Extramesorectal Lymph Node Research Articles

Simultaneous integrated boost intensity-modulated radiation therapy targeting clinically involved extramesorectal lymph nodes in locally advanced rectal cancer: A retrospective study.

Consensus is lacking regarding the management of extramesorectal lymph nodes (EMLN) in rectal cancer. Using simultaneous integrated boost intensity-modulated radiation therapy (SIB-IMRT), we targeted involved EMLN and reserved lateral pelvic lymph nodal dissection (LPLND) for nonresponders. The primary aim of this work was to determine the proportion of patients who avoided LPLND and to establish the pathological EMLN positivity rate. Consecutive patients with rectal cancer with suspicious EMLN [short axis dimension (SAD) ≥ 7 mm], receiving SIB-IMRT as part of neoadjuvant chemoradiotherapy and subsequently undergoing total mesorectal excision (TME) or watch-and-wait, were included. Our primary objective was to determine the proportion of patients with a good nodal response (EMLN SAD < 5 mm) who were spared LPLND. The 3-year locoregional relapse rate, distant metastasis-free survival (DMFS) and overall survival (OS) were also assessed. Of the 61 patients studied, 38 (62.3%) responded well to SIB-IMRT. In this group, 32 patients underwent TME alone and six were observed as per watch-and-wait. The remaining 23 (37.7%) patients with persistent EMLN received TME with LPLND. On pathological evaluation, 7 (30.4%) patients had positive nodes while 16 (69.6%) were negative. At a median follow-up of 32 months (95% CI 23.3-40.7 months), 10 (16.4%) patients developed distant metastases while none had local or pelvic relapse. The resultant 3-year DMFS and OS for the whole cohort were 84.4% and 95.1%, respectively. Overall, 5/61 (8.2%) patients encountered radiation-induced toxicity of grade 3 or above and 8/55 (14.5%) patients had severe postoperative complications. SIB-IMRT targeting EMLN followed by selective LPLND exhibits excellent oncological outcomes. While patients responding to SIB-IMRT safely avoid LPLND, the potential for increased morbidity in nonresponders must be considered.

Diagnostic Performance of Rectal CT for Staging Rectal Cancer: Comparison with Rectal MRI and Histopathology.

To compare the diagnostic performance of rectal CT with that of high-resolution rectal MRI and histopathology in assessing rectal cancer. Sixty-seven patients with rectal cancer who underwent rectal CT with rectal distension using sonographic gel and high-resolution MRI were enrolled in this study. The distance from the anal verge/anorectal junction, distance to the mesorectal fascia (MRF), extramural depth (EMD), extramesorectal lymph node (LN) involvement, extramural venous invasion (EMVI), and T/N stages in rectal CT/MRI were analyzed by two gastrointestinal radiologists. The CT findings of 20 patients who underwent radical surgery without concurrent chemoradiotherapy were compared using histopathology. Interclass correlations and kappa statistics were used. The distance from the anal verge/anorectal junction showed an excellent intraclass correlation between CT and MRI for both reviewers. For EMD, the distance to the MRF, presence of LNs, extramesorectal LN metastasis, EMVI, T stage, and intermodality kappa or weighted kappa values between CT and MRI showed excellent agreement. Among the 20 patients who underwent radical surgery, T staging, circumferential resection margin involvement, EMVI, and LN metastasis on rectal CT showed acceptable concordance rates with histopathology. Dedicated rectal CT may be on par with rectal MRI in providing critical information to patients with rectal cancer.

Neoadjuvant FOLFOXIRI prior to chemoradiotherapy for high-risk (“ugly”) locally advanced rectal cancer: study protocol of a single-arm, multicentre, open-label, phase II trial (MEND-IT)

BackgroundThe presence of mesorectal fascia (MRF) invasion, grade 4 extramural venous invasion (EMVI), tumour deposits (TD) or extensive or bilateral extramesorectal (lateral) lymph nodes (LLN) on MRI has been suggested to identify patients with indisputable, extensive locally advanced rectal cancer (LARC), at high risk of treatment failure. The aim of this study is to evaluate whether or not intensified chemotherapy prior to neoadjuvant chemoradiotherapy improves the complete response (CR) rate in these patients.MethodsThis multicentre, single-arm, open-label, phase II trial will include 128 patients with non-metastatic high-risk LARC (hr-LARC), fit for triplet chemotherapy. To ensure a study population with indisputable, unfavourable prognostic characteristics, hr-LARC is defined as LARC with on baseline MRI at least one of the following characteristics; MRF invasion, EMVI grade 4, enlarged bilateral or extensive LLN at high risk of an incomplete resection, or TD. Exclusion criteria are the presence of a homozygous DPD deficiency, distant metastases, any chemotherapy within the past 6 months, previous radiotherapy within the pelvic area precluding standard chemoradiotherapy, and any contraindication for the planned treatment. All patients will be planned for six two-weekly cycles of FOLFOXIRI (5-fluorouracil, leucovorin, oxaliplatin and irinotecan) prior to chemoradiotherapy (25 × 2 Gy or 28 × 1.8 Gy with concomitant capecitabine). A resection will be performed following radiological confirmation of resectable disease after the completion of chemoradiotherapy. A watch and wait strategy is allowed in case of a clinical complete response. The primary endpoint is the CR rate, described as a pathological CR or a sustained clinical CR one year after chemoradiotherapy. The main secondary objectives are long-term oncological outcomes, radiological and pathological response, the number of resections with clear margins, treatment-related toxicity, perioperative complications, health-related costs, and quality of life.DiscussionThis trial protocol describes the MEND-IT study. The MEND-IT study aims to evaluate the CR rate after intensified chemotherapy prior to concomitant chemoradiotherapy in a homogeneous group of patients with locally advanced rectal cancer and indisputably unfavourable characteristics, defined as hr-LARC, in order to improve their prognosis.Trial registrationClinicaltrials.gov: NCT04838496, registered on 02–04-2021 Netherlands Trial Register: NL9790.Protocol versionVersion 3 dd 11–4-2022.

Anal canal melanoma-a rare entity: A case report and review of literature

Anorectal mucosal melanoma is one of the rarest neoplasm and accounts for approximately 0.05 percent of all colorectal malignancies and 1 percent of all anal canal cancers. Patients typically present with bleeding, a mass, anorectal pain, or a change in bowel habits. Management includes surgical resection depending upon the site along with adjuvant chemotherapy, radiotherapy and immunotherapy. 48 years old gentleman who presented with 6-month-old history of bleeding per rectum, pain and tenesmus. On digital rectal examination, a semi-circular polypoidal growth was present posteriorly 2 cm from anal verge with cranio-caudal extent of 5 cm. Biopsy was suggestive of malignant melanoma. MRI pelvis revealed asymmetric circumferential thickening of 30 mm for length of 3.8 cm located 3.4 cm from anal verge with enlarged mesorectal and extra-mesorectal lymph nodes. Patient was planned for abdomino-perineal resection. Surgery and post-operative period were uneventful. Final histopathology revealed polypoidal tan-brown, partly ulcerated growth of 4 x 2.5 x 2 cm on cut-section. These findings were consistent with malignant melanoma. All 15 lymph nodes dissected were free from tumor deposits.

Anal Canal Melanoma - A Case Report and Review of Literature

Anorectal mucosal melanoma is one of the rarest neoplasms and accounts for approximately 0.05 percent of all colorectal malignancies and 1 percent of all anal canal cancers. Patients typically present with bleeding, a mass, anorectal pain, or a change in bowel habits. Management includes surgical resection depending upon the site along with adjuvant chemotherapy, radiotherapy and immunotherapy. 48 years old gentleman who presented with 6-month-old history of bleeding per rectum, pain and tenesmus. On digital rectal examination, a semicircular polypoidal growth was present posteriorly 2 cm from anal verge with cranio-caudal extent of 5 cm. Biopsy was suggestive of malignant melanoma. MRI pelvis revealed asymmetric circumferential thickening of 30 mm for length of 3.8 cm located 3.4 cm from anal verge with enlarged mesorectal and extra-mesorectal lymph nodes. Patient was planned for abdomino-perineal resection. Surgery and post-operative period were uneventful. Final histopathology revealed polypoidal tan-brown, partly ulcerated growth of 4 x 2.5 x 2 cm on cut-section. These findings were consistent with malignant melanoma. All 15 lymph nodes dissected were free from tumor deposits.

Oligometastatic Rectal Adenocarcinoma Treated With Short-Course Radiotherapy and Chemotherapy with Non-Operative Intent of the Primary for Pelvic Complete Responders

Sequential short-course radiotherapy and chemotherapy (SCRT-CH) is a promising treatment for non-operative management of rectal adenocarcinoma. This paradigm has not been evaluated for newly diagnosed oligometastatic (OM1) patients (pts). We evaluated rates of locoregional clinical complete response (cCR), rectal surgeries, and local control (LC) in newly diagnosed OM1 pts treated with definitive treatment of the primary tumor with SCRT-CH with non-operative intent for pts with locoregional cCR.From 2/2018 to 5/2020, 39 pts with newly diagnosed OM1 rectal cancer were treated with SCRT-CH and non-operative intent for locoregional cCR at a single institution. OM1 disease was considered disease confined to ≤ 2 distant sites. Pts received 25 Gy/5 fx to the pelvis with an optional boost to 35 Gy for involved extra-mesorectal lymph nodes. CH was delivered prior to and/or after RT. Locoregional cCR was assessed via DRE, sigmoidoscopy, and/or pelvic MRI following completion of SCRT-CH. Follow-up was calculated from RT completion. Survival was evaluated by Kaplan-Meier method and log rank test.All 39 pts with 47 distant sites completed SCRT and 36 (92%) had CH. 22 (56%) received all CH following RT, and 24 (62%) received at least 2 months of CH after RT. 33 pts received 1st line FOLFOX +/- bevacizumab (bev). 13 pts underwent low anterior resection and 2 pts underwent abdominoperineal resection. 19 pts had 23 distant sites treated. The most common distant site treated was liver and the most common modality was resection. Following SCRT, only 4 pts (10%) experienced a local failure (median 6.4 months, range 0.7-10.7 months). 6/39 experienced a pelvic cCR (15%); all cCR pts received SCRT first followed by at least 2 months of CH. Pts with a cCR were more likely to have received at least 2 months of CH following SCRT compared to patients without a cCR (100% vs. 59%, P < .05). The median follow-up for living pts was 16 months. The 1-year overall survival (OS) was 66% (95% CI: 51-84%) for all pts. Pts who received at least 2 months of CH following SCRT had an improved OS (1-year OS [95% CI]: 82% [68-100%] vs. 29% [10-84%], P < .001 by log-rank) compared to pts who did not.SCRT-CH with non-operative intent for pts in locoregional cCR is a promising treatment paradigm for OM1 rectal cancer pts.

Intra- and Interobserver Variability in Magnetic Resonance Imaging Measurements in Rectal Cancer Patients.

Simple SummaryColorectal cancer is the second most common cancer and was the second most common cause of cancer-related death in Europe in 2018. Accurate lymph node staging in primary rectal cancer staging is essential for the selection of the proper treatment regimen. In 2018, The European Society of Gastrointestinal and Abdominal Radiology published consensus recommendations for primary rectal cancer staging, and suggested that lymph nodes be assessed by size, morphology, and location in- or outside the mesorectal fascia. Our study aimed to assess the inter- and intraobserver variability in size, apparent diffusion coefficient measurements, and morphological characterization among inexperienced and experienced radiologists. Our data indicate that subjective variables like morphological characteristics are less reproducible than numerical variables, regardless of the level of experience of the observers.Colorectal cancer is the second most common cancer in Europe, and accurate lymph node staging in rectal cancer patients is essential for the selection of their treatment. MRI lymph node staging is complex, and few studies have been published regarding its reproducibility. This study assesses the inter- and intraobserver variability in lymph node size, apparent diffusion coefficient (ADC) measurements, and morphological characterization among inexperienced and experienced radiologists. Four radiologists with different levels of experience in MRI rectal cancer staging analyzed 36 MRI scans of 36 patients with rectal adenocarcinoma. Inter- and intraobserver variation was calculated using interclass correlation coefficients and Cohens-kappa statistics, respectively. Inter- and intraobserver agreement for the length and width measurements was good to excellent, and for that of ADC it was fair to good. Interobserver agreement for the assessment of irregular border was moderate, heterogeneous signal was fair, round shape was fair to moderate, and extramesorectal lymph node location was moderate to almost perfect. Intraobserver agreement for the assessment of irregular border was fair to substantial, heterogeneous signal was fair to moderate, round shape was fair to moderate, and extramesorectal lymph node location was substantial to almost perfect. Our data indicate that subjective variables such as morphological characteristics are less reproducible than numerical variables, regardless of the level of experience of the observers.

Is neoadjuvant chemoradiotherapy sufficient in patients with advanced rectal malignancy and positive extra-mesorectal lateral lymph nodes?

There is current debate about the optimal management of lateral pelvic lymph nodes (LPLNs) in rectal cancer between Western and Eastern centres. This paper aims to report the rate of histologically proven positive LPLNs in a group of patients undergoing the conventional Western approach to primary and recurrent rectal cancer. A retrospective cohort review of all patients who underwent LPLN dissection at Royal Prince Alfred Hospital in Sydney, Australia. This included patients who underwent pelvic exenteration who had LPLNs excised either en bloc for laterally invasive or recurrent tumours or as part of selective node dissection for suspicious lymph nodes on preoperative imaging. Histopathological results for these patients were compared with node status at preoperative imaging. Seventy-one patients satisfied the inclusion criteria. Of those patients with positive nodes on histology, 27% (9/33) with radiologically positive LPLNs were treated with preoperative radiotherapy and 75% (9/12) with radiologically positive LPLNs were not treated with preoperative radiotherapy (P=0.004). None of the 12 patients with radiologically negative nodes treated with radiotherapy had positive nodes; 25% (3/12) of the patients with radiologically negative nodes who were not treated with radiotherapy had positive nodes. Fifty-three per cent of patients developed postoperative complications. Our study suggests that in patients with radiologically positive LPLNs chemoradiotherapy may not be enough to sterilize these extra-mesorectal lymph nodes as a large proportion (27%) will have residual viable adenocarcinoma cells. In patients with radiologically negative LPLNs, however, the addition of chemoradiotherapy may serve to adequately sterilize these lymph nodes without the need for prophylactic LPLN dissection.

Prognostic Value of Tumor Regression Grade on MR in Rectal Cancer: A Large-Scale, Single-Center Experience.

ObjectiveTo determine the prognostic value of MRI-based tumor regression grading (mrTRG) in rectal cancer compared with pathological tumor regression grading (pTRG), and to assess the effect of diffusion-weighted imaging (DWI) on interobserver agreement for evaluating mrTRG.Materials and MethodsBetween 2007 and 2016, we retrospectively enrolled 321 patients (male:female = 208:113; mean age, 60.2 years) with rectal cancer who underwent both pre-chemoradiotherapy (CRT) and post-CRT MRI. Two radiologists independently determined mrTRG using a 5-point grading system with and without DWI in a one-month interval. Two pathologists graded pTRG using a 5-point grading system in consensus. Kaplan-Meier estimation and Cox-proportional hazard models were used for survival analysis. Cohen's kappa analysis was used to determine interobserver agreement.ResultsAccording to mrTRG on MRI with DWI, there were 6 mrTRG 1, 48 mrTRG 2, 109 mrTRG 3, 152 mrTRG 4, and 6 mrTRG 5. By pTRG, there were 7 pTRG 1, 59 pTRG 2, 180 pTRG 3, 73 pTRG 4, and 2 pTRG 5. A 5-year overall survival (OS) was significantly different according to the 5-point grading mrTRG (p = 0.024) and pTRG (p = 0.038). The 5-year disease-free survival (DFS) was significantly different among the five mrTRG groups (p = 0.039), but not among the five pTRG groups (p = 0.072). OS and DFS were significantly different according to post-CRT MR variables: extramural venous invasion after CRT (hazard ratio = 2.259 for OS, hazard ratio = 5.011 for DFS) and extramesorectal lymph node (hazard ratio = 2.610 for DFS). For mrTRG, k value between the two radiologists was 0.309 (fair agreement) without DWI and slightly improved to 0.376 with DWI.ConclusionmrTRG may predict OS and DFS comparably or even better compared to pTRG. The addition of DWI on T2-weighted MRI may improve interobserver agreement on mrTRG.

Effect and Safety of Radiation Therapy Boost to Extramesorectal Lymph Nodes in Rectal Cancer

PurposeIn rectal cancer, the presence of extramesorectal/lateral pelvic lymph node (LPN) is associated with higher risk of locoregional and distant recurrences. LPNs are not typically resected during a standard total mesorectal excision (TME) procedure, and the optimal management for these patients is controversial. We assessed the safety and efficacy of adding a radiation therapy boost to clinically positive LPN during neoadjuvant chemoradiation therapy for rectal cancer. Methods and MaterialsWe analyzed nonmetastatic, lymph node positive rectal adenocarcinoma patients treated with neoadjuvant chemoradiation therapy followed by TME between May 2011 and February 2018. Patients without LPN involvement received external beam radiation therapy (45 Gy in 25 fractions) to the primary tumor and regional draining lymph node basins followed by a boost (5.4 Gy in 3 fractions) to gross disease. Patients with clinically positive LPN that would not be removed during TME received an additional boost (up to a total dose between 54.0 and 59.4 Gy) to the involved LPNs. We compared locoregional control, overall survival, progression-free survival, and treatment-related toxicity between these 2 groups. ResultsFifty-three patients were included in this analysis with median follow-up of 30.6 months for the LPN– group (n = 41) and 19.9 months for the LPN+ group (n = 12). There was no difference in 3-year overall survival (90.04% vs 83.33%, P = .890) and progression-free survival (80.12% vs 80.21%, P = .529) between the 2 groups. We did not observe any LPN recurrences. There were no differences in rates of acute grade 3+ or chronic toxicities. ConclusionsDespite the well-documented negative prognostic effect of LPN metastasis, we observed promising outcomes for LPN+ patients treated with an additional radiation boost. Our results suggest that radiation therapy boost to clinically involved, unresected LPN is an effective treatment approach with limited toxicity. Additional studies are needed to optimize treatment strategies for this unique patient subset.

Total neoadjuvant treatment of locally advanced rectal cancer with high risk factors in Slovenia.

BackgroundIn the light of a high rate of distant recurrence and poor compliance of adjuvant chemotherapy in high risk rectal cancer patients the total neoadjuvant treatment was logical approach to gaining acceptance. We aimed to evaluate toxicity and efficiency of this treatment in patients with rectal cancer and high risk factors for local or distant recurrence.Patients and methodsPatients with rectal cancer stage II and III and with at least one high risk factor: T4, presence of extramural vein invasion (EMVI), positive extramesorectal lymph nodes or mesorectal fascia (MRF) involvement were treated with four cycles of induction CAPOX/FOLFOX, followed by capecitabine-based radiochemotherapy (CRT) and two consolidation cycles of CAPOX/FOLFOX before the operation. Surgery was scheduled 8–10 weeks after completition of CRT.ResultsFrom November 2016 to July 2018 66 patients were evaluable. All patients had stage III disease, 24 (36.4%) had T4 tumors, in 46 (69.7%) EMVI was present and in 47 (71.2%) MRF was involved. After induction chemotherapy, which was completed by 61 (92.4%) of patients, radiologic downstaging of T, N, stage, absence of EMVI or MRF involvement was observed in 42.4%, 62.1%, 36.4%, 69.7% and 68.2%, respectively. All patients completed radiation and 54 (81.8%) patients received both cycles of consolidation chemotherapy. Grade 3 adverse events of neoadjuvant treatment was observed in 4 (6%) patients. Five patients rejected surgery, 3 of them with radiologic complete clinical remissions. One patient did not have definitive surgery of primary tumor due to unexpected cardiac arrest few days after sigmoid colostomy formation. Among 60 operated patients pathological complete response rate was 23.3%, the rate of near complete response was 20% and in 96.7% radical resection was achieved. Pathological T, N and stage downstaging was 65%, 96.7% and 83.4%, respectively. Grade ≥ 3 perioperative complications were anastomotic leakage in 3, pelvic abscess in 1 and paralytic ileus in 2 patients. The rate of pathologic complete response (pCR) in patients irradiated with 3D conformal technique was 12.1% while with IMRT and VMAT it was 37% (p < 0.05). Hypofractionation with larger dose per fraction and simultaneous integrated boost used in the latest two was the only factor associated with pCR.ConclusionsTotal neoadjuvant treatment of high risk rectal cancer is well tolerated and highly effective with excellent tumor and node regression rate and with low toxicity rate. Longer follow up will show if this strategy will improve distant disease control and survival.

Oncologic Outcomes of Extended Robotic Resection for Rectal Cancer.

Surgery for locally advanced rectal cancers beyond the plane of total mesorectal excision (TME) or extramesorectal nodal involvement should include complete resection. This study evaluated the oncologic feasibility and safety of robot-assisted surgery for rectal cancer beyond the TME plane. The study analyzed the operative, perioperative, and oncologic outcomes for all patients who underwent robot-assisted extended rectal cancer surgery from April 2009 to February 2015. Of 36 patients, 22 underwent multivisceral en bloc resection, and 18 underwent extramesorectal lymph node (EMRLN) dissection. The median tumor location was 5cm [interquartile range (IQR), 2.2-9.0cm] from the anal verge. A total of 32 patients underwent neoadjuvant chemoradiation therapy. The median body mass index of the patients was 26.8kg/m(2) (IQR, 24.0-31.9kg/m(2)). Conversion was required for one patient because of inability to tolerate the Trendelenburg position. All the resections were R0, and there were no incomplete TMEs. The vagina and prostate or periprostatic structures were the most commonly resected (n=13/22), and the lateral pelvic nodes were the most common EMRLNs (n=16/18). The median numbers of examined mesorectal lymph nodes and EMRLNs were respectively 20 (IQR, 18.0-28.0) and 2.5 (IQR, 1.0-6.0). The median hospital stay was 4days (IQR, 3.0-5.5days). Six patients experienced Clavien-Dindo grade 3 complications, the most common of which was deep abscess (n=5, 13.8%). The 5-year actuarial local recurrence rate was 3.6%. Minimally invasive resection for rectal cancer can be performed with extended lymph node dissection or en bloc multivisceral resection using the surgical robot in selected patients. This technique is feasible and has acceptable morbidity.

Incidence and prognosis of lower rectal cancer with limited extramesorectal lymph node metastasis.

Patients with lower rectal cancer occasionally have limited extramesorectal lymph node metastasis. However, the incidence and prognosis of lower rectal cancer with limited extramesorectal lymph node metastasis remain unclear. A total of 714 patients with clinical stage II or III lower rectal cancer who underwent extramesorectal lymph node dissection at the National Cancer Center Hospital between 1985 and 2011 were reviewed. Among the 714 patients with lower rectal cancer, 35 (4.9%) had limited extramesorectal lymph node metastasis, of whom 28 (80.0%) had one or two extramesorectal lymph node metastases. The 5-year overall survival rate was 74.5%. The number of extramesorectal lymph node metastases was a significant prognostic factor. The 5-year overall survival rate of patients with three or more extramesorectal lymph node metastases was 28.6%. The incidence of limited extramesorectal lymph node metastasis in patients with lower rectal cancer was 4.9%. Although the prognosis of patients with one or two extramesorectal lymph node metastases was favorable, that of patients with three or more such metastases was unfavorable.

Obturator canal lymph node metastasis from rectal carcinoid tumor.

440 Background: The optimal treatment option for rectal carcinoid tumor remains unsettled. Trans-anal excision has been accepted for small tumors (&lt; 1-2 cm in size) without lymph node involvement. Larger tumors, and those with lymph node metastasis, however, are usually treated via low anterior resection (LAR) with total mesorectal excision (TME). Midgut carcinoid tumors have been found to have the tendency to obstruct lymphatic flow and create a detour in lymphatic passage. We hypothesize that rectal carcinoid may have similar potential to develop alternative lymphatic pathways outside of the mesorectal envelope, thus escaping surgical removal with traditional TME. Methods: A retrospective chart review of rectal carcinoid patients who underwent radical LAR with TME between 2006 and 2011 was conducted to determine if any extra-mesorectal metastasis had occurred. Results: 19 patients who underwent LAR with TME for rectal carcinoid were identified. 14 patients had radio-guided surgery (RGS). 12 of which, were injected with TC-99 intra-operatively and 2 had a preoperative injection of In-111 for octreotide scan. 6 of the 19 patients (31.5%) were found to have obturator canal lymph node metastasis, confirmed by final pathologic review. 5 of these 6 patients had the nodal metastasis to the right obturator canal. Of note, 4 of the 6 patients complained of debilitating foot and medial thigh pain on the affected side, with complete symptom resolution after surgical excision. Conclusions: Up to 31.5% of rectal carcinoid patients can have extra-mesorectal lymph node metastasis that could easily be missed by the traditional TME. Preoperative octreotide scanning with In-111 injection or intra-operative Tc-99 peri-tumor injection, with concomitant RGS can easily identify and remove such metastasis. Symptomatic improvement can be accomplished with its removal. The effect of such extra-mesorectal metastasis on patients’ long term or disease free survival is yet to be determined.

Origin of presacral local recurrence after rectal cancer treatment

The objective of this study was to obtain detailed anatomical information about the lateral lymph nodes, in order to determine whether they might play a role in presacral local recurrence of rectal cancer after total mesorectal excision without lateral lymph node dissection. Ten serially sectioned human fetal pelvises were studied at high magnification and a three-dimensional reconstruction of the fetal pelvis was made. Examination of the histological sections and the three-dimensional reconstruction showed that lateral lymph node tissue comprises a major proportion of the pelvic tissue volume. There were no lymph nodes located in the presacral area. Connections between the mesorectal and extramesorectal lymph node system were found in all fetal pelvises, located below the peritoneal reflection on the anterolateral side of the fetal rectum. At this site middle rectal vessels passed to and from the mesorectum, and branches of the autonomic nervous system bridge to innervate the rectal wall. The findings of this study support the hypothesis that tumour recurrence might arise from lateral lymph nodes.

Location of involved mesorectal and extramesorectal lymph nodes in patients with primary rectal cancer: Preoperative assessment with MR imaging

Aim The purpose of this study is to evaluate the location of involved mesorectal and extramesorectal lymph nodes as depicted on preoperative MRI. Preoperative availability of this information might be useful for the surgeon as well as the radiation therapist and medical oncologist for optimal treatment strategy: type and extent of neoadjuvant treatment as well as extent of surgical resection. Methods Forty-one patients with biopsy-proven rectal cancer were included. All patients underwent preoperative MRI using USPIO (lymph node specific contrast agent). Location of all mesorectal and extramesorectal nodes visible on MRI was recorded, as well as USPIO prediction on nodal status. Lesion-by-lesion analysis using histology after surgery was performed for patients who did not receive long course chemoradiation therapy. Results There were 438 nodes visible, 94 of which were malignant. Most nodes are located in the laterodorsal part of the mesorectum, with no difference in distribution between positive and negative nodes. In relation to height of tumor, the majority of positive nodes are located at tumor height or above. There were significantly more negative nodes (9.6%) located below tumor height as compared to positive nodes (2.1%). There were 40 extramesorectal nodes, in 16 patients, 5 of which were positive in 4 patients. All patients had distal rectal cancer. Conclusion In conclusion, positive mesorectal nodes are located in the laterodorsal part of the mesorectum, at tumor height or above. Positive nodes distal to the tumor are rare, and occur in patients with more proximal nodal metastases. Positive extramesorectal nodes mainly occur in patients with distal rectal cancer with nodal metastases in the mesorectum.

11 ORAL What is the location of the involved (extra)mesorectal lymph nodes in primary rectal cancer?

11 ORAL What is the location of the involved (extra)mesorectal lymph nodes in primary rectal cancer?

Lymph Node Metastases of Prostatic Adenocarcinoma in the Mesorectum in Patients With Adenocarcinoma or Villous Tumor of the Rectum With Collision Phenomenon in a Single Lymph Node: Report of Five Cases

Lymph node involvement is the most important prognostic factor when staging patients with rectal cancer. Cancer originating from sites other than rectum rarely may metastasize to the mesorectum. We report five patients with metastatic prostatic carcinoma to mesorectal lymph nodes, with the "collision phenomenon" in one lymph node. The diagnosis of prostate cancer was clinically unsuspected in two cases. We examined three cases of primary adenocarcinoma and two villous tumors with high-grade dysplasia (patient age range, 52-74 (mean, 63) years) of the middle or lower third of the rectum. All patients underwent low anterior rectal resection with total mesorectal excision and colorectal or coloanal anastomosis. We used a manual technique for lymph node detection after overnight fixation in 10 percent formalin. All lymph nodes identified (range, 15-32; mean, 21 nodes per patient) were examined histologically. Of 106 lymph nodes examined, 20 contained metastases: 9 from rectal adenocarcinoma, 10 from prostatic adenocarcinoma, and 1 with metastatic foci from both tumors. The diagnosis of prostatic carcinoma was readily confirmed by immunostaining for prostatic-specific antigen, and prostatic acid phosphatase. Mesorectal lymph node dissection provides prognostic information in rectal cancer, but careful examination may reveal other unsuspected pathology. Immunohistochemical staining is an essential tool in distinguishing the origin of a lymph node metastasis, especially when the histology does not look typical for rectal carcinoma. Moreover, these observations highlight the connection that can exist between mesorectal lymph node drainage, and extra mesorectal lymph nodes drainage.

Lymphoscintigraphy in patients with primary rectal cancer: the role of total mesorectal excision for primary rectal cancer--a lymphoscintigraphic study.

Total mesorectal excision based operations is the gold standard of care in patients with middle and lower rectal cancer, but the extent of resection varies widely. In our view, extended lymphadenectomy is unnecessary with precise total mesorectal excision, i.e., anatomically correct and sharp surgery. Sixteen patients with primary rectal cancer underwent rectal lymphoscintigraphy 1 day prior continence-preserving anterior resection with total mesorectal excision. The specimens were examined for integrity by postoperative angiography of the superior rectal artery in anteroposterior and lateral views. Twelve patients had only mesorectal lymph nodes, and four had additional extramesorectal iliac lymph nodes. The labeled lymph nodes were identified and removed perioperatively using a gamma probe. Activity was measured again in the preparations outside the situs. Histological examination showed tumor-free lymph nodes only. Lymph vessels can be divided anatomically into visceral and somatic, and detection of extramesorectal lymph nodes does not call for lateral lymphadenectomy. Primary rectal cancer confined to the organ metastasizes within the mesorectum and does not invade extraregional lymph nodes. The mesorectum is the major visceral route for caudocranial metastatic spread.