Pelvic Sidewall Nodes Research Articles

MRI-predicted extramural vascular invasion and tumour deposit are main predictors of disease-free survival in patients undergoing surgical resection for rectal cancer.

MRI is crucial in staging patients with rectal cancer and planning treatment. The aim was to analyse the prognostic role of MRI-predicted tumour deposits and/or extramural vascular invasion (mrTD/EMVI) in a cohort of patients with rectal cancer undergoing surgical resection, with selective neoadjuvant chemoradiotherapy (nCRT). Retrospective analysis of a single-centre cohort of consecutive patients with rectal cancer undergoing low anterior resection or abdominoperineal excision between 2008 and 2020. Unit policy was selective nCRT for MRI-predicted threatened or involved circumferential resection margin (mrCRM), or radiologically involved pelvic sidewall nodes. The primary outcome was disease-free survival. Secondary outcomes were rates of local recurrence, distant recurrence and overall survival. A total of 314 patients were analysed. Median age was 65 years (female/male: 114/200). A total of 54/314 (17%) had nCRT and 35 patients (11%) underwent abdominoperineal excision. Median follow-up was 64 months. Overall, local recurrence was detected in 18/314 (5.7%) and distant recurrence in 45/314 (14.3%). In patients not receiving nCRT (n = 260), local recurrence was detected in 11/260 (4.2%) and distant recurrence in 35/260 (13.5%). Disease-free survival was 80.5% at 5 years. Specifically, disease-free survival was 89% in mrTD/EMVI-negative and mrCRM-negative, 67% in mrTD/EMVI-positive and mrCRM-negative, and 64% in the mrCRM-positive rectal cancer (log-rank, P < 0.001). On multivariable Cox-regression analysis mrTD/EMVI was the only MRI variable associated with disease-free survival (hazard ratio 2.95; P < 0.001). mrTD/EMVI is a major prognostic indicator. Rectal cancer patients with mrCRM-negative and mrTD/EMVI-negative have excellent long-term outcomes with surgery alone. Patients with mrTD/EMVI-positive should be selectively stratified for neoadjuvant treatments in future clinical trials.

Restaging MRI of Rectal Adenocarcinoma after Neoadjuvant Chemoradiotherapy: Imaging Findings and Potential Pitfalls

Rectal adenocarcinoma constitutes about one-third of all colorectal adenocarcinoma cases. Rectal MRI has become mandatory for evaluation of patients newly diagnosed with rectal cancer because it can help accurately stage the disease, impact the choice to give neoadjuvant therapy or proceed with up-front surgery, and even direct surgical dissection planes. Better understanding of neoadjuvant chemoradiotherapy effects on rectal tumors and recognition that up to 30% of patients can have a pathologic complete response have opened the door for the nonsurgical "watch-and-wait" management approach for rectal adenocarcinoma. Candidates for this organ-preserving approach should have no evidence of malignancy on all three components of response assessment after neoadjuvant therapy (ie, digital rectal examination, endoscopy, and rectal MRI). Hence, rectal MRI again has a major role in directing patient management and possibly sparing patients from unnecessary surgical morbidity. In this article, the authors discuss the indications for neoadjuvant therapy in management of patients with rectal adenocarcinoma, describe expected imaging appearances of rectal adenocarcinoma after completion of neoadjuvant therapy, and outline the MRI tumor regression grading system. Since pelvic sidewall lymph node dissection is associated with a high risk of permanent genitourinary dysfunction, it is performed for only selected patients who have radiologic evidence of sidewall lymph node involvement. Therefore, the authors review the relevant lymphatic compartments of the pelvis and describe lymph node criteria for determining locoregional nodal spread. Finally, the authors discuss limitations of rectal MRI, describe several potential interpretation pitfalls after neoadjuvant therapy, and emphasize how these pitfalls may be avoided. © RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Expert Commentary on Lateral Pelvic Sidewall Nodes.

Expert Commentary on Lateral Pelvic Sidewall Nodes.

Robotic pelvic side-wall dissection and en-bloc excision for locally advanced and recurrent rectal cancer: outcomes on feasibility and safety.

Global differences exist in managing lateral pelvic nodes in rectal cancer. Recent studies demonstrate improved local recurrence rates in patients undergoing lateral pelvic lymph node dissections (LPND) in addition to total mesorectal excision (TME) for advanced lower rectal cancer. This study aims to report on the safety and feasibility of the robotic approach in patients undergoing pelvic sidewall lymph node dissection or en-bloc sidewall resection for advanced lower rectal cancer. Patients who underwent an elective robotic pelvic sidewall lymph node dissection or en-bloc sidewall resection for locally advanced rectal cancer with suspicious lateral lymph nodes or pelvic side wall involvement between January 2018 and March 2021 were included. Demographic, clinical, perioperative and histopathological variables were recorded and analysed. Eight patients (3 males) with a mean age of 55 (33-73) years and mean body mass index of 26.3 (20.7-30.0) kg/m2 were included. The median operative time and blood loss were 458.75 (360-540) min and 143.75 (100-300) mL, respectively. There were no conversions or intra-operative complications. There were three post-operative complications recorded (two ileus and one anastomotic leak which required an endoscopic washout in theatre and intravenous antibiotics thereafter). Median length of stay was 12.75 (7-23) days. All patients had an R0 resection, and the median lateral pelvic lymph node yield was 9.1 (6-14). This series demonstrates the practicality and the safety of the robotic approach in the introduction of this technique for en-bloc resection or LPND in patients with locally advanced rectal cancer.

Mesonephric-Like Adenocarcinoma: Two Cases Of A Rare Entity And Review Of Literature

Abstract Introduction/Objective Mesonephric-like adenocarcinoma (MLA) is a rare gynecologic malignancy occurring in the uterus and ovary and is morphologic similar to cervical mesonephric adenocarcinoma. We present two cases of mesonephric-like adenocarcinoma of the ovary. Methods The first case is a 72-year-old female presented with abdominal pain with bloating. Abdominal CT scan showed a 7.4 x 6.3 x 6.1 cm heterogenous right adnexal mass. The second case is a 66-year-old female with history of heavy bleeding and endometriosis, status post total abdominal hysterectomy with bilateral salpingo-oophorectomy 20 years ago. Abdominal CT scan demonstrated a 5.3 cm right pelvic mass and 12.5 cm right pelvic sidewall lymph node. Results Both tumors have characteristic variety of features including ductal, tubular, retiform, papillary, solid and infiltrative morphological patterns. Cytologic atypia is mild to moderate. The histological features can raise a broad differential diagnosis including primary tubo-ovarian carcinomas, sex cord-stromal tumors, and metastatic carcinomas. Immunohistochemical stains demonstrate the ovarian tumor cells are positive for multiple pan-epithelial markers (AE1/AE3); negative for sex cord-stromal markers (inhibin and calretinin); positive for PAX8, GATA3, TTF1, and CD10; and negative for ER, PR, and WT1. In the first case, a small incidental endometrial carcinoma arising from an endometrial polyp was also identified. Morphologically, it is distinct from the ovarian mesonephric-like adenocarcinoma. Conclusion Morphological and immunohistochemical features of the two tumors are consistent with MLA, a very rare ovarian tumor that is thought to arise either from mesonephric remnants in the para-ovarian tissue or by trans- differentiation from a benign or neoplastic Mullerian precursor. These tumors are reported to have a very high frequency of KRAS mutations followed by PIK3CA mutations. Due to their rarity, the clinical behavior of these tumors is unknown.

Rectal cancer lateral pelvic sidewall lymph nodes: a review of controversies and management.

The management of lateral pelvic lymphadenopathy in low rectal cancer poses an oncological and technical challenge. Interpretation of the literature is confounded by different approaches to management in the East and West, and a lack of randomized data from which to draw accurate conclusions regarding the optimal approach. Recent collaboration between Eastern and Western centres has increased the standardization of care. Despite this, significant differences in international guidelines remain. The aim of this review was to appraise the available literature and propose a management algorithm. A literature review of all relevant studies was performed to summarize the historical evidence, as well as establish the significance of clinically positive lateral pelvic sidewall nodes, and the role of neoadjuvant chemoradiotherapy and lateral pelvic node dissection. A management algorithm was developed based on this review of the literature. The management of pelvic sidewall lymphadenopathy in rectal cancer is non-standardized, with geographical differences. The mechanism of lateral lymphatic spread is well defined; the risk increases with lower tumour height and advanced T category. Existing data indicate that acceptable disease-free and overall survival can be achieved by neoadjuvant chemoradiotherapy with selective lateral pelvic node dissection. Suspicious lateral pelvic sidewall nodes, particularly in the internal iliac chain, should be considered as resectable locoregional disease, and surgery offered for enlarged nodes that do not respond to neoadjuvant chemoradiotherapy.

Incidence and treatment of positive pelvic sidewall lymph nodes in patients with rectal cancer.

The involvement of pelvic sidewall (PSW) lymph nodes in rectal cancer is a marker of locally advanced disease and poor prognosis. Eastern countries generally advocate lateral lymph node dissection (LLND) over the Western approach of neoadjuvant chemoradiotherapy and more limited surgery. The aim of this study was to evaluate how these advanced cancers were treated in three UK Health Boards. This was a retrospective review of three colorectal multidisciplinary team meetings from 2008 to 2016. All patients with rectal cancer and suspicious PSW lymph nodes on pretreatment MRI were included. There were 153 (6.2%) patients who met the inclusion criteria from a total of 2461 diagnosed rectal cancers. There was significant variability between the three centres with surgical intervention ranging from 59.2% to 84.4%, P=0.015. There were 81 patients who had neoadjuvant chemoradiotherapy prior to surgery; of these 67 (82.7%) still had positive PSW nodes on the restaging MRI, but only 13 (19.4%) had LLND. There was no difference in local recurrence (15.3% vs 11.8%, P=0.66), 5-year overall survival (69.2% vs 80.1%, P=0.16) or 5-year disease-free survival (69.2% vs 79.4%, P=0.72) between patients having LLND and those receiving standard neoadjuvant treatment followed by total mesorectal excision surgery. This study has demonstrated that rectal cancer patients with PSW positive nodal disease have advanced disease, mostly of the lower rectum, and receive a highly heterogeneous spectrum of therapies, even within a relatively small geographical area. Greater accuracy in our preoperative staging is needed to select those patients who will benefit from LLND surgery.

MRI features and texture analysis for the early prediction of therapeutic response to neoadjuvant chemoradiotherapy and tumor recurrence of locally advanced rectal cancer.

This study aimed to evaluate the efficiency of imaging features and texture analysis (TA) based on baseline rectal MRI for the early prediction of therapeutic response to neoadjuvant chemoradiotherapy (nCRT) and tumor recurrence in patients with locally advanced rectal cancer (LARC). Consecutive patients with LARC who underwent rectal MRI between January 2014 and December 2015 and surgical resection after completing nCRT were retrospectively enrolled. Imaging features were analyzed, and TA parameters were extracted from the tumor volume of interest (VOI) from baseline rectal MRI. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the optimal TA parameter cutoff values to stratify the patients. Logistic and Cox regression analyses were performed to assess the efficacy of each imaging feature and texture parameter in predicting tumor response and disease-free survival. In total, 78 consecutive patients were enrolled. In the logistic regression, good treatment response was associated with lower tumor location (OR = 13.284, p = 0.012), low Conv_Min (OR = 0.300, p = 0.013) and high Conv_Std (OR = 3.174, p = 0.016), Shape_Sphericity (OR = 3.170, p = 0.015), and Shape_Compacity (OR = 2.779, p = 0.032). In the Cox regression, a greater risk of tumor recurrence was related to higher cT stage (HR = 5.374, p = 0.044), pelvic side wall lymph node positivity (HR = 2.721, p = 0.013), and gray-level run length matrix_long-run low gray-level emphasis (HR = 2.268, p = 0.046). Imaging features and TA based on baseline rectal MRI could be valuable for predicting the treatment response to nCRT for rectal cancer and tumor recurrence. • Imaging features and texture parameters of T2-weighted MR images of rectal cancer can help to predict treatment response and the risk for tumor recurrence. • Tumor location as well as conventional and shape indices of texture features can help to predict treatment response for rectal cancer. • Clinical T stage, positive pelvic side wall lymph nodes, and the high-order texture parameter, GLRLM_LRLGE, can help to predict tumor recurrence for rectal cancer.

Imaging and Management of Rectal Cancer

High-resolution phased array external magnetic resonance imaging (MRI) is the first investigation of choice in rectal cancer for local staging, both in the primary and restaging situations. Use of MRI helps differentiate between those with good prognosis, which can be offered upfront surgery and the poor prognostic cases where treatment intensification is needed. MRI identified poor prognostic factors are threatened or involved mesorectal fascia, T3 tumors with >5 mm extramural spread, those with extramural vascular invasion, pelvic sidewall nodes and mucinous tumors. At restaging, use of MRI helps evaluate response and an MR tumor regression grading system is being evaluated. Complete response seen on clinical examination and endoscopy, needs confirmation on MRI using both T2-weighted and diffusion-weighted sequences to justify a "watch and wait" approach. In this subset of patients, MRI also plays a role in monitoring and detecting early regrowth. In those with partial response, MRI helps define surgical margins and can be used as a roadmap to decide between sphincter preserving surgeries and radical sphincter sacrificing surgeries; pelvic exenteration and pelvic sidewall lymph node dissection. Poor responders on MRI may benefit from adjuvant chemotherapy. Use of MRI thus helps in individualizing treatment in rectal cancer.

CT Staging to Triage Selection of Patients With Poor-Prognosis Rectal Cancer for Neoadjuvant Treatment.

OBJECTIVE. The purpose of this study was to evaluate CT as a screening tool for determining high risk of local recurrence of rectal tumors in a scenario of limited MRI availability. MATERIALS AND METHODS. Data were retrospectively analyzed for 180 consecutively registered patients with rectal adenocarcinoma and no previous treatment who underwent baseline CT and MRI staging within 30 days of each other. Two radiologists independently reviewed CT and MR images. CT scans were interpreted in multiplanar reformation. High risk of local recurrence was based on the MRI reference standard: T3cd (more than 5 mm of mesorectal fat infiltration) or T4 disease, N2 nodal status, mesorectal fascia involvement, extramural venous invasion, or positive pelvic sidewall nodes. The performance of CT for determination of high risk of local tumor recurrence was evaluated. RESULTS. Among the 180 patients 128 (71%) met MRI criteria for high risk of local recurrence. CT sensitivity was 84.4% (108/128) and specificity was 78.8% (41/52). The positive predictive value (PPV) of any high-risk CT feature was 90.7% (108/119). When T status was considered, the sensitivity of CT was 75.2% (79/105), specificity was 90.7% (68/75), and PPV was 91.9% (79/86). When tumors within 5.0 cm of the anal verge were excluded, sensitivity was 89.5% (51/57), specificity was 85.7% (24/28), and PPV was 92.7% (51/55). Using CT for disease staging could reduce MRI use by 66%. CONCLUSION. Tumors at high risk of local recurrence can be identified with CT without baseline MRI. Use of CT rather than MRI could markedly reduce costs of baseline staging and shorten time to initiation of neoadjuvant treatment.

Radiation Therapy Dose Escalation to Clinically Involved Pelvic Sidewall Lymph Nodes in Locally Advanced Rectal Cancer

PurposeLateral pelvic sidewall lymph nodes (PSW LN) may be involved in up to 24% of locoregionally advanced rectal cancers. PSW LN are not resected in total mesorectal excision (TME), and no standard of care regarding the management of PSW LN exists in the United States. We assessed our institutional experience of preoperative radiation therapy (RT) boost to clinically involved PSW LN that were not planned for resection. Methods and materialsData from all patients with rectal adenocarcinoma treated between 2006 and 2018 were reviewed to identify those who received a cumulative dose of >50.4 Gy to suspicious PSW LN during neoadjuvant chemoradiation therapy (nCRT). Demographic, cancer characteristic, treatment, and toxicity data were derived from the chart. ResultsOf a total of 261 patients, 12 patients met the inclusion criteria. The median age was 47.5 years, and 83% of patients were men. All patients had T3/4 disease, 17% of patients had N1b disease and the remainder had N2 disease, and 33% had M1 disease (all ≤2 metastases). Seventy-five percent of patients had moderately or poorly differentiated histology. The mean distance from the anal verge was 4.85 cm (range, 2-8.9 cm), and 58% had ≥2 PSW LN with an average short axis diameter of 1.11 cm (range, 0.4-3.2 cm). Boost doses ranged from 53.48 Gy to 60.2 Gy in 27 to 30 fractions (1.8-2.15 Gy/fraction). The median follow-up time was 18 months. One patient who received concurrent capecitabine and irinotecan had grade 3 perineal dermatitis and anemia during nCRT. The median hospitalization time for TME was 6.5 days. Within 90 days of TME, 1 patient required surgical exploration for perineal wound breakdown, and another required a blood transfusion for anemia. At the time of the last follow up, 75% of patients were alive. Local control at 12 months was 90%. ConclusionsRT dose escalation to nonresected PSW LN during nCRT was well tolerated with a low risk of acute toxicity and perioperative complications and has a high rate of local control at 12 months. RT boost warrants further study in patients with clinically involved nonresected PSW LN.

The effect of formalin fixation on the size of pelvic sidewall lymph nodes.

Although several studies have demonstrated that the size of harvested lymph nodes can be a prognostic predictor in colorectal cancer patients, some considered the size of freshly harvested nodes and others assessed the size after formalin fixation. Because the size change of lymph nodes during fixation has not been fully investigated, we conducted the present study comparing the size of lateral lymph nodes that were surgically harvested from rectal cancer patients, before and after formalin fixation. A total of 19 consecutive patients diagnosed with rectal adenocarcinoma who underwent total mesorectal excision and dissection of lateral pelvic sidewall lymph nodes were prospectively enrolled. The largest diameters of lymph nodes were measured immediately after manual harvest and after formalin fixation. The ratio of post-fixation size to pre-fixation size and the size difference between pre- and post-fixation were assessed for each lymph node. The average ratio (± standard deviation) of post-fixation size to pre-fixation size was 0.88 ± 0.40, with median value of 0.8. The size of the lymph nodes decreased by an average of 1.04mm after fixation, and the median size change after fixation was a 1-mm decrease. Although measuring lymph node size after formalin fixation can be a viable alternative to measuring the size of fresh lymph nodes before fixation, a 10 to 20% shrinkage or 1-mm size reduction should be considered when interpreting the examination findings.

Pathologic Complete Response in Rectal Cancer: Can We Detect It? Lessons Learned From a Proposed Randomized Trial of Watch-and-Wait Treatment of Rectal Cancer.

Chemoradiotherapy has the potential to downsize and downstage tumors before surgery, decrease locoregional recurrence, and induce a complete sterilization of tumor cells for middle and low locally advanced rectal cancer. A watch-and-wait tactic has been proposed for patients with clinical complete response. The purpose of this study was to verify our ability to identify complete clinical response in patients with rectal cancer based on clinical and radiologic criteria. This was a prospective study. The study was conducted at a single institution, in the setting of a watch-and-wait randomized trial. Consecutive patients with stage T3 to T4N0M0 or T(any)N+M0 cancer located within 10 cm from anal verge or T2N0 within 7 cm from anal verge were included in the study. Patients were staged and restaged 8 weeks after completion of chemoradiation (5-fluorouracil, 5040 cGy) by digital examination, colonoscopy, pelvic MRI, and thorax and abdominal CT scans. Clinical and radiologic judgments of tumor response were compared with pathologic response of patients treated by total mesorectal excision or clinical follow-up of patients selected for nonoperative treatment. A total of 118 patients were treated. Six patients were considered clinic complete responders (2 randomly assigned for surgery (1 ypT0N0 and 1 ypT2N0) and 4 patients randomly assigned for observation (3 sustained clinic complete response and 1 had tumor regrowth)). The 112 clinic incomplete responders underwent total mesorectal excision, and 18 revealed pathologic complete response. These 18 patients were not considered complete responders at restaging because they presented at least 1 of the following conditions: mucosal ulceration and/or deformity and/or substenosis of rectal lumen at digital rectal examination and colonoscopy (n = 16), ymrT1 to T4 (n = 16), ymrN+ (n = 2), involvement of circumferential resection margin on MRI (n = 3), extramural vascular invasion on MRI (n = 4), MRI tumor response grade 2 to 4 (n = 15), and pelvic side wall lymph node involvement on MRI (n = 1). Sensitivity for identification of ypT0N0 or sustained clinic complete response was 18.2%. This study has a short follow-up and small sample size. Radiologists who reviewed the restaging examination were not blinded to the pretreatment stage. Only 1 radiologist read the images of each patient. Evaluation of clinic complete response according to current adopted criteria has low sensitivity because pathologic complete response more frequently presented as clinic incomplete response (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A221).

Pelvic side wall nodes in locally advanced rectal cancer as a prognostic indicator.

613 Background: Neoadjuvant long course chemoradiotherapy is a well recognised treatment in locally advanced rectal cancer. Patients with pelvic side wall nodes are often considered for neoadjuvant treatment. We investigated whether pelvic side wall nodes identified on pre-treatment imaging is a poor prognostic factor and whether there are different patterns of recurrence compared to patients without pelvic side wall node involvement. Methods: All patients treated with long course chemoradiotherapy between January 2008 and December 2009 were identified. Patients were excluded if treatment indication was for inoperable disease, postoperative, recurrence, or palliative intent. 231 patients were identified and a retrospective analysis performed investigating patterns of recurrence and survival for patients with pelvic side wall nodes identified on pre-treatment imaging. Results: Kaplan Meier curves are presented showing patients with pelvic side wall nodes identified on pre-treatment imaging appear to have poorer outcomes and overall survival compared with those with only mesorectal nodes or no nodes. Patterns of recurrence are presented, showing patients with pelvic side wall nodes identified on pre-treatment imaging have a non significant trend to increased rates of disease recurrence (local and distal recurrence combined, 45.7% versus 27.9% for pelvic side wall nodes versus no pelvic side wall nodes). Patients with pelvic side wall nodes identified on pre-treatment imaging appear to be more likely to develop distant metastases compared to those patients who have mesorectal nodes or no nodal involvement (37% versus 23%). Conclusions: Our study highlights that patients with pelvic side wall nodes identified on pre-treatment imaging appear to have a trend to poorer overall survival, are more likely to recur and develop distant metastases. These results were not statistically significant, due to the small number of patients, and the data is consequently limited. We intend to further investigate current management strategies for this subgroup of patients, with assessment of radiotherapy treatment plans, current use of integral boosts, and surgical procedures for this subgroup of patients.

MR Imaging for Preoperative Evaluation of Primary Rectal Cancer: Practical Considerations

High-resolution magnetic resonance (MR) imaging plays a pivotal role in the pretreatment assessment of primary rectal cancer. The success of this technique depends on obtaining good-quality high-resolution T2-weighted images of the primary tumor; the mesorectal fascia, peritoneal reflection, and other pelvic viscera; and superior rectal and pelvic sidewall lymph nodes. Although orthogonal axial high-resolution T2-weighted MR images are the cornerstone for the staging of primary rectal cancer, high-resolution sagittal and coronal images provide additional value, particularly in tumors that arise in a redundant tortuous rectum. Coronal high-resolution T2-weighted MR images also improve the assessment of nodal morphology, particularly for superior rectal and pelvic sidewall nodes, and of the relationship between advanced-stage tumors and adjacent pelvic structures. Rectal gel should be used in MR imaging examinations conducted for the staging of polypoid tumors, previously treated lesions, and small rectal tumors. However, it should not be used in examinations performed to stage large or low rectal tumors. Diffusion-weighted imaging is useful for identifying nodes and, occasionally, the primary tumor when the tumor is difficult to visualize with other sequences. Three-dimensional T2-weighted imaging provides multiplanar capability with a superior signal-to-noise ratio compared with two-dimensional T2-weighted imaging.

Relevance of magnetic resonance imaging-detected pelvic sidewall lymph node involvement in rectal cancer

The significance of magnetic resonance imaging (MRI)-suspected pelvic sidewall (PSW) lymph node involvement in rectal cancer is uncertain. 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. 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. 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.

196 Factor score of multidrug resistance in treatment locally advanced rectal

High-resolution phased array external magnetic resonance imaging (MRI) is the first investigation of choice in rectal cancer for local staging, both in the primary and restaging situations. Use of MRI helps differentiate between those with good prognosis, which can be offered upfront surgery and the poor prognostic cases where treatment intensification is needed. MRI identified poor prognostic factors are threatened or involved mesorectal fascia, T3 tumors with >5 mm extramural spread, those with extramural vascular invasion, pelvic sidewall nodes and mucinous tumors. At restaging, use of MRI helps evaluate response and an MR tumor regression grading system is being evaluated. Complete response seen on clinical examination and endoscopy, needs confirmation on MRI using both T2-weighted and diffusion-weighted sequences to justify a “watch and wait” approach. In this subset of patients, MRI also plays a role in monitoring and detecting early regrowth. In those with partial response, MRI helps define surgical margins and can be used as a roadmap to decide between sphincter preserving surgeries and radical sphincter sacrificing surgeries; pelvic exenteration and pelvic sidewall lymph node dissection. Poor responders on MRI may benefit from adjuvant chemotherapy. Use of MRI thus helps in individualizing treatment in rectal cancer.

Treatment of Advanced Low Rectal Cancer-Oncological and Functional Consideration

The treatment of mid-and low rectal cancer is a challenging issue. Lateral spread of cancer cells to the pelvic side wall, sphincter preservation technique in a narrow pelvis, ultra-low ananstomosis, a high local recurrent rate, and unsatisfactory anorectal function of low anastomosis are all problems which should be solved. Total mesorectal excision resection is now the standard procedure. Lateral pelvic side wall lymph node dissection is not widely accepted as a routine procedure because of high morbidity. Now it is largely replaced by preoperative CCRT (concurrent chemoradiotherapy). Construction of a colon pouch for ultra-low anastomosis is well accepted for improvement of anorectal function after resection for lower rectal cancers.

The vascular portion of the cardinal ligament: surgical significance during radical hysterectomy for cervical cancer

The objective of the study was to analyze the histopathologic content of the vascular portion of the cardinal ligament in patients undergoing radical hysterectomy for cervical cancer. The vascular portion of the cardinal ligament was completely removed during radical hysterectomy. The maximum cervical diameter and length of the vascular ligament were measured on the fresh specimen. After inking, the pathologist separated and embedded the entire vascular segment from each side. Microscopic examination followed. Eighty-four patients were available for analysis. The mean cervical diameter was 3.9 cm (2-8), whereas the mean vascular segment length on the right and left sides were 4 cm (1-10) and 3.8 cm (1-7), respectively. Mean number of vascular segment lymph nodes were as follows: medial right = 0.7 (0-4), medial left = 0.6 (0-5), lateral right = 0.4 (0-3), and lateral left = 0.6 (0-6). Mean diameter of medial and lateral lymph nodes were 2 mm (0.25-8) and 3.3 mm (0.25-16), respectively. The length of the vascular segment correlated inversely with maximum cervical diameter. Thirty-one percent (26 of 84) had positive pelvic side wall lymph nodes. Fourteen patients had positive vascular segment lymph nodes (1 positive = 7, more than 1 positive = 7). Three of 7 patients had bilateral positive vascular segment lymph nodes; all 7 had microscopic disease in the paravaginal soft tissue, and all 7 had positive pelvic side wall lymph nodes (6 of 7 bilateral). Including the 14 patients, a total of 19 had nodal or nonnodal microscopic disease in the vascular segment. Of these, 7 had disease in the lateral half of the vascular ligament. Histologic sectioning revealed nerve twigs and/or scattered ganglia in the vascular segment but no large nerve trunks. Among a population of women with high-risk, early-stage cervical cancer, the lateral vascular segment of the cardinal ligament contained metastatic disease in a substantial number of patients. This segment contains no major nerve trunks. When radical hysterectomy is chosen as primary treatment for such patients, the vascular segment of the cardinal ligament should be completely excised.

The incidence of lateral pelvic side-wall nodal involvement in low rectal cancer may be similar in Japan and the West

There is an East-West divide with regard to the frequency, significance and management of lateral pelvic side-wall nodes associated with low rectal cancer. In Japan, removal of nodes is considered essential in curative treatment of selected patients. In the West, involved nodes are generally considered as metastatic disease. There may be international differences in rectal cancer behaviour. A review of relevant studies was undertaken using PubMed, Cochrane Library and personal archives of references; further cross-referencing was conducted. Historical developments, relevant anatomy and reports on lateral pelvic lymphadenectomy (LPLD) were identified. Outcomes following LPLD were assessed. The low rectum has lateral lymphatic drainage. Enhanced pelvic imaging techniques suggest that some patients with low rectal cancer have lateral pelvic lymph node involvement. However, there is no universal agreement on the definition of either the rectum or low rectal cancer. Selective use of LPLD has led to good outcomes in Japan. An alternative strategy might be neoadjuvant therapy for involved lateral nodes. Pelvic imaging and correlation with pathological findings are crucial in the assessment of lateral pelvic side-wall nodes. East and West should combine their experience of preoperative staging, surgical treatment and pathological assessment of low rectal cancer.