Outcomes and prognostic factors of selective lateral pelvic lymph node dissection with preoperative chemoradiotherapy for locally advanced rectal cancer

Anatomic Basis of Rectal Cancer Staging: Clarifying Controversies and Misconceptions

Rectal MRI provides a detailed depiction of pelvic anatomy; specifically, the relationship of the tumor to key anatomic structures, including the mesorectal fascia, anterior peritoneal reflection, and sphincter complex. However, anatomic inconsistencies, pitfalls, and confusion exist, which can have a strong impact on interpretation and treatment. These areas of confusion include the definition of the rectum itself, specifically differentiation of the rectum from the anal canal and the sigmoid colon, and delineation of the high versus low rectum. Other areas of confusion include the relative locations of the mesorectal fascia and peritoneum and their significance in staging and treatment, the difference between the mesorectal fascia and circumferential resection margin, involvement of the sphincter complex, and evaluation of lateral pelvic lymph nodes. The impact of these anatomic inconsistencies and sources of confusion is significant, given the importance of MRI in depicting the anatomic relationship of the tumor to critical pelvic structures, to triage surgical resection and neoadjuvant chemoradiotherapy with the goal of minimizing local recurrence. Evolving treatment paradigms also place MRI central in management of rectal cancer. ©RSNA, 2024.

The modified Glasgow prognostic score is a reliable predictor of oncological outcomes in patients with rectal cancer undergoing neoadjuvant chemoradiotherapy

There has been no reliable marker for predicting oncological outcomes in patients with locally advanced rectal cancer (LARC) undergoing neoadjuvant chemoradiotherapy (NACRT). We retrospectively analyzed 73 patients with LARC who underwent curative surgery after NACRT. The modified Glasgow prognostic score (mGPS) was assessed after NACRT, and clinical outcomes were compared between the high (mGPS = 1 or 2; n = 23) and low (mGPS = 0; n = 50) groups. Body mass index was significantly higher in the low mGPS group. The 5-year disease-free survival (DFS) rate was significantly worse in the high mGPS group than that in the low mGPS group (36.7% vs. 76.6%, p = 0.002). Univariate and multivariate analyses of DFS revealed that mGPS was the most significant predictor (p < 0.001). mGPS appears to be a reliable predictor of oncological outcomes in patients with LARC undergoing NACRT.

Patients younger than 40 years with colorectal cancer have a similar prognosis to older patients

PURPOSE

Colorectal cancer (CRC) is a leading cause of cancer-related deaths worldwide. In recent years, the proportion of patients diagnosed with CRC at younger ages has increased. The clinicopathological features and oncological outcomes in younger patients with CRC remain controversial. We aimed to analyze the clinicopathological features and oncological outcomes in younger patients with CRC.

METHODS

We examined 980 patients who underwent surgery for primary colorectal adenocarcinoma between 2006 and 2020. Patients were divided into two cohorts: younger (< 40 years old) and older (≥ 40 years old).

RESULTS

Of the 980 patients, 26 (2.7%) were under the age of 40 years. The younger group had more advanced disease (57.7% vs. 36.6%, p = 0.031) and more cases beyond the transverse colon (84.6% vs. 65.3%, p = 0.029) than the older group. Adjuvant chemotherapy was administered more frequently in the younger group (50% vs. 25.8%, p < 0.01). Relapse-free survival and overall survival were similar between the groups at all stages. Moreover, in stages II and III they were also comparable, regardless of the administration of adjuvant chemotherapy.

CONCLUSIONS

Younger patients with CRC have a prognosis equivalent to that of older patients. Further studies are needed to establish the optimal treatment strategies for these patients.

Transanally assisted lateral pelvic lymph node dissection for rectal cancer

BACKGROUND

Although lateral pelvic lymph node dissection (LLND) might be an effective approach for patients with rectal cancer with lateral lymph node metastasis, it is technically challenging because of the anatomical complexity and location of the deep pelvis. An assistance by transanal approach might be useful for a successful LLND.

METHODS

From September 2016 to May 2021, 39 patients with low rectal cancer underwent transanal total mesorectal excision with LLND. Among them, 18 patients underwent LLND using a conventional laparoscopic approach alone, while the remaining 21 underwent LLND using both conventional and transanal approaches. Their clinical outcomes were retrospectively compared.

RESULTS

The operation time for LLND on each side was significantly shorter in the transanal group (105 min vs. 54 min, P < 0.001). The intraoperative blood loss was also significantly less in the transanal group (40 g vs. 0 g, P = 0.031). The rate of overall postoperative complications ≥ grade II according to the Clavien-Dindo classification was significantly less in the transanal group (66.7% vs. 28.6%, odds ratio: 5.000, 95% confidence intervals: 1.313-19.047, P = 0.040). The number of harvested lateral lymph nodes in both groups was similar (8.5 vs. 8, P = 0.544).

CONCLUSION

The transanal approach for LLND reduced operative time, blood loss, and morbidity compared with the conventional approach alone in a cohort of patients with rectal cancer.

Significance of Wnt/β-Catenin Signal Activation for Resistance to Neoadjuvant Chemoradiotherapy in Rectal Cancer

Although a therapeutic response to neoadjuvant chemoradiotherapy (NACRT) is important to improve oncological outcomes after surgery in patients with locally advanced rectal cancer, there is no reliable predictor for this. The Wnt/β-catenin signal is known to be crucial for the tumorigenesis of colorectal cancer. This study aimed to investigate the association of Wnt/β-catenin signal activation with a pathological response to NACRT. The immunohistochemical expression of nuclear and membranous β-catenin was analyzed in biopsy samples obtained from 60 patients with locally advanced rectal cancer who received curative surgery following NACRT. The association of Wnt/β-catenin signal activation with their clinical outcomes was investigated. Notably, the body mass index of these patients was significantly higher in the low nuclear β-catenin expression group. Moreover, patients in the high nuclear β-catenin expression group tended to have more advanced disease and a higher rate of positive vascular invasion than those in the low expression group. Furthermore, the rate of good histological responses was significantly higher in the low nuclear β-catenin expression group (72% vs. 37.1%, p < 0.01). Overall, relapse-free survival tended to be better in patients with low nuclear/high membranous β-catenin expression (n = 9) than in other individuals (n = 51) (p = 0.093 and p = 0.214, respectively). Activation of the Wnt/β-catenin signal pathway represented by nuclear β-catenin accumulation was significantly associated with a poor response to NACRT in patients with rectal cancer. Analysis of nuclear β-catenin accumulation before starting treatment might help predict the therapeutic response to NACRT.

Metabolic and magnetic resonance imaging: complementary modalities for the preoperative assessment of lateral pelvic lymph nodes in rectal cancer

BACKGROUND

The management of lateral pelvic lymph nodes for rectal cancer is a topical and controversial issue. The aim of this study was to assess the relationship between lateral pelvic lymph node features on magnetic resonance imaging (MRI) and positron emission tomography-computed tomography (PET-CT) with oncological outcomes in patients with rectal cancer.

METHODS

A retrospective analysis of 284 patients with primary locally advanced rectal cancer treated with neoadjuvant therapy and surgical resection with curative intent between January 2003 and Dec 2018 was undertaken. From this study population, a select cohort of 77 patients with abnormal lateral pelvic lymph nodes on preoperative imaging had imaging re-analysed by radiologists blinded to clinical outcomes. Pre and post neoadjuvant therapy MRI and PET-CT lateral pelvic lymph node features were correlated with oncological outcomes.

RESULTS

A lateral pelvic lymph node short axis size ≥5 mm on post neoadjuvant therapy MRI was a significant predictor of worse 3-year local recurrence free survival (HR 8.35, P = 0.001). Lateral pelvic lymph node avidity on post neoadjuvant therapy PET-CT was a significant predictor of worse 3-year distant recurrence free survival (HR 5.62, P = 0.001). No correlation of oncological outcomes with overall survival was identified.

CONCLUSION

Lateral pelvic lymph node imaging features on post-neoadjuvant therapy MRI and PET-CT predicted those at risk of rectal cancer recurrence. Further studies are required to confirm these findings that suggest restaging MRI and PET-CT are complementary modalities for the preoperative assessment of lateral pelvic lymph nodes in rectal cancer.

Clinical implication and management of rectal cancer with clinically suspicious lateral pelvic lymph node metastasis: A radiation oncologist's perspective

Rectal cancer is the eighth most common malignancy worldwide. With the introduction of total mesorectal excision (TME) and neoadjuvant chemoradiation (NCRT), intrapelvic local control has been remarkably improved. However, lateral pelvic recurrence remains problematic, especially in patients with clinically suspicious lateral pelvic lymph node (LPLN). LPLN dissection has been applied for the management of LPLN metastasis, mainly in Japan and other Eastern countries, while the role of NCRT is more emphasized and LPLN dissection is performed in very limited cases in Western countries. However, the optimal management strategy for patients with rectal cancer with suspicious LPLN metastasis has not been determined. Herein, we review the latest studies on the optimal management of LPLN metastasis to suggest the most appropriate treatment policies according to current evidence and discuss future research directions.

Efficacy and Safety of Radical Resection of Rectal Cancer Combined with Selective Lateral Lymph Node Dissection in the Treatment of Low Rectal Cancer under Meta-analysis

Rectal cancer mostly occurs in the middle and low position in China, and many anatomical evidence has confirmed that Lateral Lymph Node Metastasis (LLNM) exists in middle and low rectal cancer. Laparoscopic surgery can penetrate into the pelvic cavity and magnify and narrow the visual field, which is helpful for lymph node dissection and vascular nerve protection, while it has minimally invasive characteristics and is considered to be more suitable for LLND. Relevant articles published from January 2000 to May 2022 are searched using "Rectal cancer, Lateral lymph node dissection, Radical resection of rectal cancer, Low rectal cancer, Laparoscopic therapy, Treatment of rectal cancer" as test terms, analyzed and assessed using Rev Man 5.3 software and Stata software to assess the risk bias of included references, and heterogeneity among each study is evaluated using Q test and heterogeneity (I2). The experimental results show that there is no heterogeneity among the studies (I2 = 8.46%). The heterogeneity of lymphatic metastasis in the included literature is evaluated, and the results show that there is heterogeneity between the studies (I2 = 52.06%).

Systematic review and meta-analysis of long-term oncological outcomes of lateral lymph node dissection for metastatic nodes after neoadjuvant chemoradiotherapy in rectal cancer

BACKGROUND

Standard Western management of rectal cancers with pre-treatment metastatic lateral lymph nodes (LLNs) is neoadjuvant (chemo)radiotherapy (nCRT) followed by total mesorectal excision (TME). In recent years, there is growing interest in performing an additional lateral lymph node dissection (LLND). The aim of this systematic review and meta-analysis was to investigate long-term oncological outcomes of nCRT followed by TME with or without LLND in patients with pre-treatment metastatic LLNs.

METHODS

PubMed, Ovid MEDLINE, Embase, Cochrane Library and Clinicaltrials.gov were searched to identify comparative studies reporting long-term oncological outcomes in pre-treatment metastatic LLNs of nCRT followed by TME and LLND (LLND+) vs. nCRT followed by TME only (LLND-). Newcastle-Ottawa risk-of-bias scale was used. Outcomes of interest included local recurrence (LR), disease-free survival (DFS), and overall survival (OS). Summary meta-analysis of aggregate outcomes was performed.

RESULTS

Seven studies, including 946 patients, were analysed. One (1/7) study was of good-quality after risk-of-bias analysis. Five-year LR rates after LLND+ were reduced (range 3-15%) compared to LLND- (11-27%; RR = 0.40, 95%CI [0.25-0.62], p < 0.0001). Five-year DFS was not significantly different after LLND+ (range 61-78% vs. 46-79% for LLND-; RR = 0.72, 95%CI [0.51-1.02], p = 0.143), and neither was five-year OS (range 69-91% vs. 72-80%; RR = 0.72, 95%CI [0.45-1.14], p = 0.163).

CONCLUSION

In rectal cancers with pre-treatment metastatic LLNs, nCRT followed by an additional LLND during TME reduces local recurrence risk, but does not impact disease-free or overall survival. Due to the low quality of current data, large prospective studies will be required to further determine the value of LLND.

OUP accepted manuscript

Background

Method

Results

Conclusion

Surgical Treatment of Low-Lying Rectal Cancer: Updates

Despite innovative advancements, distally located rectal cancer remains a critical disease of challenging management. The crucial location of the tumor predisposes it to a circumferential resection margin (CRM) that tends to involve the anal sphincter complex and surrounding organs, with a high incidence of delayed anastomotic complications and the risk of the pelvic sidewall or rarely inguinal lymph node metastases. In this regard, colorectal surgeons should be aware of other issues beyond total mesorectal excision (TME) performance. For decades, the concept of extralevator abdominoperineal resection to avoid compromised CRM has been introduced. However, the complexity of deep pelvic dissection with poor visualization in low-lying rectal cancer has led to transanal TME. In contrast, neoadjuvant chemoradiotherapy (NCRT) has allowed for the execution of more sphincter-saving procedures without oncologic compromise. Significant tumor regression after NCRT and complete pathologic response also permit applying the watch-and-wait protocol in some cases, now with more solid evidence. This review article will introduce the current surgical treatment options, their indication and technical details, and recent oncologic and functional outcomes. Lastly, the novel characteristics of distal rectal cancer, such as pelvic sidewall and inguinal lymph node metastases, will be discussed along with its tailored and individualized treatment approach.

Lateral Pelvic Lymph Node Dissection After Neoadjuvant Chemoradiotherapy in Patients With Rectal Cancer: A Single-Center Experience and Literature Review

Purpose

We aimed to evaluate the surgicopathological outcomes of lateral pelvic lymph node dissection (LPLD) and long-term oncological outcomes of selective LPLD after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer and compare them to those of total mesorectal excision (TME) alone based on pretreatment magnetic resonance imaging (MRI).

Methods

We compared the TME-alone group (2001–2009, n=102) with the TME with LPLD group (2011–2016, n=69), both groups having lateral lymph nodes (LLNs) of ≥5 mm in short axis diameter. The surgicopathological outcomes were analyzed retrospectively. Oncological outcomes were analyzed using the Kaplan-Meier method.

Results

The rates of overall postoperative 30-day morbidity (42.0% vs. 26.5%, P=0.095) and urinary retention (13.7% vs. 10.1%, P=0.484) were not significantly different between the LPLD and TME-alone groups, respectively. Pathologically proven LLN metastasis was identified in 24 (34.8%) LPLD cases after nCRT. The LPLD group showed a lower 5-year local recurrence (LR) rate (27.9% vs. 4.6%, P<0.001) and better recurrence-free survival (RFS) (59.6% vs. 78.2%, P=0.008) than those of the TME-alone group, while the 5-year overall survival was not significantly different between the 2 groups (76.2% vs. 86.5%, P=0.094).

Conclusion

This study suggests that LPLD is a safe and feasible procedure. The oncological outcomes suggest that selective LPLD improves LR and RFS in patients with clinically suspicious LLNs on pretreatment MRI. Considering that lateral nodal disease is not common, a multicenter large-scale study is necessary.

Extended Lymphadenectomy in Locally Advanced Rectal Cancers: A Systematic Review

Purpose

The surgical treatment of advanced low rectal cancer remains controversial. Extended lymphadenectomy (EL) is the preferred option in the East, especially in Japan, while neoadjuvant radiotherapy is the treatment of choice in the West. This review was undertaken to review available evidence supporting each of the therapies.

Methods

All studies looking at EL were included in this review. A comprehensive search was conducted as per PRISMA guidelines. Primary outcome was defined as 5-year overall survival, with secondary outcomes including 3-year overall survival, 3- and 5-year disease-free survival, length of operation, and number of complications.

Results

Thirty-one studies met the inclusion criteria. There was no significant publication bias. There was statistically significant difference in 5-year survival for patient who underwent EL (odds ratio, 1.34; 95 confidence interval, 0.09–0.5; P=0.006). There were no differences noted in secondary outcomes except for length of the operations.

Conclusion

There is evidence supporting EL in rectal cancer; however, it is difficult to interpret and not easily transferable to a Western population. Further research is necessary on this important topic.

Lateral lymph node dissection in advanced low rectal cancer treatment

Lateral lymph node (LLN) metastasis is a determinant of local recurrence in advanced low rectal cancer. Lateral lymph node dissection (LLND) is effective in removing metastatic lymph nodes, and has been shown to have a decreased local recurrence rate. However, because of its complexity and complications it induces, there is still tremendous controversy about its usage. Neoadjuvant chemoradiotherapy (nCRT) and total mesorectal excision (TME) are recommended as a conventional treatment for advanced rectal cancer. However, LLN metastasis and local recurrence still occur despite nCRT with TME. In Japan, TME with LLND is the standard surgical treatment for Stage II/III of advanced low rectal cancer. Before surgery, a proper evaluation of LLN status should be performed. Laparoscopic LLND and robotic-assisted LLND are useful for this. More research is necessary to improve the oncological outcomes of LLND. In this review, we retrospectively examine previous reports about LLND, aiming to emphasize its application prospects to improve patient survival and life quality.

Sarcopenia assessed by skeletal muscle mass volume is a prognostic factor for oncological outcomes of rectal cancer patients undergoing neoadjuvant chemoradiotherapy followed by surgery

INTRODUCTION

Recently, sarcopenia has been reported to be associated with poor postoperative outcomes in various cancers. However, its clinical significance for rectal cancer patients undergoing neoadjuvant chemoradiotherapy (NACRT) followed by surgery remains unknown.

MATERIALS AND METHODS

This study included 46 patients with locally advanced rectal cancer who underwent curative surgery after NACRT. Sarcopenia was assessed by measuring the cross-sectional psoas muscle area (PA) at L3 and total bilateral psoas muscle volume (PV). Patients with a lower PV or PA value than the median were assigned to the sarcopenia group while others were assigned to the non-sarcopenia group. Clinical outcomes were then compared between groups.

RESULTS

The sarcopenia group included 22 patients. The rate of overall postoperative complications did not differ between groups. Five-year relapse-free survival (RFS) was significantly lower in the sarcopenia group when sarcopenia was assessed by PV after NACRT (44.0% vs. 82.6%, P = 0.00494). In contrast, RFS did not differ between groups when sarcopenia was assessed by PA. Multivariable analysis identified PV after NACRT as the most significant risk factor for RFS (hazard ratio 4.00; 95% CI 1.27-12.66, P = 0.018).

CONCLUSION

Sarcopenia assessed by total PV after NACRT may be an accurate and reliable predictor of poor oncological outcomes in rectal cancer patients.

Lateral pelvic lymph nodes for rectal cancer: A review of diagnosis and management

The current status and future prospects for diagnosis and treatment of lateral pelvic lymph node (LPLN) metastasis of rectal cancer are described in this review. Magnetic resonance imaging (MRI) is recommended for the diagnosis of LPLN metastasis. A LPLN-positive status on MRI is a strong risk factor for metastasis, and evaluation by MRI is important for deciding treatment strategy. LPLN dissection (LPLD) has an advantage of reducing recurrence in the lateral pelvis but also has a disadvantage of complications; therefore, LPLD may not be appropriate for cases that are less likely to have LPLN metastasis. Radiation therapy (RT) and chemoradiation therapy (CRT) have limited effects in cases with suspected LPLN metastasis, but a combination of preoperative CRT and LPLD may improve the treatment outcome. Thus, RT and CRT plus selective LPLD may be a rational strategy to omit unnecessary LPLD and produce a favorable treatment outcome.

Malignant Features in Pretreatment Metastatic Lateral Lymph Nodes in Locally Advanced Low Rectal Cancer Predict Distant Metastases

INTRODUCTION

Pretreatment enlarged lateral lymph nodes (LLN) in patients with locally advanced low rectal cancer are predictive for local recurrences after neoadjuvant (chemo)radiotherapy (n(C)RT) followed by total mesorectal excision (TME). Not much is known of the impact on oncological outcomes when in addition malignant features are present in enlarged LLN.

PATIENTS AND METHODS

A multicenter retrospective cohort study was conducted at five tertiary referral centers in the Netherlands and Australia. All patients were diagnosed with locally advanced low rectal cancer with LLN on pretreatment magnetic resonance imaging (MRI) and underwent n(C)RT followed by TME. LLN were considered enlarged with a short axis of ≥ 5 mm. Malignant features were defined as nodes with internal heterogeneity and/or border irregularity. Outcomes of interest were local recurrence-free survival (LRFS), distant metastatic-free survival (DMFS), and overall survival (OS).

RESULTS

Out of 115 patients, the majority was male (75%) and the median age was 64 years (range 26-85 years). Median pretreatment LLN short axis was 7 mm (range 5-28 mm), and 60 patients (52%) had malignant features. After a median follow-up of 47 months, patients with larger LLN (7 + mm) had a worse LRFS (p = 0.01) but no difference in DMFS (p = 0.37) and OS (p = 0.54) compared with patients with smaller LLN (5-6 mm). LLN patients with malignant features had no difference in LRFS (p = 0.20) but worse DMFS (p = 0.004) and OS (p = 0.006) compared with patients without malignant features in the LLN. Cox regression analysis identified LLN short axis as an independent factor for LR. Malignant features in LLN were an independent factor for DMFS.

CONCLUSION

The current study suggests that pretreatment enlarged LLN that also harbor malignant features are predictive of a worse DMFS. More studies will be required to further explore the role of malignant features in LLN.

Transperineal minimally invasive abdominoperineal resection for low rectal cancer: standardized technique and clinical outcomes

BACKGROUND

Despite the increasing utilization of transanal total mesorectal excision as a promising approach for low rectal cancer, the feasibility and safety of transperineal minimally invasive abdominoperineal resection (tp-APR) remain unclear.

METHODS

In total, 25 patients who underwent tp-APR between April 2017 and May 2020 (tp-APR group) and 27 patients who underwent conventional laparoscopic APR between May 2009 and September 2016 (lap-APR group) for low rectal cancer were enrolled in this retrospective study. Clinical outcomes were compared between the groups before and after propensity score matching. The primary outcome was the incidence of the overall postoperative complications with Clavien-Dindo grade II or above. Standardized technique of tp-APR was also demonstrated.

RESULTS

On comparison, operative time, intraoperative blood loss, and overall postoperative complications with Clavien-Dindo grade II or above were significantly less in the tp-APR group both before and after propensity score matching. The rates of urinary disturbance and perineal wound infection were significantly less in the tp-APR group after matching. Further, postoperative hospital stay was significantly shorter in the tp-APR group both before and after matching. However, pathological outcomes did not differ between the groups before and after matching. There has been no local recurrence in the tp-APR group with a median follow-up period of 18 months.

CONCLUSION

Standardized tp-APR for low rectal cancer is feasible and seems superior to conventional laparoscopic APR in terms of short-term outcomes. Further larger-scale studies with a longer follow-up period are required to evaluate oncological outcomes.

Prognostic Value of Lateral Pelvic Lymph Node Dissection for Rectal Cancer: A Meta-analysis

BACKGROUND AND AIMS

The benefit of lateral pelvic lymph node dissection (LPLD) for locally advanced rectal cancer remains controversial. This meta-analysis aimed to evaluate the prognostic value of LPLD in patients with locally advanced rectal cancer.

METHODS

We performed a systematic search in PubMed, Embase, and the Cochrane Library for publications comparing radical resection plus LPLD (LPLD group) with single radical resection (non-LPLD group) for locally advanced rectal cancer. A total of 15 studies satisfied our inclusion criteria and were assessed. Random-effects and fixed-effects meta-analytical models were used where indicated, and between-study heterogeneity was assessed.

RESULTS

LPLD significantly increased grade 3-4 postoperative complications (odds ratio [OR]1.44, 95% CI 1.03-2.02; P = 0.03) compared with non-LPLD. There were no significant differences in 5-y overall survival (hazard ratio = 0.90, 95% CI 0.77-1.05; P = 0.17), 5-y disease-free survival (hazard ratio 1.12, 95% CI 0.60-2.09; P = 0.73), local recurrence (OR 0.89, 95% CI 0.53-1.51; P = 0.68) or distant recurrence (OR 0.85, 95% CI 0.64-1.12; P = 0.24).

CONCLUSIONS

We found that LPLD significantly increased grade 3-4 postoperative complications but did not increase 5-y overall survival or 5-y disease-free survival compared with single radical resection for locally advanced rectal cancer. Furthermore, it did not decrease the local recurrence or distant recurrence rates. Thus, more multicenter large-scale randomized controlled trials should be conducted to further explore whether the long-term survival benefits of LPLD truly exist.

MRI-detected extramural vascular invasion potentiates the risk for pathological metastasis to the lateral lymph nodes in rectal cancer

PURPOSE

Multidisciplinary treatment for locally advanced rectal cancer requires an accurate assessment of the risk of metastasis to the lateral lymph nodes (LNs). We herein aimed to stratify the risk of pathological metastasis to lateral LNs based on the preoperatively detected malignant features.

METHODS

All patients with rectal cancer who underwent surgery from January 2016 to July 2020 were identified. We recorded the TNM factors; perirectal and lateral LN sizes; and MRI findings, including mesorectal fascia involvement, extramural vascular invasion (EMVI), tumor site, and tumor distance from the anal verge.

RESULTS

101 patients underwent rectal resection with lateral lymph node dissection, of whom 16 (15.8%) exhibited pathological metastases to the lateral LNs. Univariate analyses demonstrated that lateral LN metastasis was significantly correlated with mrEMVI positivity (p = 0.0023) and a baseline lateral LN short-axis length of ≥ 5 mm (p < 0.0001). These significant associations were confirmed by a multivariate analysis (p = 0.0254 and 0.0027, respectively). The lateral LN metastasis rate was as high as 44% in cases bearing both risk factors, compared to 0% in cases lacking both risk factors.

CONCLUSION

The results elucidated in this study may contribute to risk stratification, which can be used when determining the indications for lateral lymph node dissection.

Indications and oncological outcomes of selective dissection for clinically suspected lateral lymph node metastasis in patients with rectal cancer based on pretreatment imaging

BACKGROUND

The aim of this study was to identify the indications and oncological outcomes of selective lateral lymph node dissection (sLLND) in rectal cancer patients.

METHODS

A retrospective study was conducted on consecutive patients with rectal cancer who had standard total mesorectal excision and sLLND at our institution. Clinicopathological characteristics and oncological outcomes were analyzed. We performed subgroup analysis and multivariate analysis based on patients with or without preoperative chemoradiotherapy to identify the related risk factors.

RESULTS

A total of 77 consecutive patients with TME and sLLND were included. Twenty-two (28.6%) patients with pathological positive lateral lymph nodes metastasis (LLNM) were identified. Forty-seven (61%) patients accepted neoadjuvant chemoradiotherapy (nCRT). The pretreatment maximum short-axis diameters of LLN (≥ 8 mm) were the independent risk factors for LLNM among patients with LLN ≥ 5 mm. Lymph node metastasis were significantly higher in patients with pretreatment LLN ≥ 8 mm than in patients with LLN 5-8 mm (63% vs. 10%, p < 0.001). The receiver operating curve analysis suggested that the optimal cutoff value of LLN short-axis diameter for predicting LLNM was 8 mm. At a median follow-up of 42 months (range 6-140 months) 3 (3.9%) patients with lateral pelvic recurrence were observed. The 3-year cumulative overall survival in patients with LLNM and patients without LLNM was 76.7% and 89.8%, respectively (p = 0.01). The 3-year cumulative disease-free survival was 53.6% in patients with LLNM and 88.3% in patients without LLNM (p = 0.008).

CONCLUSION

Patients with LLNM had a worse prognosis. The pretreatment maximum short-axis diameter of LLN (≥ 8 mm) should be considered as an indication for sLLND.

Rise and fall of total mesorectal excision with lateral pelvic lymphadenectomy for rectal cancer: an updated systematic review and meta-analysis of 11,366 patients

The role of lateral lymph node dissection (LLND) during total mesorectal excision (TME) for rectal cancer is still controversial. Many reviews were published on prophylactic LLND in rectal cancer surgery, some biased by heterogeneity of overall associated treatments. The aim of this systematic review and meta-analysis is to perform a timeline analysis of different treatments associated to prophylactic LLND vs no-LLND during TME for rectal cancer.

METHODS

A literature search was performed in PubMed, SCOPUS and WOS for publications up to 1 September 2020. We considered RCTs and CCTs comparing oncologic and functional outcomes of TME with or without LLND in patients with rectal cancer.

RESULTS

Thirty-four included articles and 29 studies enrolled 11,606 patients. No difference in 5-year local recurrence (in every subgroup analysis including preoperative neoadjuvant chemoradiotherapy), 5-year distant and overall recurrence, 5-year overall survival and 5-year disease-free survival was found between LLND group and non LLND group. The analysis of post-operative functional outcomes reported hindered quality of life (urinary, evacuatory and sexual dysfunction) in LLND patients when compared to non LLND.

CONCLUSION

Our publication does not demonstrate that TME with LLND has any oncological advantage when compared to TME alone, showing that with the advent of neoadjuvant therapy, the advantage of LLND is lost. In this review, the most important bias is the heterogeneous characteristics of patients, cancer staging, different neoadjuvant therapy, different radiotherapy techniques and fractionation used in different studies. Higher rate of functional post-operative complications does not support routinely use of LLND.

Outcome of lateral pelvic lymph node dissection with total mesorectal excision in treatment of rectal cancer: A systematic review and meta-analysis

BACKGROUND

Total mesorectal excision is the gold standard treatment of mid- and low-lying rectal cancer. Lateral pelvic lymph node dissection has been suggested as an approach to decrease recurrence and improve survival. Our meta-analysis presented here aimed to review the current outcomes of lateral pelvic lymph node dissection and total mesorectal excision in comparison with total mesorectal excision alone.

METHODS

A systematic literature search querying electronic databases was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. We reviewed articles that reported the outcomes of lateral pelvic lymph node dissection combined with total mesorectal excision in comparison with total mesorectal excision alone. The main outcome measures were local recurrence, distant metastasis, overall and disease free-survival, and complications.

RESULTS

This systematic review included 29 studies of 10,646 patients. Of those patients, 39.4% underwent total mesorectal excision with lateral pelvic lymph node dissection. The median operation time for the lateral pelvic lymph node dissection + total mesorectal excision was significantly longer than total mesorectal excision alone (360 minutes versus 294.7 minutes, P = .02). Lateral pelvic lymph node dissection + total mesorectal excision was associated with higher odds of overall complications (odds ratio = 1.48, 95% confidence interval: 1.18-1.87, P < .001) and urinary dysfunction (odds ratio = 2.1, 95% confidence interval: 1.21-3.67, P = .008) than total mesorectal excision alone. Both groups had similar rates of male sexual dysfunction (odds ratio = 1.62, 95% confidence interval: 0.94-2.79, P = .08), anastomotic leakage (odds ratio = 1.15, 95% confidence interval: 0.69-1.93, P = .59), local recurrence (hazard ratio = 0.96, 95% confidence interval: 0.75-1.25, P = .79), distant metastasis (hazard ratio = 0.96, 95% confidence interval: 0.76-1.2, P = .72), overall survival (hazard ratio = 1.056, 95% confidence interval: 0.98-1.13, P = .13), and disease-free survival (hazard ratio = 1.02, 95% confidence interval: 0.97-1.07, P = .37).

CONCLUSION

Lateral pelvic lymph node dissection was not associated with a significant reduction of recurrence rates or improvement in survival as compared with total mesorectal excision alone; however, LPLND was associated with longer operation time and increased complication rate.

Current Surgical Strategies for the Treatment of Rectal Adenocarcinoma and the Risk of Local Recurrence

BACKGROUND

Despite new medical and surgical strategies, 5-year local recurrence of rectal adenocarcinoma was reported in up to 25% of cases. Therefore, we aimed to review surgical strategies for the prevention of local recurrences in rectal cancer.

SUMMARY

After implementation of the total mesorectal excision (TME), surgical resection of rectal adenocarcinoma with anterior resection or abdominoperineal excision (APE) allowed decrease in local recurrence (3% at 5 years). More recently, extralevator APE was described as an alternative to APE, decreasing specimen perforation and recurrence rate. Moreover, technique modifications were developed to optimize rectal resection, such as the laparoscopic or robotic approach, and transanal TME. However, the technical advantages conferred by these techniques did not translate into a decreased recurrence rate. Lateral lymph node dissection is another technique, which aimed at improving the long-term outcomes; nevertheless, there is currently no evidence to recommend its routine use. Strategies to preserve the rectum are also emerging, such as local excision, and may be beneficial for subgroups of patients. Key Messages: Rectal cancer management requires a multidisciplinary approach, and surgical strategy should be tailored to patient factors: general health, previous perineal intervention, anatomy, preference, and tumor characteristics such as stage and localization.

Clinical outcomes of transanal total mesorectal excision using a lateral-first approach for low rectal cancer: a propensity score matching analysis

BACKGROUND

Although transanal total mesorectal excision (ta-TME) is adopted for rectal cancer surgery by an increasing number of surgeons, it is still technically challenging. We have employed a lateral-first approach for ta-TME to overcome technical difficulties. However, its outcomes and advantage over conventional laparoscopic TME remain unclear.

METHODS

Thirty-five consecutive patients who underwent ta-TME using a lateral-first approach (the ta-TME group) and 53 consecutive patients who underwent conventional laparoscopic TME (the lap-TME group) for low rectal cancer were included. Propensity score matching (PSM) was used to create balanced cohorts of ta-TME (n = 28) and lap-TME (n = 28). Their clinical outcomes were compared after PSM.

RESULTS

The operative time and intraoperative blood loss were significantly lower in the ta-TME group than in the lap-TME group (P = 0.042 and P < 0.001, respectively). Postoperative complications ≥ Clavien-Dindo grade II were significantly less and postoperative hospital stay was significantly shorter in the ta-TME group (35.7% vs. 78.6%, P = 0.003, and 18 days vs. 32 days, P < 0.001, respectively). The distal margin was significantly larger in the ta-TME when excluding the abdominoperineal resection cases (20 mm vs. 10 mm, P = 0.032). The positive radial margin was observed in 2 of 28 patients (7.1%) in the ta-TME group.

CONCLUSIONS

Ta-TME using a lateral-first approach is feasible and may offer several advantages over lap-TME in terms of short-term outcomes. It might be an alternative safe approach for ta-TME. To confirm the oncological superiority of this surgery, further study in a larger population and for a longer follow-up period is warranted.

Does adding lateral pelvic lymph node dissection to neoadjuvant chemotherapy improve outcomes in low rectal cancer?

PURPOSE

Lateral pelvic lymph node metastasis occurs in 15 to 20% of patients with locally advanced low rectal cancer which increases risk of local recurrence and reduced survival following neoadjuvant chemoradiotherapy (nCRT) and total mesorectal excision (TME). Adding lateral pelvic lymph node dissection (LPLND) could improve outcomes in those patients. This review aims to determine if the addition of LPLND to the conventional management of advanced rectal cancer would yield improved outcomes.

METHODS

OVID Medline, Cochrane, Clinicaltrials.gov , EMBASE, Clinicaltrialsregister.eu, Web of Knowledge and CABAbstracts were searched using the following keywords: 'lateral pelvic lymph node dissection', 'pelvis lymphadenectomy', 'chemoradi*', 'rectal cancer', 'rectal neoplasm', 'rectal carcinoma' and 'rectal tumour'. Studies were included if they were in English and included rectal cancer patients that had nCRT, rectal resection ± LPLND. Primary outcome was 3-year and 5-year local recurrence. Secondary outcome was 3-year and 5-year overall survival.

RESULTS

Six studies were identified with 1210 patients who had nCRT and TME, and 268 patients who had nCRT and rectal resection plus LPLND. Patients who had LPLND had non-significant lower 3-year and 5-year local recurrence rate compared with those who did not (p = 0.10 and p = 0.12, respectively). They demonstrated a lower 3-year overall survival but higher 5-year overall survival and both were not significant (p = 0.81 and p = 0.57, respectively).

CONCLUSION

Available evidence suggests that there is no significant reduction in local recurrence rates or improved survival from LPLND to the current treatment modalities. Further studies are required to define the role of lateral pelvic lymph node dissection in low rectal cancer.

Total mesorectal excision with and without lateral lymph node dissection: a systematic review of the literature

PURPOSE

Treatment of lateral lymph node metastasis in rectal cancer is still under debate. While these nodes are routinely resected by Japanese teams, neoadjuvant radiochemotherapy alone is performed in Western countries. We aimed to systematically report the current literature assessing the overall and disease-free survivals of patients with rectal cancer treated with total mesorectal resection (TME) with or without lateral lymph node dissection (LLND).

METHODS

MEDLINE/Pubmed, Embase, Cochrane, and Web of Science were searched from database implementation until 19 January 2019. Studies reporting overall survival or recurrence-free survival in patients with LLND for rectal cancer were included. We excluded studies including patients with recurrent rectal cancer, multivisceral resection, and/or without control group (patients with rectal surgery without LLND).

RESULTS

Eleven studies were included, accounting for a total of 4159 patients. Overall survival ranged between 55.6 and 92.6% for TME with LLND versus 49.2 and 90.2% for TME alone, with one study reporting statistically significant benefit of LLND. Recurrence-free survival ranged between 58.3 and 74.1% for TME with LLND versus 39.5 and 76.5% for TME alone. Two studies showed statistically significant differences between the two strategies, one randomized controlled trial showed improved recurrence-free survival in TME alone group (74.5% versus 74.1% with LLND at 5 years) and one observational retrospective study reported increased recurrence-free survival with more extensive resection (65.4% versus 39.5% without LLND, at 5 years).

CONCLUSION

Benefits of LLND are not clear and further randomized controlled trials should be performed to determine which strategy would allow improving survival in rectal cancer patients.

TRIAL REGISTRATION

The study protocol was registered in PROSPERO prior to study screening (CRD42019123181) and published in September 2019.

Total mesorectal excision plus lateral lymph node dissection vs TME on rectal cancer patients: a meta-analysis

OBJECTIVE

Our study is the first meta-analysis to compare total mesorectal excision (TME) plus lateral lymph node dissection (LLND) with TME on rectal cancer patients regarding outcomes including overall survival, disease-free survival, local recurrence, complications, urinary dysfunction, and sexual dysfunction.

METHODS

PubMed, Embase, and Cochrane library were searched for publications up to October 2019. Two investigators independently screened the studies for eligibility and extracted specific data. Relevant data were analyzed by Review Manager version 5.3.

RESULTS

Patients in TME + LLND group suffered more complications (OR = 1.48, 95% CI [1.07, 2.03], P = 0.02) compared with TME group; no significant difference was observed in overall survival (HR = 1.11, 95% CI [0.77, 1.61], P = 0.57), disease-free survival (HR = 1.05, 95% CI [0.85, 1.30], P = 0.64), local recurrence (OR = 0.93, 95% CI [0.56, 1.54], P = 0.78), and urinary dysfunction (OR = 1.60, 95% CI [0.66, 3.87], P = 0.3).

CONCLUSION

TME + LLND may cause more complications compared with TME on rectal cancer patients. However, the definite conclusion still requires more researches.

What is the role of lateral lymph node dissection in rectal cancer patients with clinically suspected lateral lymph node metastasis after preoperative chemoradiotherapy? A meta-analysis and systematic review

BACKGROUND

Local lateral recurrence (LLR) in rectal cancer is increasingly becoming a significant clinical issue. Preoperative neoadjuvant chemoradiotherapy (nCRT) and lateral lymph node dissection (LLND)-when each approach is separately executed-cannot cure lateral lymph node metastasis (LLNM). Here, we performed a meta-analysis to evaluate the efficacy of nCRT plus total mesorectal excision (TME) vs TME plus LLND after nCRT for rectal cancer.

METHODS

Standard databases (PubMed, Embase, MEDLINE, Cochrane Library, and Web of Science) were searched to identify all relevant studies comparing nCRT+TME and nCRT+TME+LLND. Data in the included studies were extracted, and intraoperative outcomes, postoperative complications, and oncological outcomes were evaluated.

RESULTS

Eight studies representing 1,896 patients (1,461 nCRT+TME vs 435 nCRT+TME+LLND) were included. We found that for patients with clinically suspected LLNM, the incidence of pathological LLNM was 27.8%, even after nCRT. LLND after nCRT was significantly associated with lower LLR (P = .02). Additional LLND yielded a longer operative time (P < .01) and increased the risk of urinary dysfunction (P < .01). Concerning other outcomes, no significant differences were identified between the two groups.

CONCLUSION

This is the first meta-analysis and systematic review of studies comparing nCRT+TME and nCRT+TME+LLND for rectal cancer patients. Although increasing operative time and the risk of urinary dysfunction (which might be ameliorated by minimally invasive procedures), the pooled results support the use of LLND after nCRT and TME for reducing LLR in patients with clinically suspected LLNM and provide another treatment option for high-risk patients.

Laparoscopic and robotic lateral lymph node dissection for rectal cancer

In the era of neoadjuvant chemoradiotherapy/radiotherapy and total mesorectal excision, overall oncological outcomes after curative resection of rectal cancer are excellent, with local recurrence rates as low as 5–10%. However, lateral nodal disease is a major cause of local recurrence after neoadjuvant chemoradiotherapy/radiotherapy and total mesorectal excision. Patients with lateral nodal disease have a local recurrence rate of up to 30%. The oncological benefits of lateral pelvic lymph node dissection (LPLND) in reducing local recurrence, particularly in the lateral compartment, have been demonstrated. Although LPLND is not standard in Western countries, technical improvements in minimally invasive surgery have resulted in rapid technical standardization of this complicated procedure. The feasibility and short- and long-term outcomes of laparoscopic and robotic LPLND have been reported widely. A minimally invasive approach has the advantages of less bleeding and providing a better surgical view of the deep pelvic anatomy than an open approach. With precise autonomic nerve preservation, postoperative genitourinary dysfunction has been reported to be minimal. We review recent evidence on the management of lateral nodal disease in rectal cancer and technical improvements of LPLND, focusing on laparoscopic and robotic LPLND.

The efficacy and safety of lateral lymph node dissection for patients with rectal cancer: A systematic review and meta-analysis

Lateral lymph node metastasis in rectal cancer was first reported in the 1950s, since then, there has been an on-going debate about the value of lateral lymph node dissection (LLND) in the management of rectal cancer. We carried out a systematic review and meta-analysis to evaluate the value of LLND for the patients with rectal cancer. To collect clinical studies for the comparison of LLND and non-LLND in patients with rectal cancer, PubMed, Embase, Cochrane Library, Web of Science, and Google Scholar databases were searched from inception to 2019.A total of 26 studies, including 6865 patients were enrolled. Data processing and statistical analyses were performed using Stata V.15.0 software and Review Manager 5.3 software. Outcome measures included the 5-year survival rate, recurrence rate, perioperative outcomes, urinary function, and male sexual function. Regarding efficacy, our meta-analysis results showed no difference in 5-year disease-free survival rate and local recurrences between the two groups, the Hazard Ratio (HR) and 95% confidence interval (CI) was1.07 and 0.89 to 1.28 (P = 0.496),and the Odds Ratio(OR) and 95% CI were 0.90 and 0.76 to 1.06 (P = 0.208), respectively. Concerning safety, the incidence of urinary dysfunction and male sexual dysfunction was significantly increased in the LLND group (OR = 2.14, 95%CI = 1.21-3.79, P = 0.009), and (OR = 4.19, 95%CI = 1.55-11.33, P = 0.005), respectively. In conclusion, LLND did not improve the long-term prognosis of patients with rectal cancer, and was associated with increased urinary dysfunction and male sexual dysfunction.

Lateral Nodal Features on Restaging Magnetic Resonance Imaging Associated With Lateral Local Recurrence in Low Rectal Cancer After Neoadjuvant Chemoradiotherapy or Radiotherapy

Importance

Previously, it was shown in patients with low rectal cancer that a short-axis (SA) lateral node size of 7 mm or greater on primary magnetic resonance imaging (MRI) resulted in a high lateral local recurrence (LLR) rate after chemoradiotherapy or radiotherapy ([C]RT) with total mesorectal excision (TME) and that this risk was lowered by a lateral lymph node dissection (LLND). The role of restaging MRI after (C)RT with regard to LLR risk and which specific patients might benefit from an LLND is not fully understood.

Objective

To determine the factors on primary and restaging MRI that are associated with LLR in low rectal cancer after (C)RT and to formulate specific guidelines on which patients might benefit from an LLND.

Design, Setting, and Participants

In this retrospective, multicenter, pooled cohort study, patients who underwent surgery for cT3 or cT4 low rectal cancer with a curative intent from 12 centers in 7 countries from January 2009 to December 2013 were included. All patients' MRIs were rereviewed according to a standardized protocol, with specific attention to lateral nodal features. The original cohort included 1216 patients. For this study, patients who underwent (C)RT and had a restaging MRI were selected, leaving 741 for analyses across 10 institutions, including 651 who underwent (C)RT with TME and 90 who underwent (C)RT with TME and LLND.

Main Outcomes and Measures

The main purpose was to identify the factors on primary and restaging MRI associated with LLR after (C)RT with TME. Whether high-risk patients might benefit in terms of LLR reduction from an LLND was also studied.

Results

Of the 741 included patients, 480 (64.8%) were male, and the mean (SD) age was 60.4 (12.0) years. An SA lateral node size of 7 mm or greater on primary MRI resulted in a 5-year LLR rate of 17.9% after (C)RT with TME. At 3 years, there were no LLRs in 28 patients (29.2%) with lateral nodes that were 4 mm or less on restaging MRI. Nodes that were 7 mm or greater on primary MRI and greater than 4 mm on restaging MRI in the internal iliac compartment resulted in a 5-year LLR rate of 52.3%, significantly higher compared with nodes in the obturator compartment of that size (9.5%; hazard ratio, 5.8; 95% CI, 1.6-21.3; P = .003). Compared with (C)RT with TME alone, treatment with (C)RT with TME and LLND in these unresponsive internal nodes resulted in a significantly lower LLR rate of 8.7% (hazard ratio, 6.2; 95% CI, 1.4-28.5; P = .007).

Conclusions and Relevance

Restaging MRI is important in clinical decision making in lateral nodal disease. In patients with shrinkage of lateral nodes from an SA node size of 7 mm or greater on primary MRI to an SA node size of 4 mm or less on restaging MRI, which occurs in about 30% of cases, LLND can be avoided. However, persistently enlarged nodes in the internal iliac compartment indicate an extremely high risk of LLR, and an LLND lowered LLR in these cases.

Regulation of radiosensitivity by 4-methylumbelliferone via the suppression of interleukin-1 in fibrosarcoma cells

Tumor recurrence and distant metastasis following radiotherapy, which can lead to poor prognosis, are caused by residual cancer cells that acquire radioresistance. Chemotherapy or a combination of targeted inhibitors can potentially enhance radiation sensitivity and prevent metastasis. It was previously reported that co-administration of the hyaluronan synthesis inhibitor 4-methylumbelliferone (4-MU) enhanced the lethality of X-ray irradiation in HT1080 human fibrosarcoma cells and decreased their invasiveness to a greater extent than either treatment alone. To clarify the molecular basis of these effects, the present study conducted mRNA expression profiling by cDNA microarray to identify the signaling pathways that are altered under this combination treatment. The activation state of the signaling pathways was classified by z-scores in the Ingenuity Pathway Analysis. The results revealed that the pro-inflammatory cytokines interleukin (IL)-6 and IL-8 were activated by 2 Gy X-ray irradiation, an effect that was abolished by co-administration of 4-MU. Similar trends were observed for the upstream signaling component IL-1. These results indicate that the radiosensitivity of fibrosarcoma cells is improved by suppressing inflammation through the administration of 4-MU.

Recent advances of neoadjuvant chemoradiotherapy in rectal cancer: Future treatment perspectives

Neoadjuvant chemoradiotherapy (nCRT) has been widely used as a multidisciplinary approach for stage II/III rectal cancer. However, its safety and efficacy are controversial because previous studies have shown conflicting outcomes. The present review aimed to elucidate the benefits and limitations of nCRT for patients with rectal cancer. Future perspectives of nCRT are also described. No recent randomized trials have been able to show a survival benefit, although many studies have demonstrated good local control with the use of fluoropyrimidine (e.g. 5-fluorouracil [FU] or capecitabine)-based nCRT. Addition of oxaliplatin (OX) to FU-based nCRT might improve overall survival by preventing distant metastasis, as shown in recent meta-analyses. However, control of adverse effects is an important concern with this treatment. New treatment strategies such as nonoperative management (watch and wait policy) and total neoadjuvant therapy (TNT) are promising, but the establishment of reliable diagnostic methods of metastasis is essential. Development of new biomarkers is also necessary to select patients who are more likely to benefit from nCRT.

Neoadjuvant (Chemo)radiotherapy With Total Mesorectal Excision Only Is Not Sufficient to Prevent Lateral Local Recurrence in Enlarged Nodes: Results of the Multicenter Lateral Node Study of Patients With Low cT3/4 Rectal Cancer

PURPOSE

Improvements in magnetic resonance imaging (MRI), total mesorectal excision (TME) surgery, and the use of (chemo)radiotherapy ([C]RT) have improved local control of rectal cancer; however, we have been unable to eradicate local recurrence (LR). Even in the face of TME and negative resection margins (R0), a significant proportion of patients with enlarged lateral lymph nodes (LLNs) suffer from lateral LR (LLR). Japanese studies suggest that the addition of an LLN dissection (LLND) could reduce LLR. This multicenter pooled analysis aims to ascertain whether LLNs actually pose a problem and whether LLND results in fewer LLRs.

PATIENTS AND METHODS

Data from 1,216 consecutive patients with cT3/T4 rectal cancers up to 8 cm from the anal verge who underwent surgery in a 5-year period were collected. LLND was performed in 142 patients (12%). MRIs were re-evaluated with a standardized protocol to assess LLN features.

RESULTS

On pretreatment MRI, 703 patients (58%) had visible LLN, and 192 (16%) had a short axis of at least 7 mm. One hundred eight patients developed LR (5-year LR rate, 10.0%), of which 59 (54%) were LLRs (5-year LLR rate, 5.5%). After multivariable analyses, LLNs with a short axis of at least 7 mm resulted in a significantly higher risk of LLR (hazard ratio, 2.060; P = .045) compared with LLNs of less than 7 mm. In patients with LLNs at least 7 mm, (C)RT plus TME plus LLND resulted in a 5-year LLR of 5.7%, which was significantly lower than that in patients who underwent (C)RT plus TME (5-year LLR, 19.5%; P = .042).

CONCLUSION

LLR is still a significant problem after (C)RT plus TME in LLNs with a short axis at least 7 mm on pretreatment MRI. The addition of LLND results in a significantly lower LLR rate.

Neoadjuvant (Chemo)radiotherapy With Total Mesorectal Excision Only Is Not Sufficient to Prevent Lateral Local Recurrence in Enlarged Nodes: Results of the Multicenter Lateral Node Study of Patients With Low cT3/4 Rectal Cancer

PURPOSE

Improvements in magnetic resonance imaging (MRI), total mesorectal excision (TME) surgery, and the use of (chemo)radiotherapy ([C]RT) have improved local control of rectal cancer; however, we have been unable to eradicate local recurrence (LR). Even in the face of TME and negative resection margins (R0), a significant proportion of patients with enlarged lateral lymph nodes (LLNs) suffer from lateral LR (LLR). Japanese studies suggest that the addition of an LLN dissection (LLND) could reduce LLR. This multicenter pooled analysis aims to ascertain whether LLNs actually pose a problem and whether LLND results in fewer LLRs.

PATIENTS AND METHODS

Data from 1,216 consecutive patients with cT3/T4 rectal cancers up to 8 cm from the anal verge who underwent surgery in a 5-year period were collected. LLND was performed in 142 patients (12%). MRIs were re-evaluated with a standardized protocol to assess LLN features.

RESULTS

On pretreatment MRI, 703 patients (58%) had visible LLN, and 192 (16%) had a short axis of at least 7 mm. One hundred eight patients developed LR (5-year LR rate, 10.0%), of which 59 (54%) were LLRs (5-year LLR rate, 5.5%). After multivariable analyses, LLNs with a short axis of at least 7 mm resulted in a significantly higher risk of LLR (hazard ratio, 2.060; P = .045) compared with LLNs of less than 7 mm. In patients with LLNs at least 7 mm, (C)RT plus TME plus LLND resulted in a 5-year LLR of 5.7%, which was significantly lower than that in patients who underwent (C)RT plus TME (5-year LLR, 19.5%; P = .042).

CONCLUSION

LLR is still a significant problem after (C)RT plus TME in LLNs with a short axis at least 7 mm on pretreatment MRI. The addition of LLND results in a significantly lower LLR rate.

Lateral pelvic lymph node dissection and radiation treatment for rectal cancer: Mutually exclusive or mutually beneficial?

Lateral pelvic lymph nodes (LPLN) in mid-/low rectal cancer pose a theoretical and practical challenge for the clinician and the patient, with geographical differences in management based on historical competing priorities. Although there has been a tendency to think of neoadjuvant radiation versus intraoperative LPLN dissection as a binary choice, they should be more constructively seen as complementary options in the personalized management of patients with rectal cancer. Herein we propose one potential algorithm for using these treatment options in this way based on local preoperative staging and the current evidence available. We also outline future research priorities in this area with the aim of answering several residual questions that remain.