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

The influence of neoadjuvant chemoradiotherapy combined with lateral lymph nodes dissection or not on the local recurrence of low to intermediate-stage II/III rectal cancer

BACKGROUND

Currently, the treatment options for stage II/III rectal cancer with preoperative lateral lymph nodes (LLN) enlargement are highly controversial between East and West, and the indications for diagnosing suspiciously positive enlarged LLN are inconsistent both nationally and internationally. Oriental scholars (especially Japanese) consider the LLN as a regional disease, they consider that prophylactic lateral lymph nodes dissection (LLND), regardless of whether the LLN is enlarged or not, is considered necessary if the tumor is found beneath the peritoneal reflex and invades the muscle layer. Western scholars regard LLN as distant metastases, recommending neoadjuvant chemoradiotherapy (nCRT) in conjunction with total rectal mesenteric resection (TME). In recent years, it has been found that neither of the two standard treatment regimens, East and West, significantly improved local control of tumors in patients with LLN enlargement. In contrast, nCRT combined with LLND significantly lowers the local recurrence (LR) rate. It has also been suggested that combination therapy regimens do not improve patient prognosis but increase treatment-related complications. Therefore, the suitable therapeutic option for rectal cancer with an enlarged LLN needs to be further explored.

AIM

Exploring appropriate treatment options for low to intermediate-stage II/III rectal cancer with LLN enlargement, as well as risk variables that may affect the LR in these patients with LLN enlarged.

METHODS AND PATIENTS

In this research, we retrospectively analyzed 110 patients with locally advanced mid-low (low boundary of tumor is no more than 10 cm from the anus) rectal cancer who were treated at Harbin Medical University Cancer Hospital arranged from 2017.1 to 2020.6. These patients had received nCRT and TME, and their initial rectal nuclear magnetic resonance imaging (MRI) revealed an enlarged LLN (short axis of LLN, SA ≥ 5 mm). Of these, 40 patients underwent LLND, thus, 110 patients were grouped into two groups: nCRT+TME (LLND-, n = 70) and nCRT+TME + LLND (LLND+, n = 40), and their 3 years prognoses were compared.

RESULTS

After a median follow-up of 49.0 months, the 3-year LR rate of the LLND- group was notably greater than the LLND+ group (22.8% vs. 7.5%, p = 0.04). However, there was no noteworthy difference in the 3-year progression-free survival (PFS, 70.5% vs. 77.5%, p > 0.05) rate or distant metastasis (DM) rate (20.0% vs. 17.5%, p > 0.05). Additionally, the LLND+ group experienced significantly more postoperative complications than the LLND- group (15.0% vs. 4.2%, p = 0.05). Subgroups analysis for the LLND- group revealed that patients with LLN short axis regression (ΔSA) > 35.9% after nCRT had significantly lower 3-year LR rate than patients with ΔSA ≤ 35.9% (9.1% vs. 35.1%, p = 0.01). Patients in the LLND- group with ΔSA > 35.9%, however, had comparable 3-year LR rate and DM rates to those in the LLND+ group.

CONCLUSION

LLN is an independent indicator for prognosis among people with low to intermediate-stage II/III malignant rectal tumors. Patients with poor SA regression (ΔSA ≤ 35.9%) after nCRT have a greater risk of positive LLN and a more substantial LR, and nCRT combined with LLND reduced the LR rate significantly, but considerably prolonged operative time, surgical bleeding, and postoperative complications. Patients with better SA regression (ΔSA > 35.9%), however, have a lower possibility of LR and might not need LLN clearance, in these cases, nCRT+TME is advised.

Risk factors for lateral pelvic lymph node metastasis in patients with lower rectal cancer: a systematic review and meta-analysis

Background and objective

Lateral pelvic lymph node (LPLN) metastasis is one of the prominent reasons for local recurrence (LR) in patients with rectal cancer (RC). The evaluation criteria of lateral lymph node dissection (LLND) for patients in eastern (mainly in Japan) and western countries have been controversial. The aim of this study was to analyse the risk factors for LPLN metastasis in order to guide surgical methods.

Methods

We searched relevant databases (Embase (Ovid), Medline (Ovid), PubMed, Cochrane Library, and Web of Science) for articles published between 1 January 2000 and 05 October 2022 to evaluate the risk factors for LPLN metastasis in patients with RC in this meta-analysis.

Results

A total of 24 articles with 5843 patients were included in this study. The overall results showed that female sex, age <60 years, pretherapeutic CEA level >5 ng/ml, clinical T4 stage (cT4), clinical M1 stage (cM1), distance of the tumour from the anal verge (AV) <50 mm, tumour centre located below the peritoneal reflection (Rb), short axis (SA) of LPLN ≥8 mm before nCRT, short axis (SA) of LPLN ≥5 mm after nCRT, border irregularity of LPLN, tumour size ≥50 mm, pathological T3-4 stage (pT3-4), pathological N2 stage (pN2), mesorectal lymph node metastasis (MLNM), lymphatic invasion (LI), venous invasion (VI), CRM (+) and poor differentiation were significant risk factors for LPLN metastasis (P <0.05).

Conclusion

This study summarized almost all potential risk factors of LPLN metastasis and expected to provide effective treatment strategies for patients with LRC. According to the risk factors of lateral lymph node metastasis, we can adopt different comprehensive treatment strategies. High-risk patients can perform lateral lymph node dissection to effectively reduce local recurrence; In low-risk patients, we can avoid overtreatment, reduce complications and trauma caused by lateral lymph node dissection, and maximize patient survival and quality of life.

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.

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.

Neoadjuvant chemoradiotherapy followed by lateral pelvic lymph node dissection for rectal cancer patients: A retrospective study of its safety and indications

BACKGROUND AND OBJECTIVES

There is no consensus on the safety and indications of lateral pelvic lymph node dissection (LPND) for patients with clinical lateral pelvic node metastasis (LPNM) after neoadjuvant chemoradiotherapy (nCRT).

METHODS

We retrospectively analyzed 151 patients who underwent total mesorectal excision (TME) + LPND and divided them into two groups: nCRT group (n = 73) and non-nCRT group (n = 78).

RESULTS

Thirty-one (20.5%) patients had LPNM by pathology. The operative time was significantly longer in the nCRT group (291.9 vs. 237.0 min, p < 0.001); however, the two groups had comparable intraoperative blood loss (87.3 vs. 78.9 ml, p = 0.607) and morbidity (19.2% vs. 15.7%, p = 0.537). Additionally, in the nCRT group, multivariate logistic regression analysis showed that poor/mucinous/signet adenocarcinoma (odds ratio [OR] = 6.65, 95% confidence interval [CI] = 1.03-43.03, p = 0.047) and post-nCRT LPN size ≥7 mm (OR = 26.67, 95% CI = 2.87-247.91, p = 0.004) were independent risk factors for pathological LPNM.

CONCLUSION

nCRT before TME + LPND is safe and feasible with a comparably low mortality and acceptable morbidity. Poor/mucinous/signet adenocarcinoma and post-nCRT LPN size ≥7 mm were independent predictive factors of pathological LPNM after nCRT for rectal cancer patients with clinical LPNM, and patients with these characteristics should consider LPND after nCRT.

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.

The Landmark Series: Management of Lateral Lymph Nodes in Locally Advanced Rectal Cancer

There has historically been a significant divide in the approach to the management of lateral pelvic lymph nodes in patients with rectal cancer. These differing paradigms have developed based upon competing priorities. In the West, the circumferential resection margin has been the main focus because it is a strong predictor of local recurrence, distal recurrence, and survival. This approach was supplemented by radiation and chemotherapy to treat the lateral pelvic lymph nodes and micrometastatic disease. In the East, lateral pelvic lymph nodes are considered to be locoregional; thus, surgical treatment has traditionally included routine dissection of this compartment for low rectal cancers without the use of neoadjuvant chemoradiotherapy. However, neither approach has adequately addressed the important issue of lateral compartment recurrence in patients with clinically evident lateral pelvic lymph node metastasis. The aims of the review were to present the recent key studies and evolution of lateral pelvic lymph node management in locally advanced rectal cancer and secondly to propose a management strategy for the lateral compartment based on the current evidence.

Who Should Get Lateral Pelvic Lymph Node Dissection After Neoadjuvant Chemoradiation?

BACKGROUND

Despite the use of neoadjuvant chemoradiation and total mesorectal excision for rectal cancer, lateral pelvic lymph node recurrence is still an important problem.

OBJECTIVE

This study aimed to determine the indication for lateral pelvic lymph node dissection in post neoadjuvant chemoradiation rectal cancer.

DESIGN

This is a retrospective analysis of a prospectively collected institutional database.

SETTINGS

This study was conducted at a tertiary care cancer center from January 2006 through December 2017.

PATIENTS

Patients who had rectal cancer with suspected lateral pelvic lymph node metastasis, who underwent total mesorectal excision with lateral pelvic lymph node dissection, were included.

MAIN OUTCOME MEASURES

The primary outcome measured was pathologic lateral pelvic lymph node positivity.

INTERVENTIONS

The associations between lateral pelvic lymph node size on post-neoadjuvant chemoradiation imaging and pathologic lateral pelvic lymph node positivity and recurrence outcomes were evaluated.

RESULTS

A total of 64 patients were analyzed. The mean lateral pelvic lymph node size before and after neoadjuvant chemoradiation was 12.6 ± 9.5 mm and 8.5 ± 5.4 mm. The minimum size of positive lateral pelvic lymph node was 5 mm on post neoadjuvant chemoradiation imaging. Among 13 (20.3%) patients who had a <5 mm lateral pelvic lymph node after neoadjuvant chemoradiation, none were pathologically positive. Among 51 (79.7%) patients who had a ≥5 mm lateral pelvic lymph node after neoadjuvant chemoradiation, 33 patients (64.7%) were pathologically positive. Five-year overall survival and disease-specific survival were higher in the histologic lateral pelvic lymph node negative group than in the lateral pelvic lymph node positive group (overall survival 79.6% vs 61.8%, p = 0.122; disease-specific survival 84.5% vs 66.2%, p= 0.088). After a median 39 months of follow-up, there were no patients in the <5 mm group who died of cancer. There were no lateral compartment recurrences in the entire cohort.

LIMITATIONS

Being a single-center retrospective study may limit generalizability.

CONCLUSIONS

Post-neoadjuvant chemoradiation lateral pelvic lymph node size ≥5 mm was strongly associated with pathologic positivity. No patients with size <5 mm had pathologically positive lymph nodes. Following lateral pelvic lymph node dissection, no patients with a positive lateral pelvic lymph node developed lateral compartment recurrence. Therefore, patients who have rectal cancer with clinical evidence of lateral pelvic lymph node metastasis and post-neoadjuvant chemoradiation lateral pelvic lymph node size ≥5 mm should be considered for lateral pelvic lymph node dissection at the time of total mesorectal excision. See Video Abstract at http://links.lww.com/DCR/B3. ¿QUIéN DEBE RECIBIR LINFADENECTOMíA PéLVICA LATERAL DESPUéS DE LA QUIMIORRADIACIóN NEOADYUVANTE?: A pesar del uso de quimiorradiación neoadyuvante y la escisión total de mesorectao para el cáncer de recto, la recurrencia en los ganglios linfáticos pélvicos laterales sigue siendo un problema importante.

OBJETIVO

Determinar la indicación para la disección de los ganglios linfáticos pélvicos laterales en el cáncer rectal post quimiorradiación neoadyuvante. DISEÑO:: Análisis retrospectivo de la base de datos institucional prospectivamente recopilada.

ESCENARIO

Centro de cáncer de atención terciaria, de enero de 2006 hasta diciembre de 2017.

PACIENTES

Pacientes con cáncer de recto con sospecha de metástasis en los ganglios linfáticos pélvicos laterales, que se sometieron a escisión total mesorectal con disección de los ganglios linfáticos pélvicos laterales.

PRINCIPALES MEDIDAS DE RESULTADOS

Positividad de ganglios linfáticos pélvicos laterales en histopatología.

INTERVENCIONES

Se evaluaron las asociaciones entre el tamaño de los ganglios linfáticos pélvicos laterales en imagenología postquimiorradiación neoadyuvante y la positividad y recurrencia en los ganglios linfáticos pélvicos laterales en histopatología.

RESULTADOS

Se analizaron un total de 64 pacientes. La media del tamaño de los ganglios linfáticos pélvicos laterales antes y después de la quimiorradiación neoadyuvante fue de 12.6 ± 9.5 mm y 8.5 ± 5.4 mm, respectivamente. El tamaño mínimo de los ganglios linfáticos pélvicos laterales positivos fue de 5 mm en las imágenes postquimiorradiación neoadyuvante. Entre 13 (20.3%) pacientes que tenían <5 mm de ganglio linfático lateral pélvico después de la quimiorradiación neoadyuvante; ninguno fue positivo en histopatología. Entre 51 (79.7%) pacientes con ganglio linfático pélvico lateral ≥ 5 mm después de la quimiorradiación neoadyuvante; 33 pacientes (64.7%) fueron positivos en histopatología. La supervivencia general a 5 años y la supervivencia específica de la enfermedad fueron mayores en el grupo histológico de ganglio linfático pélvico lateral negativo que en el grupo de ganglio linfático pélvico lateral positivo (Supervivencia general 79.6% vs 61.8%, p = 0.122; Supervivencia específica de la enfermedad 84.5% vs 66.2%, p = 0.088). Después de una mediana de seguimiento de 39 meses, no hubo pacientes en el grupo de <5 mm que hayan fallecido por cáncer. No hubo recurrencias en el compartimento lateral en toda la cohorte.

LIMITACIONES

Al ser un estudio retrospectivo en un solo centro puede limitar la generalización.

CONCLUSIONES

El tamaño de los ganglios linfáticos pélvicos laterales postquimiorradiación neoadyuvante ≥ 5 mm se asoció fuertemente con la positividad histopatológica. Ningún paciente con tamaño <5 mm tuvo ganglios linfáticos histopatológicamente positivos. Después de la disección de los ganglios linfáticos pélvicos laterales, ningún paciente con ganglios linfáticos pélvicos laterales positivos desarrolló recurrencia del compartimiento lateral. Por lo tanto, los pacientes con cáncer rectal con evidencia clínica de metástasis en los ganglios linfáticos pélvicos laterales y tamaño de ganglios linfáticos pélvicos laterales postquimiorradiación neoadyuvante ≥ 5 mm deben considerarse para disección de los ganglios linfáticos pélvicos laterales en el momento de la escisión total de mesorrecto. Vea el Abstract en video en http://links.lww.com/DCR/B3.

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.

The value of red blood cell distribution width in diagnosis of patients with colorectal cancer

BACKGROUND

Red blood cell distribution width (RDW) is a parameter of standard full blood count tests that reflects the size variability of erythrocytes In recent studies, RDW levels have been associated with ischemic heart disease, acute and chronic heart failure, hypertension, and inflammatory bowel disease. However, it is unclear whether RDW is associated with colorectal cancer.

METHODS

Eighty-five patients were diagnosed with colorectal cancer. Fifty-four other patients each diagnosed with colon polyps during the same period served as the control group. The patients were classified according to the seventh edition of the AJCC Cancer Staging Manual of 2009 into groups of different cancer stages, and simultaneously divided into groups with or without metastasis. The multigroup metering data was tested by a non-parametric Kruskal-Wallis H test, and the two subsets of patients formed above were compared using a Mann-Whitney U test. The association between continuous variables was assessed by Spearman correlation analysis while the association between RDW and colorectal cancer metastasis was estimated by receiver operating characteristic (ROC) curve analysis.

RESULTS

Increased RDW was observed in patients with colorectal cancer. The RDW was significantly different for each subgroup of colorectal cancer as follows: stage III + IV > stage III, T3 + T4 > T1 + T2, N1 + N2 > N0, and M1 > M0 (P < 0.05). The area under the receiver-operating characteristic curve of the RDW in the diagnosis of colorectal cancer metastasis was 0.721 (95% confidence interval of 0.612-0.831).

CONCLUSIONS

The value of RDW is closely related to colorectal cancer metastasis.

Preoperative chemoradiotherapy changes the size criterion for predicting lateral lymph node metastasis in lower rectal cancer

PURPOSE

The purpose of this study was to identify the size criteria of lateral lymph node metastasis in lower rectal cancer both in patients who underwent preoperative CRT and those who did not.

METHODS

This study enrolled 150 patients who underwent resection for primary lower rectal adenocarcinoma with lateral lymph node dissection between 2013 and 2015. Patients were divided into two groups: the CRT group, treated with preoperative chemoradiotherapy before surgery, and the non-CRT group, treated with surgery alone. The short-axis diameter of each dissected lateral lymph node was measured. Receiver-operating characteristic curves were generated to reveal the optimal cutoff values for determining lateral lymph node metastasis in both groups.

RESULTS

In the non-CRT group (n = 131), the ROC curve demonstrated that the optimal cutoff value for determining metastasis was 6.0 mm, with a sensitivity of 78.5% and specificity of 82.9%, and the AUC was 0.845. In comparison, in the CRT group (n = 19), the optimal cutoff value was 5.0 mm, with a sensitivity of 71.4% and specificity of 85.3% and an AUC of 0.836.

CONCLUSION

The cutoff size for determining lateral lymph node metastasis was smaller in the CRT group than in the non-CRT group.