due to differences in anatomy, primary rectal and colon cancer require different staging procedures, different neo-adjuvant treatment and different surgical approaches. For example, neoadjuvant radiotherapy or chemoradiotherapy is administered solely for rectal cancer. Neoadjuvant therapy and total mesorectal excision for rectal cancer might be responsible in part for the differing effect of adjuvant systemic treatment on overall survival, which is more evident in colon cancer than in rectal cancer. Apart from anatomic divergences, rectal and colon cancer also differ in their embryological origin and metastatic patterns. Moreover, they harbor a different composition of drug targets, such as v-raf murine sarcoma viral oncogene homolog B (BRAF), which is preferentially mutated in proximal colon cancers, and the epidermal growth factor receptor (EGFR), which is prevalently amplified or overexpressed in distal colorectal cancers. Despite their differences in metastatic pattern, composition of drug targets and earlier local treatment, metastatic rectal and colon cancer are, however, commonly regarded as one entity and are treated alike. In this review, we focused on rectal cancer and its biological and clinical differences and similarities relative to colon cancer. These aspects are crucial because they influence the current staging and treatment of these cancers, and might influence the design of future trials with targeted drugs.

Magnetic resonance imaging and endorectal ultrasound for diagnosis of rectal lesions

Endorectal ultrasonography (ERUS) and magnetic resonance imaging (MRI) allow exploring the morphology of the rectum in detail. Use of such data, especially assessment of the rectal wall, is an important tool for ascertaining the perianal fistula localization as well as stage of the cancer and planning it appropriate treatment, as stage T3 tumors are usually treated with neoadjuvant therapy, whereas T2 tumors are initially managed surgically. The only advantage of ERUS over MRI is the possibility of assessing T1 tumors that could be treated by transanal endoscopic microsurgery. However, MRI is better for visualizing most radiological prognostic features in rectal or anal cancer such as a circumferential resection margin less than 1 mm, T stage at T1-T2 or T3 tumors with extramural extension less than 5 mm, absence of extramural vascular invasion, N stage at N0/N1, and tumors located in the middle or upper third of the rectum. It can also evaluate the intersphincteric space or levator ani muscle involvement. Increased signal on diffusion weighted imaging (DWI) and low apparent diffusion coefficient (ADC) values as well as an irregular contour and heterogeneous internal signal intensity seem to predict the involvement of pelvic lymphatic nodes better than their size alone. Computed tomography as well as other examination techniques, including digital rectal examination, contrast edema, recto- and colonoscopy, are less useful in staging of rectal cancer but still are very important screening tools.

Dosimetric comparative study of 3 different postoperative radiotherapy techniques (3D-CRT, IMRT, and RapidArc) for II-III stage rectal cancer

Postoperative radiotherapy is critical for reducing local relapse for advanced rectal carcinoma but has many side effects. Our study compared the dose distribution of target volumes, protection of normal organs at risk (OAR), and monitor unit (MU) for 3 radiotherapy techniques (3-dimensional conformal radiation therapy [3D-CRT], intensity-modulated radiation therapy [IMRT], and RapidArc (Varian Medical Systems, Inc., Palo Alto, CA, USA)). The results advocate for the clinical application of RapidArc technique in the future.Thirty postoperative patients with rectal cancer were enrolled. The 3 radiotherapy plans mentioned above were designed for each patient. The target volume coverage indicators included average dose, conformity index (CI), and homogeneity index (HI) of planning tumor volume (PTV). OAR included the bladder, small intestine, colon, and bilateral proximal femurs. The 30 patients were divided into 3 groups (10 cases in each group) for postoperative radiotherapy with the 3D-CRT, IMRT, or RapidArc technique, respectively.Both the IMRT and RapidArc plans have a significantly higher average PTV dose and better CI and HI (P < 0.01) than 3D-CRT. IMRT and RapidArc result in significantly lower doses of irradiation for all the OAR examined. Both the IMRT and RapidArc plans have a significantly lower V40 of the bladder, small intestine, and colon than 3D-CRT (P < 0.01). The IMRT and RapidArc plans can also reduce the maximum dose (Dmax) for the left proximal femur, V30, and V40 of bilateral proximal femurs compared with 3D-CRT (P < 0.01). Compared with IMRT, RapidArc can further reduce the Dmax of the small intestine, the Dmax and V30 of the bilateral proximal femurs, and the V40 of the right proximal femur (P < 0.01). RapidArc reduces MU remarkably compared with IMRT (P < 0.01). Regarding acute side effects, IMRT and RapidArc can greatly reduce the incidence of grade 3 radiation-induced cystitis and grade 2 enteritis.Both IMRT and RapidArc are better than 3D-CRT regarding PTV coverage and OAR protection. Furthermore, RapidArc is superior to IMRT regarding protection of the small intestine and bilateral proximal femurs and requires a reduced treatment time. RapidArc could be widely applied for postoperative radiotherapy for patients with ΙΙ-ΙΙΙ stage rectal cancer.

Involving patients in a multidisciplinary European consensus process and in the development of a 'patient summary of the consensus document for colon and rectal cancer care'

CONTEXT

High-quality cancer care should be accessible for patients and healthcare professionals. Involvement of patients as partners in guideline formation and consensus processes is still rarely found. EURECCA, short for European Registration of Cancer Care, is the platform to improve outcomes of cancer care by reducing variation in the diagnostic and treatment process. EURECCA acknowledges the important role of patients in implementation of consensus information in clinical practice.

OBJECTIVE

The aim of this article is to describe the process of involving patients in the consensus process and in developing the patient summary of the consensus for colon and rectal cancer care.

METHODS

The Delphi method for achieving consensus was used. Three online voting rounds and one tele-voting round were offered to an expert panel of oncology professionals and patient representatives. At four different stages, patients and/or patient representatives were involved in the process: (1) during the consensus process, (2) lecturing about the role of the patient, (3) development of the patient summary, and (4) testing the patient summary.

RESULTS

Representatives were invited to the voting and commenting rounds of this process and given an equal vote. Although patients were not consulted during the planning stages of this process, patient involvement increased following the panel's discussion of the implementation of the consensus among the patient population. After the consensus meeting, the patient summary was written by patient representatives, oncologists and nurses. A selection of proactive patients reviewed the draft patient summary; responses were positive and several patient-reported outcomes were added. Questionnaires to evaluate the use and implementation of the patient summary in daily practice are currently being developed and tested. Patient consultation will be needed in future planning for selection of topics.

DISCUSSION

The present study may function as a model for future consensus processes to involve patients at different stages and to implement both patient and healthcare professional versions in daily practice.

An umbrella protocol for standardized data collection (SDC) in rectal cancer: a prospective uniform naming and procedure convention to support personalized medicine

Predictive models allow treating physicians to deliver tailored treatment moving from prescription by consensus to prescription by numbers. The main features of an umbrella protocol for standardizing data and procedures to create a consistent dataset useful to obtain a trustful analysis for a Decision Support System for rectal cancer are reported.