Prognostic determinants of patients with lateral nodal involvement by rectal cancer

Developments in the Use of Indocyanine Green (ICG) Fluorescence in Colorectal Surgery

Indocyanine Green (ICG) has significantly advanced minimally invasive surgery. It is widely recognized for its ability to visualize blood vessel patency in real-time across various surgical specialties. While its primary use in colorectal surgery is to evaluate anastomoses for leaks, numerous other applications have been documented in the literature. In this review, we aim to explore both established and emerging applications of ICG fluorescence in colorectal surgery, with the goal of improving patient outcomes. This includes preoperative tumor marking and the detection of metastatic disease. Some applications, such as lymphatic mapping, require further research to determine their impact on clinical practices. Conversely, others, like the intraoperative localizations of ureters, necessitate additional procedures and are not yet widely accepted by the surgical community. However, the development of alternative compounds could offer better solutions. Future research should focus on areas like quantitative ICG and protocol standardization in prospective multicenter studies.

Clinical influence of prophylactic lateral lymph node dissection on oncologic outcomes of patients with mid-low rectal cancer undergoing mesorectal excision: a meta-analysis

BACKGROUND

Although several recent meta-analyses have investigated the clinical influence of the addition of lateral lymph node dissection (LLND) on oncologic outcomes in patients with mid-low rectal cancer (RC) undergoing mesorectal excision (ME), most studies included in such meta-analyses were retrospectively designed. Therefore, this study aimed to explore the clinical influence of prophylactic LLND on oncologic outcomes in patients with mid-low RC undergoing ME.

METHODS

A comprehensive electronic search of the literature up to July 2022 was performed to identify studies that compared oncologic outcomes between patients with mid-low RC undergoing ME who underwent LLND and patients with mid-low RC undergoing ME who did not undergo LLND. A meta-analysis was performed using fixed-effects models and the generic inverse variance method to calculate hazard ratios (HRs) and 95% CIs, and heterogeneity was analyzed using I2 statistics.

RESULTS

A total of 6 studies, consisting of 3 randomized and 3 propensity score matching studies, were included in this meta-analysis. The results of the meta-analysis of 2 randomized studies demonstrated no significant effect of prophylactic LLND on improving oncologic outcomes concerning overall survival (OS) (HR, 1.22; 95% CI, 0.89-1.69; I2 = 0%; P = .22) and relapse-free survival (RFS) (HR, 1.03; 95% CI, 0.81-1.31; I2 = 28%; P = .83).

CONCLUSION

The results of this meta-analysis revealed no significant influence of prophylactic LLND on oncologic outcomes-OS and RFS-in patients with mid-low RC who underwent ME.

Clinical significance of metastatic tumor deposit foci in rectal cancer in the lateral pelvic lymph node area

BACKGROUND

Although previous studies have demonstrated that tumor deposits (TDs) are associated with worse prognosis in colon cancer, their clinical significance in rectal cancer has not been fully elucidated, especially in the lateral pelvic lymph node (LPLN) area. This study aimed to clarify the clinical significance of TDs, focusing on the number of metastatic foci, including lymph node metastases (LNMs) and TDs, in the LPLN area.

METHODS

This retrospective study involved 226 consecutive patients with cStage II/III low rectal cancer who underwent LPLN dissection. Metastatic foci, including LNM and TD, in the LPLN area were defined as lateral pelvic metastases (LP-M) and were evaluated according to LP-M status: presence (absence vs. presence), histopathological classification (LNM vs. TD), and number (one to three vs. four or more). We evaluated the relapse-free survival of each model and compared them using the Akaike information criterion (AIC) and Harrell's concordance index (c-index).

RESULTS

Forty-nine of 226 patients (22%) had LP-M, and 15 patients (7%) had TDs. The median number of LP-M per patient was one (range, 1-9). The best risk stratification power was observed for number (AIC, 758; c-index, 0.668) compared with presence (AIC, 759; c-index, 0.665) and histopathological classification (AIC, 761; c-index, 0.664). The number of LP-M was an independent prognostic factor for both relapse-free and overall survival, and was significantly associated with cumulative local recurrence.

CONCLUSION

The number of metastatic foci, including LNMs and TDs, in the LPLN area is useful for risk stratification of patients with low rectal cancer.

Difference in prognostic impact of lateral pelvic lymph node metastasis between pre- and post-neoadjuvant chemoradiotherapy in rectal cancer patients

Purpose

The prognostic significance and treatment of lateral pelvic lymph node metastasis (mLPLN) in rectal cancer patients receiving neoadjuvant chemoradiotherapy (nCRT) are not well understood. In this study, we evaluated the impact of mLPLN identified in imaging modality on outcomes.

Methods

Between January 2008 and December 2016, 1,535 patients who underwent radical resection following nCRT were identified. The association between mLPLN and disease-free survival (DFS), overall survival (OS), local recurrence-free survival (LRFS), and pelvic recurrence-free survival (PRFS) was analyzed, along with risk factors associated with OS and DFS.

Results

Overall, 329 (21.4%) of the 1,535 patients experienced disease recurrence; 71 (4.6%) had local recurrence, 25 (1.6%) had pelvic recurrence, and 312 (20.3%) had distant recurrence. The pre- and post-nCRT mLPLN (-) groups had better DFS, LRFS, PRFS, and OS than the (+) groups. LPLN sampling (LPLNs) was implemented in 24.0% of the pre-nCRT mLPLN (+) group and in 28.8% of the post-nCRT mLPLN (+) group. There was no significant difference in OS and LRFS between LPLNs group and no LPLNs group in pre- and post-nCRT mLPLN (+) groups. Pre-nCRT mLPLN was associated with poor OS (hazard ratio [HR], 1.43; P = 0.009) and post-nCRT mLPLN was associated with poor DFS (HR, 1.49; P = 0.002).

Conclusion

Pre- and post-nCRT mLPLN (+) have different prognostic effects. Post-nCRT mLPLN appears to be more important for disease control. However, pre-nCRT mLPLN should not be disregarded when devising a treatment strategy since it is an independent risk factor for OS.

Targeted lateral pelvic lymph node excision in the setting of total neoadjuvant therapy for rectal cancer

Targeted lateral pelvic node dissection in the era of total neoadjuvant therapy.

Relationship between prognostic impact of N3 lymph node metastasis at the root of the feeding artery and location of colon cancer

PURPOSE

To determine whether N3 nodal involvement predicts outcomes and whether its prognostic implications vary with tumor location in patients with Stage III colon cancer (CC).

METHODS

We defined N3 as lymph node metastases near the bases of the major feeding arteries. We retrospectively examined recurrence rates and patterns by tumor location and sites of lymph node metastases in 57 patients with N3 CC who had undergone curative resections between January 2000 and March 2019. Survival analysis was performed to compare the prognoses of patients with and without N3 lymph node metastasis.

RESULTS

Most N3 patients had large tumors (T ≥ 3); five had T2 disease. Recurrence occurred quickly in one patient with T2N3M0 disease. Multivariate survival analysis demonstrated that N3 lymph node metastasis is an independent predictor of poor prognosis in Stage III CC patients (P < 0.001). Categorizing N3 patients according to UICC-TNM staging system does not stratify risk of recurrence (P = 0.970). To investigate the impact of tumor location on recurrence risk, we classified N3 CC into two subtypes according to tumor location: metastasis at the base of the superior mesenteric artery in right-sided CC and inferior mesenteric artery in left-sided CC. The former was found to have a statistically significant poorer prognosis than the latter (P = 0.091).

CONCLUSION

N3 is a robust prognostic marker in CC patients. Recurrence risk varies by tumor location. N3 right-sided CCs with lymph node metastasis at the base of the superior mesenteric artery have poorer prognoses than do N3 left-sided CCs.

Management of inguinal lymph node metastases from rectal and anal canal adenocarcinoma

AIM

The surgical treatment of inguinal lymph node (ILN) metastases secondary to anorectal adenocarcinoma remains controversial. This study aimed to clarify the surgical treatment and management of ILN metastasis according to its classification.

METHODS

This retrospective, multi-centre, observational study included patients with synchronous or metachronous ILN metastases who were diagnosed with rectal or anal canal adenocarcinoma between January 1997 and December 2011. Treatment outcomes were analysed according to recurrence and prognosis.

RESULTS

Among 1181 consecutively enrolled patients who received treatment for rectal or anal canal adenocarcinoma at 20 referral hospitals, 76 (6.4%) and 65 (5.5%) had synchronous and metachronous ILN metastases, respectively. Among 141 patients with ILN metastasis, differentiated carcinoma, solitary ILN metastasis and ILN dissection were identified as independent predictive factors associated with a favourable prognosis. No significant difference was found in the frequency of recurrence after ILN dissection between patients with synchronous (80.6%) or metachronous (81.0%) ILN metastases. Patients who underwent R0 resection of the primary tumour and ILN dissection had a 5-year survival rate of 41.3% after ILN dissection (34.1% and 53.1% for patients with synchronous and metachronous ILN metastases, respectively, P = 0.55).

CONCLUSION

The ILN can be appropriately classified as a regional lymph node in rectal and anal canal adenocarcinoma. Moreover, aggressive ILN dissection might be effective in improving the prognosis of low rectal and anal canal adenocarcinoma with ILN metastases; thus, prophylactic ILN dissection is unnecessary.

Significant improvement after training in the assessment of lateral compartments and short-axis measurements of lateral lymph nodes in rectal cancer

OBJECTIVES

In patients with rectal cancer, the size and location of lateral lymph nodes (LLNs) are correlated to increased lateral local recurrence rates. Sufficient knowledge and accuracy when measuring these features are therefore essential. The objective of this study was to evaluate the variation in measurements and anatomical classifications of LLNs before and after training.

METHODS

Fifty-three Dutch radiologists examined three rectal MRI scans and completed a questionnaire. Presence, location, size, and suspiciousness of LLNs were reported. This assessment was repeated after a 2-hour online training by the same radiologists with the same three cases plus three additional cases. Three expert radiologists independently evaluated these 6 cases and served as the standard of reference.

RESULTS

Correct identification of the anatomical location improved in case 1 (62 to 77% (p = .077)) and in case 2 (46 to 72% (p = .007)) but decreased in case 3 (92 to 74%, p = .453). Compared to the first three cases, cases 4, 5, and 6 all had a higher initial consensus of 73%, 79%, and 85%, respectively. The mean absolute deviation of the short-axis measurements in cases 1-3 were closer-though not significantly-to the expert reference value after training with reduced ranges and standard deviations. Subjective determination of malignancy had a high consensus rate between participants and experts.

CONCLUSION

Though finding a high consensus rate for determining malignancy of LLNs, variation in short-axis measurements and anatomical location classifications were present and improved after training. Adequate training would support the challenges involved in evaluating LLNs appropriately.

KEY POINTS

• Variation was present in the assessment of the anatomical location and short-axis size of lateral lymph nodes. • In certain cases, the accuracy of short-axis measurements and anatomical location, when compared to an expert reference value, improved after a training session. • Consensus before and after training on whether an LLN was subjectively considered to be suspicious for malignancy was high.

Near-Infrared Imaging Using Indocyanine Green for Laparoscopic Lateral Pelvic Lymph Node Dissection for Clinical Stage II/III Middle-Lower Rectal Cancer: A Propensity Score-Matched Cohort Study

BACKGROUND

The examination of the efficacy of near-infrared imaging using indocyanine green in laparoscopic lateral pelvic lymph node dissection remains insufficient.

OBJECTIVE

The aim of this study was to examine whether near-infrared imaging contributed to an increase in the total number of harvested lateral pelvic lymph nodes in laparoscopic lateral pelvic lymph node dissection.

DESIGN

This was a retrospective, multi-institutional study with propensity score matching.

SETTINGS

We conducted this study within the framework of the Yokohama Clinical Oncology Group in Japan.

PATIENTS

The study population included consecutive patients with middle-low rectal cancer (clinical stage II to III) who underwent laparoscopic lateral pelvic lymph node dissection between January 2013 and February 2018.

MAIN OUTCOME MEASURES

The total number of harvested lateral pelvic lymph nodes was compared in laparoscopic lateral pelvic lymph node dissection with and without near-infrared imaging.

RESULTS

A total of 172 eligible patients were included; 84 of these patients underwent laparoscopic surgery with near-infrared imaging. After propensity score matching, 58 patients were matched in each of the near-infrared and the non-near-infrared groups. The operation time in the near-infrared group was significantly longer than that in the non-near-infrared group (426 vs 369 min), and the amount of intraoperative blood loss in the near-infrared group was significantly smaller than that in the non-near-infrared group (13 vs 110 mL). The total number of harvested lateral pelvic lymph nodes in the near-infrared group was significantly higher than that in the non-near-infrared group (14 vs 9). There were no significant differences in the postoperative complication rates of the 2 groups.

LIMITATIONS

The limitations of the present study include its retrospective design.

CONCLUSIONS

This study revealed that laparoscopic lateral pelvic lymph node dissection combined with near-infrared imaging could increase the total number of harvested lateral pelvic lymph nodes without impairing functional preservation. See Video Abstract at http://links.lww.com/DCR/B800.This study was registered with the Japanese Clinical Trials Registry as UMIN000041372 (http://www.umin.ac.jp/ctr/index.htm).IMÁGENES CASI-INFRARROJAS UTILIZANDO VERDE DE INDOCIANINA EN LA DISECCIÓN LAPAROSCÓPICA DE GANGLIOS LINFÁTICOS PÉLVICOS LATERALES EN CASOS DE CÁNCER DE RECTO MEDIO-INFERIOR DE ESTADIO CLÍNICO II / III: ESTUDIO DE COHORTES CON PUNTUACIÓN DE PROPENSIÓNANTECEDENTES:El examen de la eficacia de las imágenes casi-infrarrojas utilizando le verde de indocianina en la disección laparoscópica de los ganglios linfáticos pélvicos laterales sigue siendo insuficiente.OBJETIVO:El objetivo de este estudio fue examinar si las imágenes casi-infrarrojas contribuyeron a un aumento en el número total de ganglios linfáticos pélvicos laterales recolectados durante su disección laparoscópica.DISEÑO:Estudio retrospectivo, multi-institucional con emparejamiento por puntuación de propensión.AJUSTES:Estudio realizado dentro el marco establecido por el Grupo de Oncología Clínica de Yokohama, Japón.PACIENTES:La población estudiada incluyó pacientes consecutivos con cáncer de recto medio-bajo (estadio clínico II a III) que se sometieron a una disección laparoscópica de los ganglios linfáticos pélvicos laterales entre enero de 2013 y febrero de 2018.PRINCIPALES RESULTADOS MEDIDAS:El número total de ganglios linfáticos pélvicos laterales extraídos se comparó en la disección laparoscópica de ganglios linfáticos pélvicos laterales con y sin imágenes casi-infrarrojas.RESULTADOS:Se incluyeron un total de 172 pacientes elegibles; 84 de estos pacientes se sometieron a cirugía laparoscópica con imágenes casi-infrarrojas. Después del emparejamiento por puntuación de propensión, 58 pacientes fueron emparejados en cada uno de los grupos de luz casi-infrarroja y los sin luz. El tiempo de operación en el grupo de luz casi-infrarroja fue significativamente más largo que en el grupo sin luz (426 frente a 369 min), y la cantidad de pérdida de sangre intraoperatoria en el grupo de luz casi-infrarroja fue significativamente menor que en el grupo sin luz (13 frente a 110 ml). El número total de ganglios linfáticos pélvicos laterales recolectados en el grupo de luz casi-infrarroja fue significativamente mayor que en el grupo sin luz (14 frente a 9). No hubo diferencias significativas en las tasas de complicaciones posoperatorias de los dos grupos.LIMITACIONES:Las limitaciones del presente estudio incluyen su diseño retrospectivo.CONCLUSIONES:Este estudio reveló que la disección laparoscópica de los ganglios linfáticos pélvicos laterales combinada con imágenes casi-infrarrojas podría aumentar el número total de ganglios linfáticos pélvicos laterales recolectados sin afectar la preservación funcional. Consulte Video Resumen en http://links.lww.com/DCR/B800. (Traducción-Dr. Xavier Delgadillo)Este estudio se registró en el Registro de Ensayos Clínicos de Japón como UMIN000041372 (http://www.umin.ac.jp/ctr/index.htm).

Laparoscopic versus open lateral pelvic lymph node dissection in locally advanced rectal cancer: multicentre retrospective cohort study

BACKGROUND

Lateral pelvic lymph node dissection (LPLND) is an option in the treatment of rectal cancer and may reduce local recurrence/improve disease-free survival. Advancements in minimally invasive technology have improved the ability to identify anatomy and neurovascular structures that may help in LPLND. The aim of this retrospective study was to evaluate the technical feasibility and oncological safety of laparoscopic LPLND compared with the open LPLND.

METHOD

Between July 2010 and July 2019, patients from three tertiary referral hospitals who underwent LPLND with total mesorectal excision for primary rectal cancer were included. Baseline patient characteristics, perioperative outcomes, pathologic results, recurrence, and survival were compared between the laparoscopic and open groups.

RESULTS

There were 126 and 70 patients in the laparoscopic and open groups respectively. The laparoscopic group had less estimated blood loss (100 ml versus 300 ml, P < 0.001) and lower transfusion rate (0.8 per cent versus 10.0 per cent; P = 0.003) but longer operating times (318 min versus 270 min, P = 0.004). The laparoscopic group had fewer wound infections (1.6 per cent versus 10.0 per cent, P = 0.011) and neuropathy (0 per cent versus 4.3 per cent, P = 0.044). Lateral pelvic recurrence rate was 7.6 per cent in the laparoscopic group and 19.6 per cent in the open group (P = 0.053). Recurrence-free survival (72.2 per cent versus 63.5 per cent; P = 0.190) and overall survival (93.3 per cent versus 85.0 per cent; P = 0.118) were not significantly different.

CONCLUSION

Laparoscopic LPLND was associated with improved perioperative outcomes and non-inferior oncological outcomes.

The expression of carcinoembryonic antigen mRNA in the lavage of the dissected area of the lateral lymph nodes influences the lateral recurrence of lower rectal cancer

PURPOSE

To determine whether or not migrating cancer cells are present on the surgical plane after lateral lymph node dissection (LLND) for lower rectal cancer and related to lateral recurrence (LR), we evaluated the lavage of LLND areas by reverse-transcription polymerase chain reaction (RT-PCR) to check the expression of CEA mRNA in the residual cancer cells.

METHODS

Thirty patients who underwent curative LLND were enrolled. Lavage was collected after LLND and subjected to RT-PCR to detect CEA mRNA. The median follow-up to check for recurrence was 31.4 months.

RESULTS

CEA mRNA was detected in 9 of the 46 dissected areas. Based on the receiver operating characteristic curves, the cut-off value of PCR was set at 0.025. This cut-off point classified five patients into the high-expression group for CEA mRNA. During follow-up, LR developed in 1 of 40 low-expression areas of CEA mRNA and 3 of 6 high-expression areas. The LR rate was higher in the high-expression group than in the low-expression group (p = 0.015). A multivariate analysis showed that the high expression of CEA mRNA was likely an independent prognostic factor of LR.

CONCLUSION

The expression of CEA mRNA in the lavage of LLND areas indicates the presence of residual cancer cells that cause LR.

The Significance of Lateral Lymph Node Metastasis in Low Rectal Cancer: a Propensity Score Matching Study

BACKGROUND

The indications for lateral lymph node dissection (LLND) in rectal cancer have been controversial. The purpose of this study was to clarify the significance of lateral lymph node metastasis in low rectal cancer.

METHODS

This was a retrospective study at a high-volume cancer center in Japan. In this study, 40 patients with pathologically positive LLN (LLN+) were matched with 175 negative (LLN-) patients by propensity score matching (PSM). COX regression analysis was used to identify independent risk factors related to prognosis. The relapse-free survival rate (RFS) and overall survival rate (OS) of the 2 groups before and after matching were analyzed.

RESULTS

Of the 64 patients undergoing LLND, 40 (62.5%) patients had LLN+ disease. The LLN+ patients showed deeper infiltration of the primary tumor than the LLN- patients (T3-T4: 87.5% vs. 72.0%; p = 0.044), a greater number of metastatic lymph nodes (N2: 75.0% vs. 35.4%; p < 0.001), and a higher rate of local recurrence (30% vs. 9.1%; p < 0.001). Adjuvant chemotherapy was more common in the 40 LLN+ patients than in the 175 LLN- patients (70.0% vs. 46.8%; p = 0.008). After relapse, the rate of first-line chemotherapy administration for LLN+ patients was higher than that for the LLN- patients (62.5% vs. 29.5%; p = 0.005). The RFS of LLN+ patients was shorter than that of the LLN- patients (p = 0.005). After PSM, although more LLN+ patients received adjuvant chemotherapy than the LLN- patients (70.0% vs. 40.0%; p = 0.007), the local recurrence rate remained higher (30% vs. 10%; p = 0.025). The differences between RFS (p = 0.655) and OS rates (p = 0.164) of the 2 patient groups were not significant.

CONCLUSION

Even after LLND, patients with LLN+ low rectal cancer still showed an elevated local recurrence rate. Controlling local recurrence by adjuvant chemotherapy alone is difficult, and the additional strategic treatments are needed.

Deformation of the Pelvic Arteries Caused by Pneumoperitoneum and Postural Changes in an Animal Model

BACKGROUND/AIM

We investigated pelvic arterial deformation and shift due to intraoperative pneumoperitoneum and postural changes in an animal model.

MATERIALS AND METHODS

Computed tomography images of pigs were acquired in different body positions (supine, head down at 5° and 10°, right lateral recumbent at 5° and 15°) before and after insufflation. We used a free software (3D Slicer) for image analysis. After landmark registration using 10 markers inserted into the pelvis, pelvic arterial deformation and shift of seven arterial bifurcation points were evaluated. The distance moved was the target registration error (TRE) from the points registered in the supine position. Fiducial registration error (FRE) was measured using the 10 pelvic markers.

RESULTS

TRE average from postural changes ranged from 0.7 to 1.2 mm and was 1.4 mm due to pneumoperitoneum. TRE and FRE averages were 2.1 mm and 0.2 mm, respectively.

CONCLUSION

The pelvis was useful for registering anatomical landmarks.

Effective dissection for rectal cancer with lateral lymph node metastasis based on prognostic factors and recurrence type

PURPOSE

There are no reports showing the significance and effective range of dissection for patients with lateral lymph node metastasis (LLNM). This study aimed to investigate the indications for lateral lymph node dissection (LLND) in patients with LLNM based on prognostic factors and recurrence types.

METHODS

We reviewed 379 patients with advanced rectal cancer who were treated with total mesorectal excision plus LLND. We analyzed background factors and survival times of patients who had LLNM to determine prognostic factors and recurrence types.

RESULTS

Pathological LLNM occurred in 44 (11.6%). Among patients with LLNM, the predictors of poor prognoses, according to univariate analysis, were > 3 node metastases, the presence of node metastasis on both sides, and spreading beyond the internal iliac lymph nodes. Moreover, LLNM beyond the internal iliac region was found to be an independent prognostic risk factor. Twenty-eight of the 44 patients with lateral lymph node metastasis (64%) relapsed, 22 of whom had distant metastases and 11 of whom experienced local recurrences. Among the latter group, nine (20%) and two (5%) had recurrences in the central and lateral pelvis, respectively.

CONCLUSION

The therapeutic benefit of resection was high, especially in patients with ≤ 3 positive lateral lymph nodes, one-sided bilateral lymph node areas, and positive nodes localized near the internal iliac artery.

Therapeutic significance of D3 dissection for low rectal cancer: a comparison of dissections between the lateral pelvic lymph nodes and the lymph nodes along the root of the inferior mesenteric artery in a multicenter retrospective cohort study

PURPOSE

D3 dissection is the standard treatment modality for locally advanced low rectal cancer in Japan. The benefit of lateral pelvic lymph node (LPLN) dissection (LPLND) and lymph nodes along the root of inferior mesenteric artery (253 LN) dissection (253 LND) for low rectal cancer has often been studied separately, and few studies have investigated their benefit in the same cohort. This study aimed to clarify the therapeutic significance of dissection of the LPLN in comparison to that of dissection of the 253 LN for low rectal cancer.

METHODS

We retrospectively evaluated 3508 patients with treatment-naïve stage I-III low rectal cancer who underwent mesorectal excision between 1997 and 2012. They were identified from the Japanese Study Group for Postoperative Follow-Up of Colorectal Cancer database. The rates of metastasis, survival, and therapeutic value index (5-year overall survival (OS) rate multiplied by metastatic rate for lymph node metastasis) were compared between LPLN and 253 LN.

RESULTS

The rates of LPLN metastasis and 253 LN metastasis were 17.9% and 1.5%, respectively. The 5-year OS was significantly different between patients with and without LPLN metastasis (55.0% vs 85.5%, P < 0.0001) and between patients with and without 253 LN metastasis (36.2% vs 83.3%, P < 0.0001). The therapeutic value indexes of LPLN and 253 LN were 9.85 and 0.54, respectively.

CONCLUSIONS

LPLND may have more therapeutic value than 253 LND for patients with treatment-naïve low rectal cancer, although both the patients with LPLN metastasis and those with 253 LN metastasis remained to have poor prognosis.

Long-term Outcomes of Lower Rectal Cancer Patients Treated with Total Mesorectal Excision and Lateral Pelvic Lymph Node Dissection after Preoperative Radiotherapy or Chemoradiotherapy

OBJECTIVES

The standard strategy for advanced rectal cancer (RC) is preoperative short-course radiotherapy (SCRT)/chemoradiotherapy (CRT) plus total mesorectal excision (TME) in Western countries; however, the survival benefit of adding chemotherapy to radiotherapy remains unclear. There is accumulating evidence that either SCRT/CRT or lateral pelvic lymph node dissection (LPND) alone may not be sufficient for local control of advanced RC. We herein retrospectively evaluated the clinical outcomes of patients who were treated by SCRT/CRT+TME+LPND, particularly focusing on the prognostic impact of lateral pelvic lymph node metastasis (LPNM).

METHODS

Patients diagnosed as having clinical Stage II and III lower RC who received SCRT/CRT+TME+LPND between 1999 and 2012 at our hospital were enrolled. Adverse events (AEs), surgery-related complications (SRC), and therapeutic effects were retrospectively analyzed.

RESULTS

Fifty cases (SCRT:25, CRT:25) were analyzed. No significant differences were observed in overall survival (OS), relapse-free survival (RFS), local recurrence (LR), AE, and SRC between the SCRT and CRT groups, although the pathological therapeutic effect was higher in the CRT group. The patients with LPNM showed significantly inferior 5-year OS and 5-year RFS than those without LPNM.

CONCLUSIONS

There were no significant differences in OS, RFS, or LR between SCRT and CRT, although CRT had a significantly greater histological therapeutic effect. The prognosis of the pathological LPNM-positive cases was significantly poorer than that of pathological LPNM-negative cases.

Lateral pelvic lymphadenectomy for low rectal cancer: a META-analysis of recurrence rates

BACKGROUND

Locoregional recurrence (LR) remains a problem for patients with lower rectal cancer despite standardized surgery and improved neoadjuvant treatment regimens. Lateral pelvic lymph node dissection (LPLND) has been routine practice for some time in the Orient/East, but other regions have concerns about morbidity. As perioperative care and surgical approaches are refined, this has been revisited for selected patients. The question as to whether LPLND improves oncological outcomes was explored here.

METHODS

A systematic review of patients who underwent TME with or without LPLND from 2000 to 2020 was performed. The primary endpoint was the rate of LR between the two groups.

RESULTS

Seven papers met the predefined search criteria in which 2000 patients underwent TME alone, while 1563 patients had TME and LPLND. The rate of LR was marginally higher with TME alone when compared with TME plus LPLND, but this result was not statistically significant (9.8 vs 9.4%, odds ratio 0.75, 95% CI 0.41-1.38, *p = 0.35). In addition, four studies reported on distant recurrence rates, with TME and LPLND showing a slight reduction in overall rates (27.3 vs 29.9%, respectively, OR 0.65, 95% CI 0.45-0.92, *p = 0.02).

CONCLUSION

The addition of LPLND to TME is not associated with a significantly lower risk of LR in patients who undergo surgery for lower rectal cancer.

Joint modelling of colorectal cancer recurrence and death after resection using multi-state model with cured fraction

Curing of colorectal cancer (CRC) occurs at the time of resection but it is not immediately observable. If the cancer is not completely eliminated, the patient will not be cured of cancer and will experience recurrence as the tumor has regrown to a detectable size. The main propose of the present study was to assess the effects of different covariates on the probability of being cured as well as the time-to-recurrence, and time-to-death in CRC patients by using multi-state cure model. The information of 283 patients with CRC, who underwent resection, from 2000 to 2015 in Imam Khomeini Hospital of Hamadan, Iran, were analyzed. The results of multi-state cure model reveal that females and who experience metastasis were more likely to be apparently cured. It has been shown that sex has a significant effect on the time-to-recurrence given patient was in the not cured group. The survival time of patients of the not cured group was affected by the stage of disease. However, the survival of the apparently cured patients were affected by age at diagnosis and metastasis status. The multi-state cure model provided a flexible framework to study the effects of prognostic factors simultaneously on the transition between different states and the probability of being apparently cured of CRC.

Short- and long-term outcomes of laparoscopic versus open lateral lymph node dissection for locally advanced middle/lower rectal cancer using a propensity score-matched analysis

BACKGROUND

There are few reports on large-scale trials for the long-term outcomes regarding laparoscopic lateral lymph node dissection (LLND). We evaluated the short- and long-term outcomes of laparoscopic versus open LLND for locally advanced middle/lower rectal cancer using a propensity score-matched analysis.

METHODS

From January 2005 to December 2016, consecutive clinical stage II to III middle/lower rectal cancer patients who underwent total mesorectal excision (TME) plus LLND were retrospectively collected at three institutions. Laparoscopic LLND was compared with open LLND for the surgical and oncological outcomes, including the long-term survival, using a propensity score-matched analysis.

RESULTS

A total of 325 patients were collected. There were 142 patients who underwent open TME plus LLND (open group) and 183 patients who underwent laparoscopic TME plus LLND (laparoscopic group). A total of 93 patients each were matched to each group. Compared to the open group, the laparoscopic group had a significantly longer operative time (327 vs. 377 min; p = 0.002) but significantly less blood loss (540 vs. 50 ml; p < 0.001), fewer Clavian-Dindo grade ≥ 2 postoperative complications (49.5% vs. 34.4%; p = 0.037) and shorter postoperative hospital stay (18 vs. 14 days; p = 0.008). Furthermore, the rate of urinary retention was significantly lower in the laparoscopic group than in the open group (16.1% vs. 6.5%; p = 0.037). The estimated 3-year overall survival, relapse-free survival, and cumulative incidence of local recurrence were 91.4%, 73.1%, and 3.4% in the open group and 90.3%, 74.2%, and 4.3% in the laparoscopic group (p = 0.879, 0.893, 0.999), respectively.

CONCLUSIONS

This study showed that laparoscopic LLND had advantages over an open approach, such as less blood loss, fewer postoperative complications, and a shorter postoperative hospital stay, and the oncologic outcomes were similar to the open approach. Laparoscopic LLND could be a viable standard approach to LLND for advanced middle/lower rectal cancer surgery.

Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines 2019 for the treatment of colorectal cancer

The number of deaths from colorectal cancer in Japan continues to increase. Colorectal cancer deaths exceeded 50,000 in 2016. In the 2019 edition, revision of all aspects of treatments was performed, with corrections and additions made based on knowledge acquired since the 2016 version (drug therapy) and the 2014 version (other treatments). The Japanese Society for Cancer of the Colon and Rectum guidelines 2019 for the treatment of colorectal cancer (JSCCR guidelines 2019) have been prepared to show standard treatment strategies for colorectal cancer, to eliminate disparities among institutions in terms of treatment, to eliminate unnecessary treatment and insufficient treatment and to deepen mutual understanding between healthcare professionals and patients by making these guidelines available to the general public. These guidelines have been prepared by consensuses reached by the JSCCR Guideline Committee, based on a careful review of the evidence retrieved by literature searches and in view of the medical health insurance system and actual clinical practice settings in Japan. Therefore, these guidelines can be used as a tool for treating colorectal cancer in actual clinical practice settings. More specifically, they can be used as a guide to obtaining informed consent from patients and choosing the method of treatment for each patient. Controversial issues were selected as clinical questions, and recommendations were made. Each recommendation is accompanied by a classification of the evidence and a classification of recommendation categories based on the consensus reached by the Guideline Committee members. Here, we present the English version of the JSCCR guidelines 2019.

Rectal Cancer: Staging

The imaging of rectal cancer has evolved noticeably over the past 2 decades, paralleling the advances in therapy. The methods for imaging rectal cancer are increasingly used in clinical practice with the purpose of helping to detect, characterize and stage rectal cancer. In this setting, MR imaging emerged as the most useful imaging method for primary staging of rectal cancer; the present review focuses on the role of MR imaging in this regard.

Histopathological characteristics of lateral lymph nodes dictate local or distant metastasis and prognosis in low rectal cancer patients

Objectives: The therapeutic value of lateral lymph node dissection in low rectal cancer (RC) patients remains a matter of debate. The present study evaluated the dissection value of each lateral lymph node, based on its histopathological characteristics. Methods: This study enrolled 381 consecutive RC patients with bilateral lateral lymph node dissection, from 1995 to 2014. We investigated their clinicopathological characteristics, and the therapeutic value of each lymph node dissection. The therapeutic values of the distal internal iliac and obturator lymph nodes were further investigated on the basis of histopathological classifications, as follows: minimum metastasis (Type A), massive metastasis (Type B) without capsular invasion, and invasive metastasis (Type C) with capsular invasion and were evaluated by the local or distant recurrence and 5 year overall survival. Results: Among the lateral lymph nodes, the therapeutic values of distal internal iliac (6.1) and obturator (7.4) lymph node dissection were higher than those of common (0.4) and proximal iliac (1.2) lymph node dissection. However, our further investigation revealed that the 5 year overall survival rates of Type C (obturator/distal iliac) were 12.5%/22.9%, whereas those of Type A and Type B were 100%/91.6% and 77.8%/50.0%, respectively. Conclusions: Metastasis and prognosis of RC patients depend on the histopathological characteristics of the distal internal iliac and obturator lymph nodes. The present study provides new insights for choices of appropriate treatments for RC patients.

Prediction of lateral pelvic lymph node metastasis in patients with locally advanced rectal cancer with preoperative chemoradiotherapy: Focus on MR imaging findings

PURPOSE

To investigate the predictive factors for lateral pelvic lymph node (LPLN) metastasis in patients with locally advanced rectal cancer treated with preoperative chemoradiotherapy (CRT).

MATERIALS AND METHODS

Fifty-seven patients with locally advanced rectal cancer and LPLNs larger than 5 mm underwent LPLN dissection (LPLD) after preoperative CRT. The MRI findings, including the apparent diffusion coefficient value and LPLN size reduction rate before/after CRT; clinical factors; and pathologic results were evaluated to identify the predictive factors associated with LPLN metastasis.

RESULTS

LPLN metastasis was confirmed in 23 patients (40.4%). Metastasis was significantly higher in LPLNs with multiplicity, short-axis diameter ≥8 mm before CRT, short-axis diameter >5 mm after CRT, size reduction rate ≤33.3%, heterogeneous signal intensity, and irregular margin (P<0.05) on MR. Multivariable analysis showed that pre-CRT short-axis diameter of LPLNs ≥8 mm, size reduction rate ≤33.3%, and heterogeneous signal intensity were independently associated with LPLN metastasis.

CONCLUSIONS

The size and signal intensity of LPLN before and after CRT are useful MRI findings to predict LPLN metastasis and are helpful to determine the indications for LPLD.

Incidence and Predictive Model for Lateral Pelvic Lymph Node Metastasis in Lower Rectal Cancer

The lateral pelvic lymph node recurrence after curative resection in rectal cancer has been reported in more than 20% of cases and the lateral pelvic lymph node (LPLN) metastasis is an independent risk factor for local recurrence. A prospective cohort study with diagnosis of lower rectal cancer stages II and III performed to identify the factors with significant correlation with LPLN metastasis was categorised based on the number of positive factors and proposed a risk stratification model to uncover a possible benefit of LPLD in specific patient subgroups. Forty-three patients with lower rectal cancer underwent curative surgery, total mesorectal excision with bilateral lateral pelvic lymph node dissection. Pre-operative, female gender, raised serum CEA (> 5 ng/mL), cT4, enlarged mesorectal lymph nodes, borderline enlarged LPLN on MRI, lower location (< 5 cm from anal verge), large size (> 5 cm) and non-circumferential lesion were significant predictors for LPLN metastasis. Histopathological, higher tumour grade, higher pT and pN stage, and the presence of LVI were significant factors. On cox-proportional hazard model analysis, female gender, large tumour, cT4, enlarged mesorectal lymph nodes, borderline enlarged LPLN, pN1 and positive LVI were associated with significant hazard. In conclusion, a specific group of patients with lower rectal cancer of stages II and III might be have treated with LPND in spite of concurrent chemo-radiation to achieve satisfactory oncological outcome. The proposed stratification grouping is strongly guiding the patient for lateral pelvic lymph node dissection. Further study to prove the oncological advantage of LPND is warranted at large scale.

Diffusion kurtosis imaging in identifying the malignancy of lymph nodes during the primary staging of rectal cancer

AIM

The aim was to assess the diagnostic value of diffusion kurtosis imaging (DKI) for discriminating between benign and malignant lymph nodes in patients with rectal carcinoma.

METHOD

ighty-five patients with rectal adenocarcinoma who underwent total mesorectal excision of the rectum were studied. A total of 273 lymph nodes were harvested and subjected to histological analysis. Quantitative parameters [apparent diffusion parameter D_app of the Gaussian distribution, apparent kurtosis coefficient K_app and apparent diffusion coefficient (ADC)] of lymph nodes were derived from DKI. Differences and the diagnostic performance of these parameters were calculated by using the independent-samples t test and receiver operating characteristic curve analyses.

RESULTS

The median D_app and ADC values of metastatic lymph nodes were significantly greater than those of benign lymph nodes, whereas the median K_app of metastatic lymph nodes was statistically less than that of normal lymph nodes. D_app had the relatively highest area under the curve of 0.774. When 1126.15 × 10^-6  mm² /s was used as a D_app threshold value, the sensitivity and specificity were 96.97% and 41.82%, respectively.

CONCLUSION

DKI can help differentiate metastatic vs benign lymph nodes during the primary staging of rectal cancer.

Robotic surgery for rectal cancer

Laparoscopic surgery has gained acceptance as a less invasive approach in the treatment of colon cancer. However, laparoscopic surgery for rectal cancer, particularly cancer of the lower rectum, is still challenging because of limited accessibility. Robotic surgery overcomes the limitations of laparoscopy associated with anatomy and offers certain advantages, including 3-D imaging, dexterity and ambidextrous capability, lack of tremors, motion scaling, and a short learning curve. Robotic rectal surgery has been reported to reduce conversion rates, particularly in low anterior resection, but it is associated with longer operative times than the conventional laparoscopic approach. Postoperative morbidities are similar between the robotic and conventional laparoscopic approaches, and oncological outcomes such as the quality of the mesorectum and the status of resection margins are also equivalent. The possible superiority of robotic surgery in terms of the preservation of autonomic function has yet to be established in research based on larger numbers of patients. Although robotic rectal surgery is safe, feasible, and appears to overcome some of the technical limitations associated with conventional laparoscopic surgery, the advantages provided by this technical innovation are currently limited. To justify its expensive cost, robotic surgery is more suitable for select patients, such as obese patients, men, those with cancer of the lower rectum, and those receiving preoperative chemoradiotherapy.

Preoperative Chemoradiotherapy Might Improve the Prognosis of Patients with Locally Advanced Low Rectal Cancer and Lateral Pelvic Lymph Node Metastases

BACKGROUND

Preoperative chemoradiotherapy (CRT) is a standard treatment for locally advanced low rectal cancer (LALRC). However, the prognostic significance of CRT in patients with lateral lymph node metastasis (LLNM) is unknown. The present study aimed to examine the prognostic impact of preoperative CRT in patients with LALRC and LLNM.

METHODS

We retrospectively analyzed data for 73 patients with LALRC and LLNM who underwent total mesorectal excision and lateral lymph node dissection from 1985 to 2012. The patient population was divided into a CRT group (n = 30) who received preoperative CRT and a surgery alone group (n = 43) who were treated without CRT.

RESULTS

The 5-year overall survival (OS), 5-year relapse-free survival (RFS), and 5-year local recurrence (LR) rates were significantly better in the CRT group (78.2, 72.1, and 3.5 %, respectively) compared with the surgery alone group (41.1, 25.4, and 39.6 %, respectively). There were fewer total, mesorectal, and LLNMs in the CRT group compared with the surgery alone group. Multivariate analysis showed that surgery without CRT was an independent predictor of poorer OS (hazard ratio [HR] 3.513, p = 0.004), RFS (HR 2.696, p = 0.021), and LR rates (HR 11.094, p = 0.001). A total number of lymph node metastases ≥4 were also an independent predictor of poorer OS and RFS.

CONCLUSIONS

Preoperative CRT might have a significant prognostic impact on patients with LALRC with LLNM treated with total mesorectal excision and lateral lymph node dissection.

Oncologic significance of para-aortic lymph node and inferior mesenteric lymph node metastasis in sigmoid and rectal adenocarcinoma

BACKGROUND

Recurrence patterns or survival in colorectal cancer patients might differ according to inferior mesenteric lymph node (IMLN) metastasis. However, few studies have compared para-aortic lymph node (PALN) metastasis and IMLN metastasis. The aim of the current study is to identify survival and recurrence patterns in patients with sigmoid colon and rectal adenocarcinoma with either PALN or IMLN metastasis and to evaluate the prognostic significance of PALN and IMLN metastasis.

METHODS

A retrospective study involving 3076 patients with stage III and IV sigmoid and rectal cancer, who underwent curative surgery between January 2000 and December 2009, was performed. Clinicopathologic features, recurrence patterns, and survival outcomes of 27 patients with PALN metastasis were compared with those of 47 patients with IMLN metastasis. Patients with both IMLN and PALN metastasis were included in the PALN+ group.

RESULTS

After curative resection, there was no significant difference in the 5-year disease-free and overall survival rates between the PALN+ and IMLN+ groups (27.5% vs. 29.8%, p = 0.24, and 37% vs. 39.2%, p = 0.19, respectively). Furthermore, there were no significant differences in recurrence rate (PALN+ group, 70.4%; and IMLN+ group, 63.8%; p = 0.69) or recurrence patterns.

CONCLUSIONS

The results suggest that IMLN metastasis, similar to PALN metastasis, is associated with adverse oncologic outcomes and has prognostic significance. Therefore, it is preferable that IMLN metastasis should be considered under the category of systemic metastasis (M1).

Oncological Outcomes of Lateral Pelvic Lymph Node Metastasis in Rectal Cancer Treated With Preoperative Chemoradiotherapy

BACKGROUND

Oncological outcomes of lateral pelvic lymph node metastasis in rectal cancer treated with preoperative chemoradiotherapy remain to be elucidated.

OBJECTIVE

The purpose of this study was to clarify the therapeutic effect of chemoradiotherapy on lateral pelvic lymph node metastasis, the risk factors of lateral pelvic lymph node metastasis, and oncological outcomes of lateral pelvic lymph node dissection after chemoradiotherapy.

DESIGN

This was a nonrandomized, retrospective study.

SETTINGS

The study was conducted at a tertiary referral university hospital.

PATIENTS

Patients with rectal cancer treated with chemoradiotherapy and radical surgery from 2003 to 2015 (N = 222) were included.

INTERVENTIONS

Radiation (total, 50.4 Gy in 28 fractions) with concomitant fluorouracil-based chemotherapy was administered. Lateral pelvic lymph nodes with a diameter of ≥8 mm before chemoradiotherapy were selectively dissected.

MAIN OUTCOME MEASURES

Frequency and risk factors of lateral pelvic lymph node metastasis were examined.

RESULTS

Lateral pelvic lymph node dissection was performed in 31 patients (14.0%), and 16 (51.6%) of these patients were pathologically diagnosed as positive for metastasis. Among the patients treated with total mesorectal excision alone (n = 191), 2 (0.9%) had recurrence in the lateral pelvic lymph node area, which was pathologically confirmed after salvage R0 resection. T category downstaging (73.3% vs 12.5%; p < 0.01) and high histological regression of the primary lesion (73.3% vs 18.8%; p < 0.01) were more frequent in patients with pathologically negative lateral pelvic lymph nodes than in those with positive lateral pelvic lymph nodes. Young age, short distance from the anal verge, and enlarged lateral pelvic lymph node before chemoradiotherapy were associated with lateral pelvic lymph node metastasis.

LIMITATIONS

The study was limited by its retrospective nature and small study population.

CONCLUSIONS

The incidence of lateral pelvic lymph node metastasis after chemoradiotherapy was estimated to be 8.1% (18/222). Young age, short distance from the anal verge, and enlarged lateral pelvic lymph node before chemoradiotherapy were risk factors of lateral pelvic lymph node metastasis after chemoradiotherapy.

Extended lymphadenectomy for locally advanced and recurrent rectal cancer

PURPOSE

The purpose of this study is to assess the value of extended (lateral) lymphadenectomy (EL) in the operative management of locally advanced and recurrent rectal cancer.

METHODS

Patients that underwent exenterative surgery for locally advanced or recurrent rectal cancer between 2006 and 2009 were included in the study. A decision for EL was taken at the local multidisciplinary meeting based on the radiological findings. Perioperative and oncological outcomes were assessed and compared between the EL and non-EL group prospectively.

RESULTS

Forty-one consecutive patients were included in the study (EL = 17). The median age was 57 (40-71) for EL and 66 (39-81) years for non-EL. Of patients, 27 (EL = 13) and 14 (EL = 4) underwent pelvic exenteration and abdominosacral resection, respectively. Twelve (EL = 7) patients were diagnosed with locally advanced primary rectal cancer. Thirty-one (EL = 12) patients received neoadjuvant radiotherapy. The median intraoperative time, blood loss and hospital stay were 9 h (3-13), 1.5 l (0.3-7) and 14 days (12-72), respectively, for the EL group, and 8 h (4-15), 1.6 l (0.25-17) and 14 days (10-86), respectively, for the non-EL (p ≥ 0.394). Morbidity was similar between the two groups (EL = 4, non-EL = 9; p = 0.344). Complete tumour resection (R0) was achieved in 30 (73.17%) patients, 12 (70.58%) in the EL group and 18 (75%) in the non-EL group (p = 0.649). There was no significant difference in 5-year survival (EL = 60.7%, non-EL = 75.2%; p = 0.447), local recurrence (EL = 53.6%, non-EL = 65.4%; p = 0.489) and disease-free survival (EL = 53.6%, non-EL = 51.4%; p = 0.814).

CONCLUSIONS

The present study demonstrated that EL does not provide a statistically significant advantage in survival or recurrence rates, for patients with locally advanced primary or recurrent rectal cancer.

Single-incision Plus One Port Laparoscopic Total Mesorectal Excision and Bilateral Pelvic Node Dissection for Advanced Rectal Cancer--A Medial Umbilical Ligament Approach

We prove the safety and feasibility of single-incision plus 1 port (SILS+1) laparoscopic total mesorectal excision (TME) + lateral pelvic lymph node dissection (LPLD) via a medial umbilical approach for rectal cancer. Only a few reports have been published about single-incision multiport laparoscopic low anterior resection with LPLD. Recently, minimally invasive surgery such as single-incision plus 1 port (SILS + 1) for advanced rectal cancer has been reported as safe and feasible. To our knowledge, this is the first reported case of SILS + 1 used for LPLD. A wound protector was inserted through a 30-mm transumbilical incision. Next, a single-port access device was mounted to the wound protector and 3 ports (5 mm each) were placed. A 12-mm port was inserted in the right lower quadrant. Super-low anterior resection of the rectum and bilateral LPLD and temporary ileostomy were performed with SILS + 1, with a blood loss of 50 mL and a total surgical time of 525 minutes. The time for right lateral dissection was 74 minutes; the time for left lateral dissection was 118 minutes. The total number of dissected lymph nodes was 57 and the number of lateral lymph nodes dissected was 21 (8 left pelvic lymph nodes, 13 right pelvic lymph nodes). No postoperative anastomotic insufficiency or voiding dysfunction was observed. We have documented the safety and feasibility of SILS + 1-TME + LPLD via a medial umbilical approach for rectal cancer.

Single-incision plus one-port laparoscopic abdominoperineal resection with bilateral pelvic lymph node dissection for advanced rectal cancer: a case report

With regard to laparoscopic and robotic abdominoperineal resection (APR) for primary rectal malignancies, limited data have been published in the literature. Single-incision laparoscopic surgery (SLS) has been successfully introduced for treating colorectal cancer. Here we describe our experience of APR with SLS plus one port (SLS + 1) for treating advanced rectal cancer. A 65-year-old man underwent the procedure, which involved a 35-mm incision in the left side of the umbilicus for the insertion of a single multichannel port as well as the insertion of a 5-mm port into the right lower quadrant. The sigmoid colon and rectum were mobilized from the pelvic floor using a medial and lateral approach. After the rectum with the mesorectum was completely mobilized according to the total mesorectal excision, the sigmoid colon was intracorporeally transected. The specimen was removed through the perineal wound. Terminal colostomy was fashioned at the left lower trocar site. Lateral pelvic lymph node dissection was bilaterally performed. There were no perioperative complications. The total operating time was 592 minutes, and the estimated blood loss was 180 mL. To our knowledge, this is the first reported case of SLS + 1 APR with lateral pelvic lymph node dissection for treating rectal cancer. We conclude that SLS + 1 APR is a technically promising alternative method for treating selected patients with advanced rectal cancer.

Clinical Significance of Extramural Tumor Deposits in the Lateral Pelvic Lymph Node Area in Low Rectal Cancer: A Retrospective Study at Two Institutions

Background

The presence of extramural tumor deposits without lymph node structure (EX) is an important prognostic factor for patients with colorectal cancer. However, the clinical significance of EX in the lateral pelvic lymph node area (LP-EX) remains unclear. This study aimed to determine the prognostic implications of LP-EX for patients with low rectal cancer.

Methods

This retrospective study involved 172 consecutive patients with stage 2 or 3 low rectal cancer who underwent curative surgery including lateral pelvic lymph node (LPLN) dissection. The patients were classified into the following three groups according to the metastatic status of the LPLN area: patients without metastasis (no-LP-M group), patients with lymph node metastasis (LP-LNM group), and patients with EX (LP-EX group). Potential prognostic factors of overall survival (OS) and relapse-free survival (RFS) were identified in uni- and multivariate analyses.

Results

Classification assigned 131 patients (76 %) to the no-LP-M group, 27 patients (16 %) to the LP-LNM group, and 14 patients (8 %) to the LP-EX group. The 5-year OS rate was 80.3 % in the no-LP-M group, 61.1 % in the LP-LNM group, and 34.9 % in the LP-EX group (P < 0.001). The corresponding 5-year RFS rates were 62.2, 33.8, and 14.3 %, respectively (P < 0.001). A multivariate Cox proportional hazards regression analysis showed that the presence of LP-EX was an independent prognostic factor for OS (P = 0.006) and RFS (P = 0.001).

Conclusions

The LP-EX classification is a useful pathologic parameter that can be used to stratify patients with metastasis in the LPLN area.

Oncological benefit of lateral pelvic lymph node dissection for rectal cancer treated without preoperative chemoradiotherapy: a multicenter retrospective study using propensity score analysis

PURPOSE

We aimed to clarify the prognostic impact of lateral pelvic lymph node (LPN) dissection (LPND) for rectal cancer through a multicenter retrospective study using propensity score analysis.

METHODS

A total of 1238 patients with pathological T2-4, M0 rectal cancer who had undergone curative operation between 2007 and 2008 were examined. Majority of the patients (96 %) were treated without preoperative chemoradiotherapy (CRT). Clinical background data of the patients treated with LPND and those treated without LPND were matched using propensity scores, and hazard ratios (HRs) for cancer-specific mortality were compared.

RESULTS

LPND was performed more frequently for lower rectal cancers and in patients with more advanced disease, and 29 % of the patients were treated with LPND. After matching background features by propensity scores, LPND did not correlate with improved cancer-specific survival (CSS) among the entire study population [HR, 0.73; 95 % confidence interval (CI) 0.41-1.31; P = 0.28]; however, LPND was correlated with significantly improved CSS in female patients (HR, 0.23; 95 % CI, 0.06-0.89; P = 0.04) but not in male patients (HR, 0.95; 95 % CI, 0.48-1.89; P = 0.89). The results were similar when patients treated with LPND finally diagnosed as pathologically negative for LPN metastasis were compared with those curatively treated without LPND.

CONCLUSIONS

It is suggested that the prognostic impact of LPND for rectal cancer treated without CRT might be different between sexes, and LPND should be considered for female rectal cancer patients although they are diagnosed as clinically negative for LPN metastasis.

Long-Term Survival and Local Relapse Following Surgery Without Radiotherapy for Locally Advanced Upper Rectal Cancer: An International Multi-Institutional Study

Controversy remains regarding whether preoperative chemoradiation protocol should be applied uniformly to all rectal cancer patients regardless of tumor height. This pooled analysis was designed to evaluate whether preoperative chemoradiation can be safely omitted in higher rectal cancer.An international consortium of 7 institutions was established. A review of the database that was collected from January 2004 to May 2008 identified a series of 2102 patients with stage II/III rectal or sigmoid cancer (control arm) without concurrent chemoradiation. Data regarding patient demographics, recurrence pattern, and oncological outcomes were analyzed. The primary end point was the 5-year local recurrence rate.The local relapse rate of the sigmoid colon cancer (SC) and upper rectal cancer (UR) cohorts was significantly lower than that of the mid/low rectal cancer group (M-LR), with 5-year estimates of 2.5% for the SC group, 3.5% for the UR group, and 11.1% for the M-LR group, respectively. A multivariate analysis showed that tumor depth, nodal metastasis, venous invasion, and lower tumor level were strongly associated with local recurrence. The cumulative incidence rate of local failure was 90.6%, 92.5%, and 94.4% for tumors located within 5, 7, and 9 cm from the anal verge, respectively.Routine use of preoperative chemoradiation for stage II/III rectal tumors located more than 8 to 9 cm above the anal verge would be excessive. The integration of a more individualized approach focused on systemic control is warranted to improve survival in patients with upper rectal cancer.

The Role of Robotic Surgery for Rectal Cancer: Overcoming Technical Challenges in Laparoscopic Surgery by Advanced Techniques

The conventional laparoscopic approach to rectal surgery has several limitations, and therefore many colorectal surgeons have great expectations for the robotic surgical system as an alternative modality in overcoming challenges of laparoscopic surgery and thus enhancing oncologic and functional outcomes. This review explores the possibility of robotic surgery as an alternative approach in laparoscopic surgery for rectal cancer. The da Vinci® Surgical System was developed specifically to compensate for the technical limitations of laparoscopic instruments in rectal surgery. The robotic rectal surgery is associated with comparable or better oncologic and pathologic outcomes, as well as low morbidity and mortality. The robotic surgery is generally easier to learn than laparoscopic surgery, improving the probability of autonomic nerve preservation and genitourinary function recovery. Furthermore, in very complex procedures such as intersphincteric dissections and transabdominal transections of the levator muscle, the robotic approach is associated with increased performance and safety compared to laparoscopic surgery. The robotic surgery for rectal cancer is an advanced technique that may resolve the issues associated with laparoscopic surgery. However, high cost of robotic surgery must be addressed before it can become the new standard treatment.

Evaluation of lateral pelvic nodes in patients with advanced rectal cancer

OBJECTIVE

The purpose of this article is to discuss the importance of lateral pelvic lymph node metastasis as a predictor of local recurrence and survival in patients with advanced rectal cancer.

CONCLUSION

Prediction of lateral pelvic nodal staging on MRI shows high accuracy compared with the other imaging modalities. Diffusion-weighted MRI or (18)F-FDG PET/CT may be helpful to assesses lateral pelvic lymph node metastasis.

Disrupted interaction between CFTR and AF-6/afadin aggravates malignant phenotypes of colon cancer

How mutations or dysfunction of CFTR may increase the risk of malignancies in various tissues remains an open question. Here we report the interaction between CFTR and an adherens junction molecule, AF-6/afadin, and its involvement in the development of colon cancer. We have found that CFTR and AF-6/afadin are co-localized at the cell-cell contacts and physically interact with each other in colon cancer cell lines. Knockdown of CFTR results in reduced epithelial tightness and enhanced malignancies, with increased degradation and reduced stability of AF-6/afadin protein. The enhanced invasive phenotype of CFTR-knockdown cells can be completely reversed by either AF-6/afadin over-expression or ERK inhibitor, indicating the involvement of AF-6/MAPK pathway. More interestingly, the expression levels of CFTR and AF-6/afadin are significantly downregulated in human colon cancer tissues and lower expression of CFTR and/or AF-6/afadin is correlated with poor prognosis of colon cancer patients. The present study has revealed a previously unrecognized interaction between CFTR and AF-6/afadin that is involved in the pathogenesis of colon cancer and indicated the potential of the two as novel markers of metastasis and prognostic predictors for human colon cancer.

Factors associated with lateral pelvic recurrence after curative resection following neoadjuvant chemoradiotherapy in rectal cancer patients

PURPOSE

This study aims to determine the risk factors for lateral pelvic recurrence (LPR) in rectal cancer patients treated with neoadjuvant chemoradiotherapy (CRT) and curative surgery.

METHODS

Four hundred forty-three patients treated with neoadjuvant CRT and curative surgery from October 1999 through June 2009 were analyzed. All patients underwent total mesorectal resection without lateral pelvic lymph node (LPLN) dissection. Recurrence patterns and lateral pelvic recurrence-free survival (LPFS) were evaluated relative to clinicopathologic parameters including pelvic LN status.

RESULTS

Median follow-up was 52 months, with locoregional recurrence in 53 patients (11.9 %). Of the 53 patients, 28 (52.8 %) developed LPR, of which eight had both central and lateral PR. Multivariate analysis showed a significant relationship between LPFS and the number of lateral pelvic LN (p = 0.010) as well as the ratio of the number of positive LN/number of dissected LN (p = 0.038). The relationship between LPFS and LPLN size had a marginal trend (p = 0.085). Logistic regression analysis showed positive relationships between LPR probability and the number of LPLN (odds ratio [OR] 1.507; 95 % confidence interval [CI] 1.177-1.929; p = 0.001) as well as LPLN size (OR 1.124; CI 1.029-1.227, p = 0.009).

CONCLUSIONS

LPLN ≥ 2 and a ratio of the number of positive LN/number of dissected LN > 0.3 were prognostic of poor LPFS. The prediction curve of LPR according to the number and size of LPLN could be useful for determining the benefit of additional lateral pelvic treatment.

Survival benefit of lateral lymph node dissection according to the region of involvement and the number of lateral lymph nodes involved

PURPOSE

The effectiveness of lateral lymph node dissection for extending the survival of patients with advanced lower rectal cancer remains unclear. The purpose of this study was to clarify the survival benefit of lateral lymph node dissection according to the region of involvement and the number of lateral lymph nodes involved.

METHODS

We reviewed 131 consecutive patients with advanced lower rectal cancer, who had undergone curative resection with total mesorectal excision plus extended lateral lymph node dissection at Wakayama Medical University Hospital. Twenty-six (19.1 %) of these patients had lateral lymph involvement. We performed univariate and multivariate analyses for the 3-year disease-free and overall survival of these patients.

RESULTS

Multivariate analysis revealed that the number (>1) and the region (common iliac artery region or external iliac artery region) of lateral lymph node metastasis are independent predictive factors for recurrence and survival. The Kaplan-Meier analysis demonstrated that patients with one lymph node metastasis in the internal iliac artery or obturator region had better survival.

CONCLUSIONS

Lateral lymph node dissection resulted in survival benefit for patients with single lateral lymph node involvement in the internal iliac artery region or the obturator region.

Clinical implication of additional selective lateral lymph node excision in patients with locally advanced rectal cancer who underwent preoperative chemoradiotherapy

PURPOSE

To identify the indication and prognostic significance of lateral lymph node (LLN) excision in locally advanced rectal cancer patients underwent preoperative chemoradiotherapy.

METHODS

Included were 67 consecutive patients with suspicious LLN metastasis who underwent chemoradiotherapy and surgery including selective LLN excision (82 excisions). The excisions were grouped according to the presence of LLN metastasis and compared in terms of the clinicopathological findings and oncological results. The correlation between the largest short-axis diameter of LLN measured by imaging and metastasis rates was explored.

RESULTS

LLN metastases were identified in 32 excisions (40.0 %). The calculated short-axis LLN diameter predicting metastasis was 11.7 mm (before chemoradiotherapy) and 11.4 mm (before surgery). LLN metastasis was observed more frequently in the low rectum (p = 0.031) and associated with higher CEA levels (p = 0.048). The 3-year overall survival rates for patients with and without LLN metastasis were 60.3 % and 90.3 % (p = 0.048), while the 3-year disease-free survival rates were 31.4 % and 70.5 % (p = 0.009). The hazard ratio of LLN metastasis for recurrence was 2.938 (95 % CI = 1.258-6.863).

CONCLUSIONS

LLN metastasis in rectal cancer patients underwent chemoradiotherapy was a distinct poor prognostic factor. Selective LLN excision based on imaging studies may have a role for such patients.

A nodal positivity constant: new perspectives in lymph node evaluation and colorectal cancer

PURPOSE

To date, associations between the number of lymph nodes evaluated, staging, and survival have been examined in the context of large population-based studies conducted by a small number of investigators. Therefore, although high-quality data are available, perspective is lacking.

METHODS

Studies for this paper were identified by searches of Medline, Scopus, PubMed, and manual searching of references from articles, using the search terms ''colorectal cancer'', ''nodal status'' and ''lymph node''.

RESULTS

It is clear that survival benefit increases with the increasing number of lymph nodes harvested. Despite this observation, there has been no significant increase in the proportion of node-positive cancers over the past two decades.

CONCLUSION

The nodal positivity rate for colorectal cancer consistently approximates 40 % across a wide range of studies internationally, a phenomenon that has not previously been recognized in the literature. We review the evidence and introduce the concept of a nodal positivity constant.