Circumferential Resection Margin Involvement Research Articles

Meta-analysis of oncological outcome after abdominoperineal resection or low anterior resection for lower rectal cancer.

In lower rectal cancer, postoperative outcome is still subject of controversy between the advocates of abdominoperineal resection (APR) and low anterior resection (LAR). Reports suggest that low anterior resection may be oncologically superior to abdominoperineal excision, although no good evidence exists to support this. Publications were identified which assessed the differences comparing 5-year survival, local recurrence, circumferential resection margin rate, complications and so on. A meta-analysis was performed to clarify the safety and feasibility of the two procedures with several types of outcome measures. A total of 13 studies met the inclusion criteria, and comprised 6,850 cases. Analysis of these data showed that LAR group was highly correlated with 5-year survival (pooled OR = 1.73, 95%CI: 1.30–2.29, P = 0.0002 random-effect). And local recurrence rate of APR group was significantly higher than that in LAR group (pooled OR = 0.63, 95%CI: 0.53–0.75, P < 0.00001 fixed-effect). Also, the circumferential resection margin (CRM) were high involved in APR group than in LAR group. (5 trials reported the data, pooled OR = 0.43, 95%CI: 0.36–0.52, P < 0.00001 fixed-effect). Besides, the incidents of overall complications of APR group was higher compared with LAR group (pooled OR = 0.52, 95%CI: 0.29–0.92, P = 0.03 random-effect). Patients treated by APR have a higher rate of CRM involvement, a higher local recurrence, and poorer prognosis than LAR. And there is evidence that in selected low rectal cancer patients, LAR can be used safely with a better oncological outcome than APR. due to the inherent limitations of the present study, for example, the trails available for this systematic review are limited and the finite retrospective data, future prospective randomized controlled trials will be useful to fully investigate these outcome measures and to confirm this conclusion.

Learning curve of laparoscopic low anterior resection in terms of local recurrence.

Experience in terms of surgical case numbers required to develop proficiency for oncologic adequacy after sphincter-saving laparoscopic rectal cancer surgery has not been established. Three hundred seventeen consecutive patients underwent sphincter-saving laparoscopic rectal cancer surgery with curative intent performed by single surgeon. The learning curve was estimated using risk-adjusted cumulative sum (RA-CUSUM) and the graph of 195 consecutive patients who were treated by another surgeon was used to evaluate inter-surgeon variability in the learning curve. Overall, the 3-year local recurrence rate was 7.7% (95% confidence interval [CI], 6.4%-9.0%). The RA-CUSUM analysis demonstrated a learning curve of 110 cases for local recurrence for both of surgeons and 50-70 cases for CRM involvement. The 3-year local recurrence-free rate was better during the experienced period than during the learning period (95.1% [95% CI, 91.6%-97.1%] vs. 89.5% [95% CI, 84.4%-93.0%]; P = 0.029). These differences were obvious in subgroup analysis of stage III tumors (93.4% [95% CI, 86.6%-96.8%] vs. 78.6% [95% CI, 68.5%-85.3%]; P = 0.013). Local recurrence rates decreased with increasing surgeon experience, as did other short-term outcomes, especially in advanced disease cases.

Prognostic value of lymph node ratio staging system in stage III( rectal cancer following 30 Gy/10 f preoperative radiotherapy

To evaluate the prognostic value of the lymph node ratio(LNR) staging system for rectal cancer following 30 Gy/10 f preoperative radiotherapy. Clinical data of 282 patients with mid-lower locally advanced rectal cancer who received preoperative radiotherapy and curative surgery in the Peking University Cancer Hospital from August 2003 to August 2009 were retrospectively reviewed. The radiotherapy regimen was recommended by CACA. Total dose of 30 Gy was divided into 10 fragments (30 Gy/10 f), the biologically equivalent dose (BED) was 36 Gy, and 3D conformal radiotherapy(3D-CRT) was used. Surgery was performed 2-4 weeks after radiation. The prognostic effect of the lymph node ratio(LNR) staging system in addition to the 7th AJCC staging system were retrospectively analyzed and compared in stage III( cases with positive lymph node(s). Patients were divided into four groups by LNR quantiles: LNR1(<0.070), LNR2(0.070-0.142), LNR3(0.143-0.307) and LNR4(>0.307). A total of 108 eligible cases were included in the study. The 3-year disease-free survival (3-yr DFS) was 61.1%. On univariate analysis, circumferential resection margin involvement(P=0.034), tumor differentiation (P=0.002), N stage (P=0.001), TNM stage(P=0.000) and LNR(P=0.003) were significantly associated with 3-yr DFS. On multivariate analysis, abdominoperineal resection (P=0.006, HR=2.611, 95%CI:1.323-5.153), G3-4 differentiation (P=0.015, HR=2.208, 95%CI:1.163-4.192), ypN2a/N2b stage(as covariate: P=0.024, HR=2.568, 95%CI:1.135-5.810; P=0.001, HR=3.759, 95%CI:1.776-7.958) were independent risk factors for decreased 3-yr DFS. Other factors including LNR were excluded in Cox regression model. The 3-yr DFS was statistically different among subcategories of ypN stage. There was no statistical difference of 3-yr DFS in pair-wise comparison of LNR1 and LNR2, LNR2 and LNR3 and LNR3 and LNR4. Additional use of LNR over AJCC staging system did not improve the prediction of prognosis for III(B/C stages and for each stratum of ypN stages, despite the prognostic separation by LNR in III(A stage. The LNR staging system in addition to the 7th AJCC staging system does not provide further detailed stratification of the prognosis for stage III( rectal cancer following 30 Gy/10 f preoperative radiotherapy. Lymph node ratio is premature as a prognostic factor in clinical practice.

Circumferential resection margins of rectal tumours post-radiotherapy: how can MRI aid surgical planning?

Magnetic resonance imaging (MRI) is known to have high predictive accuracy for circumferential resection margin (CRM) involvement of pre-treatment rectal tumours. This study aims to assess predictive accuracy of MRI for CRM involvement in rectal cancers post-long-course chemoradiotherapy (CRT) and in particular to understand how this information can influence surgical planning. Forty-seven rectal cancers treated with CRT followed by bowel resection in one hospital since 2005 were reviewed for clinical, radiological and pathological characteristics. Using a validated pro forma, a radiologist blinded to final histology and original MRI report predicted CRM status from post-CRT MRI images. Results were compared to histological CRM status of final specimen, and differential analysis by type of surgical operation was performed. Overall accuracy of MRI for CRM involvement post-CRT was 72 % with a negative predictive value of 92 %. Abdominoperineal excision (APE) post-CRT was associated with non-significantly higher rates of histologically involved CRM than anterior resection (AR; 41 vs. 21 %) as were mucinous adenocarcinomas when compared to non-mucinous (56 vs. 21 %). Overall accuracy and positive predictive value were non-significantly higher for cancer treated with a standard APE than AR, and negative predictive value was high for both groups. MRI post-CRT has high negative predictive value for CRM status. Such information is of particular clinical relevance in low rectal cancers treated with APE as it can indicate when a standard surgical approach is likely to be sufficient.

Differences in Circumferential Resection Margin Involvement After Abdominoperineal Excision and Low Anterior Resection No Longer Significant

The aim of this study was to evaluate whether the abdominoperineal excision (APE) is associated with an increased risk of circumferential resection margin (CRM) involvement after rectal cancer surgery in comparison with low anterior resection (LAR). The oncologic inferiority of the APE technique in comparison with LAR has been widely reported in literature. However, because of large evolvement in rectal cancer care, outcomes after APE may have improved since then. The population-based dataset of the Dutch Surgical Colorectal Audit was used selecting 5017 patients with primary rectal cancer undergoing surgery in 2010 to 2011. Propensity scores were calculated for the likelihood of performing an APE given relevant patient and tumor characteristics, and used in the multivariate analysis of CRM involvement. The APE was associated with a slight, nonsignificant, increased risk of CRM involvement [odds ratio (OR) = 1.33; confidence interval (CI) = 0.93-1.90]. Absolute percentages of CRM involvement were 8% and 12% after LAR and APE, respectively.In the subgroup analysis, advanced rectal tumors (cT3-4) were associated to a higher risk of CRM involvement after APE (OR = 1.61; CI = 1.05-1.90), whereas smaller tumors (cT1-2) were not (OR = 0.62; CI = 0.27-1.40). The results suggest that on a national level the APE procedure itself is not a strong predictor anymore for CRM involvement after rectal cancer surgery. However, in advanced tumors, results after APE are inferior to LAR.

Impact of interval between neoadjuvant chemoradiotherapy and surgery for rectal cancer on surgical and oncologic outcome.

The aim of this study was to evaluate the effect of a longer interval between long-course neoadjuvant chemoradiotherapy and surgery on surgical and oncologic outcome. A total of 233 consecutive patients with clinical stage II and III rectal cancer were divided into 2 groups according to the neoadjuvant-surgery interval: short-interval group (≤ 7 weeks, n = 111), and long-interval group (>7 weeks, n = 122). Data on neoadjuvant-surgery interval, operative time, perioperative complications, final pathology, disease recurrence, and mortality were prospectively collected and analyzed. The two groups were comparable in terms of demographics, tumor, and treatment characteristics. Operative time and perioperative complications were not influenced by a longer interval. Patients in the long-interval group had a significantly higher pathologic complete response (pCR) rate (27.1% vs. 15.3%, P = 0.029), and a decreased rate of circumferential resection margin involvement (1.6% vs. 8.1%, P = 0.020). After a median follow-up of 42 months (range 6-90 months), the 3-year local recurrence rate was 12.9% in the short-interval group versus 4.8% in the long-interval group (P = 0.025). A neoadjuvant-surgery interval >7 weeks is safe and is associated with a higher rate of pCR and R0 resection, and decreased local recurrence.

Longitudinal and circumferential resection margin in adenocarcinoma of distal esophagus and cardia.

Multiple factors are implicated in the long-term survival of patients who have undergone esophagectomy, among these the involvement of longitudinal and circumferential resection margins are well known important prognostic factors. A few studies have assessed the impact of the operative approach on the status of the resection margins, and the data are not well reported, often unclear and, more importantly, there is no scientific evidence or published guideline on what the optimal proximal, distal or circumferential resection margin clearance should be. Owing to the lack of clarity on these points, we undertook a systematic literature review of the impact of longitudinal and circumferential resection margins in patients with operable esophageal cancer, the prognostic significance of margin involvement and the role of neoadjuvant therapy.

Low Rectal Cancer: The Great Challenge for the Multidisciplinary Team—Contributions from High-Resolution Magnetic Resonance Imaging for the Correct Therapeutic Approach

Low rectal tumors involve a major challenge for the multidisciplinary team (MDT) in terms of local control and preservation of the sphincter function, and therefore for radiologists, since correct therapeutic decisions are based on accurate initial staging. Despite the progress achieved with total mesorectal excision, low rectal tumors continue to demand more effort from the MDT as far as results are concerned. Information exchange between the surgeon and the radiologist is of the utmost importance for the treatment of these patients. Pooled analysis of the information provided by the surgeon, through the digital rectal examination, and by the radiologist, with the anatomical detail and surgical planes provided by high-resolution (HR) magnetic resonance imaging (MRI), contributes to the proper selection of treatment by the MDT. Patients treated with low anterior resection have lower rates of perforation and circumferential resection margin involvement than those patients treated with abdominoperineal excision. In this multidisciplinary review in which a radiologist and a surgeon were involved, the relevant anatomy of low rectal tumors determined by HR MRI is described, together with the usefulness of the information provided for the appropriate selection of the treatment and the surgical technique. The importance of the assessment of response to chemoradiotherapy through the tumor regression grading adapted to MRI is also highlighted, taking into account that HR MRI has recently been validated as a staging method after neoadjuvant treatment, as well as its correlation with survival outcomes.

Permanent stoma rates: a misleading marker of quality in rectal cancer surgery

The latest National Bowel Cancer Audit Programme (NBOCAP) audit identified our colorectal unit as an outlier with regard to the high permanent stoma rate. The aim of this study was to perform an audit of the rationale for stoma formation in patients undergoing rectal cancer resection in our unit. A review was conducted of all rectal cancer operations between April 2011 and March 2013. Preoperative staging investigations and operation reports were reviewed to identify the reasons for nonrestorative surgery. Postoperative histology reports were used to identify circumferential resection margin (CRM) involvement and tumour height. One-hundred and twenty-five patients underwent surgery for rectal cancer, of whom 102 underwent elective resection with curative intent. The permanent stoma rate was 63.2% when emergency and palliative procedures were included and 54.9% when only elective curative cases were considered. Tertiary referrals made up 31.4% of elective cases. The main reasons for nonrestorative surgery included multivisceral resection (n = 24) for locally advanced cancer and operations for lesions close to the anal sphincter (n = 21). The median length of stay was 8 days, the 90-day mortality was 2.9% and the rate of CRM involvement was 2.0%. Our unit provides multivisceral surgery for locally advanced rectal cancer and receives a substantial number of tertiary referrals. Many of the rectal cancers referred are locally advanced or threaten the anal sphincter. This study demonstrates that the complexity of a unit's case-mix can have a profound effect on the permanent stoma rate. Stoma rates taken at face value do not therefore provide an accurate representation of surgical quality. What does this paper add to the literature? The study reviews the practice of a colorectal surgical unit with an interest in multivisceral surgery with regard to the permanent stoma rate. The reasons for nonrestorative surgery are analysed, and the problems associated with the use of stoma rates as a marker of quality in colorectal surgery are highlighted.

A single surgeon's series of transthoracic oesophageal resections.

Significant controversy persists over the optimum surgical management of oesophageal carcinoma. The authors report on a consecutive personal series of open transthoracic oesophageal resections. Data relating to resections performed between mid-1993 and the end of 2010 were analysed. Patient and tumour assessment evolved over this period. Preoperative chemotherapy in appropriate cases was introduced in 2002. A laparotomy and right lateral thoracotomy approach (Ivor-Lewis) was used. In all cases the pylorus was not interfered with, no attempt was made to perform a radical lymphadenectomy but surgical strategy was focused on producing an R0 resection and a hand sewn anastomosis was fashioned. A total of 165 resections were performed; 130 patients (80%) were male. The median age was 66 years (range: 31-82 years). Eighty per cent had an adenocarcinoma. Sixty-four per cent of the tumours were T3/T4 and sixty-two per cent node positive. Forty patients (24%) had an involved circumferential resection margin (CRM). Five patients (3.0%) had no resection and a quarter (26%) developed morbidity of some form. There was one clinical anastomotic leak (0.6%) and three benign strictures requiring dilation (1.8%). In-hospital mortality was 3.0% (5 patients). Disease specific survival at one, two and five years was 77%, 42% and 36% respectively. Neither CRM involvement nor preoperative chemotherapy influenced survival significantly. No patient required intervention to disrupt the pylorus. Excellent outcomes are achievable following open transthoracic oesophagectomy without radical lymphadenectomy using a hand sewn gastro-oesophageal anastomosis and without disrupting the pylorus.

Restaging of Locally Advanced Rectal Cancer With Magnetic Resonance Imaging and Endoluminal Ultrasound After Preoperative Chemoradiotherapy

Magnetic resonance imaging and endoluminal ultrasound play an important role in the restaging of locally advanced rectal cancer after preoperative chemoradiotherapy, yet their diagnostic accuracy is still controversial. Meta-analysis was performed to estimate the diagnostic performance of MRI and endoluminal ultrasound. Electronic databases from 1996 to March 2012 were searched. Either MRI or endoluminal ultrasound was used to restage rectal cancer after chemoradiotherapy or radiation. T category, lymph node, and circumferential resection involvement were measured. The sensitivity estimate for rectal cancer diagnosis (T0) by endoluminal ultrasound (37.0%; 95% CI, 24.0%-52.1%) was higher (p = 0.04) than the sensitivity estimate for MRI (15.3%; 95% CI, 6.5%-32.0%). For T3-4 category, sensitivity estimates of MRI and endoluminal ultrasound were comparable, 82.1% and 87.6%, whereas specificity estimates were poor (53.5% and 66.4%). For lymph node involvement, there was no significant difference between the sensitivity estimates for MRI (61.8%) and endoluminal ultrasound (49.8%). Specificity estimates for MRI and endoluminal ultrasound were 72.0% and 78.7%. For circumferential resection margin involvement, MRI sensitivity and specificity were 85.4% and 80.0%. To identify the heterogeneity, metaregression was performed on covariates. However, few of the covariates were identified to be statistically significant because of the lack of adequate original data. Accurate restaging of locally advanced rectal cancer by MRI and endoluminal ultrasound is still a challenge. Identifying T0 rectal cancer by imaging is not reliable. Before performing surgery, restaging is important, but some of the T0-2 patients are likely overestimated as T3-4. Both modalities for lymph node involvement are not very good. Magnetic resonance imaging may be a good method to reassess circumferential resection margin.

Robotic versus open total mesorectal excision for rectal cancer: Comparative study of short and long-term outcomes

BackgroundDespite the several series in which the short-term outcomes of robotic-assisted surgery were investigated, data concerning the long-term outcomes are still scarce. MethodsThe prospectively collected records of 65 consecutive patients with extraperitoneal rectal cancer who underwent robotic total mesorectal excision (RTME) were compared with those of 109 consecutive patients treated with open surgery (OTME). Patient characteristics, pathological findings, local and systemic recurrence rates and 5-year survival rates were compared. ResultsThere were no statistically significant differences in postoperative complications, reoperation and 30-day mortality. There were significant differences comparing groups: number of lymph nodes harvested (RTME: 20.1 vs. OTME: 14.1, P < 0.001), estimated blood loss (RTME: 0 vs. OTME: 150 ml, P = 0.003), operation time (RTME: 299.0 vs. OTME: 207.5 min, P < 0.001) and length of postoperative stay (RTME: 6 vs. OTME: 9 days, P < 0.001). The rate of circumferential resection margin involvement and distal resection margin were not statistically different between groups. There were no statistically significant differences at the 5-year follow-up: overall survival, disease-free survival and cancer-specific survival. The cumulative local recurrence rate was statistically lower in the robotic group (RTME: 3.4% vs. OTME: 16.1%, P = 0.024). ConclusionRTME showed a significant reduction in local recurrence rate and a higher, although not statistically significant, long-term cancer-specific survival with respect to OTME. Prospective randomized studies are needed to confirm or deny significantly better local control rates with robotic surgery.

Oncological superiority of extralevator abdominoperineal resection over conventional abdominoperineal resection: a meta-analysis

The oncological superiority, i.e., lower circumferential resection margin (CRM) involvement, lower intraoperative perforation (IOP), and local recurrence (LR) rates, of extralevator abdominoperineal resection (EAPR) over conventional abdominoperineal resection (APR) for rectal cancer is inconclusive. This meta-analysis systematically compared the rates of CRM involvement, IOP, and LR of rectal cancer patients treated by EAPR and APR, respectively. An electronic literature search of MEDLINE, EMBASE, and Cochrane Library through May 2013 was performed by two investigators independently to identify studies evaluating the CRM involvement, IOP, and LR rates of EAPR and APR, and search results were cross-checked to reach a consensus. Data was extracted accordingly. A Mantel-Haenszel random effects model was used to calculate the odds ratio (OR) with 95 % confidence intervals (95 % CI). Six studies with a total of 881 patients were included. Meta-analysis of CRM involvement and IOP data from all six studies demonstrated significant lower CRM involvement (OR, 0.36; 95%CI, 0.23-0.58; P < 0.0001) and IOP (OR, 0.31; 95%CI, 0.12-0.80; P = 0.02) rates of EAPR. Data from four studies also showed that EAPR was associated with a lower LR rate than APR (OR, 0.27; 95%CI, 0.08-0.95; P = 0.04). No differences of between-study heterogeneity or publication bias were seen in any of the meta-analyses. Extralevator abdominoperineal resection could achieve better CRM involvement outcome and lower IOP and LR rates, demonstrating an oncological superiority over conventional abdominoperineal resection.

Diagnostic Accuracy of Computed Tomography and Magnetic Resonance Imaging Obtained after Neoadjuvant Chemoradiotherapy in Predicting the Local Tumor Stage and Circumferential Resection Margin Status of Rectal Cancer

This study was supported by grant No. 02-2012-050 from Seoul National University Bundang Hospital. Purpose: To measure the diagnostic accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) obtained after neoadjuvant chemoradiotherapy (CRT) in patients with rectal cancer for a prediction of the local tumor stage and circumferential resection margin (CRM). Materials and Methods: Two independent radiologists reviewed CT and MRI obtained after neoadjuvant CRT. The accuracy of the local tumor staging and the diagnostic performance for the prediction of CRM involvement were calculated. The agreement between the measurements of the distance to potential CRM on both imaging modalities and the histopathology findings was assessed using Bland-Altman plots. Results: 57 patients (mean age, 59.2 years; 24 females) were included. The accuracy of T and N staging were 43.9% (95% confidence interval, 30.8–57.7%) and 77.2% (64.2– 87.3%) on CT and 63.2% (49.4–75.6%) and 77.2% (64.2–87.3%) on MRI for Observer 1. The accuracy of T and N staging were 54.4% (40.7–67.7%) and 77.2% (64.2–87.3%) on CT and 68.4% (54.7–80.1%) and 80.7% (68.1–90.0%) on MRI for Observer 2. Sensitivity and specificity on CRM involvement were 83.3% (43.7–97.0%) and 88.2% (76.6–94.5%) on CT and 100% (61.0–100%) and 90.2% (79.0–95.7%) on MRI for Observer 1. Sensitivity and specificity on CRM involvement were 66.7% (30.0–90.3%) and 88.2% (76.7– 94.5%) on CT and 100% (61.0–100%) and 90.2% (79.0–95.7%) on MRI for Observer 2. Bland-Altman plots showed wide discrepancies between measurements of the distance to CRM on each CT and MRI and those on histopathology findings. Conclusion: CT and MRI showed limited performance in predicting the local tumor staging and CRM involvement in patients with neoadjuvant CRT although MRI tended to show a better performance than CT. Index terms Rectal Neoplasms Multidetector Computed Tomography Magnetic Resonance Imaging Sensitivity and Specificity Chemoradiotherapy Diagnostic Accuracy of Computed Tomography and Magnetic Resonance Imaging Obtained after Neoadjuvant Chemoradiotherapy in Predicting the Local Tumor Stage and Circumferential Resection Margin Status of Rectal Cancer 직장암으로 수술 전 방사선 항암요법을 받은 환자에서 종양 병기와 수술 절제면 종양 침범 여부 예측에 대한 전산화단층촬영 및 자기공명영상의 진단 정확도에 관한 연구

Multimodal imaging evaluation in staging of rectal cancer.

Rectal cancer is a common cancer and a major cause of mortality in Western countries. Accurate staging is essential for determining the optimal treatment strategies and planning appropriate surgical procedures to control rectal cancer. Endorectal ultrasonography (EUS) is suitable for assessing the extent of tumor invasion, particularly in early-stage or superficial rectal cancer cases. In advanced cases with distant metastases, computed tomography (CT) is the primary approach used to evaluate the disease. Magnetic resonance imaging (MRI) is often used to assess preoperative staging and the circumferential resection margin involvement, which assists in evaluating a patient's risk of recurrence and their optimal therapeutic strategy. Positron emission tomography (PET)-CT may be useful in detecting occult synchronous tumors or metastases at the time of initial presentation. Restaging after neoadjuvant chemoradiotherapy (CRT) remains a challenge with all modalities because it is difficult to reliably differentiate between the tumor mass and other radiation-induced changes in the images. EUS does not appear to have a useful role in post-therapeutic response assessments. Although CT is most commonly used to evaluate treatment responses, its utility for identifying and following-up metastatic lesions is limited. Preoperative high-resolution MRI in combination with diffusion-weighted imaging, and/or PET-CT could provide valuable prognostic information for rectal cancer patients with locally advanced disease receiving preoperative CRT. Based on these results, we conclude that a combination of multimodal imaging methods should be used to precisely assess the restaging of rectal cancer following CRT.

Accuracy of High-Resolution MRI with Lumen Distention in Rectal Cancer Staging and Circumferential Margin Involvement Prediction

ObjectiveTo evaluate the accuracy of magnetic resonance imaging (MRI) with lumen distention for rectal cancer staging and circumferential resection margin (CRM) involvement prediction.Materials and MethodsSeventy-three patients with primary rectal cancer underwent high-resolution MRI with a phased-array coil performed using 60-80 mL room air rectal distention, 1-3 weeks before surgery. MRI results were compared to postoperative histopathological findings. The overall MRI T staging accuracy was calculated. CRM involvement prediction and the N staging, the accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were assessed for each T stage. The agreement between MRI and histological results was assessed using weighted-kappa statistics.ResultsThe overall MRI accuracy for T staging was 93.6% (k = 0.85). The accuracy, sensitivity, specificity, PPV and NPV for each T stage were as follows: 91.8%, 86.2%, 95.5%, 92.6% and 91.3% for the group ≤ T2; 90.4%, 94.6%, 86.1%, 87.5% and 94% for T3; 98,6%, 85.7%, 100%, 100% and 98.5% for T4, respectively. The predictive CRM accuracy was 94.5% (k = 0.86); the sensitivity, specificity, PPV and NPV were 89.5%, 96.3%, 89.5%, and 96.3% respectively. The N staging accuracy was 68.49% (k = 0.4).ConclusionMRI performed with rectal lumen distention has proved to be an effective technique both for rectal cancer staging and involved CRM predicting.

Preoperative Evaluation of Lower Rectal Cancer by Pelvic MR with and without Gel Filling

Purpose : To assess the usefulness of rectal filling using ultrasonographic gel in patients with lower rectal cancer. Materials and Methods: Twenty five patients with lower rectal cancer were enrolled. High resolution pelvic MR was performed twice before and after gel filling. Independently and retrospectively, two radiologists reviewed each set of MR images using five-grade scales for sphincter involvement, CRM (circumferential resection margin) involvement and depiction of the tumor. Same two radiologists retrospectively performed consensus review of each set of MR images for tumor distance from the anal verge and T&N staging. Results: Tumor depiction scores from MR with gel filling were significantly higher than those of MR without distention (p 0.05). Distance from the anal verge was significantly different between MR with gel filling and rigid endoscopy (6.8 1.6 cm vs. 5.8 1.6 cm, p=0.001). There were no significant differences between pathological staging and MR staging with or without gel filling. Conclusion: MR with gel filling improved tumor depiction. And also MR with gel filling revealed same ability for the predictions of CRM or sphincter invasion in patients with lower rectal cancer, comparing with MR without gel filling. Index words : Rectal cancer∙Magnetic resonance imaging (MRI)∙Rectum∙Ultrasonographic transmission gel Preoperative staging

Magnetic resonance imaging in rectal cancer: A surgeon’s perspective

Magnetic resonance imaging (MRI) in rectal cancer was first investigated in 1999 and has become almost mandatory in planning rectal cancer treatment. MRI has a high accuracy in predicting circumferential resection margin involvement and is used to plan neoadjuvant therapy. The accuracy of MRI in assessing mesorectal lymph nodes remains moderate, as there are no reliable criteria to assess nodal involvement. MRI seems to be good in assessing peritoneal involvement in upper rectal cancer; this however has been assessed in only a few studies and needs further research. For low rectal cancers, mesorectum is thin at the level of levator ani especially in relation to prostate; so predicting circumferential resection margin involvement is not easy. However high spatial resolution coronal imaging shows levator muscles, sphincter complex and intersphincteric plane accurately. This is used to stage low rectal tumors and plan plane of surgery (standard surgery, intersphincteric resection, Extralevator abdominoperineal resection). While most centres perform MRI post chemoradiotherapy, its role in accurate staging post neoadjuvant therapy remains debatable. THe role of Diffusion weighted MRI post neoadjuvant therapy is being evaluated in research settings.

Preoperative Magnetic Resonance Imaging Assessment of Circumferential Resection Margin Predicts Disease-Free Survival and Local Recurrence: 5-Year Follow-Up Results of the MERCURY Study

The prognostic relevance of preoperative high-resolution magnetic resonance imaging (MRI) assessment of circumferential resection margin (CRM) involvement is unknown. This follow-up study of 374 patients with rectal cancer reports the relationship between preoperative MRI assessment of CRM staging, American Joint Committee on Cancer (AJCC) TNM stage, and clinical variables with overall survival (OS), disease-free survival (DFS), and time to local recurrence (LR). Patients underwent protocol high-resolution pelvic MRI. Tumor distance to the mesorectal fascia of ≤ 1 mm was recorded as an MRI-involved CRM. A Cox proportional hazards model was used in multivariate analysis to determine the relationship of MRI assessment of CRM to survivorship after adjusting for preoperative covariates. Surviving patients were followed for a median of 62 months. The 5-year OS was 62.2% in patients with MRI-clear CRM compared with 42.2% in patients with MRI-involved CRM with a hazard ratio (HR) of 1.97 (95% CI, 1.27 to 3.04; P < .01). The 5-year DFS was 67.2% (95% CI, 61.4% to 73%) for MRI-clear CRM compared with 47.3% (95% CI, 33.7% to 60.9%) for MRI-involved CRM with an HR of 1.65 (95% CI, 1.01 to 2.69; P < .05). Local recurrence HR for MRI-involved CRM was 3.50 (95% CI, 1.53 to 8.00; P < .05). MRI-involved CRM was the only preoperative staging parameter that remained significant for OS, DFS, and LR on multivariate analysis. High-resolution MRI preoperative assessment of CRM status is superior to AJCC TNM-based criteria for assessing risk of LR, DFS, and OS. Furthermore, MRI CRM involvement is significantly associated with distant metastatic disease; therefore, colorectal cancer teams could intensify treatment and follow-up accordingly to improve survival outcomes.

Comparison of short- and long-term outcomes after extralevator abdominoperineal excision and standard abdominoperineal excision for rectal cancer: a systematic review and meta-analysis

Whether the introduction of extralevator abdominoperineal excision (ELAPE) improves survival and safety remains controversial. We conducted a systematic review and meta-analysis of all comparative studies to define the efficacy and safety of ELAPE and standard abdominoperineal excision (APE). A search for all major databases and relevant journals from inception to July 2013 without restriction on languages or regions was performed. Outcome measures were the oncological parameters of circumferential resection margin (CRM) involvement, intraoperative bowel perforation (IOP), and local recurrence, as well as other parameters of blood loss, operative time, length of hospitalization, and postoperative complication. The test of heterogeneity was performed with the Q statistic. A total of 949 patients were included in the meta-analysis. Oncological pooled estimates of intraoperative bowel perforation rate (RR 0.34; 95% CI 0.21-0.54; P<0.00001), CRM involvement (RR 0.44; 95% CI 0.34-0.56; P<0.00001), and local recurrence (RR 0.32; 95% CI 0.14-0.74; P=0.008) all showed outcomes that were significantly lower in ELAPE than in APE. A similar incidence of postoperative complication was attributed to both groups, including overall complication (RR 0.93; 95% CI 0.66-1.32; P=0.69), perineal wound complication (RR 0.72; 95% CI 0.33-1.55; P=0.39), and urinary dysfunction (RR 1.53; 95% CI 0.88-2.67; P=0.13). ELAPE has a lower intraoperative bowel perforation rate, positive CRM rate, and local recurrence rate than APE. There is evidence that in selected low rectal cancer patients, ELAPE is a more efficient and equally safe option to replace APE. Due to the inherent limitations of the present study, future randomized controlled trials will be useful to confirm this conclusion.