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The article discusses the histopathological and radiological detection of extramural venous invasion (EMVI) in rectal cancer. Topics include prevalence of stopathological EMVI in rectal cancer, use of high-resolution magnetic resonance imaging (MRI) in detecting EMVI before and after preoperative therapy, and potential of MRI in EMVI as an imaging biomarker.

Some interesting shifts have taken place in the diagnostic approach for detection of colorectal lesions over the past decade. This article accompanies the recent EURECCA consensus group reccomendations for optimal management of colon and rectal cancers. In summary, imaging has a crucial role to play in the diagnosis, staging assessment and follow up of patients with colon and rectal cancer. Recent advances include the use of CT colonography instead of Barium Enema in the diagnosis of colonoic cancer and as an alternative to colonoscopy. Modern mutlidetector CT scanning techniques have also shown improvements in prognostic stratification of patients with colonic cancer and clinical trials are underway testing the selective use of neoadjuvant therapy for imaging identified high risk colon cancers. In rectal cancer, high resolution MRI with a voxel size less or equal to 3 × 1 × 1 mm3 on T2-weighted images has a proven ability to accurately stage patients with rectal cancer. Moreover, preoperative identification of prognostic features allows stratification of patients into different prognostic groups based on assessment of depth of extramural spread, relationship of the tumour edge to the mesorectal fascia (MRF) and extramural venous invasion (EMVI). These poor prognostic features predict an increased risk of local recurrence and/or metastatic disease and should form the basis for preoperative local staging and multidisciplinary preoperative discussion of patient treatment options. [ABSTRACT FROM AUTHOR]

Background: Short-course radiotherapy (SRT) with immediate surgery and long-course chemoradiotherapy (CRT) are currently the standard preoperative treatment options for rectal cancer. SRT with surgery delayed for 4-8 weeks (SRT-delay) is an option described for patients with locally advanced tumours who are not fit for CRT. This study examined early toxicity, response to radiotherapy (RT) and short-term outcomes of SRT-delay. Methods: Patients in the Stockholm region diagnosed with rectal cancer between January 2002 and December 2008, who received SRT (25 Gy over 5-7 days) and had surgery with resection of the primary tumour more than 4 weeks after the start of RT, were identified from a prospective register. Additional data were obtained by retrospective review of clinical records. Results: A total of 112 patients had SRT and delayed surgery. The reasons given for SRT included primary unresectable disease and co-morbidities. Severe RT-induced toxicity was noted in six patients (5·4 per cent). Signs of tumour regression were seen on magnetic resonance imaging in 74 per cent of patients reassessed after RT. Pathological stage (44·9 versus 60·7 per cent stage 0-II; P < 0·001), tumour category (11·9 versus 29·4 per cent T0-T2; P < 0·001) and node category (45·8 versus 63·6 per cent N0; P = 0·014) were significantly lower than those at initial assessment. Nine patients (8·0 per cent) had a complete pathological response. Conclusion: The SRT-delay schedule was a feasible alternative with low toxicity. The study indicated a downstaging effect of SRT if surgery was delayed. Copyright © 2012 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background: The significance of magnetic resonance imaging (MRI)-suspected pelvic sidewall (PSW) lymph node involvement in rectal cancer is uncertain. Methods: Magnetic resonance images were reviewed retrospectively by specialist gastrointestinal radiologists for the presence of suspicious PSW nodes. Scans and outcome data were from patients with biopsy-proven rectal cancer and a minimum of 5 years' follow-up in the Magnetic Resonance Imaging and Rectal Cancer European Equivalence Study. Overall disease-free survival (DFS) was analysed using the Kaplan-Meier product-limit method and stratified according to preoperative therapy. Binary logistic regression was used to match patients for propensity of clinical and staging characteristics, and further survival analysis was carried out to determine associations between suspicious PSW nodes on MRI and survival outcomes. Results: Of 325 patients, 38 (11·7 per cent) had MRI-identified suspicious PSW nodes on baseline scans. Such nodes were associated with poor outcomes. Five-year DFS was 42 and 70·7 per cent respectively for patients with, and without suspicious PSW nodes (P < 0·001). Among patients undergoing primary surgery, MRI-suspected PSW node involvement was associated with worse 5-year DFS (31 versus 76·3 per cent; P = 0·001), but the presence of suspicious nodes had no impact on survival among patients who received preoperative therapy. After propensity matching for clinical and tumour characteristics, the presence of suspicious PSW nodes on MRI was not an independent prognostic variable. Conclusion: Patients with suspicious PSW nodes on MRI had significantly worse DFS that appeared improved with the use of preoperative therapy. These nodes were associated with adverse features of the primary tumour and were not an independent prognostic factor. [ABSTRACT FROM AUTHOR]

Background: A pathologically involved margin in rectal cancer is defined as tumour within 1 mm of the surgical resection margin. There is no standard definition of a predicted safe margin on magnetic resonance imaging (MRI). The aim of this study was to assess which cut-off (1, 2 or 5 mm) was the best predictor of local recurrence based on preoperative MRI assessment of the circumferential resection margin (CRM). Methods: Data were collected prospectively on the distance between the tumour and mesorectal fascia for patients with documented radiological margin status in the MERCURY study. Positive margin and local recurrence rates were compared for MRI distances from the tumour to the mesorectal fascia of 1 mm or less, more than 1 mm up to 2 mm, more than 2 mm up to 5 mm, and more than 5 mm. The Cox proportional hazard regression method was used to determine the effect of level of margin involvement on time to local recurrence. Results: Univariable analysis showed that, relative to a distance measured by MRI of more than 5 mm, the hazard ratio (HR) for local recurrence was 3.90 (95 per cent confidence interval 1.99 to 7.63; P < 0.001) for a margin of 1 mm or less, 0.81 (0.36 to 1.85; P = 0.620) for a margin of more than 1mm up to 2mm, and 0.33 (0.10 to 1.08; P = 0.067) for a margin greater than 2 mm up to 5 mm. Multivariable analysis of the effect of MRI distance to the mesorectal fascia and preoperative treatment on local recurrence showed that a margin of 1 mm or less remained significant regardless of preoperative treatment (HR 3.72, 1.43 to 9.71; P = 0.007). Conclusion: For preoperative staging of rectal cancer, the best cut-off distance for predicting CRM involvement using MRI is 1 mm. Using a cut-off greater than this does not appear to identify patients at higher risk of local recurrence. [ABSTRACT FROM AUTHOR]

The article discusses the sites of local recurrence following radical total mesorectal excision for rectal cancer in an effort to elucidate the reasons for recurrence. A metastatic disease corresponding to the lateral pelvic lymph nodes is not a major cause of local recurrence. Patients with tumors in the upper rectum are often have a high anterior resection, leaving distal mesorectum and rectum intact. Surgery for rectal cancer appears to represent remaining mesorectum.

Abstract: Aim: This prospective study reports the results of a multimodality treatment protocol in patients with locally advanced rectal cancer and assesses outcome after curative vs non-curative surgery and in relation to primary advanced vs locally recurrent cancer. Methods: Between 1991 and 2002, 122 patients completed the protocol. Fifty-eight had primary advanced and sixty-four had locally recurrent rectal cancer. Median follow up was 82 months (5–143). Results: A potentially curative resection was achieved in 59% of the patients with primary advanced and in 34% of patients with locally recurrent cancer. After curative resection, 53 and 59%, respectively, were free from recurrence during the observation time (median 82 months) and the overall 5-year survival was 34 and 40%. Overall 5-year survival in all patients with primary advanced cancer was 29 and 16% in all patients with locally recurrent rectal cancer. Conclusion: Multimodality treatment may cure at least a third of patients with locally advanced rectal cancer provided a radical resection is performed. As the post-operative morbidity is high, an optimised patient selection for neo-adjuvant treatment and surgery is essential. However, palliative surgery may benefit the patient if local control is achieved. Future studies should focus on the problem of distant metastasis. [Copyright &y& Elsevier]

Assesses the prognostic impact of an involved circumferential resection margin (CRM) identified at preoperative magnetic resonance imaging in patients with rectal cancer. Tumor involvement of the CRM that predicts a high risk of local recurrence of rectal cancer; Analysis of pertinent topics and relevant issues; Implications on studies of surgery.

The aim of this study was to compare three imaging strategies for the diagnosis of local recurrence of rectal cancer: (a) MR imaging; (b) MR imaging after administration of enteral superparamagnetic particles (Ferristene); and (c) contrast-enhanced CT. Seventeen patients with previous surgery for rectal cancer were examined, 12 patients with local tumour recurrence in the pelvis and 5 patients with postoperative changes. Pelvic multi-coil MR imaging before and after oral administration of superparamagnetic contrast medium [Abdoscan (Ferristene USAN), Nycomed-Amersham, Lidingö, Sweden] as well as abdominal and pelvic CT was performed in all patients. The examinations were independently evaluated by three different radiologists. The general effect of the oral MR contrast medium, the delineation of normal and pathological structures as well as confidence in the diagnosis were registered on a visual analog scale (VAS). The diagnosis according to MR before and after oral contrast medium, and CT, was compared, in 16 patients, with the final diagnosis which was verified by biopsy (n = 3), surgery (n = 6), clinical follow-up (n = 4) and by follow-up with MR or CT (n = 3). No significant improvement in MR image quality was found after enteral contrast medium. The post-contrast MR diagnosis was not changed in any of the patients. The diagnosis on MR correlated with the final diagnosis in 12 of 16 patients (sensitivity 91 %, accuracy 62 %) and the diagnosis on CT in 11 of 16 patients (sensitivity 82 %, accuracy 56 %). The radiologists' “confidence” in the diagnosis and the degree of accordance with the final diagnosis did not score higher on MR after than before oral contrast administration; however, the accordance with the final diagnosis scored better on MR than on CT. No advantages of orally administered superparamagnetic contrast medium were observed in the examined patient group. Magnetic resonance is preferable to CT in diagnosing local tumour recurrence. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare MR imaging and endoscopic ultrasonography (EUS) for the local staging of rectal tumours. Forty-nine patients were examined on a 1.5-T MR unit using either a pelvic phased-array coil (n = 37) alone or combined with an endorectal coil (n = 12). Sagittal and axial sequences with T2-weighted fast spin-echo and axial T1-weighted spin-echo techniques were employed. The EUS technique was performed using a flexible endosonoscope. The results were compared with findings at histopathological sectioning of the specimen. The T-stage on MR correlated with histopathology in 32 of 49 patients and on EUS in 29 of 49 patients. The N-stage on MR correlated with histopathology in 22 of 49 patients and on EUS in 26 of 49 patients. Tumour penetration of the rectal wall was predicted by MR with 86 % sensitivity and 65 % specificity, and by EUS with 89% sensitivity and 33% specificity. Preoperative radiotherapy was administered to 40 of the patients after the examinations which may explain some of the overstaging by MR and EUS. Three patients with surgically and histopathologically confirmed invasion of neighbouring organs in the pelvis were detected preoperatively on MR but none on EUS. Tumour penetration of the rectal wall and local lymph node metastases cannot accurately be predicted with MR or EUS. Magnetic resonance, however, seems to be more useful for preoperative identification of clinically occult advanced disease. [ABSTRACT FROM AUTHOR]