Prognostic implications of the distribution of lymph node metastases in rectal cancer after neoadjuvant chemoradiotherapy

Sequential Lateral Lymphatic Metastasis Shows Similar Oncologic Outcomes to Upward Spread in Advanced Rectal Cancer After Preoperative Chemoradiotherapy

BACKGROUND

Whether lateral pelvic node metastasis should be considered as a regional or systemic disease is a long-standing debate. Although previous Japanese studies have considered it to be locoregional disease, Western countries consider it a systemic disease and do not perform lateral pelvic node dissection after preoperative chemoradiotherapy.

OBJECTIVE

To evaluate whether lateral pelvic node metastasis is a systemic or regional disease that is amenable to curative resection.

DESIGN

Retrospective analysis of a prospectively collected database.

SETTING

This study was conducted at a tertiary cancer center.

PATIENTS

There were 616 consecutive patients who underwent curative total mesorectal excision alone or with lateral pelvic node dissection after preoperative chemoradiotherapy for locally advanced rectal cancer between 2011 and 2019.

MAIN OUTCOME MEASURES

Three-year disease-free and overall survival.

RESULTS

A total of 360 patients underwent total mesorectal excision, and 160 patients underwent total mesorectal excision with lateral pelvic node dissection. There was no difference in the 3-year disease-free survival (DFS; p = 0.844) or overall survival rates ( p = 0.921) between the groups. Patients with lateral pelvic node metastasis showed DFS similar to those with perirectal lymph node metastasis in the total mesorectal excision group. In a subgroup analysis, patients with internal iliac pelvic node metastasis showed a disease-free survival comparable to those with perirectal node involvement, and patients with other lateral pelvic node metastasis showed a DFS similar to those with intermediate node involvement. In the lateral pelvic node dissection group, the lateral pelvic node metastatic rate was 32.5%. On multivariate analysis, fewer than 8 of the unilateral harvested lateral pelvic nodes and advanced ypT stage were significantly associated with poor disease-free survival.

LIMITATION

The retrospective design.

CONCLUSIONS

Lateral lymphatic metastasis showed oncologic outcomes similar to those of upward spread, especially perirectal lymph nodes metastasis. Large cohort studies with long-term follow-up are required to confirm these results. See Video Abstract .

LAS METSTASIS LINFTICAS SECUENCIALES LATERALES MUESTRAN RESULTADOS ONCOLGICOS SIMILARES EN LA PROPAGACIN ASCENDENTE DEL CNCER RECTAL AVANZADO DESPUS DE LA RADIOQUIMIOTERAPIA PREOPERATORIA

ANTECEDENTES:Es un debate muy antiguo si las metástasis en los ganglios pélvicos laterales deben considerarse una enfermedad regional o sistémica. Si bien estudios japoneses anteriores las consideran como una enfermedad locorregional, en los países de occidente se las considera como una enfermedad sistémica por la cual no se realiza disección de ganglios pélvicos laterales después de una radioquimioterapia preoperatoria.OBJETIVOS:Evaluar si la metástasis en los ganglios pélvicos laterales se consideran como enfermedad sistémica o enfermedad regional susceptible de resección curativa.DISEÑO:Análisis retrospectivo de una base de datos recopilada prospectivamente.AJUSTE:Este estudio se realizó en un centro oncológico terciario.PACIENTES:616 pacientes consecutivos se sometieron a excisión total del mesorrecto curativa sola o con disección de los ganglios pélvicos laterales después de radioquimioterapia preoperatoria en casos de cáncer de recto localmente avanzado entre 2011 y 2019.PRINCIPALES MEDIDAS DE RESULTADO:Sobrevida global y libre de enfermedad a 3 años.RESULTADOS:Un total de 360 pacientes se sometieron a excisión total del mesorrecto y 160 pacientes se sometieron a excisión total del mesorrecto con disección de ganglios pélvicos laterales.No hubo diferencias en la sobrevida libre de enfermedad a 3 años (p = 0,844) ni en las tasas de sobrevida general (p = 0,921) entre los grupos. Los pacientes con metástasis en los ganglios pélvicos laterales mostraron una sobrevida libre de enfermedad similar a aquellos con metástasis en los ganglios linfáticos perirrectales que se encontraban en el grupo de excisión total del mesorrecto.En el análisis de subgrupos, los pacientes con metástasis en los ganglios pélvicos ilíacos internos mostraron una sobrevida libre de enfermedad comparable a aquellos con afección de los ganglios perirrectales y los pacientes con otras metástasis en los ganglios pélvicos laterales mostraron una sobrevida libre de enfermedad similar a aquellos con afección de los ganglios intermedios.En el grupo de disección de los ganglios pélvicos laterales, la tasa de metástasis en dichos ganglios fué del 32,5%. En el análisis multivariado, < de 8 ganglios pélvicos laterales resecados unilateralmente y el estadio ypT avanzado se asociaron significativamente con una menor sobrevida libre de enfermedad.LIMITACIÓN:El diseño retrospectivo del estudio.CONCLUSIONES:Las metástasis linfáticas laterales mostraron resultados oncológicos similares a la diseminación ascendente, especialmente las metástasis en los ganglios linfáticos perirrectales. Se requieren grandes estudios de cohortes con seguimiento a largo plazo para confirmar estos resultados. (Traducción-Dr. Xavier Delgadillo ).

Upper limit of radiation treatment portals in rectal cancer: is it wise to keep using bony landmarks in the present era of 3D conformal treatment?

Background

This study aimed to compare the levels of L5-S1 interspace and the bifurcation of common iliac vessels on simulation images of rectal cancer patients to evaluate the adequacy of superior borders in conventional 2D planning for covering internal iliac vessels.

Materials and methods

Simulation images of 236 rectal cancer patients who received neoadjuvant chemoradiation and surgery were analyzed. The images were retrieved from the radiation treatment database and included delineations of L5-S1 interspace and common iliac vessel bifurcation. Distances between these landmarks were measured.

Results

Among the 236 patients, the majority had the common iliac artery bifurcation positioned above the L5-S1 interspace. Specifically, 78.3% of patients had the right common iliac bifurcation above L5-S1 interspace, with an average distance of 2.02 cm. For the left common iliac artery, 77.11% of patients had the bifurcation above L5-S1 interspace, with an average distance of 1.99 cm. Notably, there were cases where the bifurcations were not at the same level.

Conclusion

Using the L5-S1 junction as the upper border of the treatment portal may result in missing proximal nodes at risk of metastases. However, further research is needed to determine the significance of failures above the L5-S1 interspace for justifying the inclusion of the common iliac artery bifurcation in the treatment portal.

New Opportunities for Minimizing Toxicity in Rectal Cancer Management

Advances in multimodal management of locally advanced rectal cancer (LARC), consisting of preoperative chemotherapy and/or radiotherapy followed by surgery with or without adjuvant chemotherapy, have improved local disease control and patient survival but are associated with significant risk for acute and long-term morbidity. Recently published trials, evaluating treatment dose intensification via the addition of preoperative induction or consolidation chemotherapy (total neoadjuvant therapy [TNT]), have demonstrated improved tumor response rates while maintaining acceptable toxicity. In addition, TNT has led to an increased number of patients achieving a clinical complete response and thus eligible to pursue a nonoperative, organ-preserving, watch and wait approach, thereby avoiding toxicities associated with surgery, such as bowel dysfunction and stoma-related complications. Ongoing trials using immune checkpoint inhibitors in patients with mismatch repair-deficient tumors suggest that this subgroup of patients with LARC could potentially be treated with immunotherapy alone, sparing them the toxicity associated with preoperative treatment and surgery. However, the majority of rectal cancers are mismatch repair-proficient and less responsive to immune checkpoint inhibitors and require multimodal management. The synergy noted in preclinical studies between immunotherapy and radiotherapy on immunogenic tumor cell death has led to the design of ongoing clinical trials that explore the benefit of combining radiotherapy, chemotherapy, and immunotherapy (mainly of immune checkpoint inhibitors) and aim to increase the number of patients eligible for organ preservation.

Mesenteric location of lymph node metastasis for colorectal cancer

BACKGROUND

The number of lymph node metastasis (LNM) is a strong prognostic factor in the treatment of colorectal cancer (CRC). However, the impact of the mesentery location on LNM remains unclear. We assessed the impact LNM location on the recurrence of stage III CRC.

METHODS

Subjects with CRC and pathologically positive LNM were enrolled retrospectively. We defined three groups: LNM adjacent to the tumour (group A), metastases with horizontal or vertical spread (group B), and metastases with both horizontal and vertical spread (group C). Recurrence-free survival (RFS) was the primary outcome measure used for the study.

RESULTS

A total of 241 (Group A: 121, B: 90, and C: 30) patients were recruited for the study. Multivariate analysis by Cox regression model indicated LNM location to be an independent predisposing risk factor for recurrence [group B: Hazard ratio (HR) 2.01, 95% Confidential interval (CI) 1.12-3.60, P = 0.019; group C: HR 3.00, 95% CI 1.34-6.72, P = 0.008]. Addition of mesentery spread to the N classification was significant risk factor for recurrence (mN2a: HR 2.01, 95% CI 1.07-3.78, P = 0.029; mN2b: HR 3.96, 95% CI 2.12-7.40, P < 0.01). Comparison of Harrell's C-index values was conducted, and the modified N staging risk was 0.6377, whereas the TNM N stage classification was 0.5869.

CONCLUSION

Mesentery location of LNM was a risk factor and consideration of it might be beneficial for accurate prediction of CRC prognosis.

A Phase II trial of Higher RadiOtherapy Dose In The Eradication of early rectal cancer (APHRODITE): protocol for a multicentre, open-label randomised controlled trial

INTRODUCTION

The standard of care for patients with localised rectal cancer is radical surgery, often combined with preoperative neoadjuvant (chemo)radiotherapy. While oncologically effective, this treatment strategy is associated with operative mortality risks, significant morbidity and stoma formation. An alternative approach is chemoradiotherapy to try to achieve a sustained clinical complete response (cCR). This non-surgical management can be attractive, particularly for patients at high risk of surgical complications. Modern radiotherapy techniques allow increased treatment conformality, enabling increased radiation dose to the tumour while reducing dose to normal tissue. The objective of this trial is to assess if radiotherapy dose escalation increases the cCR rate, with acceptable toxicity, for treatment of patients with early rectal cancer unsuitable for radical surgery.

METHODS AND ANALYSIS

APHRODITE (A Phase II trial of Higher RadiOtherapy Dose In The Eradication of early rectal cancer) is a multicentre, open-label randomised controlled phase II trial aiming to recruit 104 participants from 10 to 12 UK sites. Participants will be allocated with a 2:1 ratio of intervention:control. The intervention is escalated dose radiotherapy (62 Gy to primary tumour, 50.4 Gy to surrounding mesorectum in 28 fractions) using simultaneous integrated boost. The control arm will receive 50.4 Gy to the primary tumour and surrounding mesorectum. Both arms will use intensity-modulated radiotherapy and daily image guidance, combined with concurrent chemotherapy (capecitabine, 5-fluorouracil/leucovorin or omitted). The primary endpoint is the proportion of participants with cCR at 6 months after start of treatment. Secondary outcomes include early and late toxicities, time to stoma formation, overall survival and patient-reported outcomes (European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaires QLQ-C30 and QLQ-CR29, low anterior resection syndrome (LARS) questionnaire).

ETHICS AND DISSEMINATION

The trial obtained ethical approval from North West Greater Manchester East Research Ethics Committee (reference number 19/NW/0565) and is funded by Yorkshire Cancer Research. The final trial results will be published in peer-reviewed journals and adhere to International Committee of Medical Journal Editors guidelines.

TRIAL REGISTRATION NUMBER

ISRCTN16158514.

Pathological Evaluation of Rectal Cancer Specimens Using Micro-Computed Tomography

Whole-block imaging (WBI) using micro-computed tomography (micro-CT) allows the nondestructive reconstruction of a three-dimensional view of tissues, implying that WBI may be used for accurate pathological evaluation of patients with rectal cancer. HOWEVER, the clinical impact of this approach is unclear. We aimed to clarify the efficacy of WBI in the whole-mount specimens of locally advanced rectal cancer. A total of 237 whole-mount formalin-fixed paraffin-embedded blocks from 13 patients with rectal cancer who underwent surgical treatment were enrolled and scanned with micro-CT to generate three-dimensional images. WBI was evaluated following the conventional pathological review of the corresponding whole-slide imaging (WSI). WBI identified all tumor sites detected using WSI. Furthermore, WBI revealed one additional tumor site, which was not detected using WSI. Tumor resection margin was significantly closer to the soft-tissue edge when measured using WBI (7.7 mm vs. 6.6 mm, p < 0.01). Seventy-six percent of tumor deposits on WSI were changed according to the evidence of tumor interaction with the surrounding tissues confirmed using WBI. Furthermore, WBI revealed 25 additional lymph nodes, six of which were metastatic. The combination of conventional hematoxylin and eosin-stained imaging and WBI may contribute to an accurate pathological assessment.

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.

Prognostic Value of the Distribution of Lymph Node Metastasis in Locally Advanced Rectal Cancer After Neoadjuvant Chemoradiotherapy

Background: The objective of this study is to assess the prognostic value of lymph node metastasis distribution (LND) in locally advanced rectal cancer (LARC) after neoadjuvant chemoradiotherapy (nCRT). Methods: This study included 179 patients with pathological stage III LARC who underwent nCRT followed by radical surgery. LND was classified into three groups: LND1, lymph node metastasis at the mesorectum (140/179, 78.2%); LND2, lymph node metastasis along the inferior mesenteric artery trunk nodes (26/179, 14.5%); LND3, lymph node metastasis at the origin of the IMA (13/179, 7.3%). Clinicopathologic characteristics were analyzed to identify independent prognostic factors. Result: LND showed better stratification for 3-year DFS (LND1 66.8, LND2 50, and LND3 15.4%, P < 0.01) compared to the ypN (3-year DFS: N1 59.9 and N2 60.3%, P = 0.34) and ypTNM (3-year DFS: IIIA 68.6%, IIIB 57.5%, and IIIC 53.5, P = 0.19) staging systems. Similar results were found for 3-year LRFS and DMFS. According to multivariate survival analysis, LND was shown to be an independent prognostic factor for DFS, LRFS, and DMFS in patients with positive lymph nodes (P < 0.01, in all cases). Conclusion: LND is an independent prognostic factor in stage III rectal cancer after nCRT. LND can be used as a supplementary indicator for the ypTNM staging system in patients with LARC after nCRT.

8-Oxoguanine DNA Glycosylase (OGG1) Cys326 Variant: Increased Risk for Worse Outcome of Patients with Locally Advanced Rectal Cancer after Multimodal Therapy

Despite excellent loco-regional control by multimodal treatment of locally advanced rectal cancer, a substantial portion of patients succumb to this disease. As many treatment effects are mediated via reactive oxygen species (ROS), we evaluated the effect of single nucleotide polymorphisms (SNPs) in ROS-related genes on clinical outcome. Based on the literature, eight SNPs in seven ROS-related genes were assayed. Eligible patients (n = 287) diagnosed with UICC stage II/III rectal cancer were treated multimodally starting with neoadjuvant radiochemotherapy (N-RCT) according to the clinical trial protocols of CAO/ARO/AIO-94, CAO/ARO/AIO-04, TransValid-A, and TransValid-B. The median follow-up was 64.4 months. The Ser326Cys polymorphism in the human OGG1 gene affected clinical outcome, in particular cancer-specific survival (CSS). This effect was comparable in extent to the ypN status, an already established strong prognosticator for patient outcome. Homozygous and heterozygous carriers of the Cys326 variant (n = 105) encountered a significantly worse CSS (p = 0.0004 according to the log-rank test, p = 0.01 upon multiple testing adjustment). Cox regression elicited a hazard ratio for CSS of 3.64 (95% confidence interval 1.70-7.78) for patients harboring the Cys326 allele. In a multivariable analysis, the effect of Cys326 on CSS was preserved. We propose the genetic polymorphism Ser326Cys as a promising biomarker for outcome in rectal cancer.

Horizontal spread of pericolic lymph node metastasis as a prognostic factor for recurrence in Stage III colorectal cancer

AIM

Main lymph node (LN) metastasis dissected with a high vascular tie at the root of the feeding artery is a poor prognostic factor in colorectal cancer (CRC). However, the effects of horizontal spread on recurrence after curative resection remain unclear. The purpose of this study is to evaluate the relationship between the horizontal spread of LN metastasis and recurrence in CRC.

METHOD

In this retrospective study, 189 CRC patients (98 men, 91 women) who underwent curative resection at our hospital from 2003 to 2018 and had only pericolic LN metastasis were divided into two groups: patients with LN metastasis beside the tumour only (T group, n = 121) and those with LN metastasis with horizontal spread (S group, n = 68) (mean follow-up period 50.9 ± 34.1 months). The primary outcome was recurrence-free survival (RFS). We investigated the correlation between clinicopathological background factors and recurrence using Cox regression analysis.

RESULTS

Fewer than three LN metastases (N1) were found in 157 patients (107 T group, 50 S group), and four or more metastases (N2a) were found in 32 patients (14 T group, 18 S group). Univariate analyses revealed significantly shorter RFS in the S group [hazard ratio (HR) 1.95, 95% CI 1.07-3.55; p = 0.03). Multivariate analyses revealed that horizontal spread is an independent risk factor for recurrence (HR 1.95, 95% CI 1.05-3.68; p = 0.03).

CONCLUSION

Although further investigation is needed, horizontal spread of LN metastasis is a prognostic factor for recurrence in Stage III CRC.

Risk of nodal disease in patients with MRI-detected extramural vascular invasion in rectal cancer: a systematic review and meta-analysis

BACKGROUND

The impact of magnetic resonance imaging-detected extramural vascular invasion (mrEMVI) in distant metastasis is well known but its correlation with prevalence of lymph node metastasis is less studied. The aim of this systematic review and meta-analysis was to assess the prevalence of nodal disease in mrEMVI-positive and negative cases in rectal cancer.

METHODS

Following guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses, a systematic literature search in PubMed, Web of Science, Cochrane Library, and EMBase was carried out to identify relevant studies published up to May 2019.

RESULTS

Our literature search generated 10 studies (863 and 1212 mrEMVI-positive and negative patients, respectively). The two groups (mrEMVI-positive and negative) were significantly different in terms of nodal disease status (odds ratio [OR] 3.15; 95% confidence interval [CI] 2.12-4.67; p < 0.001). The prevalence of nodal disease was 75.90% vs 52.56% in the positive mrEMVI vs negative mrEMVI group, respectively (p < 0.001). The prevalence of positive lymph node in positive mrEMVI patients treated with neoadjuvant/adjuvant chemoradiotherapy (nCRT/CRT) (OR 2.47; 95% CI 1.65-3.69; p < 0.001) was less compared with the patients who underwent surgery alone (OR 6.25; 95% CI 3.74-10.44; p < 0.001).

CONCLUSION

The probability of positive lymph nodes in cases of positive mrEMVI is distinctly greater compared with negative cases in rectal cancer. Positive mrEMVI indicates risk of nodal disease prevalence increased by threefold in rectal cancer.

Locally recurrent rectal cancer: what the radiologist should know

Despite advances in surgical techniques and chemoradiation therapy, recurrent rectal cancer remains a cause of morbidity and mortality. After successful treatment of rectal cancer, patients are typically enrolled in a surveillance strategy that includes imaging as studies have shown improved prognosis when recurrent rectal cancer is detected during imaging surveillance versus based on development of symptoms. Additionally, patients who experience a complete clinical response with chemoradiation therapy may elect to enroll in a "watch-and-wait" strategy that includes imaging surveillance rather than surgical resection. Factors that increase the likelihood of recurrence, patterns of recurrence, and the imaging appearances of recurrent rectal cancer are reviewed with a focus on CT, PET CT, and MR imaging.

Oxaliplatin-Based Adjuvant Chemotherapy for Rectal Cancer After Preoperative Chemoradiotherapy (ADORE): Long-Term Results of a Randomized Controlled Trial

PURPOSE

We evaluated the role of oxaliplatin as adjuvant chemotherapy in patients with rectal cancer who received preoperative chemoradiotherapy (CRT) with fluoropyrimidine monotherapy and total mesorectal excision (TME).

METHODS

The ADORE trial (adjuvant oxaliplatin in rectal cancer) is a multicenter, randomized trial in patients with postoperative ypStage II (ypT3-4N0) or III (ypT_anyN1-2) rectal cancer after fluoropyrimidine-based preoperative CRT and TME. Patients were randomly assigned (1:1) to receive adjuvant chemotherapy either with FL (fluorouracil 380 mg/m² and leucovorin 20 mg/m²) or FOLFOX (oxaliplatin 85 mg/m², leucovorin 200 mg/m², and fluorouracil bolus 400 mg/m² on day 1, fluorouracil infusion 2,400 mg/m² for 46 hours). Stratification factors included ypStage and participating center. Primary end point was disease-free survival (DFS).

RESULTS

A total of 321 patients were enrolled between November 19, 2008, and June 12, 2012. Six-year DFS rates were 68.2% in the FOLFOX arm versus 56.8% in the FL arm, with a stratified hazard ratio of 0.63 (95% CI, 0.43 to 0.93; P = .018) by intention-to-treat analysis. In the subgroup analysis for DFS, FOLFOX was favorable versus FL in patients with ypStage III, ypN1b, ypN2, high-grade histology, minimally regressed tumor, and an absence of lymphovascular or perineural invasion. Six-year overall survival rate was 78.1% in the FOLFOX arm versus76.4% in the FL arm (hazard ratio, 0.73; 95% CI, 0.45 to 1.19; P = .21). In the subgroup analysis for OS, FOLFOX was favorable versus FL in patients with ypN2 and minimally regressed tumor.

CONCLUSION

Adjuvant FOLFOX improved DFS in patients with rectal cancer with ypStage II and III disease after preoperative CRT. Adjuvant FOLFOX may be considered on the basis of the postoperative pathologic stage in those who received preoperative CRT and TME.

Type of preoperative therapy and stage-specific survival after surgery for rectal cancer: a nationwide population-based cohort study

Preoperative chemoradiation therapy (CRT) may induce downstaging in rectal cancer (RC). Short-course radiation therapy (SC-RT) with immediate surgery does not cause substantial downstaging. However, the TNM classification adds the “y” prefix in both groups to indicate possible treatment effects. We aim to compare stage-specific survival in these patients. RC patients treated with surgery only, preoperative SC-RT followed by surgery within 10 days, or preoperative CRT, and diagnosed between 2008 and 2014 were included in this population-based study. Clinicopathological and outcome characteristics were analyzed. The study included 11,925 patients. Large discrepancies existed between clinical and pathological stages after surgery only. Surgery-only patients were older with more comorbidities compared with SC-RT and CRT and had worse 5-year survival (64%, 76%, and 74%, respectively; p < 0.001). Five-year survival for stage I was similar after CRT and SC-RT (85% vs. 85%; p = 0.167) and comparable between CRT-treated patients with stage I and those reaching a pathological complete response (pCR; 85% vs. 89%; p = 0.113). CRT was independently associated with worse overall survival compared with SC-RT for stage II (HR 1.57 [95%CI 1.27–1.95]; p < 0.001) and stage III (HR 1.43 [95%CI 1.23–1.70]; p < 0.001). Stage I disease after CRT has an excellent prognosis, comparable with pCR and with same-stage SC-RT-treated patients without regression. Stage II or III after CRT has worse prognosis than after SC-RT with immediate surgery. TNM should take the impact of preoperative therapy type on stage-specific survival into account. In addition, clinical stage was a poor predictor of pathological stage.

Clinical Implications of Lymph Node Metastasis in Colorectal Cancer: Current Status and Future Perspectives

Lymph node metastasis is regarded as an indubitable prognostic factor for predicting disease recurrence and survival in patients with colorectal cancer. Lymph node status based on examination of a resected specimen is a key element of the current staging system and is also a crucial factor to determine use of adjuvant chemotherapy after surgical resection. However, the current tumor-node-metastasis (TNM) staging system only incorporates the number of metastatic lymph nodes in the N category. Numerous attempts have been made to supplement this simplified N staging including lymph node ratio, distribution of metastatic lymph nodes, tumor deposits, or extracapsular invasion. In addition, several attempts have been made to identify more specific prognostic factors in resected colorectal specimens than lymph node status. In this review, we will discuss controversies in lymph node staging and factors that may influence survival beyond lymph node status.

Prognostic Implication of Negative Lymph Node Count in ypN+ Rectal Cancer after Neoadjuvant Chemoradiotherapy and Construction of a Prediction Nomogram

PURPOSE

This study aimed to investigate the prognostic significance of negative lymph nodes (NLNs) for ypN+ rectal cancer after neoadjuvant chemoradiotherapy (nCRT) and radical surgery and to construct a nomogram predicting disease-free survival (DFS).

METHOD

One hundred fifty-eight eligible patients were included. X-tile analysis was performed to determine cutoff values of NLNs. Clinicopathological and survival outcomes were compared. A Cox regression analysis was performed to identify prognostic factors of DFS. A nomogram was constructed and validated internally.

RESULTS

X-tile analysis identified cutoff values of 4 and 16 in terms of DFS (χ² = 8.129, p = 0.017). The 3-year DFS rates for low (≤ 4), middle (5-16), and high (≥ 17) NLNs group was 15.2, 55.5, and 73.1%, respectively (P = 0.017). NLN count (NLNs ≥ 17, HR = 0.400, P = 0.022), IMA nodal metastasis (HR = 1.944, P = 0.025), tumor differentiation (poor/anaplastic, HR = 1.805, P = 0.021), and ypT4 stage (HR = 7.787, P = 0.047) were independent prognostic factors of DFS. A predicting nomogram incorporating the four significant predictors was developed with a C-index of 0.64.

CONCLUSION

NLN count was an independent prognostic factor of DFS in patients with ypN+ rectal cancer following nCRT. A nomogram incorporating NLN count, IMA nodal metastasis, tumor differentiation, and ypT stage could stratify rectal cancer patients with different DFS and might be helpful during clinical decision-making.

Prognostic Significance of D3 Lymph Node for Survival in Patients With Colorectal Cancer

BACKGROUND

The aim of this study was to investigate the prognostic value of D3 lymph node (TSLN) for the survival of patients with colorectal cancer.

METHODS

A total of 156 patients with R0 resected colorectal cancer were selected from 2011 to 2015 to carry out a retrospective study. The survival rate according to the groups of positive lymph node number (N: 1-3, N2: 4-6, N3: ≥7) and TSLN (TSLN [-], TSLN [+]) was analyzed. The influences of covariates on the 5-year overall survival (OS) and 5-year disease-free survival (DFS) were determined by the Cox proportional risk model of backward stepwise analysis. Kaplan-Meier survival analysis was used to draw survival curves between and within groups.

RESULTS

During the median follow-up period (44.0 months), the 5-year DFS rate and OS rate were 45.0% and 46.0%, respectively. Survival analysis of the TSLN group showed that the 5-year OS rate and 5-year DFS rate in the TSLN (+) group (20.0 and 16.2%, respectively) were significantly lower than those in the TSLN (-) group (68.3 and 51.6%, respectively) (P < 0.001). The 5-year OS rate and DFS rate of the TSLN (+) and TSLN (-) subgroups in the N1 group were 16.7%, 33.3%, 56.7%, and 55.7%, respectively (P < 0.001). Multivariate analysis showed that positive lymph node, TSLN, and Pathological T stage were independent prognostic factors of DFS and OS for 5 years. Patients in the TSLN (+) group had a poorer prognosis.

CONCLUSIONS

TSLN metastasis is an independent factor influencing the prognosis of patients, and patients with TSLN (+) have a poor prognosis. As an independent prognostic factor, this factor should be considered when evaluating the prognosis of patients.

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.

Using a Lymph Node Count Metric to Identify Underperforming Hospitals After Rectal Cancer Surgery

BACKGROUND

Investigating methods to assess the quality of cancer surgery and then benchmarking hospitals on these quality indicators can lead to improvements in cancer care in the United States. We sought to determine the utility of lymph node count as a quality metric.

METHODS

We performed a retrospective analysis of the California Cancer Registry database (2004-2011) merged with Office of Statewide Health Planning and Development inpatient database. Patients with locally advanced rectal adenocarcinoma who underwent neoadjuvant therapy and resection were included. Hospital quality score was defined as the proportion of patients at a particular hospital that had adequate examination with at least nine lymph nodes. High-quality score hospitals were those that retrieved nine or more nodes among ≥25% of operations. A multivariate Cox proportional hazards (standard and shared frailty) model was used to determine differences in overall survival adjusting for age, hospital volume, race, sex, insurance, comorbidity, T-stage, response to neoadjuvant therapy, adjuvant chemotherapy, and teaching hospital status as covariates.

RESULTS

A total of 2704 patients were treated at 228 hospitals (low-scoring hospital = 85 and high-scoring hospital = 143). Patient- and disease-specific characteristics were similar between the groups. Socioeconomic status and hospital characteristics were strongly associated with score status. High-scoring hospitals had higher sphincter preservation (P = 0.004), lower complications (P = 0.021), and a trend toward lower mortality (P = 0.079). Care at high-scoring hospitals independently predicted overall survival (hazard ratio: 0.74; 95% confidence interval: 0.61-0.90; P = 0.003).

CONCLUSIONS

This study demonstrates that hospital quality score based on lymph node count can be used to identify underperforming hospitals.

Short- and Long-Term Oncological Outcome After Rectal Cancer Surgery: a Systematic Review and Meta-Analysis Comparing Open Versus Laparoscopic Rectal Cancer Surgery

BACKGROUND

While several trials have compared laparoscopic to open surgery for colon cancer showing similar oncological results, oncological quality of laparoscopic versus open rectal resection is not well investigated.

METHODS

A systematic literature search for randomized controlled trials was conducted in MEDLINE, the Cochrane Library, and Embase. Qualitative and quantitative meta-analyses of short-term (rate of complete resections, number of harvested lymph nodes, circumferential resection margin positivity) and long-term (recurrence, disease-free and overall survival) oncologic results were conducted.

RESULTS

Fourteen randomized controlled trials were identified including 3528 patients. Patients in the open resection group had significantly more complete resections (OR 0.70; 95% CI 0.51-0.97; p = 0.03) and a higher number of resected lymph nodes (mean difference - 0.92; 95% CI - 1.08 to 0.75; p < 0.001). No differences were detected in the frequency of positive circumferential resection margins (OR 0.82; 95% CI 0.62-1.10; p = 0.18). Furthermore, no significant differences of long-term oncologic outcome parameters after 5 years including locoregional recurrence (OR 0.95; 95% CI 0.44-2.05; p = 0.89), disease-free survival (OR 1.16; 95% CI 0.84-1.58; p = 0.36), and overall survival (OR 1.04; 95% CI 0.76-1.41; p = 0.82) were found. Most trials exhibited a relevant risk of bias and several studies provided no information on the surgical expertise of the participating surgeons.

CONCLUSION

Differences in oncologic outcome between laparoscopic and open rectal surgery for rectal cancer were detected for the complete resection rate and the number of resected lymph nodes in favor of the open approach. No statistically significant differences were found in oncologic long-term outcome parameters.

Lymph node ratio as a valuable prognostic factor for patients with colorectal liver-only metastasis undergoing curative resection

Background

Recent studies have suggested that the lymph node ratio (LNR) is a prognostic indicator for various malignancies. However, LNR has not been evaluated in colorectal liver-only metastasis (CRLM). This study aimed to investigate the prognostic value of LNR in patients with CRLM after curative resection.

Patients and methods

We retrospectively investigated the clinicopathologic features of 154 CRLM patients who underwent curative resection between 2005 and 2015. We classified patients into low and high groups based on their LNR by using the X-tile software. Survival curves were plotted through Kaplan–Meier method and compared by log-rank test. Cox proportional hazards analysis was performed to identify the factors associated with recurrence-free survival (RFS) and overall survival (OS).

Results

The patients were divided into two groups in which 124 patients were identified as LNR ≤0.33 and 30 patients as LNR >0.33. Compared to low LNR, high LNR was significantly associated with poor 3-year RFS (47.2% vs 16.7%, P=0.001) and OS (72.8% vs 45.3%, P=0.003) rates. Multivariate analysis indicated that the LNR was an independent predictor for 3-year RFS (hazard ratio, 2.124; 95% CI, 1.339–3.368; P=0.001) and OS (HR, 2.287; 95% CI, 1.282–4.079; P=0.005). However, the node (N) stage and lymph node distribution were not significantly associated with the 3-year RFS (P=0.071, P=0.226) or OS (P=0.452, P=0.791) in patients with CRLM.

Conclusion

This study demonstrated that LNR was an independent predictor for 3-year RFS and OS in patients with CRLM who underwent curative resection and that its prognostic value was superior to that of N stage and lymph node distribution.

Preoperative Intensity-modulated Chemoradiation Therapy with Simultaneous Integrated Boost in Rectal Cancer: 2-year Follow-up Results of Phase II Study

Background

The aim of the study was to investigate the feasibility and safety of experimental fractionation using intensity modulated radiation therapy with a simultaneous integrated boost (IMRT-SIB) to shorten the overall treatment time without dose escalation in preoperative radiochemotherapy of locally advanced rectal cancer.

Patients and methods

Between January 2014 and November 2015, a total of 51 patients with operable stage II-III rectal adenocarcinoma were treated. The preoperative treatment with intensity modulated radiation therapy (IMRT) and a pelvic dose of 41.8 Gy and simultaneously delivered 46.2 Gy to T2/3 and 48.4 Gy to T4 tumour in 22 fractions, with standard concomitant capecitabine, was completed in 50 patients out of whom 47 were operated. The median follow-up was 35 months.

Results

The rate of acute toxicity G ≥ 3 was 2.4%. The total downstaging rate was 89% and radical resection was achieved in 98% of patients. Pathologic complete response (pCR) was observed in 25.5% of patients, with 2-year local control (LC), disease free survival (DFS), and overall survival (OS) of 100% for this patient group. An intention-to-treat analysis revealed pN to be a significant prognostic factor for DFS and OS (P = 0.005 and 0.030, respectively). LC for the entire group was 100%, and 2-year DFS and OS were 90% (95 % CI 98.4–81.6) and 92.2% (95% CI 99.6–84.7), respectively.

Conclusions

The experimental regime in this study resulted in a high rate of pCR with a low acute toxicity profile. Excellent early results translated into encouraging 2-year LC, DFS, and OS.

Can we Save the rectum by watchful waiting or TransAnal microsurgery following (chemo) Radiotherapy versus Total mesorectal excision for early REctal Cancer (STAR-TREC study)?: protocol for a multicentre, randomised feasibility study

INTRODUCTION

Total mesorectal excision (TME) is the highly effective standard treatment for rectal cancer but is associated with significant morbidity and may be overtreatment for low-risk cancers. This study is designed to determine the feasibility of international recruitment in a study comparing organ-saving approaches versus standard TME surgery.

METHODS AND ANALYSIS

STAR-TREC trial is a multicentre international randomised, three-arm parallel, phase II feasibility study in patients with biopsy-proven adenocarcinoma of the rectum. The trial is coordinated from Birmingham, UK with national hubs in Radboudumc (the Netherlands) and Odense University Hospital Svendborg UMC (Denmark). Patients with rectal cancer, staged by CT and MRI as ≤cT3b (up to 5 mm of extramural spread) N0 M0 can be included. Patients will be randomised to either standard TME surgery (control), organ-saving treatment using long-course concurrent chemoradiation or organ-saving treatment using short-course radiotherapy. For patients treated with an organ-saving strategy, clinical response to (chemo)radiotherapy determines the next treatment step. An active surveillance regime will be performed in the case of a complete clinical regression. In the case of incomplete clinical regression, patients will proceed to local excision using an optimised platform such as transanal endoscopic microsurgery or other transanal techniques (eg, transanal endoscopic operation or transanal minimally invasive surgery). The primary endpoint of this phase II study is to demonstrate sufficient international recruitment in order to sustain a phase III study incorporating pelvic failure as the primary endpoint. Success in phase II is defined as randomisation of at least four cases per month internationally in year 1, rising to at least six cases per month internationally during year 2.

ETHICS AND DISSEMINATION

The medical ethical committees of all the participating countries have approved the study protocol. Results of the primary and secondary endpoints will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ISRCTN14240288, 20 October 2016. NCT02945566; Pre-results, October 2016.

Inferior Mesenteric Artery Lymph Node Metastasis Is an Independent Prognostic Factor for Stage III Sigmoid Colon and Rectal Cancer

It is unclear whether the number or distribution of lymph node metastases can provide a more accurate prognosis. The aim of this study was to evaluate the prognostic impact of inferior mesenteric artery (IMA) lymph node metastasis (LNM) in sigmoid colon and rectal cancer. We included 188 patients who underwent curative resection for stage III sigmoid colon and rectal cancer between January 2001 and December 2012. Patients were divided into 2 groups based on the presence of IMA-LNM (LNM-positive versus LNM-negative group). Clinicopathologic characteristics, 3-year recurrence-free survival and 5-year overall survival rates, and recurrence patterns were compared between the 2 groups. Of 188 patients, 9 patients (4.79%) were in the LNM-positive group. After curative resection, 3-year recurrence-free survival and 5-year overall survival rates were significantly lower in the LNM-positive group compared to the LNM-negative group (44.44% versus 69.98%, P = 0.016 for 3-year recurrence-free survival and 48.61% versus 81.73%, P = 0.018 for 5-year overall survival). Multivariate analysis revealed that the presence of IMA-LNM (P = 0.04), not the number of LNMs (P = 0.153), was an independent prognostic factor for recurrence-free survival. The para-aortic LNM rate was significantly higher in the LNM-positive group (P = 0.0078). IMA-LNM is an independent predictor of survival for stage III sigmoid colon and rectal cancer patients. Evaluation of IMA-LNM enables accurate estimation of patient prognosis and enhances appropriate postoperative therapy.

A nomogram to predict distant metastasis after neoadjuvant chemoradiotherapy and radical surgery in patients with locally advanced rectal cancer

PURPOSE

To compare distant metastasis (DM) in locally advanced rectal cancer (LARC) patients treated with neoadjuvant chemoradiotherapy (nCRT) and surgery alone, and to develop a predictive nomogram for DM following nCRT.

METHODS

Propensity-scoring match analysis was performed to compare DM in LARC treated with nCRT (n = 375) and surgery alone (n = 375). Cox regression was performed to identify predictors of DM following nCRT. A nomogram was developed and validated by internal (n = 425) and external validation (n = 97).

RESULTS

The 5-year local recurrence rate was significantly lower in the nCRT group (5.6% vs. 10.4%; P = 0.020). The 5-year DM rates (nCRT vs. surgery alone: 25.3% vs. 24.4%; P = 0.235) were similar between groups. Cox regression showed that the post-nCRT pathologic stage (ypTNM stage, OR = 2.022, P = 0.002), IMA nodal metastasis (OR = 2.171, P = 0.023), and CRM involvement (OR = 2.535, P = 0.016) were independently associated with DM following nCRT. A predictive nomogram was developed with a C-index of 0.70 on internal validation, and 0.71 on the external validation.

CONCLUSION

NCRT improved local control, but not distant metastasis. A nomogram to predict 3- and 5-year DM rates, using clinicopathological parameters, was successfully developed. This prognostic tool could support decision-making in clinical practice and follow-up strategies.

Good and complete responding locally advanced rectal tumors after chemoradiotherapy: where are the residual positive nodes located on restaging MRI?

PURPOSE

Aim of this study was to evaluate the distribution of persistent mesorectal lymph node metastases on restaging MRI in patients with a good or complete response of their primary tumor (ypT0-2) after CRT for locally advanced rectal cancer.

METHODS

Two hundred and twenty eight locally advanced rectal cancer patients underwent CRT, which resulted in a good response (downstaging to yT0-2) in 144 patients. Forty-nine patients were excluded (no surgery/insufficient follow-up or lacking lesion-by-lesion histology results). This resulted in a final study group of 95 yT0-2 patients. For the patients with a yN(+)-status, a detailed lesion-by-lesion comparison between restaging MRI and histology was performed to evaluate the characteristics and distribution of the individual N(+)-nodes.

RESULTS

7/95 patients (7%) had a yT0-2N(+) status (11/880 (1%) N(+) nodes): no N(+) were found below the tumor level, 55% of the N(+) nodes were located at the level of the tumor, and 45% proximal to the tumor (at a median distance of 1.4 cm above the tumor level). In axial plane, 82% of the nodes were located at the ipsilateral circumference of the tumor, at a median distance of 0.9 cm from the tumor/rectal wall.

CONCLUSIONS

The incidence of persistent metastatic mesorectal nodes after CRT in patients with a good tumor response after CRT is very low. No N(+) nodes are found below the tumor level. All N(+) nodes are located at the level of or proximal to the primary tumor, of which the majority very close to the tumor/lumen.

Distal intramural and tumor spread in the mesorectum after neoadjuvant radiochemotherapy in rectal cancer: about 124 consecutive patients

This observational prospective study aimed to assess the distribution of intramural and mesorectal tumor spread in mid/low rectal cancer after neoadjuvant radiochemotherapy. Distribution of mesorectal metastatic lymph nodes (MLNs) and mesorectal extranodal cancer tissue (EX), according to the tumor location, were analyzed. Distal intramural tumor spread was also performed. A total of 1676 LNs, 135 MLNs, and 69 EX were detected on 124 consecutive surgical specimens. Forty-two patients (34%) had MLNs. Six patients (4.8%) were classified as ypN1c. Distal viable cancer spread was observed in 3 patients (2.4%), all with mid rectal carcinoma. Two patients (1.6%) presented distal direct intramural extension less than 1 cm; and 1 (0.8%), with EX localized no more than 2 cm from the lower edge of the tumor. MLNs (76%) and EX (94%) were preferentially localized in the peritumoral area and in the first 3 cm just above the tumor. No viable distal intramural or mesorectal spread was observed in low rectal carcinoma. Distal intramural and mesorectal cancer spread is a rare event after neoadjuvant RCT. These results suggest that the 1-cm distal margin recommended in patients with low rectal carcinoma could be reduced with insurance to obtain a negative distal margin. The knowledge of preferential localization of MLNs and EX would help the pathologist to improve patient's lymph node staging.

Update on advances and controversy in rectal cancer treatment

Changes in the multidisciplinary treatment of rectal cancer have been recently proposed. We performed a comprehensive review of the current data on neoadjuvant and adjuvant treatment of rectal cancer, focussing on chemoradiotherapy treatment and timing of surgery. Six components were proposed as the framework for the treatment of rectal cancer: neoadjuvant therapy and changing patterns in patient selection, long- or short-course radiotherapy, adverse effects of radiotherapy, timing of surgery, non-operative management of rectal cancer and postoperative adjuvant therapy. Lack of a consistent difference in terms of local recurrence has been observed between short-course radiotherapy and long-course chemoradiotherapy. Indications for preoperative radiotherapy have been reconsidered in the last years. An interval of 10-11 weeks seemed to be the optimal timing, with no impact on patient safety. Since assessment criteria of clinical complete response are not well defined, and the basis for non-operative management of rectal cancer is still not clear, further investigations are required. There is controversy about standard treatments for patients with locally advanced rectal cancer that are being analyzed by ongoing studies. Tailored treatments could avoid over-treatment for a large number of patients without any impairment of the oncologic results.

Adjuvant chemotherapy for rectal cancer: Is it needed?

Adjuvant chemotherapy has become a standard treatment of advanced rectal cancer in the West. The benefits of adjuvant chemotherapy after surgery alone have been well established. However, controversy surrounds the use adjuvant chemotherapy in patients who received preoperative chemoradiotherapy, despite it being recommended by a number of international guidelines. Results of recent multicentre randomised control trials showed no benefit of adjuvant chemotherapy in terms of survival and rates of distant metastases. However, concerns exist regarding the quality of the studies including inadequate staging modalities, out-dated chemotherapeutic regimens and surgical approaches and small sample sizes. It has become evident that not all the patients respond to adjuvant chemotherapy and more personalised approach should be employed when considering the benefits of adjuvant chemotherapy. The present review discusses the strengths and weaknesses of the current evidence-base and suggests improvements for future studies.

Effect of Lymph Node Count on Pathological Stage III Rectal Cancer with Preoperative Radiotherapy

Lymph node (LN) status after surgery for rectal cancer is affected by preoperative radiotherapy. The purpose of this study was to perform a population-based evaluation of the impact of pathologic LN status after neoadjuvant radiotherapy on survival. A total of 1,650 patients receiving neoadjuvant chemotherapy in Surveillance, Epidemiology, and End Results Program (SEER)-registered ypIII stage rectal cancer was analyzed. We identified the optimal cutoff for retrieved LNs as 10 (χ2 = 14.006, P < 0.001), which was validated as an independent prognosis factors in a Cox regression model. Further analysis showed that the LN count was only a prognosis factor with the number from 8 to 16(except for 13).After the number 16, the 5-year survival rate decreased gradually. Collectively, our results confirmed that the number of LNs in yp III stage rectal patients was a prognosis factor only with the numbers from 8 to 16(except for 13). Using the total mesorectal excision technique with an adequate pathologic examination, a large number of LNs retrieved (≥17) might indicate worse tumor response grade and poorer survival.

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

The current therapeutic approach to patients with locally advanced rectal cancer is neoadjuvant radiotherapy or chemoradiotherapy followed by total mesorectal excision. We aimed to investigate the number, size, and distribution of metastatic and nonmetastatic lymph nodes within the mesorectum; whether neoadjuvant therapy has any impact on the number and size of the lymph nodes; and the impact of metastatic lymph node localization on overall and disease-free survival. Specimens from 50 consecutive patients with stage II/III rectal cancer receiving either neoadjuvant radiotherapy or chemoradiotherapy were investigated. Lymph node dissection was carried out by careful visual inspection and palpation. The localization of the each lymph node within the mesorectum and the relation with the tumor site were noted. The size and the number of lymph nodes retrieved decreased significantly with neoadjuvant therapy. Majority of the metastatic and nonmetastatic lymph nodes were located at or proximally to the tumor level and posterior side of the mesorectum. No relation was observed between the overall and disease-free survival, and the localization of the metastatic lymph nodes. Presence of lymph node metastases proximal to the tumor level has no impact on survival compared with the presence of lymph node metastasis only in the peritumoral region of the mesorectum. Although neoadjuvant therapy decreases the size and the number of lymph nodes, reaching an ideal number of lymph nodes for accurate staging is still possible with careful naked eye examination and dissection of perirectal fat. As the majority of metastatic and nonmetastatic lymph nodes are located in peritumoral and proximal compartment, and posterior side of the mesorectum, these regions should be the major interest of dissection.

cRGD-installed polymeric micelles loading platinum anticancer drugs enable cooperative treatment against lymph node metastasis

Lymph node metastasis (LNM) is correlated with decreased survival, indicating high tumor malignancy and being a potential source for subsequent fatal metastases. Targeted therapies inhibiting the formation of LNM, while eliminating established metastatic foci, could provide synergistic effects by reducing the incidence and growth of metastasis. Based on the inhibitory activity of cRGD peptide against the development of metastasis, and the LNM targeting ability of systemically injected drug-loaded polymeric micelles, herein, we studied the capability of cRGD-installed polymeric micelles incorporating the platinum anticancer drug (1,2-diaminocylohexane)platinum(II) (DACHPt) for cooperatively inhibiting the formation and progression of LNM. As cRGD-installed DACHPt-loaded micelles (cRGD-DACHPt/m) presented similar size, drug loading and surface charge to non-conjugated micelles (MeO-DACHPt/m), the differences in the biological performance of the micelles were endorsed to the effect of the ligand. In a syngeneic melanoma model, both MeO-DACHPt/m and cRGD-DACHPt/m showed comparable antitumor activity against the primary tumors and the established metastatic foci in lymph nodes. However, cRGD-DACHPt/m significantly enhanced the efficacy against LNM draining from primary tumors through the effective inhibition of the spreading of cancer cells. This improved inhibition was associated with the ability of cRGD-DACHPt/m to reduce the migration of melanoma cells, which was higher than that of MeO-DACHPt/m, free cRGD and their combination. These results support our strategy of using cRGD-installed micelles for attaining cooperative therapies against LNM exploiting the inhibitory function of the peptide and the cytotoxic effect of the micelles.

Preoperative Submucosal Injection of Carbon Nanoparticles Improves Lymph Node Staging Accuracy in Rectal Cancer after Neoadjuvant Chemoradiotherapy

BACKGROUND

The aim of this study was to evaluate the association between the number of nodes harvested and the rate of node positivity, and to evaluate the effect of carbon nanoparticles (CNPs) in improving lymph node detection and staging accuracy in patients who received neoadjuvant chemoradiotherapy (NCRT) followed by curative resection.

STUDY DESIGN

Between September 2008 and June 2014, 152 consecutive rectal cancer patients treated with NCRT and curative resection were included. Forty-five patients underwent preoperative submucosal injection of CNPs (CNP group); the other patients underwent surgery only (control group). The relationship between the number of lymph nodes harvested and the rate of node positivity was investigated. A comparison of the number of harvested lymph nodes and the node positivity rate between the 2 groups was also performed. The lymph nodes in the CNP group were analyzed in detail.

RESULTS

The rate of node positivity increased gradually from 8.6% in patients with 1 to 5 nodes assessed to 37.8% in patients with 17 to 44 nodes assessed. The number of lymph nodes harvested was an independent risk factor for node positivity (p = 0.036). The mean number of lymph nodes retrieved in the CNP group was more than in the control group (21.1 vs 8.0, p = 0.000). The percentage of patients with positive lymph nodes was lower than in the control group (19.6% vs 35.6%, p = 0.037). In the CNP group, of 58 metastatic lymph nodes, 45 (77.6%) were dyed. Of 37 metastatic lymph nodes smaller than 5 mm, 33 (89.2%) were dyed.

CONCLUSIONS

More precise oncologic prognosis assessment was provided for patients with rectal cancer after NCRT by increasing the number of lymph nodes counted using a dye-tracing method, indicating that the use of CNPs is beneficial.

Lymph node count after preoperative radiotherapy is an independently prognostic factor for pathologically lymph node-negative patients with rectal cancer

Recent studies indicated that preoperative radiotherapy significantly reduces the lymph nodes (LNs) harvest from patients with rectal cancer. This may weaken the prognostic value of current standard of LNs retrieval (≥12 LNs). This study investigates the prognostic impact of the LN counts on pathologically LN-negative (ypN0) after preoperative radiotherapy for patients with rectal cancer.Surveillance, Epidemiology and End Results (SEER) registered nonmetastatic rectal cancer patients diagnosed between 1998 and 2005 were included in this study. Optimal cutoff value for number of LNs retrieved was determined by X-tile program. Log-rank tests were adopted to compare the rectal cause specific survival (RCSS) for ypN0 patients using separated cutoff value of LN counting from 2 to 20. Correlation between LN count and tumor regression was investigated in an additional 221 patients from Fudan University Shanghai Cancer Center (FUSCC).The results showed that there were fewer number of LNs examined in patients with preoperative radiotherapy than those without (8.9 vs 10.9, P < 0.001). X-tile program identified the difference in survival was most significant (maximum of χ log-rank values) for the number 4. And 5-year RCSS increased accordingly with the cutoff values ranging from 4 to 15, which were confirmed as optimal cutoff and validated as independent prognostic factors in multivariate regression analysis (χ = 50.65, P < 0.001). Patients in FUSCC set were found to have fewer LNs retrieval in group of good tumor regression than in that of poor one (P = 0.01).These results confirmed the reduced number of LN retrieval in patients with rectal cancer treated with preop-RT. LN count is still an independently prognostic factor for ypN0 rectal cancer.

Organ preservation in rectal cancer: have all questions been answered?

Improved treatment strategies have eliminated local control as the major problem in rectal cancer. With increasing awareness of long-term toxic effects in survivors of rectal cancer, organ-preservation strategies are becoming more popular. After chemoradiotherapy, both watchful waiting and local excision are used as possible alternatives for radical surgery. Although these seem attractive strategies, many issues about the safety of organ preservation remain. Additionally, radiotherapy strategies are mainly aimed at intermediate and high-risk rectal tumours, and adaptation of this standard practice for a completely new treatment indication has yet to start. This Review will discuss the options and problems of organ preservation, and address the research questions that need to be answered in the coming years, with a specific focus on radiotherapy.

Future directions in surgery for colorectal cancer: the evolving role of transanal endoscopic surgery

SUMMARY 

The morbidity associated with radical surgery for rectal cancer has launched a revolution in increasingly less-invasive methods of resection, including a recent resurgence in transanal endoscopic surgical approaches. The next evolution in transanal surgery for rectal cancer is natural orifice translumenal endoscopic surgery (NOTES). To date, 14 series of transanal NOTES total mesorectal excision (TME) for rectal cancer have been published (n = 76). Overall, the intraoperative and postoperative complication rates of 8 and 28%, respectively, compare favorably to those expected from laparoscopic and open TME. Short-term follow-up after NOTES TME has yielded no cancer recurrence in average-risk patients. High-risk patients have cancer recurrence rates similar to those after laparoscopic TME. Overall, these early data support transanal NOTES TME as a safe and viable alternative to conventional TME. Advances in instrumentation, surgical expertise and neoadjuvant treatment may expand current indications for NOTES even further.

A distribution weighted prognostic scoring model for node status in advanced rectal cancer

Purpose

There are various lymph node-based staging systems. Nevertheless, there is debate over the use of parameters such as the number of involved lymph nodes and the lymph node ratio. As a possible option, the distribution of metastatic lymph nodes may have a prognostic significance in rectal cancer. This study is designed to evaluate the impact of distribution-weighted nodal staging on oncologic outcome in rectal cancer.

Materials and Methods

From a prospectively maintained colorectal cancer database of our institution, a total of 435 patients who underwent a curative low anterior resection for mid and upper rectal cancer between 1995 and 2004 were enrolled. Patients were divided into 3 groups according to the location of apical metastatic nodes. A location-weighted prognostic score was calculated by a scoring model using a logistic regression test for location based-statistical weight to number of lymph nodes. All cases were categorized in quartiles from lymph node I to lymph node IV using this protocol.

Results

The location of lymph node metastasis was an independent factor that was associated with a poor prognostic outcome (p<0.001). Based on this result, the location-weighted-nodal prognostic scoring model did not show lesser significant results (p<0.0001) in both overall survival and cancer-free survival analyses.

Conclusion

The location of apical nodes among the metastatic nodes does not have a lesser significant impact on oncologic result in patients with advanced rectal cancer. A location-weighted prognostic scoring model, which considered the numbers of involved lymph nodes as the rate of significance according to the location, may more precisely predict the survival outcome in patients with lymph node metastasis.

Need for objective and reproducible criteria in histopathological assessment of total mesorectal excision specimens: lessons from a national improvement project

AIM

Data on quality control of the pathologic evaluation of total mesorectal excision (TME) specimens are scarce. We aimed to assess differences between evaluation by local pathologists participating in PROject on CAncer of the REctum (PROCARE; a Belgian improvement project on rectal cancer) and by a review panel of experts.

METHOD

Based on photographic material and histopathology slides, a Review Committee of gastrointestinal expert pathologists re-evaluated the mesorectal plane, the tumour differentiation grade, the (y)pT stage and the tumour regression grade in 444 patients previously routinely assessed by local pathologists.

RESULTS

The surgical plane was reported in 89% of patients and the circumferential resection margin in 88% of patients by the local pathologist. The median number of lymph nodes harvested in patients undergoing neoadjuvant radiochemotherapy was 11 and 14 in the other patients. The Review Committee downgraded the surgical plane from (intra)mesorectal to intramuscular in 17% of patients, and upgraded it from intramuscular to (intra)mesorectal in 27%. Tumour differentiation grade, T stage and tumour regression grade differed between local pathologists and the Review Committee in 15%, 10% and 38%, respectively, of patients. T stage was upgraded, mainly from T2 to T3, in 8% of patients. Tumour regression was judged by the Review Committee to be less advanced in 15% of patients.

CONCLUSION

Acknowledging some shortcomings, this study gives a realistic view of clinical practice. There are differences in interpretation with regard to both macroscopic and microscopic analysis of TME specimens. These findings indicate a need for more objective and reproducible criteria in histopathology. Being aware of this is a first step for improvement.

In vivo lymph node mapping and pattern of metastasis spread in locally advanced mid/low rectal cancer after neoadjuvant chemoradiotherapy

PURPOSE

The lymph node status is one of the strongest prognostic determinants in rectal cancers. After chemoradiotherapy (CRT), lymph nodes are difficult to detect. This study aims to evaluate the feasibility of lymph node mapping in the mesorectum after CRT to analyze the pattern of metastasis spread and to assess the reliability of blue dye injection in sentinel lymph node detection.

METHOD

Ten patients with cN+ mid/low RCs after CRT were prospectively enrolled. The protocol scheduled intraoperative blue dye injection, surgery, and specimen examination with fat clearance technique. The mesorectum was divided into three equal "levels" (upper, middle, and lower); each level was divided into three equal "sectors" (right anterolateral, posterior, and left anterolateral). Lymph nodes were defined "small" if ≤5 mm.

RESULTS

Two hundred seventy-six lymph nodes were retrieved in ten patients; 76.5 % were small lymph nodes. Six patients were pN+ (33 metastatic lymph nodes, 76 % small); small lymph node analysis upstaged one patient from N0 to N1 and four patients from N1 to N2. Metastasis distribution across sectors was continuous, without "skip sectors." The blue dye detected the sentinel lymph node in all patients; in half of the cases, it was out of the tumor sector. Blue dye identified 69.7 % of metastatic lymph nodes; its sensitivity decreased together with the metastatic deposit size (84 % macrometastases, 28.6 % micrometastases, 0 % occult tumor cells; p = 0.004).

CONCLUSION

The fat clearance technique should be the standard pathological examination in patients with RCs after CRT; N staging was improved by small lymph node identification. Lymph node metastases have a continuous spread through mesorectal sectors. Blue dye injection is effective in sentinel lymph node detection.