The effect of neoadjuvant therapy on the size, number, and distribution of mesorectal lymph nodes

Impact of neoadjuvant therapy on nodal harvest in clinical stage III rectal cancer: Establishing optimum cut-offs by disease response

INTRODUCTION

A minimum lymph node harvest (LNH) of 12 is the current standard for appropriate nodal staging in resectable rectal cancer. However, the rise of neoadjuvant chemoradiation (NCRT) and total neoadjuvant therapy (TNT) has been associated with decreasing number of LNH. We hypothesize that as tumor response to neoadjuvant therapy increases, the optimum for LNH to achieve appropriate nodal staging should decrease.

METHODS

Patients with clinical stage III rectal adenocarcinoma who underwent NCRT/TNT followed by resection were identified from the National Cancer Database. A JoinPoint regression analysis was used to determine the LNH for each tumor regression grade (TRG) category beyond which the rate of positive nodes does not significantly change.

RESULTS

Thirteen thousand four hundred and twenty-six patients met inclusion criteria. Of these, 2406 (17.9%) achieved TRG 0 or ypT0 and 8210 (61.2%) achieved ypN0. Collectively, 2043 patients (15.2%) were reported to have a pathologic complete response (ypT0 ypN0). Positive pathologic nodes were found in 15%, 23%, 31%, 54%, and 53% as ypT stage increased from ypT0 to ypT4, respectively. Similarly, ypN+ rates were 15%, 36%, 41%, and 55% in TRG 0-3. No JoinPoint was identified for TRG 0, whereas inflection points were found at 6-10 nodes for TRG1 (p = 0.002) and TRG 2 (p = 0.016), and at 11-15 nodes for TRG 3.

CONCLUSION

The benchmark of retrieving 12 nodes in resectable stage III rectal cancer is not consistently achieved after NCRT/TNT. We demonstrate that the LNH requirement to establish accurate pathologic nodal staging can vary depending on the tumor response to neoadjuvant therapies.

Association between the number of retrieved lymph nodes and demographic/tumour-related characteristics in colorectal cancer: a systematic review and meta-analysis

OBJECTIVE

Clinical practice guidelines recommend retrieving at least 12 lymph nodes for correct staging in colorectal cancer. However, it is difficult to retrieve adequate lymph nodes because of various factors. We aimed to evaluate the association between the number of retrieved lymph nodes and demographic/tumour-related characteristics in colorectal cancer.

DESIGN

Systematic review and meta-analysis of primary studies.

DATA SOURCES

PubMed, Embase, Cochrane and Web of Science were searched from January 2016 to June 2023.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies that evaluated the association between retrieved lymph nodes and demographic/tumour-related characteristics in colorectal cancer were included.

DATA EXTRACTION AND SYNTHESIS

OR with 95% conference intervals was extracted and pooled.

RESULTS

A total of 54 studies containing 2 05 821 patients were included in this meta-analysis. The results showed that fewer nodes were retrieved from elderly patients (OR=0.70, 95% CI (0.54 to 0.90), p=0.005), and from tumours located in the left colon than in the right colon (OR=0.43, 95% CI (0.33 to 0.56), p<0.001). More lymph nodes were obtained from females than males (OR=1.15, 95% CI (1.04 to 1.28), p=0.006), from the advanced T stage (T3+T4) than T1+T2 stage (OR=1.57, 95% CI (1.25 to 1.97), p<0.001) and from the N2 stage than N0 stage (OR=1.32, 95% CI (1.15 to 1.51), p<0.001). Body mass index, ethnicity, N1 stage, M stage, tumour differentiation and lymph-vascular invasion were not significantly associated with the lymph node yield.

CONCLUSIONS

The study results suggest that clinicians have an increased opportunity to retrieve sufficient lymph nodes for accurate pathological staging to guide treatment decisions in patients with colorectal cancer who are young, female, with tumours located in the right colon, advanced T stage and N2 stage.

Examined lymph node numbers influence prognosis in rectal cancer treated with neoadjuvant therapy

Background

The number of lymph nodes examined (LNe) is often insufficient in patients with rectal cancer (RC) treated with neoadjuvant therapy; however, its prognostic value remains controversial. Thus, we retrospectively explored whether LNe had an influence on staging and prognosis and investigated whether there was a cut-off value for better prognosis in patients with RC treated with neoadjuvant therapy.

Methods

Data were collected from seven prospective hospital databases in China from July 2002 to May 2018. Binary logistic regression models were used to predict lymph node metastasis. The cut-off value for LNe was determined using X-tile 3.6.1. Survival outcomes and risk factors were analyzed using the log-rank test and Cox regression model.

Results

A total of 482 patients were included, of whom 459 had complete overall survival (OS) information. Using the percentile method, the total number of lymph nodes examined (TLNe) was 14-16 (40th-60th percentile), and the proportion of patients with lymph node metastasis reached a maximum of 48.1%. Cox multivariate analysis showed that the odds ratio (OR) remained the highest when TLNe was 14-16 (OR = 3.379, P = 0.003). The 3-year and 5-year OS were 85.4% and 77.8%, respectively. Negative lymph nodes examined (NLNe) of ≤6 was an independent risk factor for 3-year and 5-year OS (3-year OS 71.1% vs. 85.9%, P = 0.004; 5-year OS 66.3% vs. 74.3%, P = 0.035). Subgroup analysis for patients with ypN + showed that higher 3-year and 5-year OS were achieved when the TLNe was >10, 78.8% vs. 54.0% (P = 0.005), and 60.8% vs. 36.0% (P = 0.012), respectively. Patients with ypN0M0 had a higher 5-year OS when the TLNe was >19 (P = 0.055).

Conclusion

The TLNe and NLNe influenced the staging accuracy and demonstrated prognostic value in patients with RC treated with neoadjuvant therapy.

Required distal mesorectal resection margin in partial mesorectal excision: a systematic review on distal mesorectal spread

BACKGROUND

The required distal margin in partial mesorectal excision (PME) is controversial. The aim of this systematic review was to determine incidence and distance of distal mesorectal spread (DMS).

METHODS

A systematic search was performed using PubMed, Embase and Google Scholar databases. Articles eligible for inclusion were studies reporting on the presence of distal mesorectal spread in patients with rectal cancer who underwent radical resection.

RESULTS

Out of 2493 articles, 22 studies with a total of 1921 patients were included, of whom 340 underwent long-course neoadjuvant chemoradiotherapy (CRT). DMS was reported in 207 of 1921 (10.8%) specimens (1.2% in CRT group and 12.8% in non-CRT group), with specified distance of DMS relative to the tumor in 84 (40.6%) of the cases. Mean and median DMS were 20.2 and 20.0 mm, respectively. Distal margins of 40 mm and 30 mm would result in 10% and 32% residual tumor, respectively, which translates into 1% and 4% overall residual cancer risk given 11% incidence of DMS. The maximum reported DMS was 50 mm in 1 of 84 cases. In subgroup analysis, for T3, the mean DMS was 18.8 mm (range 8-40 mm) and 27.2 mm (range 10-40 mm) for T4 rectal cancer.

CONCLUSIONS

DMS occurred in 11% of cases, with a maximum of 50 mm in less than 1% of the DMS cases. For PME, substantial overtreatment is present if a distal margin of 5 cm is routinely utilized. Prospective studies evaluating more limited margins based on high-quality preoperative magnetic resonance imaging and pathological assessment are required.

Short-term outcomes following development of a dedicated pelvic exenteration service in a tertiary centre

BACKGROUND

Pelvic exenteration surgery (PE) offers potentially curative resection for locally advanced malignancy but is associated with significant complexity and morbidity. Specialised teams are recommended to achieve optimal patient outcomes. This study aims to analyse short-term outcomes at a tertiary setting before and after creating a dedicated PE service.

METHODS

Patients undergoing PE between 2008 and October 2021 at the Royal Adelaide Hospital and St. Andrews Hospital in South Australia were included, with prospective data collection since June 2017. Patients operated on prior and post the creation of the PE service were compared via univariate analyses.

RESULTS

In total, 113 patients were included, with a significant increase in volume of cases post creation of the PE service, (n = 46 pre versus n = 67 post). There were significant differences in the type of neoadjuvant therapy and patient co-morbidity, with more advanced disease stage and a higher likelihood of bone involvement (P < 0.05) in the latter period. An increased proportion of patients had flap reconstruction (40.3 versus 33.9%, P = 0.010) as well as lateral lymph node dissection (13.4 versus 2.2%, P = 0.046). Despite this, peri-operative outcomes such as urosepsis (11.9 versus 28.3%, P = 0.028) and Clavien-Dindo grade of complications grade improved. R0 resections were achieved in 93.9% of curative cases (93.9 versus 84.2%, P = 0.171).

CONCLUSION

The development of a PE service significantly improved short term patient outcomes, despite the inclusion of patients with more advanced disease and comorbidity.

Prognostic Characteristics of Patients With Colorectal Cancer Who Have Benign Mesenteric Lymph Node Enlargement: A Multi-institutional Cohort Study

BACKGROUND

The characteristics of patients with colorectal cancer who have benign mesenteric lymph node enlargement are not well documented.

OBJECTIVE

The aim of this study is to assess the clinical and prognostic significance of benign mesenteric lymph node enlargement in patients with colorectal cancer.

DESIGN

This is a prospective cohort study.

SETTING

This study was conducted at multitertiary institutions.

PATIENTS

We included 601 patients with stage 0, I, and II colorectal cancer in Tianjin, Shandong, and Zhejiang from January 2010 to April 2014. Patients underwent curative surgery and were separated into 2 groups by the presence of benign mesenteric lymph node enlargement: the enlargement group (n = 275) and the control group (n = 326).

MAIN OUTCOME MEASURES

Univariate log rank and multivariate Cox regression analyses were constructed to identify risk factors for recurrence and mortality.

RESULTS

The risk of recurrence in the enlargement group after curative resection was significantly lower than in the control group, with the 1-, 3-, and 5-year disease-free survival rates being 97.1%, 91.6%, and 86.9% in the enlargement group and 95.7%, 86.2%, and 78.2% in the control group (p = 0.004). The postoperative 1-, 3-, and 5-year overall survival rates were 99.6%, 94.9%, and 90.5% in the enlargement group and 99.4%, 91.4%, and 82.1% in the control group (p = 0.001). Patients in the enlargement group had a higher percentage of patients at a younger age, family tumor history, right-sided tumors, and larger tumor size compared with the control group. For patients in the enlargement group, no significant correlation was observed between the number of enlarged lymph nodes and disease-free survival or overall survival (p = 0.113 and 0.386). Adjusted Cox regression model showed that benign mesenteric lymph node enlargement was an independent prognostic risk factor for both disease-free survival (HR, 0.587; 95% CI, 0.399-0.861; p = 0.007) and overall survival (HR, 0.506; 95% CI, 0.328-0.779; p = 0.002).

LIMITATIONS

No immunological results could be compared with clinicopathological findings.

CONCLUSIONS

The study indicates that benign mesenteric lymph node enlargement can be a useful positive factor in predicting recurrence and long-term survival concerning patients with colorectal cancer. See Video Abstract at http://links.lww.com/DCR/B785.

CARACTERSTICAS PRONSTICAS DE LOS PACIENTES PORTADORES DE CNCER COLORRECTAL CON AGRANDAMIENTO BENIGNO DE LOS GANGLIOS LINFTICOS MESENTRICOS UN ESTUDIO DE COHORTE MULTIINSTITUCIONAL

ANTECEDENTES:Las características de los pacientes portadores de cáncer colorrectal con agrandamiento benigno de los ganglios linfáticos mesentéricos no se encuentran bien documentados.OBJETIVO:El objetivo de este estudio es evaluar la importancia clínica y pronóstica del agrandamiento benigno de los ganglios linfáticos mesentéricos en pacientes con cáncer colorrectal.DISEÑO:Este es un estudio de cohorte de tipo prospectivo.AJUSTE:Este estudio se llevó a cabo en instituciones de educación superior.PACIENTES:Incluimos a 601 pacientes con cáncer colorrectal en estadio 0, I, II en Tianjin, Shandong y Zhejiang desde enero de 2010 hasta abril de 2014. Los pacientes fueron sometidos a cirugía curativa y fueron separaron en dos grupos tomando en cuenta la presencia del agrandamiento benigno de los ganglios linfáticos mesentéricos: grupo con agrandamiento (n = 275) y grupo control (n = 326).PRINCIPALES MEDIDAS DE RESULTADO:Se construyeron análisis de rango logarítmico de una variante y de regresión de Cox con variante múltiple para identificar los factores de riesgo de recurrencia y mortalidad.RESULTADOS:El riesgo de recurrencia en el grupo con agrandamiento tras la resección curativa fue significativamente menor que en el grupo de control, con tasas de periodo libre de enfermedad a los 1, 3 y 5 años de 97,1, 91,6, y 86,9% en el grupo de agrandamiento y con tasas de 95,7, 86,2, y 78,2% en el grupo control respectivamente (p = 0,004). Las tasas postoperatorias de supervivencia general a los 1, 3 y 5 años fueron 99,6, 94,9, y 90,5% en el grupo de agrandamiento y de 99,4, 91,4, y 82,1% en el grupo de control, respectivamente (p = 0,001). Los pacientes del grupo con agrandamiento tenían un porcentaje más elevado de menor edad, antecedente familiar tumoral, tumores del lado derecho y de mayor tamaño tumoral con respecto al grupo de control. Para los pacientes con agrandamiento, no se observó una correlación significativa entre el número de ganglios linfáticos agrandados y el periodo libre de enfermedad o la supervivencia general (p = 0,113 y 0,386). El modelo de regresión de Cox ajustado mostró que el agrandamiento benigno de los ganglios linfáticos mesentéricos era un factor de riesgo pronóstico independiente tanto para la supervivencia libre de enfermedad (cociente de riesgo 0,587; IC del 95%: 0,399-0,861; p = 0,007) como para la supervivencia global (cociente de riesgo 0,506; IC del 95%: 0,328- 0,779; p = 0,002).LIMITACIONES:No fue posible comparar los resultados inmunológicos con los hallazgos clínico-patológicos.CONCLUSIONES:El estudio indica que el agrandamiento benigno de los ganglios linfáticos mesentéricos puede ser un factor positivo útil para predecir la recurrencia y la supervivencia a largo plazo en pacientes con cáncer colorrectal. Consulte Video Resumen en http://links.lww.com/DCR/B785. (Traducción-Dr. Osvaldo Gauto).

Lymph Nodes With Germinal Centers Are Not Associated With Tumor Response After Neoadjuvant Treatment in Locally Advanced Rectal Cancer

In patients with locally advanced rectal cancer, neoadjuvant radiotherapy or chemoradiotherapy followed by total mesorectal excision as a standard of care. We aimed to explore the number, size, germinal centers, extracapsular invasion of lymph nodes (LN), and their impact on overall survival and disease free survival. Furthermore we also investigated the characteristics of lymph nodes in patients who received neoadjuvant therapy and those who underwent surgery between 2011 and 2018. The count and measurement of lymph nodes was assessed by careful visual inspection and manual palpation. The predictive cut-off value of the lymph node ratio (LNR) was determined based on the receiver operating characteristic (ROC), method and the survival outcomes based on Kaplan-Meier curves. We found that the size and the number of lymph nodes decreased significantly after neoadjuvant treatment. The mean LN for patients who received neoadjuvant therapy was 12.68 ± 6.69 and for patients who did not receive neoadjuvant therapy was 16.29 ± 5.61 ( P = .012). The average size for patients who received neoadjuvant therapy followed by surgery was 3.30 ± 1.10 versus 4.22 ± 1.18 mm for control group (surgery only) ( P < .001), an LNR of 0.13 (sensitivity: 86%, specificity: 47%, AUC: 60%, 95% CI, 0.41%-0.76%) predicted recurrence and metastasis. Presence of lymph nodes with germinal centers was significantly associated with absence of vascular invasion, nodal tumor deposits, distant metastasis, and lower age group (<50 years). However there was no association seen between overall survival and relapse free, total number of lymph nodes enlarged and extracapsular invasion in positive nodes.

Finally there is no association between lymph nodes with germinal centers and tumor response after neoadjuvant treatment in locally advanced rectal cancer.

Effects of neoadjuvant chemotherapy plus chemoradiotherapy on lymph nodes in rectal adenocarcinoma

The pathological nodal stage, determination of which requires examination of ≥ 12 lymph nodes, is one of the main prognostic factors in rectal cancer. Neoadjuvant chemoradiotherapy (CRT) may reduce the number of both lymph nodes retrieved and positive lymph nodes. Induction chemotherapy before CRT aimed at reducing the rate of distant metastases. However, the impact of this new treatment on number of lymph nodes retrieved and positive lymph nodes is unknown. This study was performed to evaluate the effects of neoadjuvant chemotherapy on lymph nodes in locally advanced rectal cancer treated by CRT. We retrospectively included patients with T2 - 4 Nx M0 rectal cancer and compared those receiving neoadjuvant chemotherapy plus CRT with those receiving CRT alone. From 2012 to 2019, 85 patients were treated with neoadjuvant chemotherapy + CRT and 189 with CRT alone. The number of lymph nodes retrieved (19 vs. 17, respectively, P = 0.434), the rate of specimens with ≥ 12 lymph nodes (92% vs. 88%, respectively, P = 0.397), and the median number of positive lymph nodes (1 vs. 2, respectively, P = 0.878) were similar between the two groups. However, the rate of pN0 was higher after neoadjuvant chemotherapy + CRT compared to CRT (75% vs. 62%, respectively, P = 0.030). Neoadjuvant chemotherapy before CRT for locally advanced rectal cancer did not modify the number of lymph nodes retrieved or the number of positive lymph nodes compared to CRT alone. However, it significantly increased the rate of tumors without any positive lymph nodes (ypN0).

Prognostic value of platelet-associated biomarkers in rectal cancer patients received neoadjuvant chemoradiation: A retrospective study

PURPOSE

Platelet volume has been shown to prognostic value in patients with colorectal cancer. However, the changes of other platelet-associated biomarkers in rectal cancer patients, before and after the neoadjuvant chemoradiation therapy (NACRT), remain unclear. In this study, we investigated the prognostic value of platelet-associated biomarkers in rectal cancer patients with NACRT.

PATIENTS AND METHODS

A total of 75 patients with locally advanced (T3-4 or N+) rectal cancer (LARC) cancer were selected and followed up from the Affiliated Cancer Hospital of Zhengzhou University between June 2013 and September 2016. The data of platelet-associated biomarkers, including the platelet count, platelet to lymphocyte ratio (PLR), lymphocyte to monocyte ratio (LMR), mean platelet volume (MPV), and platelet distribution width (PDW) both pre- and post- NACRT, were collected. The associations between these platelet-associated biomarkers and the overall survival (OS), as well as disease-free survival (DFS) of patients, were analysed. Patients were divided into groups with high or low values of the platelet-associated biomarkers, and the outcomes were compared by using Cox regression and Kaplan-Meier analysis.

RESULTS

We found that pre-PLR (HR: 4.104; 95%CI: 1.411-11.421; P=0.009) and pre-LMR (HR: 0.384; 95%CI: 0.124-1.185; P=0.066) could predict the OS in LARC patients after NACRT by multivariate Cox regression analysis, a cut-off value of pre-PLR>7.02 and pre-LMR ≤7.10 could be used as independent prognostic factors for OS by Kaplan-Meier method. The pre-MPV value could be used as an independent prognostic factor for DFS by Kaplan-Meier analysis (P=0.037). Moreover, post-CEA was correlated with OS and DFS in LARC patients with NACRT.

CONCLUSION

In LARC patients with NACRT, the pre-PLR and pre-LMR are independent prognostic factors for OS, while pre-MPV has predictive value for DFS.

Large negative lymph nodes - a surrogate for immune activation in rectal cancer patients?

AIM

The size of regional, tumor draining lymph nodes without metastasis (LNneg) found in rectal cancer resection specimens varies and seems to be related to patient survival. Yet, the histopathological features influencing LNneg size in rectal cancer have not been studied in detail. Our pilot study focused on investigating the relationship between lymph node (LN) size and LNneg microarchitecture in rectal cancer (RC) resection specimens.

METHOD

In this retrospective cohort study, resection specimens from 146 RC patients, treated with either surgery alone (n = 29) or neoadjuvant therapy followed by resection (n = 117), were included in the study. Histology of LNnegs was reviewed to establish number of lymphoid follicles and presence of intranodal fat. Longest long axis and area of each LN were measured digitally.

RESULTS

1830 LNnegs were measured. The microarchitecture was analyzed in a subset of 680 LNnegs. 153 (22.5 %) LNnegs contained intranodal fat. After neoadjuvant treatment, presence of intranodal fat was related to smaller LNneg area (median (range) area of LNneg without intranodal fat: 4.51 mm² (0.15-46.89 mm²), with intranodal fat: 3.46 mm² (0.12-27.22 mm²), p = 0.048). A higher number of lymphoid follicles was related to a larger LNneg area in both patient groups (p < 0.001).

CONCLUSION

Our pilot data suggest that in rectal cancer the presence of large regional LNnegs may reflect increased immune activation due to tumor related antigens. Further studies are warranted to investigate whether histologically visible microarchitectural features of LNnegs such as lymphoid follicles translate to particular features in radiological images and hence could potentially help to identify LNneg with more certainty at the time of pre-treatment disease staging.

A systematic review and meta-analysis of pT2 rectal cancer spread and recurrence pattern: Implications for target design in radiation therapy for organ preservation

BACKGROUND

There are no guidelines on clinical target volume (CTV) delineation for cT2 rectal cancer treated with organ preservation.

MATERIALS AND METHODS

A systematic review and meta-analysis were performed to determine the extent of distal mesorectal (DMS) and distal intramural spread (DIS), the risk of lateral lymph node (LLN) metastases in pT2 tumours, and regional recurrence pattern after organ preservation.

RESULTS

The rate of DMS > 1 cm was 1.9% (95% CI: 0.4-5.4%), maximum extent: 1.3 cm. The rate of DIS > 0.5 cm was 4.7% (95% CI: 1.3-11.5%), maximum extent: 0.8 cm. The rate of LLN metastases was 8.2% (95% CI: 6.7-9.9%) for tumours below or at peritoneal reflexion and 0% for higher tumours. Regional nodal recurrences alone were recorded in 1.0% (95% CI: 0.5-1.7%) of patients after watch-and-wait and in 2.1% (95% CI: 1.2-3.4%) after preoperative radiotherapy and local excision. Thus, the following rules for CTV delineation are proposed: caudal border 1.5 cm from the tumour to account for DMS or 1 cm to account for DIS, whichever is more caudal; cranial border at S2/S3 interspace; inclusion of LLN for tumours at or below peritoneal reflexion. A planning study was performed in eight patients to compare dose-volume parameters obtained using these rules to that obtained using current guidelines for advanced cancers. The proposed rules led to a mean 18% relative reduction of planning target volume, which resulted in better sparing of organs-at-risk.

CONCLUSION

This meta-analysis suggests a smaller CTV for cT2 tumours than the current guidelines designed for advanced cancers.

Clinical application of laparoscopic cylindrical abdominoperineal resection and extraperitoneal sigmoidostomy for low rectal cancer

AIM: To evaluate the clinical efficacy of laparoscopic cylindrical abdominoperineal resection and extraperitoneal sigmoidostomy for low rectal cancer.

METHODS: We retrospectively analyzed the clinicopathological data for 25 low rectal cancer patients who underwent laparoscopic cylindrical abdominoperineal resection and extraperitoneal sigmoidostomy at the First Hospital of Wuhan from January 2013 to February 2015.

RESULTS: Laparoscopic surgery was successful in all the 25 cases. Operative time was 162.5 min ± 35.6 min, and intraoperative blood loss was 55.5 mL ± 26.8 mL. Fat liquefaction and infection at the perineal incision occurred in two cases. After a median follow-up of 25 mo (range, 3-36 mo), no recurrence occurred.

CONCLUSION: Laparoscopic cylindrical abdominoperineal resection plus extraperitoneal sigmoidostomy is feasible for low rectal cancer and is associated with few complications, low recurrence rate, and satisfactory short-term curative effect.