The prognostic value of lymph node yield in the earliest stage of colorectal cancer: a multicenter cohort study

Should endoscopic submucosal dissection be offered to patients with early colorectal cancer?

BACKGROUND

Endoscopic submucosal dissection is increasingly used to treat early-stage colorectal cancer. This study evaluated the feasibility of endoscopic submucosal dissection in this setting and the determinants of lymph node metastasis.

METHODS

We reviewed patients who underwent colorectal endoscopic submucosal dissection for early-stage colorectal cancer at a tertiary center between 2011 and 2023. The primary outcome was the identification of high-risk pathologic features predictive of lymph node metastasis in patients undergoing oncologic colon resection following endoscopic submucosal dissection.

RESULTS

We reviewed 1,398 patients who underwent endoscopic submucosal dissection, and 83 (6%) had colorectal cancer. Twenty-four patients (29%) were closely monitored after endoscopic submucosal dissection, and 59 (71%) underwent oncologic colon resection because of high-risk pathologies of the endoscopic submucosal dissection specimen. In the oncologic colon resection group, the mean age was 62.7 years (±10.2), with 56% male predominance, and 14% showed positive lymph nodes in the final pathology. Analysis comparing patients with and without lymph node metastasis showed significant differences in sex, lesion size, submucosal invasion depth, and budding scores. Multivariate analysis showed that lesions with a submucosal invasion depth ≥2.00 mm of the endoscopic submucosal dissection resection specimen had higher odds of lymph node metastasis (odds ratio 18.7, P = .028), whereas lesions with a diameter >20 mm were associated with a lower likelihood of lymph node metastasis (odds ratio 0.07, P = .036).

CONCLUSION

The study highlights the oncologic safety of early-stage endoscopic submucosal dissection as a viable treatment option for carefully selected patients with colorectal cancer. After tissue resection with endoscopic submucosal dissection, if the lesion size is less than 20 mm, depth of invasion up to 2 mm may be considered safe in the absence of other high-risk pathologic factors.

Survival analysis in pT1-3 and paracolic lymph-node invasion colorectal cancer: the prognostic role of positive paracolic lymph-node ratio for adjuvant chemotherapy

PURPOSE

Several studies have observed that some stage III colorectal cancer (CRC) patients cannot benefit from standard adjuvant chemotherapy. However, there is no unified screening standard to date.

METHODS

Consecutive patients with pathologically confirmed colon adenocarcinoma treated in 3 centers between January 2016 and December 2018 were included. Patients were divided into four groups according to different stages and positive paracolic lymph-node ratio (P-LNR) [Cohort 1: pT1-3N0M0, Cohort 2: pT1-3N + (P-LNR ≤ 0.15)M0, Cohort 3: pT4N0M0, Cohort 4: stage III patients except for pT1-3N + (P-LNR ≤ 0.15)M0], and further overall survival was compared by Kaplan-Meier method. The univariate and multivariate analyses were employed for cox proportional hazards model.

RESULTS

We retrospectively reviewed 5581 consecutive CRC patients with, and 2861 eligible patients were enrolled for further analysis. The optimal cut-off value of P-LNR in our study was 0.15. There was no significant difference in OS (91.36 vs. 93.74%) and DFS (87.65 vs. 90.96%) between stage III patients with pT1-3N + (P-LNR ≤ 0.15)M0 and those with pT1-3N0M0. Further analysis demonstrated that CRC patients with pT1-3N + (P-LNR ≤ 0.15)M0 were less likely to benefit from 8 cycles of CAPOX or FOLFOX chemotherapy and suffered fewer adverse events from declining chemotherapy. Comparing with 0-4 cycles versus 8 cycles, the overall survival rates were 91.35 versus 90.19% (P = 0.79), and with a DFS of 87.50 versus 88.24% (P = 0.49), the duration of adjuvant chemotherapy was not an independent risk factor for patients with pT1-3N + (P-LNR ≤ 0.15)M0 (HR: 0.70, 95% CI 0.90-1.30, P = 0.42).

CONCLUSION

The concept of P-LNR we proposed might have a high clinical application value and accurately enable clinicians to screen out specific CRC patients who decline or prefer limited chemotherapy.

TRIAL REGISTRY

The clinical trial registration number: ChiCTR2300076883.

Diagnostic Performance of MRI and FDG PET/CT for Preoperative Locoregional Staging of Colon Cancer: Systematic Review and Meta-Analysis

BACKGROUND. CT is the standard-of-care test for preoperative locoregional staging of colon cancer (CC) but has limited diagnostic performance. More accurate preoperative staging would guide selection among expanding patient-tailored treatment options. OBJECTIVE. The purpose of this study was to evaluate through systematic review the diagnostic performance of MRI for T and N staging and that of FDG PET/CT for N staging in the locoregional staging of CC. EVIDENCE ACQUISITION. PubMed, Embase, and the Cochrane Library were searched through December 31, 2023, for studies reporting the diagnostic performance of MRI or FDG PET/CT for primary (nonrectal) CC before resection without neoadjuvant therapy, with histopathology used as the reference standard. Study quality was assessed using the QUADAS-2 tool. Publication bias was assessed using the Deeks funnel plot asymmetry test. Primary outcomes were estimated pooled predictive values, which were stratified by T and N categories for MRI and by N categories for PET/CT. Secondary outcomes were pooled sensitivity and specificity. EVIDENCE SYNTHESIS. The systematic review included 11 MRI studies (686 patients) and five PET/CT studies (408 patients). Thirteen studies had at least one risk of bias or concern of applicability. The Deek funnel plot asymmetry test indicated possible publication bias in MRI studies for differentiation of T3cd-T4 disease from T1-T3ab disease and differentiation of node-negative disease from node-positive disease. For MRI, for discriminating T1-T2 from T3-T4 disease, PPV was 64.8% (95% CI, 52.9-75.5%) and NPV was 88.9% (95% CI, 82.7-93.7%); for discriminating T1-T3ab from T3cd-T4 disease, PPV was 83.4% (95% CI, 75.0-90.3%) and NPV was 74.6% (95% CI, 58.2-86.7%); for discriminating T1-T3 from T4 disease, PPV was 94.0% (95% CI, 89.4-97.3%) and NPV was 39.9% (95% CI, 24.9-56.6%); for discriminating node-negative from node-positive disease, PPV was 74.9% (95% CI, 69.3-80.0%) and NPV was 53.9% (95% CI, 45.3-62.0%). For PET/CT, for discriminating node-negative from node-positive disease, PPV was 76.4% (95% CI, 67.9-85.1%) and NPV was 68.2% (95% CI, 56.8-78.6%). Across outcomes, MRI and PET/CT showed pooled sensitivity of 55.1-81.4% and pooled specificity of 70.3-88.1%. CONCLUSION. MRI had the strongest predictive performance for T1-T2 and T4 disease. MRI and PET/CT otherwise had limited predictive values, sensitivity, and specificity for evaluated outcomes related to T and N staging. CLINICAL IMPACT. MRI and FDG PET/CT had overall limited utility for preoperative locoregional staging of colon cancer. TRIAL REGISTRATION. PROSPERO (International Prospective Register of Systematic Reviews) CRD42022326887.

Acetone compression improves lymph node yield and metastasis detection in colorectal cancer

Lymph node status is one of the most important prognostic factors in colorectal cancer, and accurate pathological nodal staging and detection of lymph node metastases is crucial for determination of post-operative management. Current guidelines, including the TNM staging system and European Society for Medical Oncology (ESMO) guidelines, recommend examination of at least 12 lymph nodes. However, identification of an adequate number of lymph nodes can be challenging, especially in the setting of neoadjuvant treatment, which may reduce nodal size. In this study, we investigated 384 colorectal cancer resections that were processed at our department of pathology between January 2012 and December 2022, in which the number of detected lymph nodes was less than 12 subsequent to conventional preparation of mesocolic fat tissue. By means of acetone compression, lymph node harvest increased significantly (p < 0.0001), and the intended number of ≥ 12 lymph nodes was achieved in 98% of resection specimens. The number of nodal positive cases increased significantly from n = 95 (24.7%) before versus n = 131 (34.1%) after acetone compression due to additionally identified lymph node metastases (p < 0.001). In 36 patients (9.4%) initially considered as nodal negative, acetone compression led to a staging adjustment to a nodal positive category and thereby drove a recommendation to offer post-operative therapy. In conclusion, acetone compression is a reliable and useful method implementable in routine surgical pathology for the retrieval of lymph nodes in colorectal cancer specimen, allowing for an adequate lymph node sampling and an increase in nodal staging reliability.

Management after non-curative endoscopic resection of T1 rectal cancer

Since the introduction of population-based screening, increasing numbers of T1 rectal cancers are detected and removed by local endoscopic resection. Patients can be cured with endoscopic resection alone, but there is a possibility of residual tumor cells remaining after the initial resection. These can be located intraluminally at the resection site or extraluminally in the form of (lymph node) metastases. To decrease the risk of residual cells progressing towards more advanced disease, additional treatment is usually needed. However, with the currently available risk stratification models, it remains challenging to determine who should and should not be further treated after non-curative endoscopic resection. In this review, the different management strategies for patients with non-curatively treated T1 rectal cancers are discussed, along with the available evidence for each strategy and relevant considerations for clinical decision making. Furthermore, we provide practical guidance on the management and surveillance following non-curative endoscopic resection of T1 rectal cancer.

Finding the minimum number of retrieved lymph nodes in node-negative colorectal cancer using Real-world Data and the SEER database

BACKGROUND

Current clinical guidelines recommend the removal of at least 12 lymph nodes (LNs) in resectable colorectal cancer (CRC). With advancements in lymphadenectomy technologies, the number of retrieved lymph nodes (rLNs) has markedly increased. This study aimed to investigate the lowest number of rLNs in node-negative patients.

MATERIALS AND METHODS

A total of 1103 N0 and 208 N1a stage patients were enrolled in our cohort, while 8503 N0 and 1276 N1a patients from the Surveillance, Epidemiology, and End Results CRC database were included. Propensity score matching and multivariate Cox regression analyses were performed to mitigate the influence of selection bias and control for potential confounding variables.

RESULTS

The median number of rLNs in N0 patients increased from 13.5 (interquartile range [IQR]: 9-18) in 2013 to 17 (IQR: 15-20) in 2019. The restrictive cubic spline illustrated a nonlinear relationship between rLNs and prognosis (nonlinearity, P =0.009), with a threshold ( N =16) influencing clinical outcomes. Patients at either N0 or N1a stage with sufficient rLNs (≥16) demonstrated superior prognoses to those with a limited rLNs (<16). After adjusting for clinical confounders, similar prognoses were observed in N0 limited and N1a adequate populations. Furthermore, Kaplan-Meier curves revealed that N0 limited patients who received chemotherapy exhibited better outcomes than those who did not.

CONCLUSIONS

Among patients with node-negative CRC, it is crucial to remove 16 or more LNs effectively. Fewer than 16 rLNs should be regarded as an independent risk factor, implying the need for adjuvant chemotherapy.

Robot-assisted fluorescent sentinel lymph node identification in early-stage colon cancer

BACKGROUND

Patients with cT1-2 colon cancer (CC) have a 10-20% risk of lymph node metastases. Sentinel lymph node identification (SLNi) could improve staging and reduce morbidity in future organ-preserving CC surgery. This pilot study aimed to assess safety and feasibility of robot-assisted fluorescence-guided SLNi using submucosally injected indocyanine green (ICG) in patients with cT1-2N0M0 CC.

METHODS

Ten consecutive patients with cT1-2N0M0 CC were included in this prospective feasibility study. Intraoperative submucosal, peritumoral injection of ICG was performed during a colonoscopy. Subsequently, the near-infrared fluorescence 'Firefly' mode of the da Vinci Xi robotic surgical system was used for SLNi. SLNs were marked with a suture, after which a segmental colectomy was performed. The SLN was postoperatively ultrastaged using serial slicing and immunohistochemistry, in addition to the standard pathological examination of the specimen. Colonoscopy time, detection time (time from ICG injection to first SLNi), and total SLNi time were measured (time from the start of colonoscopy to start of segmental resection). Intraoperative, postoperative, and pathological outcomes were registered.

RESULTS

In all patients, at least one SLN was identified (mean 2.3 SLNs, SLN diameter range 1-13 mm). No tracer-related adverse events were noted. Median colonoscopy time was 12 min, detection time was 6 min, and total SLNi time was 30.5 min. Two patients had lymph node metastases present in the SLN, and there were no patients with false negative SLNs. No patient was upstaged due to ultrastaging of the SLN after an initial negative standard pathological examination. Half of the patients unexpectedly had pT3 tumours.

CONCLUSIONS

Robot-assisted fluorescence-guided SLNi using submucosally injected ICG in ten patients with cT1-2N0M0 CC was safe and feasible. SLNi was performed in an acceptable timespan and SLNs down to 1 mm were detected. All lymph node metastases would have been detected if SLN biopsy had been performed.

A DNA Methylation-based Epigenetic Signature for the Identification of Lymph Node Metastasis in T1 Colorectal Cancer

OBJECTIVE

This study aimed to unravel the lymph node metastasis (LNM)-related methylated DNA (mDNA) landscape and develop a mDNA signature to identify LNM in patients with T1 colorectal cancers (T1 CRC).

BACKGROUND

Considering the invasiveness of T1 CRC, current guidelines recommend endoscopic resection in patients with LNM-negative, and radical surgical resection only for high-risk LNM-positive patients. Unfortunately, the clinicopathological criteria for LNM risk stratification are imperfect, resulting in frequent misdiagnosis leading to unnecessary radical surgeries and postsurgical complications.

METHODS

We conducted genome-wide methylation profiling of 39 T1 CRC specimens to identify differentially methylated CpGs between LNM-positive and LNM-negative, and performed quantitative pyrosequencing analysis in 235 specimens from 3 independent patient cohorts, including 195 resected tissues (training cohort: n=128, validation cohort: n=67) and 40 pretreatment biopsies.

RESULTS

Using logistic regression analysis, we developed a 9-CpG signature to distinguish LNM-positive versus LNM-negative surgical specimens in the training cohort [area under the curve (AUC)=0.831, 95% confidence interval (CI)=0.755-0.892; P <0.0001], which was subsequently validated in additional surgical specimens (AUC=0.825; 95% CI=0.696-0.955; P =0.003) and pretreatment biopsies (AUC=0.836; 95% CI=0.640-1.000, P =0.0036). This diagnostic power was further improved by combining the signature with conventional clinicopathological features.

CONCLUSIONS

We established a novel epigenetic signature that can robustly identify LNM in surgical specimens and even pretreatment biopsies from patients with T1 CRC. Our signature has strong translational potential to improve the selection of high-risk patients who require radical surgery while sparing others from its complications and expense.

Full-Thickness Scar Resection After R1/Rx Excised T1 Colorectal Cancers as an Alternative to Completion Surgery

INTRODUCTION

Local full-thickness resections of the scar (FTRS) after local excision of a T1 colorectal cancer (CRC) with uncertain resection margins is proposed as an alternative strategy to completion surgery (CS), provided that no local intramural residual cancer (LIRC) is found. However, a comparison on long-term oncological outcome between both strategies is missing.

METHODS

A large cohort of patients with consecutive T1 CRC between 2000 and 2017 was used. Patients were selected if they underwent a macroscopically complete local excision of a T1 CRC but positive or unassessable (R1/Rx) resection margins at histology and without lymphovascular invasion or poor differentiation. Patients treated with CS or FTRS were compared on the presence of CRC recurrence, a 5-year overall survival, disease-free survival, and metastasis-free survival.

RESULTS

Of 3,697 patients with a T1 CRC, 434 met the inclusion criteria (mean age 66 years, 61% men). Three hundred thirty-four patients underwent CS, and 100 patients underwent FTRS. The median follow-up period was 64 months. CRC recurrence was seen in 7 patients who underwent CS (2.2%, 95% CI 0.9%-4.6%) and in 8 patients who underwent FTRS (9.0%, 95% CI 3.9%-17.7%). Disease-free survival was lower in FTRS strategy (96.8% vs 89.9%, P = 0.019), but 5 of the 8 FTRS recurrences could be treated with salvage surgery. The metastasis-free survival (CS 96.8% vs FTRS 92.1%, P = 0.10) and overall survival (CS 95.6% vs FTRS 94.4%, P = 0.55) did not differ significantly between both strategies.

DISCUSSION

FTRS after local excision of a T1 CRC with R1/Rx resection margins as a sole risk factor, followed by surveillance and salvage surgery in case of CRC recurrence, could be a valid alternative strategy to CS.

Current Perspectives on the Importance of Pathological Features in Prognostication and Guidance of Adjuvant Chemotherapy in Colon Cancer

There is not a clear consensus on which pathological features and biomarkers are important in guiding prognosis and adjuvant therapy in colon cancer. The Pathology in Colon Cancer, Prognosis and Uptake of Adjuvant Therapy (PiCC UP) Australia and New Zealand questionnaire was distributed to colorectal surgeons, medical oncologists and pathologists after institutional board approval. The aim of this study was to understand current specialist attitudes towards pathological features in the prognostication of colon cancer and adjuvant therapy in stage II disease. A 5-scale Likert score was used to assess attitudes towards 23 pathological features for prognosis and 18 features for adjuvant therapy. Data were analysed using a rating scale and graded response model in item response theory (IRT) on STATA (Stata MP, version 15; StataCorp LP). One hundred and sixty-four specialists (45 oncologists, 86 surgeons and 33 pathologists) participated. Based on IRT modelling, the most important pathological features for prognosis in colon cancer were distant metastases, lymph node metastases and liver metastases. Other features seen as important were tumour rupture, involved margin, radial margin, CRM, lymphovascular invasion and grade of differentiation. Size of tumour, location, lymph node ratio and EGFR status were considered less important. The most important features in decision making for adjuvant therapy in stage II colon cancer were tumour rupture, lymphovascular invasion and microsatellite instability. BRAF status, size of tumour, location, tumour budding and tumour infiltrating lymphocytes were factored as lesser importance. Biomarkers such as CDX2, EGFR, KRAS and BRAF status present areas for further research to improve precision oncology. This study provides the most current status on the importance of pathological features in prognostication and recommendations for adjuvant therapy in Australia and New Zealand. Results of this nationwide study may be useful to help in guiding prognosis and adjuvant treatment in colon cancer.

The Risk Analyses of Lymph Node Metastasis and Recurrence for Submucosal Invasive Colorectal Cancer: Novel Criteria to Skip Completion Surgery

Simple Summary

Completion surgery is recommended for patients with submucosal invasive colorectal cancer (pT1 CRC) with known risk factors for lymph node metastasis (LNM). However, completion surgery would be able to be skipped for more of the population with very low risk for LNM and recurrence. The present study thus analyzed both short- and long-term outcomes for high-risk pT1 CRC patients who underwent surgery, showing that lymphovascular invasion was a potential independent risk factor for LNM, and rectal cancer and undifferentiated histology were independent risk factors for poor relapse-free survival in patients with high-risk pT1 CRC. No LNMs were observed in pT1 CRCs with an SM invasion depth ≤2000 µm that had no other risk factors except for budding. Based on the results, novel criteria to skip completion surgery for high-risk pT1 CRC have been established in the current study, which were also validated in an independent validation cohort.

Abstract

(1) Background: Additional surgical resection after endoscopic resection (ER) is recommended for patients with submucosal invasive colorectal cancer (pT1 CRC) who have risk factors for lymph node metastasis (LNM) (high-risk pT1 CRC). This study aimed to identify risk factors for LNM and metastatic recurrence and to determine the low-risk population for whom additional surgery can be omitted among high-risk pT1 CRCs. (2) Methods: We retrospectively identified 404 patients with pT1 CRC who underwent ER or surgery, and patients were divided into three groups: low-risk (n = 79); high-risk pT1 with ER (n = 40); and high-risk with surgery (n = 285). We also enrolled another 64 patients with high-risk pT1 CRC in an independent validation cohort. (3) Results: In the high-risk with surgery group, LNM was seen in 11.2%, and vascular and lymphatic invasions were significantly independent risk factors for LNM on multivariate analysis. No LNMs were observed in pT1 CRCs with a negative vertical margin and SM invasion depth ≤2000 µm that had no other risk factors except for budding. Five patients developed metastatic recurrence in the high-risk with surgery group, and rectal cancer and undifferentiated histology were significantly independent risk factors for poor relapse-free survival. No LNM or recurrent cases were seen in high-risk pT1 CRCs that met these criteria: differentiated adenocarcinoma, no lymphovascular invasion, colon cancer, SM invasion depth ≤2000 μm, and a negative vertical margin, which were validated in an independent validation cohort. (4) Conclusions: Completion surgery may be skipped for high-risk pT1 CRCs that meet our proposed criteria.

Tumor Location as a Prognostic Factor in T1 Colorectal Cancer

The incidence of T1 colorectal cancer is expected to increase because of the prevalence of colorectal cancer screening and the progress of endoscopic treatment such as endoscopic submucosal dissection or endoscopic full-thickness resection. Currently, the requirement for additional surgery after endoscopic resection of T1 colorectal cancer is determined according to several treatment guidelines (in USA, Europe, and Japan) referring to the following pathological findings: lymphovascular invasion, tumor differentiation, depth of invasion, and tumor budding, all of which are reported to be risk factors for lymph node metastasis. In addition to these factors, in this review, we investigate whether tumor location, which is an objective factor, has an impact on the presence of lymph node metastasis and recurrence. From recent studies, left-sided location, especially the sigmoid colon in addition to rectum, could be a risk factor for lymph node metastasis and cancer recurrence. The treatment of T1 colorectal cancer should be managed considering these findings.

Pathological Features and Prognostication in Colorectal Cancer

The prognostication of colorectal cancer (CRC) has traditionally relied on staging as defined by the Union for International Cancer Control (UICC) and American Joint Committee on Cancer (AJCC) TNM staging classifications. However, clinically, there appears to be differences in survival patterns independent of stage, suggesting a complex interaction of stage, pathological features, and biomarkers playing a role in guiding prognosis, risk stratification, and guiding neoadjuvant and adjuvant therapies. Histological features such as tumour budding, perineural invasion, apical lymph node involvement, lymph node yield, lymph node ratio, and molecular features such as MSI, KRAS, BRAF, and CDX2 may assist in prognostication and optimising adjuvant treatment. This study provides a comprehensive review of the pathological features and biomarkers that are important in the prognostication and treatment of CRC. We review the importance of pathological features and biomarkers that may be important in colorectal cancer based on the current evidence in the literature.

A prospective study of dual-energy computed tomography for differentiating metastatic and non-metastatic lymph nodes of colorectal cancer

Background

Colorectal cancer (CRC) is the third most common malignancy worldwide, and lymph node metastasis is considered to be a risk factor for local recurrence and a poor prognosis in colorectal cancer. However, there remains a lack of reliable and non-invasive biomarkers to identify the lymph node status of CRC patients preoperatively. The purpose of this study was to explore the ability of dual-energy computed tomography (DECT) to differentiate metastatic from non-metastatic lymph nodes in colorectal cancer.

Methods

Seventy-one patients with primary colorectal cancer underwent contrast-enhanced dual-energy computed tomography imaging preoperatively. The colorectal specimen was scanned postoperatively, and lymph nodes were matched to the pathology report. The following dual-energy computed tomography quantitative parameters were analyzed: dual-energy curve slope value (λ_HU), standardized iodine concentration (n△HU), iodine water ratio (nIWR), electron density value (nρ_eff), and effective atom-number (nZ), based on metastatic and non-metastatic lymph node differentiation. Also, sensitivity and specificity analyses were performed using receiver operating characteristic curves.

Results

In all patients, one hundred and fifty lymph nodes, including 66 non-metastatic and 84 metastatic lymph nodes, were matched using the radiological-pathological correlation. Metastatic nodes had significantly greater λ_HU, n△HU, and nIWR values than non-metastatic nodes in both the arterial and venous phases (P<0.01). The area under curve (AUC), sensitivity, and specificity were 0.80, 80%, and 66% for λ_HU; 0.86, 70%, and 95% for n△HU; and 0.88, 71%, and 95% for nIWR in the arterial phase. There was no significant difference in electron density and effective Z values between metastatic and non-metastatic lymph nodes.

Conclusions

DECT quantitative parameters may help differentiate between metastatic and normal lymph nodes in patients with CRC.

2D vs 3D laparoscopic right colectomy: A propensity score-matching comparison of personal experience with systematic review and meta-analysis

BACKGROUND

The benefits of laparoscopic approach for right colectomy have been well established. However, the technical difficulty to construct the intra-corporeal anastomosis is still cumbersome.

AIM

To analyze the results of 3D and 2D laparoscopic right colectomy and to compare it to the published series through a systematic review and meta-analysis.

METHODS

A retrospective study with propensity score matching analysis of patients undergoing laparoscopic right colectomy at Umbria2 Hospitals from January 2014 to March 2020 was performed. A systematic review was accomplished comparing 2D and 3D right colectomy.

RESULTS

In the personal series 47 patients of the 2D group were matched to 47 patients of the 3D group. The 3D group showed a favorable trend in terms of mean operative time (170.7 ± 32.9 min vs 183.8 ± 35.4 min; P = 0.053) and a significant lower anastomotic time (16.9 ± 2.3 min vs 19.6 ± 2.9 min, P < 0.001). The complete mesocolic excision (CME) subgroups analysis showed a shorter anastomotic time (16.5 ± 1.8 min vs 19.9 ± 3.0 min; P < 0.001) and operative time (175.0 ± 38.5 min vs 193.7 ± 37.1 min; P = 0.063) in the 3D group. Six studies and our series were included in the meta-analysis with 551 patients (2D group: 291; 3D group: 260).The pooled analysis demonstrated a significant difference in favour of the 3D group regarding the operative time (P < 0.001) and the anastomotic time (P < 0.001) while no differences were identified between groups in terms of blood loss (P = 0.827), LNH yield (P = 0.243), time to first flatus (P = 0.333), postoperative complications (P = 0.718) and length of stay (P = 0.835).

CONCLUSION

The meta-analysis results showed that 3D laparoscopic right colectomy shortens operative and anastomotic time without affecting the standard lymphadenectomy. In our series, the advantage of the 3D system becomes evident when CME and/or more complex associated procedure are requested significantly reducing both the total operative and the anastomotic time.

Offerhaus G, Siersema PD, Tollenaar RAEM, Hardwick JCH, Hawinkels LJAC, Moons LMG, Lacle MM, Mesker WE, Boonstra JJ. Tumour-stroma ratio has poor prognostic value in non-pedunculated T1 colorectal cancer: A multi-centre case-cohort study

BACKGROUND

Current risk stratification models for early invasive (T1) colorectal cancer are not able to discriminate accurately between prognostic favourable and unfavourable tumours, resulting in over-treatment of a large (>80%) proportion of T1 colorectal cancer patients. The tumour-stroma ratio (TSR), which is a measure for the relative amount of desmoplastic tumour stroma, is reported to be a strong independent prognostic factor in advanced-stage colorectal cancer, with a high stromal content being associated with worse prognosis and survival. We aimed to investigate whether the TSR predicts clinical outcome in patients with non-pedunculated T1 colorectal cancer.

METHODS

Hematoxylin and eosin (H&E)-stained tumour tissue slides from a retrospective multi-centre case cohort of patients with non-pedunculated surgically treated T1 colorectal cancer were assessed for TSR by two independent observers who were blinded for clinical outcomes. The primary end point was adverse outcome, which was defined as the presence of lymph node metastasis in the resection specimen or colorectal cancer recurrence during follow-up.

RESULTS

All 261 patients in the case cohort had H&E slides available for TSR scoring. Of these, 183 were scored as stroma-low, and 78 were scored as stroma-high. There was moderate inter-observer agreement (κ = 0.42). In total, 41 patients had lymph node metastasis, 17 patients had recurrent cancer and five had both. Stroma-high tumours were not associated with an increased risk for an adverse outcome (adjusted hazard ratio = 0.66, 95% confidence interval 0.37-1.18; p = 0.163).

CONCLUSIONS

Our study emphasises that existing prognosticators may not be simply extrapolated to T1 colorectal cancers, even though their prognostic value has been widely validated in more advanced-stage tumours.

The Critical Role of Tumor Size in Predicting Prognosis for T1 Colon Cancer

BACKGROUND

The role of horizontal growth index of tumor size in survival prediction is still underappreciated in colon cancer because of the identification of vertical infiltration index reflected by T stage. We sought to reveal the impact of T stage on the prognostic and predictive value of tumor size in colon cancer.

MATERIALS AND METHODS

Data of patients with stage I-III colon cancer were extracted from Surveillance, Epidemiology, and End Results Program (SEER) and Fudan University Shanghai Cancer Center (FUSCC) databases. Harrell's concordance index (c-index) and time-dependent receiver operating characteristic curve (ROC) were used to analyze the discriminative ability of prognostic factors.

RESULTS

Stratified analyses based on T stage found that the increase of T stage significantly and negatively repressed the effect of tumor size on death and recurrence risk. In addition, tumor size showed the greatest hazard ratio of cancer-specific death and relapse in T1 colon cancer. Even more importantly, the discriminatory ability of tumor size outperformed any other widely accepted prognostic clinical features in predicting cancer-specific survival (SEER: c-index 0.637, area under the ROC [AUC] 0.649; FUSCC: c-index 0.673, AUC 0.686) and disease-free survival (FUSCC: c-index 0.645, AUC 0.656) in T1 stage colon cancer.

CONCLUSION

Tumor size is a critical clinical factor with considerable prognostic and predictive value for T1 colon cancer, and it should be selectively incorporated into the current staging system to facilitate prediction of death and recurrence risk.

IMPLICATIONS FOR PRACTICE

To date, no consensus has been reached about the prognostic and predictive value of tumor size in colon cancer. Although tumor size is an independent prognostic factor for patients with colon cancer, the impact of tumor size on death or recurrence risk decreased notably with the increase of T stage. More importantly, the discriminative ability of tumor size outperformed any other clinical factors including N stage in patients with T1 colon cancer. Therefore, tumor size should be recommended to be incorporated into current staging systems to facilitate prognosis prediction for patients with T1 colon cancer.

Near-infrared fluorescence imaging for sentinel lymph node identification in colon cancer: a prospective single-center study and systematic review with meta-analysis

Background

Near-infrared (NIR) fluorescence imaging has the potential to overcome the current drawbacks of sentinel lymph node mapping (SLNM) in colon cancer. Our aim was to provide an overview of current SLNM performance and of factors influencing successful sentinel lymph node (SLN) identification using NIR fluorescence imaging in colon cancer.

Methods

A systematic review and meta-analysis was conducted to identify currently used methods and results. Additionally, we performed a single-center study using indocyanine green (ICG) as SLNM dye in colon cancer patients scheduled for a laparoscopic colectomy. SLNs were analyzed with conventional hematoxylin-and-eosin staining and additionally with serial sectioning and immunohistochemistry (extended histopathological assessment). A true-positive procedure was defined as a tumor-positive SLN either by conventional hematoxylin-and-eosin staining or by extended histopathological assessment, independently of regional lymph node status. SLN procedures were determined to be true negatives if SLNs and regional lymph nodes revealed no metastases after conventional and advanced histopathology. SLN procedures yielding tumor-negative SLNs in combination with tumor-positive regional lymph nodes were classified as false negatives. Sensitivity, negative predictive value and detection rate were calculated.

Results

This systematic review and meta-analysis included 8 studies describing 227 SLN procedures. A pooled sensitivity of 0.63 (95% CI 0.51–0.74), negative predictive value 0.81 (95% CI 0.73–0.86) and detection rate of 0.94 (95% CI 0.85–0.97) were found. Upstaging as a result of extended histopathological assessment was 0.15 (95% CI 0.07–0.25). In our single-center study, we included 30 patients. Five false-negative SLNs were identified, resulting in a sensitivity of 44% and negative predictive value of 80%, with a detection rate of 89.7%. Eight patients had lymph node metastases, in three cases detected after extended pathological assessment, resulting in an upstaging of 13% (3 of 23 patients with negative nodes by conventional hematoxylin and eosin staining).

Conclusions

Several anatomical and technical difficulties make SLNM with NIR fluorescence imaging in colon cancer particularly challenging when compared to other types of cancer. As a consequence, reports of SLNM accuracy vary widely. Future studies should try to standardize the SLNM procedure and focus on early-stage colon tumors, validation of tracer composition, injection mode and improvement of real-time optical guidance.

Electronic supplementary material

The online version of this article (10.1007/s10151-019-02107-6) contains supplementary material, which is available to authorized users.

Clinicopathologic and epidemiological characteristics of prognostic factors in post-surgical survival of colorectal cancer patients in Jiangsu Province, China

Poor survival among colorectal cancer (CRC) patients has been widely associated with clinico-epidemiological features and treatment regimen. In Jiangsu (China), however, it is not known which one of the prognostic factors explains the survival disparities among patients with CRC. This prospective study using 1078 patients (stages I-IV) that underwent surgery at Jiangsu Hospital, explored the relevant factors affecting the prognoses of right-side colon cancer (RCC), left-side colon cancer (LCC) and rectal cancer (ReC) patients. Of these cases, 234 (21.7%), 241 (22.4%) and 603 (55.9%) were found to have RCC, LCC and ReC respectively. Compared to LCC, RCC exhibited a greater proportion of older patients, poorly differentiated carcinomas, higher T-stage and higher TNM-stage. The overall survival (OS) for RCC was 60 vs.78 or 77 months for LCC or ReC respectively (P = 0.030). There were no significant differences in OS between LCC and ReC across the subgroups (P = 0.633). In multivariate analysis, RCC patients had age (>60 vs. ≤60 years, HR = 1.529, P = 0.019), N-stage (N1 vs. N0, HR = 4.056, P = 0.012) and M-stage (M1 vs. M0, HR = 3.442, P < 0.0001) as independent prognostic factors, whereas smoking status was found to be a predictor of mortality (smoker vs. nonsmoker, HR = 2.343, P = 0.017) for LCC. In addition, age (>60 vs. ≤60 years, HR = 2.199, P < 0.0001), alcohol consumption (drinker vs. nondrinker, HR = 0.510, P = 0.034), tumor grade (Poor vs. well/moderate, HR = 2.759, P = 0.031) and T-stage (T3-4 vs. T1-2, HR = 1.742, P < 0.0001) were found to be predictors of mortality for ReC. There were significant pairwise interactions across subgroups. Furthermore, significant differences were observed for LCC vs. RCC (OS, HR = 0.783, P = 0.039), but no statistically significant differences for ReC vs. RCC (P = 0.149) and LCC vs. ReC (P = 0.355). Nevertheless, significant differences remained between ReC vs. RCC for male (HR = 0.591, P = 0.009), drinker (HR = 0.396, P = 0.005), rural resident (HR = 0.437,P = 0.022), tumor grade (well/moderate, HR = 0.475, P = 0.022), T-stage (T1-2, HR = 0.362, P = 0.001), N-stage (N0, HR = 0.604, P = 0.011), M-stage(M0, HR = 0.401, P = 0.006) and TNM-stage (I-II, HR = 0.567, P = 0.005). Statistically significant differences were observed for LCC vs. RCC for gender (female, HR = 0.495, P = 0.003) and T-stage (T1-2, HR = 0.417, P = 0.010) as well as for LCC vs. ReC in patients with smoking habits (HR = 1.951, P = 0.002) and M-stage (M0, HR = 2.291, P = 0.003). These findings suggest that the variations in CRC post-surgical survival in China may be primarily explained with the clinicopathologic features and epidemiological characteristic of the patients. Patients with RCC had significantly worse OS compared to both LCC and ReC in several subgroups.

The adequacy of lymph node clearance in colon cancer surgery performed in a non-specialist centre; implications for practice

BACKGROUND

Despite recent medical advances, surgery remains the mainstay treatment in colon cancer. It is well established that better patient outcomes are achieved when complex surgery including pancreatic, oesophageal and rectal surgeries are carried out in high-volume centres. However, it is unclear as to whether or not colon cancer patients receive the same benefit. Lymph node adequacy is a key performance indicator of successful oncological colonic resection which impacts on patient outcome.

AIM

To assess the adequacy of lymph node clearance during colonic resection performed with curative intent in a non-specialist centre post introduction of the National Cancer Strategy.

METHODS

Retrospective analysis was performed of a prospectively maintained database examining the lymph node clearance of all oncological resections for colon cancer over a 7-year period (Nov 2010-Dec 2017) at a satellite unit with links to a regional specialist centre. Primary outcome measured was the number of lymph nodes retrieved. Secondary outcomes included resection margins, 30-day complication rate and survival at 1 year. Statistical analysis was performed using SPSS Statistics for Windows, version 24.0 (IBM Corp, Armonk, N.Y., USA).

RESULTS

One hundred sixty-seven patients were included. Mean age was 71.0 ± 11.6 years. Majority were male (n = 90, 53.6%). The majority of resections was right sided (n = 112.66.7%) with 78.6% of all resections being undertaken electively. All margins were free of tumour. The average lymph node count was 19.93 ± 8.63 (4.62) with only 17 (10.2%) of specimens containing < 12 nodes. The anastomotic leak rate was 3.3%. There was no association between surgeon or pathologist volume, nor emergent status and achieving oncological lymph node count (p = 0.14, 0.29, 0.97). 90.5% of patients were alive at 1 year.

CONCLUSIONS

This study demonstrates that colonic cancer surgery can be safely performed in a non- specialist centre with technical outcomes comparable to nationally reported figures.

Pedunculated Morphology of T1 Colorectal Tumors Associates With Reduced Risk of Adverse Outcome

BACKGROUND & AIMS

Risk stratification for adverse events, such as metastasis to lymph nodes, is based only on histologic features of tumors. We aimed to compare adverse outcomes of pedunculated vs nonpedunculated T1 colorectal cancers (CRC).

METHODS

We performed a retrospective study of 1656 patients diagnosed with T1CRC from 2000 through 2014 at 14 hospitals in The Netherlands. The median follow-up time of patients was 42.5 months (interquartile range, 18.5-77.5 mo). We evaluated the association between tumor morphology and the primary composite end point, adverse outcome, adjusted for clinical variables, histologic variables, resection margins, and treatment approach. Adverse outcome was defined as metastasis to lymph nodes, distant metastases, local recurrence, or residual tissue. Secondary end points were tumor metastasis, recurrence, and incomplete resection.

RESULTS

Adverse outcome occurred in 67 of 723 patients (9.3%) with pedunculated T1CRCs vs 155 of 933 patients (16.6%) with nonpedunculated T1CRCs. Pedunculated morphology was independently associated with decreased risk of adverse outcome (adjusted odds ratio [OR], 0.59; 95% CI, 0.42-0.83; P = .003). Metastasis, incomplete resection, and recurrence were observed in 5.8%, 4.6%, and 3.9% of pedunculated T1CRCs vs 10.6%, 8.0%, and 6.6% of nonpedunculated T1CRCs, respectively. Pedunculated morphology was independently associated with a reduced risk of metastasis (adjusted OR, 0.62; 95% CI, 0.41-0.94; P = .03), incomplete resection (adjusted OR, 0.57; 95% CI, 0.36-0.91; P = .02), and recurrence (adjusted hazard ratio, 0.52; 95% CI, 0.32-0.85; P = .009). Metastasis, incomplete resection, and recurrence did not differ significantly between low-risk pedunculated vs nonpedunculated T1CRCs (0.8% vs 2.9%, P = .38; 1.5% vs 0%, P = .99; 1.5% vs 0%; P = .99). However, incomplete resection and recurrence were significantly lower for high-risk pedunculated vs nonpedunculated T1CRCs (6.5% vs 12.5%; P = .007; 4.4% vs 8.6%; P = .03).

CONCLUSIONS

In a retrospective study of patients with T1CRC, we found pedunculated morphology to be associated independently with a decreased risk of adverse outcome in a T1CRC population at high risk of adverse outcome. Incorporating morphologic features of tumors in risk assessment could help predict outcomes of patients with T1CRC and help identify the best candidates for surgery.

Acetone clearance of mesocolic or mesorectal fat increases lymph node yield and may improve detection of high-risk Stage II colorectal cancer patients

AIM

Lymph node (LN) status is key to determining the need for adjuvant therapy in colorectal cancer (CRC) and for disease which has progressed to Stage II (T3-T4, N0, M0). A yield of fewer than 12 LNs is considered a risk factor similar to high-grade histology and vascular, lymphatic and perineural invasion. The aim of this retrospective study was to investigate the effect of acetone fat clearance of the mesocolon or mesorectum on LN yield and the identification of patients with high-risk Stage II CRC.

METHOD

After conventional LN retrieval, fatty tissue derived from the mesocolon or mesorectum of 80 CRC specimens was incubated in acetone for 24 h. A second dissection was then performed by a trained technician. The total number of LNs as well as tumour involvement (LNpositive and LNnegative) were assessed at each stage. In addition, LN morphology was assessed and clinicopathological data were extracted from existing pathology reports.

RESULTS

Eighty CRC specimens were available for study. 1548 (94%) LN were negative and 96 (6%) were positive. The median (range) LN yield per specimen was 12 (3-41) LN increasing to 18 (4-48) LN after fat clearance (P < 0.001). After fat clearance, 534 additional LNs were identified in 75 (94%) of the specimens, and all but 10 were negative. The pN stage did not change in six patients who were found to be LN positive after fat clearance. However, the number of high-risk Stage II CRC patients decreased from 11 to 7. Although important for these patients, this downstaging did not reach statistical significance (P = 0.125).

CONCLUSION

Acetone clearance of mesocolic or mesorectal fat increases median LN yield and may in a larger study decrease the number of patients classified as having high-risk Stage II CRC.

Introduction of a colorectal cancer screening programme: results from a single-centre study

AIM

In 2014, a national colorectal cancer (CRC) screening programme was launched in the Netherlands. It is difficult to assess for the individual patients with CRC whether the oncological benefits of surgery will outweigh the morbidity of the procedure, especially in early lesions. This study compares patient and tumour characteristics between screen-detected and nonscreen-detected patients. Also, we present an overview of treatment options and clinical dilemmas when treating patients with early-stage colorectal disease.

METHOD

Between January 2014 and December 2016, all patients with nonmalignant polyps or CRC who were referred to the Department of Surgery of the Leiden University Medical Centre in the Netherlands were included. Baseline characteristics, type of treatment and short-term outcomes of patients with screen-detected and nonscreen-detected colorectal tumours were compared.

RESULTS

A total of 426 patients were included, of whom 240 (56.3%) were identified by screening. Nonscreen-detected patients more often had comorbidity (P = 0.03), the primary tumour was more often located in the rectum (P = 0.001) and there was a higher rate of metastatic disease (P < 0.001). Of 354 surgically treated patients, postoperative adverse events did not significantly differ between the two groups (P = 0.38). Of 46 patients with T1 CRC in the endoscopic resection specimen, 23 underwent surgical resection of whom only 30.4% had residual invasive disease at colectomy.

CONCLUSION

Despite differences in comorbidity, stage and surgical outcome of patients with screen-detected tumours compared to nonscreen-detected tumours were not significantly different. Considering its limited oncological benefits as well as the rate of adverse events, surgery for nonmalignant polyps and T1 CRC should be considered carefully.