Colorectal cancer and lymph nodes: The obsession with the number 12

Prognostic impact of log odds of positive lymph nodes (LODDS) in the stratification of patients with rectal cancer

INTRODUCTION

The use of the N category of the TNM staging system, lymph node ratio (LNR) and log odds of positive lymph nodes (LODDS) in predicting overall survival (OS) and disease-free survival (DFS) in patients with rectal cancer is still controversial.

MATERIAL AND METHODS

A retrospective study of 445 patients with rectal cancer who underwent surgery between 2008 and 2017 in the University Complex Hospital of Vigo was performed. Patients were stratified according to number of lymph nodes examined (NLNE), N staging, LNR and LODDS. The analysis was performed using the log-rank test, Kaplan-Meier functions, Cox regression and ROC curves.

RESULTS

Five-year OS and DFS were 73.7% and 62.5%, respectively. No statistically significant differences were observed depending on NLNE. Increased LNR and LODDS were associated with shorter OS and DFS, independently of NLNE. Multivariate analysis showed that N stage, LNR and LODDS were independently associated with OS and DFS; however, the LODDS system obtained the best area under the curve, with greater predictive capacity for OS (AUC: 0.679) and DFS (AUC: 0.711).

CONCLUSION

LODDS and LNR give prognostic information that is not related to NLNE. LODDS provides better prognostic accuracy in patients with negative nodes than LNR and N stage.

Feasibility of indocyanine green (ICG) fluorescence in ex vivo pathological dissection of colorectal lymph nodes-a pilot study

Accurate lymph node (LN) retrieval during colorectal carcinoma resection is pivotal for precise N-staging and the determination of adjuvant therapy. Current guidelines recommend the examination of at least 12 mesocolic or mesorectal lymph nodes for accurate staging. Traditional histological processing techniques, reliant on visual inspection and palpation, are time-consuming and heavily dependent on the examiner's expertise and availability. Various methods have been documented to enhance LN retrieval from colorectal specimens, including intra-arterial ex vivo methylene blue injection. Recent studies have explored the utility of indocyanine green (ICG) fluorescence imaging for visualizing pericolic lymph nodes and identifying sentinel lymph nodes in colorectal malignancies. This study included 10 patients who underwent colon resection for malignant tumors. During surgery, intravenous ICG dye and an endoscopic camera were employed to assess intestinal perfusion. Post-resection, ex vivo intra-arterial administration of ICG dye was performed on the specimens, followed by routine histological processing and an ICG-assisted lymph node dissection. The objective was to evaluate whether ICG imaging could identify additional lymph nodes compared to routine manual dissection and to assess the clinical relevance of these findings. For each patient, a minimum of 12 lymph nodes (median = 25.5, interquartile range = 12.25, maximum = 33) were examined. ICG imaging facilitated the detection of a median of three additional lymph nodes not identified during routine processing. Metastatic lymph nodes were found in four patients however no additional metastatic nodes were detected with ICG assistance. Our findings suggest that ex vivo intra-arterial administration of indocyanine green dye can augment lymph node dissection, particularly in cases where the number of lymph nodes retrieved is below the recommended threshold of 12.

Comparison of the prognostic value of lymph node yield, lymph node ratio, and number of lymph node metastases in patients with oral squamous cell carcinoma

BACKGROUND

The aim of this study was to assess the prognostic significance of lymph node yield (LNY), lymph node ratio (LNR), and the number of lymph node metastases (LNMs) in patients affected by oral squamous cell carcinoma (OSCC).

METHODS

The study included patients who underwent surgical treatment for primary OSCC. Receiver operating characteristic curves were generated to determine the optimal threshold values. Kaplan-Meier curves were employed, along with the log-rank test, for the analysis of survival. To compare the performance in terms of model fit, we computed Akaike's information criterion (AIC).

RESULTS

This study enrolled 429 patients. Prognostic thresholds were determined at 22 for LNY, 6.6% for LNR, and 3 for the number of LNMs. The log-rank test revealed a significant improvement in both overall survival and progression-free survival for patients with a LNR of ≤6.6% or a number of LNMs of ≤3 (p < 0.05). Interestingly, LNY did not demonstrate prognostic significance. The AIC analyses indicated that the number of LNMs is a superior prognostic indicator compared to LNY and LNR.

CONCLUSIONS

Incorporating LNR or the number of LNMs into the TNM classification has the potential to improve the prognostic value, as in other types of cancers. Particularly, the inclusion of the number of LNMs should be contemplated for future N staging.

Effect of centre volume on pathological outcomes and postoperative complications after surgery for colorectal cancer: results of a multicentre national study

BACKGROUND

The association between volume, complications and pathological outcomes is still under debate regarding colorectal cancer surgery. The aim of the study was to assess the association between centre volume and severe complications, mortality, less-than-radical oncologic surgery, and indications for neoadjuvant therapy.

METHODS

Retrospective analysis of 16,883 colorectal cancer cases from 80 centres (2018-2021). Outcomes: 30-day mortality; Clavien-Dindo grade >2 complications; removal of ≥ 12 lymph nodes; non-radical resection; neoadjuvant therapy. Quartiles of hospital volumes were classified as LOW, MEDIUM, HIGH, and VERY HIGH. Independent predictors, both overall and for rectal cancer, were evaluated using logistic regression including age, gender, AJCC stage and cancer site.

RESULTS

LOW-volume centres reported a higher rate of severe postoperative complications (OR 1.50, 95% c.i. 1.15-1.096, P = 0.003). The rate of ≥ 12 lymph nodes removed in LOW-volume (OR 0.68, 95% c.i. 0.56-0.85, P < 0.001) and MEDIUM-volume (OR 0.72, 95% c.i. 0.62-0.83, P < 0.001) centres was lower than in VERY HIGH-volume centres. Of the 4676 rectal cancer patients, the rate of ≥ 12 lymph nodes removed was lower in LOW-volume than in VERY HIGH-volume centres (OR 0.57, 95% c.i. 0.41-0.80, P = 0.001). A lower rate of neoadjuvant chemoradiation was associated with HIGH (OR 0.66, 95% c.i. 0.56-0.77, P < 0.001), MEDIUM (OR 0.75, 95% c.i. 0.60-0.92, P = 0.006), and LOW (OR 0.70, 95% c.i. 0.52-0.94, P = 0.019) volume centres (vs. VERY HIGH).

CONCLUSION

Colorectal cancer surgery in low-volume centres is at higher risk of suboptimal management, poor postoperative outcomes, and less-than-adequate oncologic resections. Centralisation of rectal cancer cases should be taken into consideration to optimise the outcomes.

Lymph node retrieval colon cancer: Are we making the grade?

BACKGROUND

Adequate lymph node (LN) excision is imperative for pathologic staging and determination of adjuvant treatment.

METHODS

he 2004-2017 National Cancer Database (NCDB) was queried for curative colon cancer resections. Tumors were categorized by location: left, right, and transverse colon cancers. Adequate (12-20 LNs) vs. inadequate (<12 LNs) lymphadenectomy was examined and sub-analysis of <12 LNs, 12-20 LNs or >20 LNs. Primary outcome was predictors of inadequate lymph node retrieval.

RESULTS

Of 101,551 patients, 11.2% (11,439) had inadequate lymphadenectomy. The inadequate lymphadenectomy rate steadily decreased. On multivariable analysis, inadequate LN retrieval was associated with transverse (OR 1.49, CI [1.30-1.71]) and left colon cancers (OR 2.66, CI [2.42-2.93], whereas income >$63,333 had decreased likelihood of inadequate LN retrieval (OR 0.68, CI[0.56-0.82].

CONCLUSION

We are making the grade as NCDB data demonstrates a steady decrease in inadequate lymphadenectomy (2004-2017). There remain socioeconomic risk factors for inadequate lymphadenectomy that need to be addressed.

Size and number of lymph nodes were risk factors of recurrence in stage II colorectal cancer

BACKGROUND

Size and number of lymph nodes (LNs) were reported to be associated with the prognosis of stage II colorectal cancer (CRC). The purpose of this study was to determine the prognostic role of the size of LNs (SLNs) measured by computer tomography (CT) and the number of retrieved LNs (NLNs) in the relapse-free survival (RFS) and overall survival (OS) among stage II CRC patients.

METHODS

Consecutive patients diagnosed with stage II CRC at Fudan University Shanghai Cancer Center (FUSCC) from January 2011 to December 2015 were reviewed, and 351 patients were randomly divided into two cohorts for cross-validation. The optimal cut-off values were obtained using X-tile program. Kaplan-Meier curves and Cox regression analyses were conducted for the two cohorts.

RESULTS

Data from 351 stage II CRC patients were analyzed. The cut-off values for SLNs and NLNs were 5.8 mm and 22, respectively, determined by the X-tile in the training cohort. In the validation cohort, Kaplan-Meier curves demonstrated SLNs (P = 0.0034) and NLNs (P = 0.0451) were positively correlated with RFS but not with OS. The median follow-up time in the training cohort and the validation cohort were 60.8 months and 61.0 months respectively. Univariate and multivariate analysis revealed that both SLNs (training cohort: Hazard Ratio (HR) = 2.361, 95% Confidence interval (CI): 1.044-5.338, P = 0.039; validation cohort: HR = 2.979, 95%CI: 1.435-5.184, P = 0.003) and NLNs (training cohort: HR = 0.335, 95%CI: 0.113-0.994, P = 0.049; validation cohort: HR = 0.375, 95%CI: 0.156-0.900, P = 0.021) were independent prognostic factors for RFS whereas not for OS.

CONCLUSION

SLNs and NLNs are independent prognostic factors for patients with stage II CRC. Patients with SLNs > 5.8 mm and NLNs ≤ 22 are apt to have higher risk of recurrence.

A systematic review and meta-analysis of the use of methylene blue to improve the lymph node harvest in rectal cancer surgery

BACKGROUND

Methylene blue staining of the resected specimen has been described as an alternative to the conventional palpation and visual inspection method to improve lymph node harvest. This meta-analysis evaluates the usefulness of this technique in surgery for rectal cancer, particularly after neoadjuvant therapy.

METHODS

Randomized controlled trials (RCTs) comparing lymph node harvest in methylene blue-stained rectal specimens to those of unstained specimens were identified from the Medline, Embase, and Cochrane databases. Non-randomized studies and those with only colonic resections were excluded. The quality of RCTs was assessed using Cochrane's risk of bias tool. A weighted mean difference (WMD) was calculated for overall harvest, harvest after neoadjuvant therapy, and metastatic nodal yield. In contrast, the risk difference (RD) was calculated to compare yields of less than 12 lymph nodes between the stained and unstained specimens.

RESULTS

Study selection comprised seven RCTs with 343 patients in the unstained group and 337 in the stained group. Overall lymph node harvest and harvest after neoadjuvant therapy were significantly higher in stained specimens with a WMD of 13.4 and 10.6 and a 95% confidence interval (CI) of 9.5-17.2 and 4.8-16.3, respectively. Harvest of metastatic lymph nodes was significantly higher in the stained group (WMD 1.0, 95% CI 0.6-1.4). The yield of less than 12 lymph nodes was significantly higher in the unstained group with RD of 0.292 and 95% CI of 0.182-0.403.

CONCLUSION

Despite a small number of patients, this meta-analysis confirms improved lymph node harvest in surgical specimens stained with methylene blue compared with unstained specimens.

Prognostic value of log odds of positive lymph nodes, lymph node ratio, and N stage in patients with colorectal signet ring cell carcinoma: A retrospective cohort study

Aim

Little attention has been paid in the prognosis of colorectal signet ring cell carcinoma (SRCC). This study aims to explore the predictive capacity of log odds of positive lymph nodes (LODDS), lymph node ratio (LNR), and pN stage in the prognosis of patients with colorectal SRCC.

Methods

A retrospective cohort study was designed, and data were extracted from the Surveillance, Epidemiology and End Results (SEER) database. Data on demographic characteristics, clinicopathological features, and treatment were extracted. Outcomes were overall survival (OS) and cancer-specific survival (CSS). Association of LODDS, LNR, and pN stage with OS and CSS were explored using Cox proportional hazard model and Cox competing risk model, respectively, with results showing as hazard ratio and 95% confidence interval (CI). Predictive performance of LODDS, LNR, and pN stage in OS and CSS was assessed by calculating C-index.

Results

A total of 2,198 patients were included in this study. LODDS, LNR, and pN stage were associated with the OS and CSS of colorectal SRCC patients (all P < 0.05). LODDS showed a good performance in the OS (C-index: 0.704, 95% CI: 0.690-0.718), which was superior to LNR (C-index: 0.657, 95% CI: 0.643-0.671) and pN stage (C-index: 0.643, 95% CI: 0.629-0.657). The C-index of LODDS, LNR, and pN stage for CSS was 0.733 (95% CI: 0.719-0.747), 0.713 (95% CI: 0.697-0.729), and 0.667 (95% CI: 0.651-0.683), respectively.

Conclusions

LODDS displayed a better predictive capacity in the OS and CSS than LNR and pN stage, indicating that LODDS may be effective to predict the prognosis of colorectal SRCC in the clinic.

New staging systems for left-sided colon cancer based on the number of retrieved and metastatic lymph nodes provide a more accurate prognosis

Objectives: We aimed to explore reasonable lymph node classification strategies for left-sided colon cancer (LCC) patients. Methods: 48,425 LCC patients from 2010 to 2015 were identified in the US Surveillance, Epidemiology, and End Results database. We proposed an innovative revised nodal (rN) staging of the 8th American Joint Committee on Cancer (AJCC) Tumor/Node/Metastasis (TNM) classification based on the cut-off value of retrieved lymph nodes and survival analyses in patients with LCC. Log odds of positive lymph nodes (LODDS) stage is a numerical classification strategy obtained by a formula that incorporates the numbers of retrieved and positive lymph nodes. To develop the TrN or TLODDS classification, patients with similar survival rates were grouped by combining T and rN or LODDS stage. The TrN or TLODDS classification was further evaluated in a validation set of 12,436 LCC patients from 2016 to 2017 in the same database and a Chinese application set of 958 LCC patients. Results: We developed novel TrN and TLODDS classifications for LCC patients that incorporated 7 stages with reference to the AJCC staging system. In comparison to the 8th AJCC TNM and TrN classifications, TLODDS classification demonstrated significantly better discrimination (area under the receiver operating characteristic curve, 0.650 vs. 0.656 vs. 0.661, p < 0.001), better model-fitting (Akaike information criteria, 309,287 vs. 308,767 vs. 308,467), and superior net benefits. The predictive performance of the TrN and TLODDS classifications was further verified in the validation and application sets. Conclusion: Both the TrN and TLODDS classifications have better discriminatory ability, model-fitting, and net benefits than the existing TNM classification, and represent an alternative to the current TNM classification for LCC patients.

Evaluation of lymph node adequacy in patients with colorectal cancer: Results from a referral center in Iran

Background

The presence of lymph node metastasis is one of the most important prognostic factors for long-term survival of patients with colorectal cancer. Therefore, thorough pathologic examination of at least 12 lymph nodes is essential for accurate staging of this disease, as well as for choosing the best adjuvant treatment. The aim of this study is to assess the adequacy of lymph node harvest in patients with colorectal cancer.

Methods

This observational, cross-sectional study was performed on 584 patients with colorectal adenocarcinoma who had undergone surgery from 2012 to 2017. Thereafter, the relevant demographic, pathological, and surgical data were extracted from the patients' medical records; and a relationship between the number of evaluated lymph nodes and other variables was also assessed.

Results

Among 584 studies cases in this study, 336 (57.5%) subjects had fewer than 12 evaluated lymph nodes. Mean and median number of the evaluated lymph nodes were calculated as 10.7 (±5.6) and 10, respectively. The patients aged 60 years old and older and the cases with tumors located in descending colon and rectum were observed to have a higher likelihood of inadequate lymph node retrieval. After an average follow-up of a 60-month period, 63% of the patients were alive. For the patients in whom fewer than 12 lymph nodes had been assessed, the median survival was estimated to be 48 months. For the patients in whom the number of evaluated lymph nodes was ≥12, median survival was calculated to be 54 months.

Conclusion

The number of lymph nodes evaluated in our study was less than the standard number in more than half of the patients. Among various other factors, older age and tumor location in descending colon and rectum are found to be associated with suboptimal assessment of lymph nodes. The number of lymph nodes dissected is also associated with survival.

A modified mTNM staging system based on lymph node ratio for colon neuroendocrine tumors: A recursive partitioning analysis

BACKGROUND

In the current tumor-lymph node-metastasis (TNM) staging system for colon neuroendocrine tumors, lymph node status is divided into N1 and N0. An assessment of the lymph node ratio (LNR) and a proposal for a modified mTNM staging system were the objectives of this study.

METHODS

Selecting the optimal cut-off value of LNR was done using X-tile. A Cox regression model and the Kaplan-Meier method were performed to calculate patient cancer-specific survival in the Surveillance, Epidemiology and End Results cohort. Recursive partitioning analysis was used to improve TNM staging.

RESULTS

The study included 674 patients. The current TNM staging system showed inadequate discriminatory power between stage I and stage II patients (p = 0.088). The optimal cut-off value was determined as 0.6 for LNR. Based on multivariate Cox regression analysis, the modified mN classification could be classified into mN 0 (LNR = 0.00), mN 1 (LNR = 0.01-0.60), and mN 2 (LNR > 0.60), and was found to be an independent factor affecting prognosis (p < 0.001). Using the American Joint Committee on Cancer T and modified mN classifications, the modified mTNM system was constructed, and it exhibited better prognostic discriminatory power ability than the traditional TNM system (C-index: 0.587 vs. 0.665).

CONCLUSIONS

Our study determined that LNR is a prognostic factor in colon NET patients. In addition, to more accurately assess the prognosis of colon NET patients, we proposed a modified mTNM staging system.

Nomograms predicting cancer-specific survival for stage IV colorectal cancer with synchronous lung metastases

This study aimed to establish a nomogram for the prediction of cancer-specific survival (CSS) of CRC patients with synchronous LM. The final prognostic nomogram based on prognostic factors was evaluated by concordance index (C-index), time-dependent receiver operating characteristic curves, and calibration curves. In the training and validation groups, the C-index for the nomogram was 0.648 and 0.638, and the AUC was 0.793 and 0.785, respectively. The high quality of the calibration curves in the nomogram models for CSS at 1-, 3-, and 5-year was observed. The nomogram model provided a conventional and useful tool to evaluate the 1-, 3-, and 5-year CSS of CRC patients with synchronous LM.

Pattern of recurrence and survival after D2 right colectomy for cancer: is there place for a routine more extended lymphadenectomy?

BACKGROUND

Conventional Right Colectomy with D2 lymphadenectomy (RC-D2) currently represent the most common surgical treatment of right-sided colon cancer (RCC). However, whether it should be still considered a standard of care, or replaced by a routine more extended D3 lymphadenectomy remains unclear. In the present study, we aim to critically review the patterns of relapse and the survival outcomes obtained from our 11-year experience of RC-D2.

METHODS

Clinical data of 489 patients who underwent RC-D2 for RCC at two centres, from January 2009 to January 2020, were retrospectively reviewed. Patients with synchronous distant metastases and/or widespread nodal involvement at diagnosis were excluded. Post-operative clinical-pathological characteristics and survival outcomes were evaluated including the pattern of disease relapse.

RESULTS

We enrolled a total of 400 patients with information follow-up. Postoperative morbidity was 14%. The median follow-up was 62 months. Cancer recurrence was observed in 55 patients (13.8%). Among them, 40 patients (72.7%) developed systemic metastases, and lymph-node involvement was found in 7 cases (12.8%). None developed isolated central lymph-node metastasis (CLM), in the D3 site. The estimated 3- and 5-year relapse-free survival were 86.1% and 84.4%, respectively. The estimated 3- and 5-year cancer-specific OS were 94.5% and 92.2%, respectively.

CONCLUSIONS

The absence of isolated CLM, as well as the cancer-specific OS reported in our series, support the routine use of RC-D2 for RCC. However, D3 lymphadenectomy may be recommended in selected patients, such as those with pre-operatively known CLM, or with lymph-node metastases close to the origin of the ileocolic vessels.

Change point analysis validation of the learning curve in laparoscopic colorectal surgery: Experience from a non-structured training setting

BACKGROUND

The introduction of minimal invasive principles in colorectal surgery was a major breakthrough, resulting in multiple clinical benefits, at the cost, though, of a notably steep learning process. The development of structured nation-wide training programs led to the easier completion of the learning curve; however, these programs are not yet universally available, thus prohibiting the wider adoption of laparoscopic colorectal surgery.

AIM

To display our experience in the learning curve status of laparoscopic colorectal surgery under a non-structured training setting.

METHODS

We analyzed all laparoscopic colorectal procedures performed in the 2012-2019 period under a non-structured training setting. Cumulative sum analysis and change-point analysis (CPA) were introduced.

RESULTS

Overall, 214 patients were included. In terms of operative time, CPA identified the 110^th case as the first turning point. A plateau was reached after the 145^th case. Subgroup analysis estimated the 58^th for colon and 52^nd case for rectum operations as the respective turning points. A learning curve pattern was confirmed for pathology outcomes, but not in the conversion to open surgery and morbidity endpoints.

CONCLUSION

The learning curves in our setting validate the comparability of the results, despite the absence of National or Surgical Society driven training programs.

Natural orifice versus transabdominal specimen extraction in laparoscopic surgery for colorectal cancer: meta-analysis

BACKGROUND

Natural orifice specimen extraction (NOSE) is a technique that involves collecting a specimen for extraction through a natural opening avoiding a mini-laparotomy incision. The aim of this study was to compare NOSE and transabdominal specimen extraction in laparoscopic (LAP) colorectal cancer surgery for postoperative outcomes and oncological safety.

METHOD

A systematic search was conducted in five electronic databases from inception till October 2020. Articles were selected based on the inclusion criteria (studies comparing LAP and NOSE colorectal surgeries reporting at least one of the outcomes) and analysed. Primary outcomes included postoperative complications, pathological results (resection margins and lymph node collection), and oncological outcomes. Secondary outcomes included operating time, blood losses, use of analgesics, functional recovery, duration of hospital stay, and cosmetic results. Fixed and random-effect models were used to measure the pooled estimates.

RESULTS

Nineteen studies involving a total of 3432 participants were analysed (3 randomized clinical trials (RCTs) and 16 retrospective non-randomized studies). Pooled results showed significantly reduced postoperative complications (OR 0.54; 95 per cent c.i. 0.44 to 0.67; P < 0.00001). Pathological outcomes of NOSE were comparable to LAP with no significant difference noted in terms of resection margins (P > 0.05) and lymph node collection (weighted mean difference (WMD) -0.47; 95 per cent c.i. -0.94 to 0; P = 0.05). Pooled analysis demonstrated comparable long-term outcomes in terms of cancer recurrence (OR 0.94; 95 per cent c.i. 0.63 to 1.39; P = 0.75), 5-year disease-free survival (HR 0.97; 95 per cent c.i. 0.73 to 1.29; P = 0.83), and overall survival (HR 0.93, 95 per cent c.i. 0.58 to -1.51; P = 0.78). Finally, the NOSE group had decreased use of additional analgesia after surgery and earlier resumption of oral intake when compared with LAP (respectively OR 0.28; 95 per cent c.i. 0.20 to 0.37; P < 0.00001 and WMD -0.35; 95 per cent c.i. -0.54 to -0.15; P = 0.0005).

CONCLUSION

This meta-analysis showed that in comparison with LAP, NOSE decreases severe postoperative morbidity while improving postoperative recovery without compromising oncological safety, but it is limited by the small number of RCTs performed in this field.

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.

The Effect of Lymph Node Harvest on Prognosis in Locally Advanced Middle-Low Rectal Cancer After Neoadjuvant Chemoradiotherapy

OBJECTIVE

The purpose of this study was to investigate the relationship between lymph node harvest and the prognosis in locally advanced rectal cancer (LARC) patients after neoadjuvant chemoradiotherapy (nCRT).

METHODS

Patients who were diagnosed with clinical LARC and treated with nCRT and radical surgery between June 2008 and July 2017 were included in this study. The relationship between lymph node retrieval and prognosis was analyzed. Other lymph node-related indicators were explored.

RESULTS

A total of 837 patients with a median follow-up of 61 (7-139) months were included in the study. The five-year DFS and OS rates of all patients were 74.9% and 82.3%, respectively. Multivariate survival analysis suggested that dissection of ≥ 12 lymph nodes did not improve OS or DFS. 7 was selected as the best cutoff value for the total number of lymph nodes retrieved by Cox multivariate analysis (χ2 = 10.072, HR: 0.503, P=0.002). Dissection of ≥ 5 positive lymph nodes (PLNs) was an independent prognostic factor for poorer DFS (HR: 2.104, P=0.004) and OS (HR: 3.471, p<0.001). A positive lymph node ratio (LNR) of more than 0.29 was also an independent prognostic factor for poorer DFS (HR: 1.951, P=0.002) and OS (HR: 2.434, p<0.001).

CONCLUSION

The recommends that at least 7 harvested lymph nodes may be more appropriate for LARC patients with nCRT. PLN and LNR may be prognostic factors for LARC patients with ypN+ after nCRT.

[Mobilization of splenic flexure - routine or selective (results of a single-center randomized study)]

OBJECTIVE

To evaluate safety and effectiveness of routine splenic flexure mobilization (SFM) in surgical treatment of rectal cancer (RC).

MATERIAL AND METHODS

A single-center randomized study was performed between 2016 and 2019. Patients were randomized into 2 groups (SFM (+), n=156, SFM(-), n=67). Standard anterior and low anterior rectal resection was used. We used a combination of medial, lateral, and anterior approaches for SFM. Intraoperative, early and late postoperative complications, histological data, local recurrence, overall 3-year, relapse-free and cancer-specific survival were analyzed.

RESULTS

Surgery time was 253.2±72.8 and 252.0±78.0 min in the SFM(+) and SFM(-) groups, respectively (p=0.98). Blood loss was 53.3±53.6 and 67.0±108.8 ml, respectively (p=0.85), length of specimen - 28.6 (95% CI 27.2-29.9) and 24.0 cm (95% CI 22.2-25.7) (p<0.0001). Length of residual fragment of sigmoid colon was 5.0 (95% CI 3.9-6.1) and 9.1 cm (95% CI 7.2-11.1) (p<0.0001), respectively. The number of examined lymph nodes was 15.5 (95% CI 14.2-16.8) and 16.1 (95% CI 14.2-18.1) (p=0.52), number of affected lymph nodes - 1.5 (95% CI 0.9-2.1) and 1.5 (95% CI 0.9-2.2), respectively (p=0.38). Spleen damage was more common in the SFM (-) group (4.5% vs. 1.3%, p=0.12). Logistic regression analysis indicates that SFM does not affect the incidence of spleen damage. Severity of postoperative complications was similar (p=0.63). Anastomotic leak (AL) was more common in the SFM group (-) (17.9% vs. 9.6%, p=0.04). AL grade B was more common in the SFM(-) group (p=0.0001). Logistic regression analysis revealed the following predictors of anastomotic leakage: length of specimen and length of residual sigmoid colon. There was no significant relationship between SFM and incidence of local and systemic recurrences. Overall, cancer-specific and relapse-free 3-year survival was similar.

CONCLUSION

SFM is a safe procedure with various advantages. However, this approach does not improve intraoperative, early and long-term postoperative outcomes that does not allow us to recommend this approach for routine application.

Clinicopathological Factors Affecting Lymph Node Yield and Positivity in Left-Sided Colon and Rectal Cancers

Background

Colorectal cancer (CRC) is a significant cause of cancer‐related deaths worldwide and is the third most common cause of cancer deaths in the UK. The status of lymph node metastasis is a key factor for predicting the prognosis of a patient's CRC.

Aims

This study aimed to analyze the demographics of left-sided colonic and rectal cancers at a single institution. We looked closely at the correlation between patient age and various histological factors. We tried to find any significant difference in lymph node yield (LNY) between laparoscopic surgery (LS) and open surgery (OS). We aimed to identify any statistical correlation between LNY and lymph node positivity (LNP) with other patient, surgical and histopathological features.

Methodology

This is a retrospective, non-interventional review of consecutive patients who underwent left-sided colonic and rectal cancer resections over a three-year period between 01 April 2018 and 31 March 2021. Descriptive and inferential statistical analyses were used. Chi-squared / Fisher exact test was used on a categorical scale between two or more groups and non-parametric setting for qualitative data analysis.

Results

A total of 102 patients were included in the study. No statistical correlation was found between the age of the patient with the LNY, LNP, location of the tumor, type, and urgency of the operation. LNY ranged between one and 43 nodes (median (interquartile range (IQR)) 17, 8). There was no statistically significant difference in LNY between laparoscopic surgery (LS) and open surgery (OS) (p=0.1449). Significant statistical correlation was identified between LNP and completeness of resection (CoR) (p=0.039), vascular invasion (VI) (p<0.001), perineural invasion (PI) (p<0.001), and circumferential resectional margin involvement (CRMI) (p=0.039).

Discussion

LNY and LNP are important prognostic indices in colorectal cancer. Patient age, tumor location, the urgency of surgery, and consultant experience did not significantly impact the LNY. Our study showed a positive correlation between LNP and CRMI, VI and PI comparable to literature. Contrary to other studies, we found no statistical significance between LS vs. OS and LNY. Whether 12 nodes per patient is an appropriate level remains controversial.

Stage II colon cancer staging using the number of retrieved lymph nodes may be superior to current TNM staging for prognosis stratification: the Japanese study group for postoperative follow-up of colorectal cancer

PURPOSE

The purpose of the study was to compare staging of stage II colon cancer using the number of retrieved lymph nodes (RN) to current TNM staging for stratification of prognosis.

METHODS

The subjects were 6307 patients with stage II colon cancer who underwent curative resection at 24 Japanese institutions. The cutoff for the number of RN was established using Akaike information criterion (AIC) values for relapse-free survival (RFS) and overall survival (OS). Comparison of survival using TNM and T + RN (TRN) staging was performed using a Cox proportional hazards regression model.

RESULTS

AIC was lowest for 14 retrieved lymph nodes for RFS and OS. This number was used as the cutoff. In multivariate analysis, age (≥ 69), male gender, V1, CEA (> 5), pT (T4a, T4b), and RN-L were independent factors associated with RFS and OS. Six combinations of pT and RN categories were used to establish three subgroups: TRN stages IIA, IIB, and IIC. The 5-year RFS was 83.9%, 72.3%, and 71.8% in TNM stages IIA, IIB, and IIC; and 86.0%, 76.9%, and 60.3% in TRN stages IIA, IIB, and IIC. The 5-year OS was 90.0%, 81.3%, and 82.6% for the TNM stages; and 91.6%, 85.0%, and 71.9% for the TRN stages. The AIC for RFS was lower for TRN (22,318.2) than for TNM (22,390.6), and that for OS was also lower for TRN (16,285.3) than for TNM (16,355.1).

CONCLUSION

Stage II colon cancer staging using the number of retrieved lymph nodes may be superior to current TNM staging for prognosis stratification.

Has the increase in the regional nodes evaluated improved survival rates for patients with locoregional colon cancer?

Background: The guidelines for colon cancer surgery have been evolving over the past three decades. The advances in colectomy have focused mainly on the number of regional nodes evaluated (RNE).

Methods: Data in this retrospective analysis were extracted from the Surveillance, Epidemiology, and End Results (SEER) linked database.

Results: Rapid growth of RNE (the median rising from 10 (6-16) to 17 (13-23)) occurred from 2000 to 2009. The rate of colon cancer patients with positive lymph nodes following colectomy was greatly decreasing only in the group with RNE greater than 12 after 2000. Patients with T4 and/or N+ cannot obtain survival benefit from the increasing trend of RNE. The apparent survival benefit for T1-3N0 patients may result from augmented false negatives in patients from previous periods.

Conclusions: The golden period of surgical development in colon cancer, using RNE as an alternative indicator, occurred in the first decade of the 21st century. Although a more extensive lymph node evaluation is able to reduce the risk of underestimated staging, the increase of RNE does not provide survival benefits for locoregional colon cancer. A proper reduction in the scope of lymph node dissection may be reasonable in radical surgery for colon cancer.

Prediction of Recurrence in Patients with Stage III Colon Cancer Using Conventional Clinicopathological Factors and Peripheral Blood Test Data: A New Analysis with Artificial Intelligence

BACKGROUND

Survival rate may be predicted by tumor-node-metastasis staging systems in colon cancer. In clinical practice, about 20 to 30 clinicopathological factors and blood test data have been used. Various predictive factors for recurrence have been advocated; however, the interactions are complex and remain to be established. We used artificial intelligence (AI) to examine predictive factors related to recurrence.

METHODS

The study group comprised 217 patients who underwent curative surgery for stage III colon cancer. Using a self-organizing map (SOM), an AI-based method, patients with only 23 clinicopathological factors, patients with 23 clinicopathological factors and 34 of preoperative blood test data (pre-data), and those with 23 clinicopathological factors and 31 of postoperative blood test data (post-data) were classified into several clusters with various rates of recurrence.

RESULTS

When only clinicopathological factors were used, the percentage of T4b disease, the percentage of N2 disease, and the number of metastatic lymph nodes were significantly higher in a cluster with a higher rate of recurrence. When clinicopathological factors and pre-data were used, three described pathological factors and the serum C-reactive protein (CRP) levels were significantly higher and the serum total protein (TP) levels, serum albumin levels, and the percentage of lymphocytes were significantly lower in a cluster with a higher rate of recurrence. When clinicopathological factors and post-data were used, three described pathological factors, serum CRP levels, and serum carcinoembryonic antigen levels were significantly higher and serum TP levels, serum albumin levels, and the percentage of lymphocytes were significantly lower in a cluster with a higher rate of recurrence.

CONCLUSIONS

This AI-based analysis extracted several risk factors for recurrence from more than 50 pathological and blood test factors before and after surgery separately. This analysis may predict the risk of recurrence of a new patient by confirming which clusters this patient belongs to.

Molecular Lymph Node Staging with One-Step Nucleic Acid Amplification and its Prognostic Value for Patients with Colon Cancer: The First Follow-up Study

Background

Molecular lymph node workup with one-step nucleic acid amplification (OSNA) is a validated diagnostic adjunct in breast cancer and also appealing for colon cancer (CC) staging. This study, for the first time, evaluates the prognostic value of OSNA in CC.

Patients and methods

The retrospective study includes patients with stage I-III CC from three centres. Lymph nodes were investigated with haematoxylin and eosin (H&E) and with OSNA, applying a 250 copies/μL threshold of CK19 mRNA. Diagnostic value of H&E and OSNA was assessed by survival analysis, sensitivity, specificity and time-dependent receiver operating characteristic curves.

Results

Eighty-seven patients were included [mean follow-up 53.4 months (± 24.9)]. Disease recurrence occurred in 16.1% after 19.8 months (± 12.3). Staging with H&E independently predicted worse cancer-specific survival in multivariate analysis (HR = 10.77, 95% CI 1.07–108.7, p = 0.019) but not OSNA (HR = 3.08, 95% CI 0.26–36.07, p = 0.197). With cancer-specific death or recurrence as gold standard, H&E sensitivity was 46.7% (95% CI 21.3–73.4%) and specificity 84.7% (95% CI 74.3–92.1%). OSNA sensitivity and specificity were 60.0% (95% CI 32.3–83.7%) and 75.0% (95% CI 63.4–84.5%), respectively.

Conclusions

In patients with CC, OSNA does not add relevant prognostic value to conventional H&E contrasting findings in other cancers. Further studies should assess lower thresholds for OSNA (< 250 copies/μL).

Examining More Lymph Nodes May Improve the Prognosis of Patients With Right Colon Cancer: Determining the Optimal Minimum Lymph Node Count

OBJECTIVES

The objective is to determine the optimal minimum lymph node examination number for right colon cancer (RCC) patients.

METHODS

We comprehensively analysed the Surveillance, Epidemiology and End Results database data from 2004 to 2016 to determine the 13-year trend in the number of lymph nodes examined among 108,703 left colon cancer and 165,937 RCC patients. 133,137 RCC patients eligible for inclusion were used to determine the optimal minimum for lymph node examination. We used restricted cubic splines to analyse the dose-response relationship between the number of lymph nodes examined and prognosis. X-tiles and decision trees were used to determine the optimal cutoff for the number of lymph nodes based on the survival outcomes of patients with RCC. The Kaplan-Meier method and COX model were used to estimate the overall survival and independent prognostic factors, and a prediction model was constructed. The C-index, calibration curve, net reclassification improvement and integrated discrimination improvement were used to determine the predictive performance of the model, and decision curve analysis was used to evaluate the benefits.

RESULTS

Lymph node examinations were common among colon cancer patients over the 13-year study period. It is generally agreed that at least 12 lymph nodes must be examined to ensure proper dissection and accurate staging of RCC; however, the optimal number of lymph nodes to be examined is controversial. The dose-response relationship indicated that 12 was not the optimal minimum number of lymph nodes for RCC patients. X-tile and survival decision-tree analysis indicated that 20 nodes was the optimal number. Survival analysis indicated that <20 nodes examined was a risk factor for poor prognosis, and the classification performance was superior for 20 nodes compared to 12 nodes.

CONCLUSION

Lymph node examination in RCC patients should be altered. Our research suggests that a 20-node measure may be more suitable for RCC patients.

Impact factors of lymph node retrieval on survival in locally advanced rectal cancer with neoadjuvant therapy

BACKGROUND

Conventional clinical guidelines recommend that at least 12 lymph nodes should be removed during radical rectal cancer surgery to achieve accurate staging. The current application of neoadjuvant therapy has changed the number of lymph node dissection.

AIM

To investigate factors affecting the number of lymph nodes dissected after neoadjuvant chemoradiotherapy in locally advanced rectal cancer and to evaluate the relationship of the total number of retrieved lymph nodes (TLN) with disease-free survival (DFS) and overall survival (OS).

METHODS

A total of 231 patients with locally advanced rectal cancer from 2015 to 2017 were included in this study. According to the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) tumor-node-metastasis (TNM) classification system and the NCCN guidelines for rectal cancer, the patients were divided into two groups: group A (TLN ≥ 12, n = 177) and group B (TLN < 12, n = 54). Factors influencing lymph node retrieval were analyzed by univariate and binary logistic regression analysis. DFS and OS were evaluated by Kaplan-Meier curves and Cox regression models.

RESULTS

The median number of lymph nodes dissected was 18 (range, 12-45) in group A and 8 (range, 2-11) in group B. The lymph node ratio (number of positive lymph nodes/total number of lymph nodes) (P = 0.039) and the interval between neoadjuvant therapy and radical surgery (P = 0.002) were independent factors of the TLN. However,TLN was not associated with sex, age, ASA score, clinical T or N stage, pathological T stage, tumor response grade (Dworak), downstaging, pathological complete response, radiotherapy dose, preoperative concurrent chemotherapy regimen, tumor distance from anal verge, multivisceral resection, preoperative carcinoembryonic antigen level, perineural invasion, intravascular tumor embolus or degree of differentiation. The pathological T stage (P < 0.001) and TLN (P < 0.001) were independent factors of DFS, and pathological T stage (P = 0.011) and perineural invasion (P = 0.002) were independent factors of OS. In addition, the risk of distant recurrence was greater for TLN < 12 (P = 0.009).

CONCLUSION

A shorter interval to surgery after neoadjuvant chemoradiotherapy for rectal cancer under indications may cause increased number of lymph nodes harvested. Tumor shrinkage and more extensive lymph node retrieval may lead to a more favorable prognosis.

Lymph Node Harvest After Neoadjuvant Treatment for Rectal Cancer and Its Impact on Oncological Outcomes

The aim of this study was to analyze the influence of neoadjuvant treatment on nodal harvest after rectal cancer surgery and its impact on long-term oncological outcomes. A retrospective analysis of patients with rectal cancer who received curative intent treatment from 2002 to 2012 in our institution was performed. Data on various clinic-pathological and treatment details were recovered from the records. The number of nodes harvested after surgery was analyzed. The influence of number of nodes harvested on overall survival and disease free survival was analyzed. Among the 459 patients included in this study, 326 underwent surgery after neoadjuvant treatment (NAT). The mean number of nodes harvested was significantly lower in patients who received NAT compared with those who did not (8.9 ± 5.77 vs 14 ± 9.84, p < 0.001). However, the mean number of pathologically positive nodes was not significantly different. A minimum of 12 nodes were harvested in only 27.9% of patients who received NAT. No lymph nodes were identified in the specimen in 15 patients (4.6%) who underwent surgery after NAT. The only independent factors influencing harvest of a minimum of 12 nodes were patient age and NAT. The 5-year overall survival was not significantly different in patients in whom < 12 or ≥ 12 nodes were harvested (64% vs 69% respectively, p = 0.5). Neoadjuvant chemoradiation significantly reduces nodal harvest in patients undergoing treatment for rectal cancer. However, this reduced nodal harvest did not adversely impact survival in patients. However, every effort must be made by the surgeon and the pathologist to maximize the nodal harvest.

The prognostic impact of neoadjuvant chemoradiotherapy on lymph node sampling in patients with locally advanced rectal cancer

According to the American Joint Committee on Cancer, at least 12 lymph nodes are required to accurately stage locally advanced rectal cancer (LARC). Neoadjuvant chemoradiation therapy (NACRT) reduces the number of lymph nodes retrieved during surgery. In this study, we evaluated the effect of NACRT on lymph node retrieval and prognosis in patients with LARC. We performed an observational study of 142 patients with LARC. Although our analysis was retrospective, data were collected prospectively. Half the patients were treated with NACRT and total mesorectal excision (TME) and the other half underwent TME only. The number of lymph nodes retrieved and the number of metastatic lymph nodes were significantly reduced in the NACRT group (P > 0.001). In the univariate and multivariate analyses, only NACRT and patient age were significantly associated with reduced lymph node retrieval. The number of metastatic lymph nodes and the lymph node ratio (LNR) both had a significant effect on prognosis when the patient population was examined as a whole (P = 0.003 and P = 0.001, respectively). However, the LNR was the only significant, independent prognostic factor in both treatment groups (P = 0.007 for the NACRT group; P = 0.04 for the no-NACRT group). NACRT improves patient prognosis only when the number of metastatic lymph nodes is reduced. The number of metastatic lymph nodes and the LNR are important prognostic factors. Lymph node retrieval remains an indispensable tool for staging and prognostic assessment of patients with rectal carcinoma treated with NACRT.

Budget Impact Analysis of Molecular Lymph Node Staging Versus Conventional Histopathology Staging in Colorectal Carcinoma

BACKGROUND

The presence of lymph node (LN) metastasis is a critical prognostic factor in colorectal cancer (CRC) patients and is also an indicator for adjuvant chemotherapy. The gold standard (GS) technique for LN diagnosis and staging is based on the analysis of haematoxylin and eosin (H&E)-stained slides, but its sensitivity is low. As a result, patients may not be properly diagnosed and some may have local recurrence or distant metastases after curative-intent surgery. Many of these diagnostic and treatment problems could be avoided if the one-step nucleic acid amplification assay (OSNA) was used rather than the GS technique. OSNA is a fast, automated, standardised, highly sensitive, quantitative technique for detecting LN metastases.

OBJECTIVES

The aim of this study was to assess the budget impact of introducing OSNA LN analysis in early-stage CRC patients in the Spanish National Health System (NHS).

METHODS

A budget impact analysis comparing two scenarios (GS vs. OSNA) was developed within the Spanish NHS framework over a 3-year time frame (2017-2019). The patient population consisted of newly diagnosed CRC patients undergoing surgical treatment, and the following costs were included: initial surgery, pathological diagnosis, staging, follow-up expenses, systemic treatment and surgery after recurrence. One- and two-way sensitivity analyses were performed.

RESULTS

Using OSNA instead of the GS would have saved €1,509,182, €6,854,501 and €10,814,082 during the first, second and third years of the analysis, respectively, because patients incur additional costs in later years, leading to savings of more than €19 million for the NHS over the 3-year time horizon.

CONCLUSIONS

Introducing OSNA in CRC LN analysis may represent not only an economic benefit for the NHS but also a clinical benefit for CRC patients since a more accurate staging could be performed, thus avoiding unnecessary treatments.

Factors affecting retrieval of 12 or more lymph nodes in pT1 colorectal cancers

Objective

The aim of this study was to identify clinicopathological factors that affect the number of lymph nodes (LNs) (12 or more) retrieved from patients with colorectal cancer (CRC), particularly those with pathologic T1 (pT1) disease.

Methods

From 429 CRC patients, 75 pT1 cancers were identified and digitally scanned. Binary logistic regression analysis was performed to identify the clinicopathological factors affecting the number of LNs retrieved from all 429 patients and from the subset of patients with pT1 CRC.

Results

For the 429 patients, the mean number of harvested LNs per specimen was 20 (median, 19). The number of retrieved LNs was independently associated with maximum tumor diameter > 2.3 cm and right-sided tumor location. The mean number of LNs retrieved from the 75 patients with pT1 CRC was 14 (median, 15); retrieval of 12 or more LNs from this group was independently associated with maximum tumor diameter > 14.1 mm.

Conclusion

The number of LNs retrieved from patients with CRC was associated with maximum tumor diameter and right-sided tumor location. For patients with pT1 CRC, maximum tumor diameter was independently associated with the harvesting of 12 or more LNs.

Comparison of Oncologic Outcomes in Laparoscopic versus Open Surgery for Non-Metastatic Colorectal Cancer: Personal Experience in a Single Institution

The oncologic merits of the laparoscopic technique for colorectal cancer surgery remain debatable. Eligible patients with non-metastatic colorectal cancer who were scheduled for an elective resection by one surgeon in a medical institution were randomized to either laparoscopic or open surgery. During this period, a total of 188 patients received laparoscopic surgery and the other 163 patients received the open approach. The primary endpoint was cancer-free five-year survival after operative treatment, and the secondary endpoint was the tumor recurrence incidence. Besides, surgical complications were also compared. There was no statistically significant difference between open and laparoscopic groups regarding the average number of lymph nodes dissected, ileus, anastomosis leakage, overall mortality rate, cancer recurrence rate, or cancer-free five-year survival. Even though performing a laparoscopic approach used a significantly longer operation time, this technique was more effective for colorectal cancer treatment in terms of shorter hospital stay and less blood loss. Meanwhile, fewer patients receiving the laparoscopic approach developed postoperative urinary tract infection, wound infection, or pneumonia, which reached statistical significance. For non-metastatic colorectal cancer patients, laparoscopic surgery resulted in better short-term outcomes, whether in several surgical complications and intra-operative blood loss. Though there was no significant statistical difference in terms of cancer-free five-year survival and tumor recurrence, it is strongly recommended that patients undergo laparoscopic surgery if not contraindicated.

The relation between oncologic outcomes and metastatic lymph node location following laparoscopic resection of stage III colon cancer

PURPOSE

Colon cancers are staged by assessing more than 12 lymph nodes, but there is still a controversy over the number of lymph nodes. Only a few studies of metastatic lymph node position in colon cancer have been published with its significance not completely understood. This study aimed to compare survival rates according to metastatic lymph node position following radical lymph node dissection for stage III colon cancers.

METHODS

This retrospective study evaluated data prospectively collected at a tertiary teaching hospital from 349 patients who underwent laparoscopic colectomy with radical node dissection between December 2009 and December 2014. Lymph nodes were numbered and classified into lymph node metastasis (LNM) groups LNM1, LNM2, and LNM3 and their short- and long-term outcomes were compared.

RESULTS

The LNM1, LNM2, and LNM3 groups included 229, 94, and 26 patients, respectively. Patient characteristics differed by locations (p < 0.001). A mean 34.6 lymph nodes were harvested, and a mean 2.6, 5, and 9 metastatic nodes were identified, respectively (p < 0.001), a finding that is proportional to the cancer stage (tau-b = 0.284, p < 0.001; rho = 0.3, p < 0.001). The 5-year disease-free survival rate did not differ among the three groups; however, the LNM3 group had the poorest overall and cancer-specific survival rates. Risk factors associated with cancer-specific survival rate were identified with neural invasion, poorly differentiated tumors, and the location of pathologic lymph nodes (LNM).

CONCLUSION

Metastatic lymph node location affects oncologic outcomes of stage III colon cancer. The patients for LNM3 metastasis should receive a more aggressive adjuvant treatment.

Clinicopathological Factors Influencing Lymph Node Yield in Colorectal Cancer: A Retrospective Study

Many colorectal resections do not meet the minimum of 12 lymph nodes (LNs) recommended by the American Joint Committee on Cancer for accurate staging of colorectal cancer. The aim of this study was to investigate factors affecting the number of the adequate nodal yield in colorectal specimens subject to routine pathological assessment. We have retrospectively analysed the data of 2319 curatively resected colorectal cancer patients in San Raffaele Scientific Institute, Milan, between 1993 and 2017 (1259 colon cancer patients and 675 rectal cancer patients plus 385 rectal cancer patients who underwent neoadjuvant therapy). The factors influencing lymph node retrieval were subjected to uni- and multivariate analyses. Moreover, a survival analysis was carried out to verify the prognostic implications of nodal counts. The mean number of evaluated nodes was 24.08 ± 11.4, 20.34 ± 11.8, and 15.33 ± 9.64 in surgically treated right-sided colon cancer, left-sided colon cancer, and rectal tumors, respectively. More than 12 lymph nodes were reported in surgical specimens in 1094 (86.9%) cases in the colon cohort and in 425 (63%) cases in the rectal cohort, and patients who underwent neoadjuvant chemoradiation were analysed separately. On univariate analysis of the colon cancer group, higher LNs counts were associated with female sex, right colon cancer, emergency surgery, pT3-T4 diseases, higher tumor size, and resected specimen length. On multivariate analysis right colon tumors, larger mean size of tumor, length of specimen, pT3-T4 disease, and female sex were found to significantly affect lymph node retrieval. Colon cancer patients with 12 or more lymph nodes removed had a significantly better long-term survival than those with 11 or fewer nodes (P = 0.002, log-rank test). Rectal cancer patients with 12 or more lymph nodes removed approached but did not reach a statistically different survival (P = 0.055, log-rank test). Multiple tumor and patients' factors are associated with lymph node yield, but only the removal of at least 12 lymph nodes will reliably determine lymph node status.

Predictive Value of the Number of Harvested Lymph Nodes and Cut-Off for Lymph Node Ratio in the Prognosis of Stage II and III Colorectal Cancer Patients

Purpose/aim: The appropriate staging of colorectal cancer requires at least 12 lymph nodes to be sampled. We evaluated whether lymph node sampling (LNS) and lymph node ratio (LNR) can predict the prognosis of stage II-III patients.

MATERIALS AND METHODS

This is a retrospective study on 432 patients classified in LNS ≥12 and LNS <12. Disease-free survival (DFS) was computed using the Kaplan-Meier method. We stratified stage III patients into 4 quartiles base on LNR values. To determine the optimal LNR cut-off, receiver operating characteristic (ROC) curve analysis was performed.

RESULTS

There was a positive association between the number of lymph node sampled and the number of metastatic lymph nodes (p < 0.01). Among stage II patients, the DFS was 81% for LNS ≥ 12 and 72% for LNS < 12 (p = 0.158). Among stage III patients, the DFS was 58% (p < 0.001). We found a significant association between LNR quartiles and relapse in stage III patients but only in the LNS ≥ 12 group. ROC curve analysis indicated an ideal LNR cut-off value at 0.194 (sensitivity 65% and specificity 61%). The DFS of patients with LNR below 0.194 was 71%, and that of patients with LNR above 0.194 was 45% (log-rank test, p < 0.001). In the patients with LNS ≥ 12, the cut-off of 0.257 could predict recurrence (specificity 86%).

CONCLUSIONS

Stage II patients with LNS < 12 tend to have shorter DFS than stage II patients with LNS ≥ 12. In stage III patients, an appropriate LNR cut-off is a better prognostic predictor than LNR quartile, especially in patients with LNS ≥ 12.

Reconsideration of the optimal minimum lymph node count for young colon cancer patients: a population-based study

BACKGROUND

Currently, young colon cancer (CC) patients continue to increase and represent a heterogeneous patient group. The aim of this study was to explore the optimal minimum lymph node count after CC resection for young patients.

METHODS

We performed a comprehensive search of the Surveillance, Epidemiology, and End Results (SEER) database, 2360 CC patients aged from 20 to 40 were analyzed. X-tile was used to determine the optimal cut-off point of lymph node based on survival outcomes of young patients. The cancer specific survival (CSS) was estimated with Kaplan-Meier method, the Cox proportional hazards regression model was used to analyse independent prognostic factors and exact 95% confidence intervals (CIs).

RESULTS

Using X-tile analysis, 22-node measure was identified as the optimal choice for CC patients aged < 40. The 5-year CSS were 85.8% and 80.9% for patients examining ≥22 nodes and < 22 nodes. Furthermore, we identified that examining < 22 nodes was an independent adverse prognostic factor in patients aged < 40. In addition, the revised 22-node measure could examine more positive nodes than the standard 12-node measure in young patients.

CONCLUSIONS

For young colon cancer patients, the lymph node examination should be differently evaluated. We suggest that 22-node measure may be more suitable for CC patients aged < 40.

TRIAL REGISTRATION

Retrospectively registered.

Prognostic value of total number of lymph nodes retrieved differs between left-sided colon cancer and right-sided colon cancer in stage III patients with colon cancer

Background

The consensus is that a minimum of 12 lymph nodes should be analyzed at colectomy for colon cancer. However, right colon cancer and left colon cancer have different characteristics, and this threshold value for total number of lymph nodes retrieved may not be universally applicable.

Methods

The data of 63,243 patients with colon cancer treated between 2004 and 2012 were retrieved from the National Cancer Institute’s Surveillance, Epidemiology, and End Results database. Multivariate Cox regression analysis was used to determine the predictive value of total number of lymph nodes for survival after adjusting for lymph nodes ratio. The predictive value in left-sided colon cancer and right-sided colon cancer was compared. The optimal total number of lymph nodes cutoff value for prediction of overall survival was identified using the online tool Cutoff Finder. Survival of patients with high total number of lymph nodes (≥12) and low total number of lymph nodes (< 12) was compared by Kaplan–Meier analysis.

Results

After stratifying by lymph nodes ratio status, total number of lymph nodes≥12 remained an independent predictor of survival in the whole cohort and in right-sided colon cancer, but not in left-sided colon cancer. The optimal cutoff value for total number of lymph nodes was determined to be 11. Low total number of lymph nodes (< 11) was associated with significantly poorer survival after adjusting for lymph nodes ratio in all subgroups except in the subgroup with high lymph nodes ratio (0.5–1.0).

Conclusions

Previous reports of the prognostic significance of total number of lymph nodes on node-positive colon cancer were confounded by lymph nodes ratio. The 12-node standard for total number of lymph nodes may not be equally applicable in right-sided colon cancer and left-sided colon cancer.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4431-5) contains supplementary material, which is available to authorized users.

Rectal cancer and the pathologist

Examination of the rectum by pathologists is instrumental in the management of patients affected by rectal carcinoma. That role includes evaluation of multiple gross and microscopic features that convey prognostic implications. The analysis is based on the authors' experience handling rectal specimens along with review of the pertinent literature in these areas: margins of excision, quality of the mesorectum, diligence and techniques to sample lymph nodes, tumor budding, grading of residual amount of carcinoma after preoperative therapy, vascular/perineural invasion, and staging the tumor. Pathologists must communicate the findings in a clear manner. Evaluation of margins and completeness of mesorectum are markers of the quality of surgical excision. The number of lymph nodes obtained and examined is dependent in great part on the diligence of the pathologist finding them in the mesenteric adipose tissue. There are grades for budding and response to prior chemoradiation therapy. The location of vascular invasion (extramural vs. intramural) may predict aggressive behavior. Pathologists proactively are to choose sections of tumor for molecular testing. Meticulous macro- and microscopic evaluation of specimens for rectal carcinoma by pathologist is needed to determine an accurate assessment of staging and other prognostic factors. The modern pathologists play a pivotal part in the care and management of patients suffering from rectal adenocarcinoma. That role goes from the initial histological diagnosis to the gross and microscopic examination of the excised specimens. Based on that examination pathologists issue statements that not only evaluate the quality of the surgical procedure, but also through the application of molecular tests they give light on prognostic factors and information for therapeutic purposes.

Determinants of lymph node count and positivity in patients undergoing surgery for colon cancer

Prognosis in colon cancer is based on pathological criteria including TNM staging. However, there are deficiencies in this approach, and the lymph node ratio (LNR) has been proposed to improve the prediction of outcomes. LNR is dependent on optimal retrieval of lymph nodes-lymph node count (LNC). Recent studies have suggested that an elevated preoperative systemic inflammatory response (SIR) was associated with a lower LNC and a higher LNR. However, there are a number of potential confounding factors. The aim of the present study was to examine, in detail, these relationships in a large cohort of patients.A prospectively maintained database of all patients undergoing colon cancer resection in our institution was examined. The SIR was measured by a number of inflammatory markers and their scores: modified Glasgow Prognostic Score (mGPS) (C-reactive protein/albumin), neutrophil lymphocyte ratio (NLR), platelet lymphocyte ratio (PLR), and lymphocyte monocyte ratio (LMR) using standard thresholds. The relationships between LNC and LNR, and clinicopathological characteristics (including the mGPS, NLR, PLR, and LMR) were examined using chi-square test for trend and binary logistic regression analysis, where appropriate.Of the 896 patients included in the study, 418 (47%) were male, the median LNC was 17 (1-71), and the median LNR in node positive disease was 0.16 (0.03-1). On multivariate analysis, there was a significant independent relationship between an elevated LNC (≥12) and laparoscopic surgery (P < .001), right-sided tumors (P < .001), later date of resection (2007-2016) (P < .001), T stage (P < .001), and venous invasion (P < .001). In those patients with a LNC ≥12 and node-positive disease (n = 272), on multivariate analysis, there was a significant relationship between an elevated LNR (≥0.25), and T stage (P < .01) and differentiation (P < .05). Finally, in patients with node-positive disease who had surgery later (2007-2016), LNR was directly superior to N stage for both cancer-specific survival (LNR: hazard ratio [HR] 2.62, 95% confidence interval [CI] 1.25-5.52, P = .011) and overall survival (LNR: HR 2.02, 95% CI 1.12-3.68, P = .022).Neither LNC nor LNR was associated with markers of the SIR; however, LNC and LNR were directly associated. In high-quality surgical and pathological practice, LNR had superior prognostic value compared with N stage in patients undergoing surgery for colon cancer.

A comparative study of short-term outcomes of colorectal cancer surgery in the elderly population

BACKGROUND

Colorectal Cancer (CRC) is a disease of the elderly, and with an ageing population, oncological surgical procedures for CRC in the elderly is expected to increase. However, the balance between surgical benefits and risks associated with age and comorbidities in elderly patients is obscure.

MATERIALS AND METHODS

A retrospective database of consecutive patients who received CRC surgery was used to compare short-term surgical and oncological outcomes between patients aged ≥75 and <75 years old undergoing CRC resection.

RESULTS

There were 54 patients (63.5%) in the <75 group and 31 patients (36.5%) in the ≥75 group. Overall, there were no differences between the <75 and ≥75 groups in postoperative HDU/ITU stay, median hospital LOS or 30-day mortality rates. Patients ≥75 had a higher preoperative performance status (25.9% versus 71.0%, p < .001), but no difference in ASA Grade and referral pattern, proportion of emergency operations, cancer staging, resection margins, achievement of curative resection or median lymph node yield. There was a significantly higher use of adjuvant chemotherapy in the <75 age group (48.1% versus 25.8%, p = .043).

CONCLUSIONS

With adequate patient selection, CRC resection in elderly patients is not associated with higher postoperative mortality or worse short-term oncological benefits.

Tumor size, tumor location, and antitumor inflammatory response are associated with lymph node size in colorectal cancer patients

Lymph node size affects lymph node retrieval in surgical specimen and is used as criterion for pre-operative radiological estimation of metastatic disease. However, factors determining lymph node size remain to be established. Therefore, the association between lymph node size and presence of metastatic cancer deposits as well as different primary tumor characteristics was analyzed in a prospective cross-sectional study. Visible and palpable nodes were harvested, and conventional histology, immunohistochemistry, and molecular analysis were performed. The study cohort comprised 148 patients (median age 69 years, range 36-92). Lymph node dissection rendered 4167 nodes. Mean lymph node count was 28 (median 26, range 9-67). Metastatic disease was detected in 320 (8%) nodes and was associated with lymph node size (P<0.001). Positive nodes measuring ≤2 mm caused upstaging within the N category in one third of cases, but did not identify patients as node-positive as all patients also had positive larger nodes. Large tumor size (P=0.001), right tumor location (P<0.001), and deep tumor penetration (P=0.024) were all independently associated with lymph node size, whereas high lymphocytic antitumor reaction just missed statistical significance (P=0.053) in multivariable analysis. Microsatellite instability had no influence on lymph node size when analysis was restricted to right-sided tumors. In conclusion, analysis of small lymph nodes may lead to upstaging within the N category, but they do not identify a patient as node-positive and do therefore not influence clinical decision-making in the adjuvant setting. The majority of enlarged lymph nodes, including those measuring >1 cm, are not involved by cancer. Different tumor characteristics, such as large primary tumor size, right tumor location, and deep tumor penetration are independently associated with lymph node size and need to be considered when interpreting enlarged nodes detected by radiological imaging.

Population-based study to re-evaluate optimal lymph node yield in colonic cancer

BACKGROUND

It is well established that lymph node (LN) yield in colonic cancer resection has prognostic significance, although optimal numbers are not clear. Here, LN thresholds associated with both LN positivity and survival were evaluated in a single population-based data set.

METHODS

Treatment records were linked to the Ontario Cancer Registry to identify a 25 per cent random sample of all patients with stage II/III colonic cancer between 2002 and 2008. Multivariable regression and Cox models evaluated factors associated with LN positivity and cancer-specific survival (CSS) respectively. Optimal thresholds were obtained using sequential regression analysis.

RESULTS

On adjusted analysis of 5508 eligible patients, younger age (P < 0·001), left-sided tumours (P = 0·003), higher T category (P < 0·001) and greater LN yield (relative risk 0·89, 95 per cent c.i. 0·81 to 0·97; P = 0·007) were associated with a greater likelihood of LN positivity. Regression analyses with multiple thresholds suggested no substantial increase in LN positivity beyond 12-14 LNs. Cox analysis of stage II disease showed that lower LN yield was associated with a significant increase in the risk of death from cancer (CSS hazard ratio range 1·55-1·74; P < 0·001) compared with a greater LN yield, with no significant survival benefit beyond a yield of 20 LNs. Similarly, for stage III disease, a lower LN yield was associated with an increase in the risk of death from cancer (CSS hazard ratio range 1·49-2·20; P < 0·001) versus a large LN yield. In stage III disease, there was no observed LN threshold for survival benefit in the data set.

CONCLUSION

There is incongruity in the optimal LN evaluation for colonic cancer. Although the historically stated threshold of 12 LNs may ensure accurate staging in colonic cancer, thresholds for optimal survival are associated with far greater yields.

More is better: Lymph node harvesting in colorectal cancer

INTRODUCTION

We sought to determine if lymph node harvesting and survival for CRC were comparable between laparoscopic and open resections in a community hospital setting.

METHODS

A retrospective chart review of patients at two community hospitals who underwent open or laparoscopic resection for CRC between January 2008 and September 2013 was performed.

RESULTS

Three hundred seventy-one patients had open and 110 had laparoscopic resections. There was no difference between open (17.85) and laparoscopic (18.91) approaches (p = 0.171) in the number of lymph nodes harvested. Patients who had more nodes removed tended toward improved survival, independent of stage (p = 0.052), an effect that was more pronounced in the open resection group (p = 0.031). There was no difference in survival between the open and laparoscopic groups overall (HR 1.52, p = 0.208).

DISCUSSION

No survival advantage was found between the open and laparoscopic resection groups, affirming that the choice of operative approach for CRC does not affect the quality of the oncologic procedure in a community hospital setting. Patients who had more lymph nodes removed tended toward improved survival. The explanation for this effect remains unclear.

Oncologic Outcomes Following Laparoscopic versus Open Resection of pT4 Colon Cancer: A Systematic Review and Meta-analysis

BACKGROUND

Locally advanced colon cancer is considered a relative contraindication for laparoscopic resection, and clinical trials addressing the oncologic safety are lacking.

OBJECTIVE

The aim of this study was to synthesize the oncologic outcomes associated with laparoscopic versus conventional open surgery for locally advanced colon cancers.

DATA SOURCES

We systematically searched Medline, Embase, Central, and ClinicalTrials.gov.

STUDY SELECTION

Two reviewers independently screened the literature for controlled trials or observational studies comparing curative-intent laparoscopic and open surgery for colon cancer. Studies were included if it was possible to determine outcomes for the T4 colon cancers separately, either reported in the article or calculated with individual patient data.

INTERVENTIONS

Included studies were systematically reviewed and assessed for risk of bias. Meta-analyses were done by using random-effects models.

MAIN OUTCOME MEASURES

Outcomes of interest were disease-free survival, overall survival, resection margins, and lymph node harvest.

RESULTS

Of 2878 identified studies, 5 observational studies met eligibility criteria with a total of 1268 patients (675 laparoscopic, 593 open). There was no significant difference in overall survival (HR, 1.28; 95% CI, 0.94-1.72), disease-free survival (HR, 1.20; 95% CI, 0.90-1.61), or positive surgical margins (OR, 1.16; 95% CI, 0.58-2.32) between the groups. The open group had a larger lymph node retrieval (pooled mean difference, 2.26 nodes; 95% CI, 0.58-3.93). The pooled rate of conversion from laparoscopy to an open procedure was 18.6% (95% CI, 9.3%-27.9%).

LIMITATIONS

These results are limited by the inherent selection bias in the included nonrandomized studies.

CONCLUSIONS

Based on the available literature, minimally invasive resection of selected locally advanced colon cancer is oncologically safe. There is a small increase in lymph node harvest with open resections, but it is unclear whether this is clinically significant. Surgeons should be prepared for a significant rate of conversion to laparotomy as required to perform en bloc resection.

Lymph node retrieval in colorectal cancer: determining factors and prognostic significance

PURPOSE

The study aimed to analyze clinicopathological factors that determine the extent of lymph node retrieval and to evaluate its prognostic impact in patients with colorectal cancer (CRC).

METHODS

The number of retrieved lymph nodes was analyzed in 381 CRC specimens. Lymph node count was related to different clinicopathological variables by binary logistic regression. Progression-free survival (PFS) and cancer-specific survival (CSS) were determined using the Kaplan-Meier method and Cox regression models.

RESULTS

The median number of retrieved lymph nodes was 20 (mean 21 ± 10, range 1-65) in right-sided, 13 (16 ± 10, 1-66) in left-sided, and 15 (18 ± 11, 3-64) in rectal tumors. The number of retrieved lymph nodes was independently associated with T-classification (p < 0.001), N-classification (p = 0.014), and tumor size (p = 0.005) as well as right-sided tumor location (p = 0.012). There was no association with age, sex, tumor grade, mismatch-repair status, and lymph or blood vessel invasion. The longer the surgical specimen, the higher were the numbers of retrieved and positive lymph nodes (p < 0.001, respectively). In patients with locally advanced (T3/T4) tumors (n = 283), analysis of more than 12 lymph nodes was independently associated with PFS (HR = 0.63, p = 0.025) and CSS (HR = 0.54, p = 0.004). In the subset of T3/T4 N0 patients (n = 130), analysis of more than 12 lymph nodes similarly proved to be an independent predictor of outcome (PFS, HR = 0.48, p = 0.046; OS, HR = 0.41, p = 0.026).

CONCLUSION

The number of retrieved lymph nodes is associated with higher tumor stage, tumor size, and right-sided location. Low lymph node count indicates adverse outcome in patients with locally advanced (T3/T4) disease.

A Nomogram to Predict Adequate Lymph Node Recovery before Resection of Colorectal Cancer

Increased lymph node count (LNC) has been associated with prolonged survival in colorectal cancer (CRC), but the underlying mechanisms are still poorly understood. The study aims to identify new predictors and develop a preoperative nomogram for predicting the probability of adequate LNC (≥ 12). 501 eligible patients were retrospectively selected to identify clinical-pathological factors associated with LNC ≥ 12 through univariate and multivariate logistic regression analyses. The nomogram was built according to multivariate analyses of preoperative factors. Model performance was assessed with concordance index (c-index) and area under the receiver operating characteristic curve (AUC), followed by internal validation and calibration using 1000-resample bootstrapping. Clinical validity of the nomogram and LNC impact on stage migration were also evaluated. Multivariate analyses showed patient age, CA19-9, circulating lymphocytes, neutrophils, platelets, tumor diameter, histology and deposit significantly correlated with LNC (P < 0.05). The effects were marginal for CEA, anemia and CRC location (0.05 < P < 0.1). The multivariate analyses of preoperative factors suggested decreased age, CEA, CA19-9, neutrophils, proximal location, and increased platelets and diameter were significantly associated with increased probability of LNC ≥ 12 (P < 0.05). The nomogram achieved c-indexes of 0.75 and 0.73 before and after correction for overfitting. The AUC was 0.75 (95% CI, 0.70–0.79) and the clinically valid threshold probabilities were between 10% and 60% for the nomogram to predict LNC < 12. Additionally, increased probability of adequate LNC before surgery was associated with increased LNC and negative lymph nodes rather than increased positive lymph nodes, lymph node ratio, pN stages or AJCC stages. Collectively, the results indicate the LNC is multifactorial and irrelevant to stage migration. The significant correlations with preoperative circulating markers may provide new explanations for LNC-related survival advantage which is reflected by the implication of regional and systemic antitumor immune responses.

A nomogram improves AJCC stages for colorectal cancers by introducing CEA, modified lymph node ratio and negative lymph node count

Lymph node stages (pN stages) are primary contributors to survival heterogeneity of the 7^th AJCC staging system for colorectal cancer (CRC), indicating spaces for modifications. To implement the modifications, we selected eligible CRC patients from the Surveillance Epidemiology and End Results (SEER) database as participants in a training (n = 6675) and a test cohort (n = 6760), and verified tumor deposits to be metastatic lymph nodes to derive modified lymph node count (mLNC), lymph node ratio (mLNR), and positive lymph node count (mPLNC). After multivariate Cox regression analyses with forward stepwise elimination of the mLNC and mPLNC for the training cohort, a nomogram was constructed to predict overall survival (OS) via incorporating preoperative carcinoembryonic antigen, pT stages, negative lymph node count, mLNR and metastasis. Internal validations of the nomogram showed concordance indexes (c-index) of 0.750 (95% CI, 0.736-0.764) and 0.749 before and after corrections for overfitting. Serial performance evaluations indicated that the nomogram outperformed the AJCC stages (c-index = 0.725) with increased accuracy, net benefits, risk assessment ability, but comparable complexity and clinical validity. All the results were reproducible in the test cohort. In summary, the proposed nomogram may serve as an alternative to the AJCC stages. However, validations with longer follow-up periods are required.

Exploration of the Optimal Minimum Lymph Node Count after Colon Cancer Resection for Patients Aged 80 Years and Older

The elderly colon cancer (CC) patients are increasing and represent a heterogeneous patient group. The objectives of this study were to identify the features of lymph node examination and to explore the optimal minimum lymph node count after CC resection for patients aged ≥80. Using the Surveillance, Epidemiology, and End Results (SEER) database, we identified 65719 CC patients in stage I-III between 2004 and 2012, 26.0% of patients were aged ≥80. The median node count decreased with increasing age, which were 25.5, 20.2, 17.8 and 16.9 for patients aged 20–39, 40–59, 60–79, and ≥80. The rate of ≥12 nodes and the rate of node positivity for patients aged ≥80 were obviously lower than younger patients. Using X-tile analysis, we determined 9 nodes as the optimal node count for patients aged ≥80. Then, we compared the 5-year cancer specific survival (CSS) between patients with ≥9 nodes and <9 nodes. The results showed the 5-year CSSs were improved for patients with ≥9 nodes. Furthermore, the rate of node positivity and survival under the 9-node measure were equal to 12-node measure. Therefore, the lymph node examination should be discriminately evaluated for elder patients, and 9-node measure was available for patients aged ≥80.

Preoperative carcinoembryonic antigen and prognosis of colorectal cancer. An independent prognostic factor still reliable

To evaluate whether, in a sample of patients radically treated for colorectal carcinoma, the preoperative determination of the carcinoembryonic antigen (p-CEA) may have a prognostic value and constitute an independent risk factor in relation to disease-free survival. The preoperative CEA seems to be related both to the staging of colorectal neoplasia and to the patient's prognosis, although this-to date-has not been conclusively demonstrated and is still a matter of intense debate in the scientific community. This is a retrospective analysis of prospectively collected data. A total of 395 patients were radically treated for colorectal carcinoma. The preoperative CEA was statistically compared with the 2010 American Joint Committee on Cancer (AJCC) staging, the T and N parameters, and grading. All parameters recorded in our database were tested for an association with disease-free survival (DFS). Only factors significantly associated (P < 0.05) with the DFS were used to build multivariate stepwise forward logistic regression models to establish their independent predictors. A statistically significant relationship was found between p-CEA and tumor staging (P < 0.001), T (P < 0.001) and N parameters (P = 0.006). In a multivariate analysis, the independent prognostic factors found were: p-CEA, stages N1 and N2 according to AJCC, and G3 grading (grade). A statistically significant difference (P < 0.001) was evident between the DFS of patients with normal and high p-CEA levels. Preoperative CEA makes a pre-operative selection possible of those patients for whom it is likely to be able to predict a more advanced staging.

Lymph Node Ratio and Liver Metachronous Metastases in Colorectal Cancer

The authors seek to assess whether the lymph node ratio (LNR) could predict the risk of metachronous liver metastases. Using the goal of sampling 12 lymph nodes for a proper staging of colorectal cancer is often “uncommon,” and the LNR is what allows for a better prognosis selection of patients. A homogeneous group of 280 patients, followed up for at least 5 years, was evaluated. To highlight the groups with the highest risk of metachronous liver metastases, patients were divided into 4 quartiles groups in relation to the LNR. The number of lymph nodes sampled in group “Stage I” was significantly lower. Even if statistical significance between the global LNR and the development of liver metastases has not been reached, the subdivision into quartiles has made it possible to highlight that in the more advanced ratio groups, a higher incidence of metachronous liver metastases (P &lt; 0.028) was registered and was a different distribution of patients with or without liver metastasis in function of quartiles (P = 0.01). The LNR has enabled us to prognosticate patients who are at greater risk of developing metachronous liver metastases. The lower lymph node sampling in the patients with less advanced staging (I) and in patients with node-negative cancer (I + II) who developed liver metastases, leads us to believe that some patients have been understaged. We believe that the LNR, especially in cases of adequate lymph node sampling, is a useful gauge to better substratify “node-positive” patients.

Laparoscopic colorectal cancer resections in the obese: a systematic review

BACKGROUND

Laparoscopic colorectal cancer operations in obese patients pose technical challenges that may negatively impact oncologic adequacy. A meta-analysis was performed to assess the oncologic outcomes of laparoscopic colorectal cancer resections in obese compared to non-obese patients. Short- and long-term outcomes were assessed secondarily.

METHODS

A systematic literature search was conducted from inception until October 01, 2014. Studies that compared outcomes of laparoscopic colorectal malignant neoplasms in obese and non-obese patients were selected for meta-analysis. Studies that defined obesity as body mass index (BMI) ≥ 30 kg/m² were included. Oncologic, operative, and postoperative outcomes were evaluated. Pooled odds ratios (OR) and weighted mean differences (WMD) with 95 % confidence intervals (CI) were calculated using fixed-effects models. For oncologic and survival outcomes, a subgroup analysis was conducted for rectal cancer and a secondary analysis was conducted for Asian studies that used a BMI cutoff of 25 kg/m².

RESULTS

Thirteen observational studies with a total of 4550 patients were included in the meta-analysis. Lymph node retrieval, distal, and circumferential margins, and 5-year disease-free and overall survival were similar in the obese and non-obese groups. Conversion rate (OR 2.11, 95 % CI 1.58-2.81), postoperative morbidity (OR 1.54, 95 % CI 1.21-1.97), wound infection (OR 2.43, 95 % CI 1.46-4.03), and anastomotic leak (OR 1.65, 95 % CI 1.01-2.71) were all significantly increased in the obese group.

CONCLUSIONS

Laparoscopic colorectal cancer operations in obese patients pose an increased technical challenge as demonstrated by higher conversion rates and higher risk of postoperative complications compared to non-obese patients. Despite these challenges, oncologic adequacy of laparoscopic colorectal cancer resections is comparable in both groups.