Impact of number of nodes retrieved on outcome in patients with rectal cancer

INFLUENCE OF NEOADJUVANT THERAPY ON THE RATIO OF LYMPH NODES

BACKGROUND

To evaluate the relationship between the ratio of affected lymph nodes (LNR) and clinical and anatomopathological variables in patients with rectal adenocarcinoma submitted or not to neoadjuvant chemoradiotherapy.

METHODS

The LNR was determined by dividing the number of compromised LNR by the total number of LNR dissected in the surgical specimen. Patients were divided into two groups: with QRT and without QRT. In each group, the relationship between LNR and the following variables was evaluated: degree of cell differentiation, depth of invasion in the rectal wall, angiolymphatic /perineural invasion, degree of tumor regression and occurrence of metastases. The LNR was evaluated in patients with more than 1, LNR (LNR >12) or less (LNR<12) in the surgical specimen with overall survival (OS) and disease-free survival (DFS). The results were expressed as the mean with the respective standard deviation. Qualitative variables were analyzed using Fisher's exact test, while quantitative variables were analyzed using the Kruskal -Wallis and Mann-Whitney tests. The significance level was 5%.

RESULTS

We evaluated 282 patients with QRT and 114 without QRT, between 1995-2011. In the QRT Group, LNR showed a significant association with mucinous tumors (P=0.007) and degree of tumor regression (P=0.003). In both groups, LNR was associated with poorly differentiated tumors (P=0.001, P=0.02), presence of angiolymphatic invasion (P<0.0001 and P=0.01), perineural (P=0.0007, P=0.02), degree of rectal wall invasion (T3>T2; P<0.0001, P=0.02); Compromised LNR (P<0.0001, P<0.01), metastases (P<0.0001, P<0.01). In patients with QRT, LNR<12 was associated with DFS (5.889; 95%CI1.935-19.687; P=0.018) and LNR>12 with DFS and OS (17.984; 95%CI5.931-54.351; P<0.001 and 10.286; 95%CI 2.654-39.854; P=0.007, respectively).

CONCLUSION

LNR was associated with histological aspects of poor prognosis, regardless of the use of QRT. In the occurrence of less than 12 evaluated LNR, the LNR was associated only with the DFS.

BACKGROUND

• Assessment of the lymph nodes during pathological analysis of the surgical specimen is crucial to determine treatment and prognosis.

BACKGROUND

• Neoadjuvance therapy reduces the number of lymph nodes, being lower than recommended, therefore the lymph node ratio can be an alternative analysis for a better prognosis.

Quality of Surgical Outcome Reporting in Randomised Clinical Trials of Multimodal Rectal Cancer Treatment: A Systematic Review

INTRODUCTION

Randomised controlled trials (RCTs) continue to provide the best evidence for treatment options, but the quality of reporting in RCTs and the completeness rate of reporting of surgical outcomes and complication data vary widely. The aim of this study was to measure the quality of reporting of the surgical outcome and complication data in RCTs of rectal cancer treatment and whether this quality has changed over time.

METHODS

Eligible articles with the keywords ("rectal cancer" OR "rectal carcinoma") AND ("radiation" OR "radiotherapy") that were RCTs and published in the English, German, Polish, or Italian language were identified by reviewing all abstracts published from 1982 through 2022. Two authors independently screened and analysed all studies. The quality of the surgical outcome and complication data was assessed based on fourteen criteria, and the quality of RCTs was evaluated based on a modified Jadad scale. The primary outcome was the quality of reporting in RCTs and the completeness rate of reporting of surgical results and complication data.

RESULTS

A total of 340 articles reporting multimodal therapy outcomes for 143,576 rectal cancer patients were analysed. A total of 7 articles (2%) met all 14 reporting criteria, 13 met 13 criteria, 27 met from 11 to 12 criteria, 36 met from 9 to 10 criteria, 76 met from 7 to 8 criteria, and most articles met fewer than 7 criteria (mean 5.5 criteria). Commonly underreported criteria included complication severity (15% of articles), macroscopic integrity of mesorectal excision (17% of articles), length of stay (18% of articles), number of lymph nodes (21% of articles), distance between the tumour and circumferential resection margin (CRM) (26% of articles), surgical radicality according to the site of the primary tumour (R0 vs. R1 + R2) (29% of articles), and CRM status (38% of articles).

CONCLUSION

Inconsistent surgical outcome and complication data reporting in multimodal rectal cancer treatment RCTs is standard. Standardised reporting of clinical and oncological outcomes should be established to facilitate comparing studies and results of related research topics.

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.

Use of Carbon Nanoparticles to Improve the Efficiency of Harvesting Lymph Nodes in Rectal Cancer

BACKGROUND

The accurate determination of lymph node status in patients with rectal cancer requires harvesting a certain number of lymph nodes. This study investigated whether using carbon nanoparticles (CNs) could improve the efficiency of harvesting lymph nodes in rectal cancer patients.

MATERIALS AND METHODS

Data from patients with rectal cancer treated with radical resection were collected from Nanfang Hospital between January 2014 and June 2021. Patients in the CN group received a CN suspension 1 day before surgery, which was endoscopically injected around the tumor. A 1:1 case-matched study was performed using the propensity score. The efficiency of harvesting lymph nodes was investigated by comparing the number of total nodes, total time, and percentage of nodes <5 mm in size between the CN and non-CN groups.

RESULTS

A total of 768 patients were included, with 246 patients who underwent CN injection and 522 patients who did not. After matching, 246 pairs of patients were analyzed. After matching, the number of total nodes of each sample was significantly higher in the CN group than in the non-CN group ( P <0.001). The total time for node detection ( P <0.001) was significantly shorter in the CN group. The percentage of nodes <5 mm in size was increased significantly in the CN group ( P <0.001). Among patients with clinical staging I/II, the difference in positive LNs was significant (21.79% vs. 11.95%, P =0.029).

CONCLUSIONS

The application of CNs improved the efficiency of harvesting lymph nodes during rectal cancer surgery.

Comparison of robotic versus laparoscopic right colectomy node retrieval in the obese population

Data are scarce comparing robotic and laparoscopic colectomy node retrieval based on body mass index or age. With differences in anastomosis, mobilization, and ligation between these approaches, obese and/or elderly patients undergoing robotic surgery may have differences in node yield compared to laparoscopy. A retrospective review was conducted between four institutions from February 1, 2019 through August 1, 2021, during which 144 right colectomies were performed. Benign pathology, open colectomies, and conversions to open were excluded. All included surgeons had at least five patients to ensure experience. The population was categorized by a robotic or laparoscopic approach. Records were reviewed focusing on age, body mass index, surgical approach, anastomosis, pathology, and node count. The node count was then compared by body mass index and age between the robotic or laparoscopic approach to identify differences. After applied exclusions and outlier analysis, our final sample consisted of 80 patients. Both body mass index and age were significant, (p = 0.002 and p = 0.005, respectively). Body mass index ≤ 25.0 and age < 60 years old had higher average node counts. These variables interacted, (p = 0.003); those with both < 60 years old and body mass index ≤ 25 showed the greatest number of nodes (36.9). Laparoscopy yielded more nodes in ≥ 60 years old than robotics (27.4 verses 20.9), though this was not significant (p = 0.68). Node retrieval in overweight and obese patients did not differ between approaches (p = 0.48). Both body mass index and age influence the number of nodes that can be extracted in right hemicolectomies by experienced surgeons.

Comparison of high or modified low tie of the inferior mesenteric artery in laparoscopic rectal cancer surgery: A meta-analysis

OBJECTIVE

The purpose of this study was to perform a meta-analysis comparing the oncological, intraoperative and safety outcomes in laparoscopic rectal cancer surgery with and without preservation of the left colic artery (LCA).

METHOD

We searched several databases including PubMed, Web of Science, Cochrane Library, and Embase databases. This meta-analysis included randomized clinical trials, prospective, and retrospective comparative studies regarding high- or modified low-tie ligation of the inferior mesenteric artery in laparoscopic rectal cancer surgery.

RESULTS

Of 641 potentially eligible articles, 16 studies with 3050 participants met the eligibility criteria and were included in the meta-analysis. There was no significant difference in estimated blood loss (WMD -2.63, 95% CI -5.69 to 0.43; P = .09), the number of harvested lymph nodes (WMD -0.35, 95% CI -1.60 to 0.20; P = .50), the number of apical lymph node yield (WMD -0.19, 95% CI -0.52 to 0.13; P = .24), the number of apical lymph node metastasis (OR 0.76, 95% CI 0.40 to 1.45; P = .40), rate of conversion to open surgery (OR 0.74, 95% CI 0.50 to 1.09; P = .513), rate of urinary dysfunction (OR 1.39, 95% CI 0.71 to 2.74; P = .34), rate of recurrence and metastasis (OR 1.10, 95% CI 0.75 to 1.61; P = .64), 5-year survival rate (OR 0.89, 95% CI 0.67 to 1.18; P = .42). However, this meta-analysis demonstrated a statistically significant difference in operating time (WMD -9.92, 95% CI -15.49 to -5.84; P = .0005), rate of diverting stom (OR 1.42, 95% CI 1.06 to 1.92; P = .02), rate of anastomotic leakage (OR 2.673, 95% CI 1.91 to 3.62; P < .00001), time to first flatus (WMD 0.29, 95% CI 0.11 to 0.48; P = .002), time of hospitalization (WMD 0.64, 95% CI 0.14 to 1.15; P = .01) between the 2 surgical techniques.

COCLUSION

The available evidence suggests that preserving the left colic artery is a safe, effective technique for patients with laparoscopic rectal cancer. nique for patients with laparoscopic rectal cancer.

Impact of obesity on morbidity and oncologic outcomes after total mesorectal excision for mid and low rectal cancer

BACKGROUND

A recent meta-analysis showed that obesity increased the conversion rate and postoperative morbidity of rectal cancer surgery, but did not influence pathological results. However, this meta-analysis included patients with cancer of the upper rectum and had many biases. The aim of the present retrospective study was to investigate the impact of obesity, defined as a body mass index (BMI) ≥ 30 kg/m², on postoperative morbidity and short- and long-term oncologic outcomes of total mesorectal excision for mid and low rectal cancer in consecutive patients.

METHODS

This study included all eligible patients who were operated on for mid and lower rectal cancer between 1999 and 2018 in our hospital. We compared 90-day postoperative morbidity and mortality, and short- and long-term oncologic outcomes between obese and non-obese patients.

RESULTS

Three hundred and ninety patients [280 males, mean age 65.7 ± 11.3 years, 59 obese individuals (15.1%)] were included. There was no difference in the 90-day mortality rate between obese and non-obese groups (p = 0.068). There was a difference in the overall 90-day morbidity rate between the obese and non-obese groups that disappeared after propensity score matching of the patients. There was no difference in short-term oncological parameters, with a median follow-up of 43 (20-84) months, and there were no significant differences in disease-free and overall survival between obese and non-obese patients (p = 0.42 and p = 0.11, respectively).

CONCLUSIONS

Obesity does not affect the 90-day morbidity rate, or short- and long-term oncologic results in patients operated on for mid and lower rectal cancer.

Preoperative chemoradiotherapy with capecitabine and triweekly oxaliplatin versus capecitabine monotherapy for locally advanced rectal cancer: a propensity-score matched study

Background

Distant metastasis has been the main failure pattern for locoregionally advanced rectal cancer (LARC) patients, and intensified neoadjuvant chemotherapy has become a popular research topic. The present study aimed to compare the survival outcomes, acute toxicities and surgical complications in LARC patients who received preoperative chemoradiotherapy with triweekly oxaliplatin and capecitabine (triweekly XELOX) or capecitabine.

Methods: Between 2007 and 2017, patients with clinically staged II-III rectal cancer who were treated with preoperative chemoradiotherapy using either triweekly XELOX (oxaliplatin 130 mg/m² plus capecitabine 825 mg/m²) or capecitabine were included. Variables potentially influencing chemotherapy treatment selection were used to generate propensity scores (PS). The association between chemotherapy regimens and survival endpoints, including distant metastasis-free survival (DMFS), overall survival (OS) and disease-free survival (DFS), were evaluated and adjusted with PS. The acute toxicities and surgical complications were also compared.

Results

A total of 810 patients were included in the analysis; 277 (34.2%) patients received triweekly XELOX, and 533 (65.8%) received capecitabine. The pathological complete response (pCR) rates were 20.2 and 19.9% (P = 0.912) for the groups treated with triweekly XELOX and capecitabine, respectively. The 5-year DMFS, OS and DFS with triweekly XELOX versus capecitabine were 75.6% vs. 77.6% (P = 0.555), 79.2% vs. 83.3% (P = 0.101), and 69.9% vs. 73.7% (P = 0.283), respectively. Triweekly XELOX was not associated with an increased risk of severe toxicity during chemoradiotherapy, but it increased the risk of postoperative complications compared to capecitabine. After PS adjustment, the differences between the two groups remained insignificant in pCR rate, survival outcomes, and acute toxicities, and the difference in surgical complications disappeared.

Conclusions

Triweekly XELOX or capecitabine concurrent with neoadjuvant radiotherapy leads to similar long-term survival outcomes, acute toxicities and surgical complications in LARC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09855-z.

Exploration of a modified stage for pN0 colon cancer patients

Exploring a modified stage (mStage) for pN0 colon cancer patients. 39,637 pN0 colon cancer patients were collected from the SEER database (2010–2015) (development cohort) and 455 pN0 colon cancer patients from the Second Affiliated Hospital of Harbin Medical University (2011–2015) (validation cohort). The optimal lymph nodes examined (LNE) stratification for cancer-specific survival (CSS) was obtained by X-tile software in the development cohort. LNE is combined with conventional T stage to form the mStage. The novel N stage was built based on the LNE (N0a: LNE ≥ 26, N0b: LNE = 11–25 and N0c: LNE ≤ 10). The mStage include mStageA (T1N0a, T1N0b, T1N0c and T2N0a), mStageB (T2N0b, T2N0c and T3N0a), mStageC (T3N0b), mStageD (T3N0c, T4aN0a and T4bN0a), mStageE (T4aN0b and T4bN0b) and mStageF (T4aN0c and T4bN0c). Cox regression model showed that mStage was an independent prognostic factor. AUC showed that the predictive accuracy of mStage was better than the conventional T stage for 5-year CSS in the development (0.700 vs. 0.678, P < 0.001) and validation cohort (0.649 vs. 0.603, P = 0.018). The C-index also showed that mStage had a superior model-fitting. Besides, calibration curves for 3-year and 5-year CSS revealed good consistencies between observed and predicted survival rates. For pN0 colon cancer patients, mStage might be superior to conventional T stage in predicting the prognosis.

Effects of surgical approach on short- and long-term outcomes in early-stage rectal cancer: a multicenter, propensity score-weighted cohort study

BACKGROUND

Randomized controlled trials have been unable to demonstrate noninferiority of minimally invasive surgery for rectal cancer. The aim of this study was to assess oncologic resection success, short- and long-term morbidity, and overall survival by operative approach in a homogenous early-stage rectal cancer cohort.

METHODS

This is a multicenter, propensity score-weighted cohort study utilizing deidentified data from the National Cancer Database. Individuals who underwent a formal proctectomy for early-stage rectal cancer (T1-2, N0, M0) from 2010 to 2015 were included. The primary outcome was a composite variable indicating successful oncologic resection stratified by operative approach, defined as negative margins with at least 12 lymph nodes evaluated.

RESULTS

Among 3649 proctectomies for rectal adenocarcinoma, 1660 (45%) were approached open, 1461 (40%) laparoscopically, and 528 (15%) robotically. After propensity score weighting, compared to open approach, there were no differences in odds of successful oncologic resection (OR_adj = 1.07, 95% CI 0.9, 1.28 and OR_adj = 1.28, 95% CI 0.97, 1.7). Open approach was associated with longer mean (± SD) length of stay compared to laparoscopic (7.7 ± 0.18 vs. 6.5 ± 0.25 days, p < 0.001) and robotic (7.7 ± 0.18 vs. 6.3 ± 0.35 days, p < 0.001) approaches. In regard to 90-day mortality, compared to open approach, laparoscopic (OR_adj = 0.56, 95% CI 0.36, 0.88) and robotic (OR_adj = 0.45, 95% CI 0.22, 0.94) approaches were associated with a reduced odd of 90-day mortality. This mortality benefit persists in the long-term for laparoscopic approach (p = 0.003).

CONCLUSION

For individuals with early-stage rectal cancer treated with proctectomy, successful oncologic resection can be achieved irrespective of technical approach. Minimally invasive approaches provide short-term reduction in morbidity. Surgical approach must be tailored to each patient based on surgeon experience and judgement in collaboration with a multi-disciplinary team.

Robotic Versus Laparoscopic Surgery for Rectal Cancer: A Comprehensive Review of Oncological Outcomes

The treatment of rectal cancer is complex and involves specialized multidisciplinary care, although the tenet is still rooted in a high-quality total mesorectal excision. The robotic platform is one of many tools in the arsenal to assist dissection in the low pelvis. This article is a comprehensive review of the oncological outcome comparing robotic vs laparoscopic rectal cancer resection, with a particular focus on total mesorectal excision. There is no statistical difference in total mesorectal grade, circumferential margin, distal margin, and lymph node harvest. Survival data are less mature, but there is also no difference in disease-free or overall survival between the two techniques. Although additional randomized trials are still needed to validate these findings, both techniques are currently acceptable in the minimally invasive treatment of rectal cancer, and surgeon preference is paramount to safe and optimal resection.

A Prognostic Nomogram for T3N0 Rectal Cancer After Total Mesorectal Excision to Help Select Patients for Adjuvant Therapy

Background

The recurrence rate of T3N0 rectal cancer after total mesorectal excision (TME) is relatively low, meaning that not all patients need adjuvant therapy (AT) (radiotherapy, chemotherapy, or chemoradiotherapy).

Methods

Patients diagnosed with pT3N0M0 rectal cancer after TME were analyzed using the SEER database, of which 4367 did not receive AT and 2794 received AT. Propensity score matching was used to balance the two groups in terms of confounding factors. Cox proportional hazards regression analysis was used to screen independent prognostic factors, which were then used to establish a nomogram. The patients were then divided into three groups with X-tile software according to their risk scores. We enrolled 334 patients as external validation.

Results

The C-index of the model was 0.725 (95% confidence interval: 0.694–0.756). We divided the patients into three different risk layers based on the nomogram prediction scores, and found that AT did not improve the prognosis of low- and moderate-risk patients, while high-risk patients benefited from AT. External validation data also support the above conclusions.

Conclusion

This study developed a nomogram that effectively and comprehensively evaluates the prognosis of T3N0 rectal cancer patients after TME. After using the nomogram, we recommend AT for high-risk patients, but not for low- and moderate-risk patients.

Brazilian society of surgical oncology: Guidelines for the surgical treatment of mid-low rectal cancer

BACKGROUND

Colorectal cancer (CRC) is the third leading cause of cancer in North America, Western Europe, and Brazil, and represents an important public health problem. It is estimated that approximately 30% of all the CRC cases correspond to tumors located in the rectum, requiring complex multidisciplinary treatment. In an effort to provide surgeons who treat rectal cancer with the most current information based on the best evidence in the literature, the Brazilian Society of Surgical Oncology (SBCO) has produced the present guidelines for rectal cancer treatment that is focused on the main topics related to daily clinical practice.

OBJECTIVES

The SBCO developed the present guidelines to provide recommendations on the main topics related to the treatment of mid-low rectal cancer based on current scientific evidence.

METHODS

Between May and June 2021, 11 experts in CRC surgery met to develop the guidelines for the treatment of mid-low rectal cancer. A total of 22 relevant topics were disseminated among the participants. The methodological quality of a final list with 221 sources was evaluated, all the evidence was examined and revised, and the treatment guideline was formulated by the 11-expert committee. To reach a final consensus, all the topics were reviewed via a videoconference meeting that was attended by all 11 of the experts.

RESULTS

The prepared guidelines contained 22 topics considered to be highly relevant in the treatment of mid-low rectal cancer, covering subjects related to the tests required for staging, surgical technique-related aspects, recommended measures to reduce surgical complications, neoadjuvant strategies, and nonoperative treatments. In addition, a checklist was proposed to summarize the important information and offer an updated tool to assist surgeons who treat rectal cancer provide the best care to their patients.

CONCLUSION

These guidelines summarize concisely the recommendations based on the most current scientific evidence on the most relevant aspects of the treatment of mid-low rectal cancer and are a practical guide that can help surgeons who treat rectal cancer make the best therapeutic decision.

The impact of lymph node ratio on overall survival in patients with colorectal cancer

Background

Lymph node metastasis is a predominant prognostic indicator in colorectal cancer. Number of lymph nodes removed surgically was demonstrated to correlate with staging accuracy and oncological outcomes. However, number of lymph nodes removed depends on uncontrolled variables. Therefore, a more reliable prognostic indicator is needed. Calculation of ratio of positive lymph nodes to total number of removed lymph nodes may be an appealing solution.

Materials and Methods

We retrospectively analyzed data of 156 Stage III colorectal cancer patients whom underwent surgery between 2008 and 2015. Patients' demographic characteristics, tumor grade, location, vascular-perineural invasion status, number of removed lymph nodes, and ratio of positive lymph nodes to number of removed lymph nodes were recorded. Spearman correlation analysis was used to determine the correlation coefficient while Kaplan-Meier method and Cox proportional hazard regression model were performed for the prediction of survival and multivariate analysis, respectively.

Results

Number of removed lymph nodes did not correlate with survival, but it was inversely correlated with number of positive lymph nodes. Multivariate analysis showed that ratio of removed positive lymph nodes to the total number of lymph nodes was a significant prognostic factor for survival for a ratio equal or above 0.31 was a poor prognostic indicator (108 months vs. 34 months, hazard ratio: 4.24 [95% confidence interval: 2.15-8.34]; P < 0.019). Tumor characteristics failed to demonstrate any prognostic value.

Conclusions

This study showed that positive lymph node ratio (PLNR) is an important prognostic factor for Stage III colorectal cancer. Although 0.31 can be taken as threshold for "PLNR," prospective trials including larger patient groups are needed to validate its role as a prognostic indicator.

Lower conversion rate with robotic assisted rectal resections compared with conventional laparoscopy; a national cohort study

Background

Conversion from laparoscopic to open access colorectal surgery is associated with a poorer postoperative outcome. The aim of this study was to assess conversion rates and outcomes after standard laparoscopic rectal resection (LR) and robotic laparoscopic rectal resection (RR).

Methods

A national 5-year cohort study utilizing prospectively recorded data on patients who underwent elective major laparoscopic resection for rectal cancer. Data were retrieved from the Norwegian Registry for Gastrointestinal Surgery and from the Norwegian Colorectal Cancer Registry. Primary end point was conversion rate. Secondary end points were postoperative complications within 30 days and histopathological results. Chi-square test, two-sided T test, and Mann–Whitney U test were used for univariable analyses. Both univariable and multivariable logistic regression analyses were used to analyze the relations between different predictors and outcomes, and propensity score matching was performed to address potential treatment assignment bias.

Results

A total of 1284 patients were included, of whom 375 underwent RR and 909 LR. Conversion rate was 8 out of 375 (2.1%) for RR compared with 87 out of 909 (9.6%) for LR (p < 0.001). RR was associated with reduced risk for conversion compared with LR (aOR 0.22, 95% CI 0.10–0.46). There were no other outcome differences between RR and LR. Factors associated with increased risk for conversion were male gender, severe cardiac disease and BMI > 30. Conversion was associated with higher rates of major complications (20 out of 95 (21.2%) vs 135 out of 1189 (11.4%) p = 0.005), reoperations (13 out of 95 (13.7%) vs 93 out of 1189 (7.1%) p = 0.020), and longer hospital stay (median 8 days vs 6 days, p = 0.001).

Conclusion

Conversion rate was lower with robotic assisted rectal resections compared with conventional laparoscopy. Conversions were associated with higher rates of postoperative complications.

Evaluating disparities in delivery of neoadjuvant guideline-based chemoradiation for rectal cancer: A multicenter, propensity score-weighted cohort study

BACKGROUND

Despite guideline recommendations, some patients still receive care inappropriate for their clinical stage of disease. Identification of factors that contribute to variation in guideline base care may help eradicate disparities in the treatment of early and locally advanced rectal cancer.

METHODS

The American College of Surgeons National Cancer Database from 2010 to 2015 was analyzed with propensity score weighting to identify factors associated with delivery and omission of neoadjuvant guideline-based chemoradiation (GBC) for those with early and locally advanced rectal cancer.

RESULTS

Only 74% of patients with rectal cancer received stage-appropriate neoadjuvant chemoradiation; 4544 (88%) of those with early stage disease and 8675 (68%) in locally advanced disease. Chemotherapy and radiotherapy were not planned in 27% and 34% respectively, of those who did not receive GBC. Factors associated with receipt of non-guideline-based neoadjuvant chemoradiation were age >65 years, Medicare insurance, treatment at a community facility, West-South-Central geography, having locally advanced disease, and Charlson-Deyo score >3. Receipt of ideal guideline-based neoadjuvant chemoradiation conferred a survival benefit at 5 years.

CONCLUSION

Patient and non-patient factors contribute to disparities in guideline-based delivery of neoadjuvant chemoradiation in the treatment of rectal cancer. Identification of these risk factors are important to help standardize care and improve survival outcomes.

Technical considerations depending on the level of vascular ligation in laparoscopic rectal resection

AIM

In addition to ischemia there is also anastomotic ends tension proven to be a risk factor for anastomotic leak. HT vascular ligation is accepted as a rule, in attempt to achieve tension-free anastomosis. LT is a preferred option, based on the more accurate preservation of proximal intestinal segment microperfusion and lower risk of damage to the hypogastric plexus. The aim of this study is evaluation of comparative indicators in high tie (HT) and low tie (LT) laparoscopic rectal resections.

METHODS

A prospective nonrandomized comparative cohort study of patients in our department with cancer of the rectum in clinical stage I-III, operated on in laparoscopic approach over a 6-years period.

RESULTS

For the period 2015-2020, a number of 208 laparoscopic surgeries have been done for rectal cancer. Patients were divided into three groups-group A with HT vascular ligation 116 pts. (69%), group B-53 pts. (25%), underwent low ligation-LT and group C-39pts. (19%) low tie plus lymph node dissection of the apical LN group (LT-appic LND). The distribution was made without randomization, based on the operators' expertise. Anastomotic leaks were 3.8% in group A, 3.0% in group B and 2.9% in group C (p > 0.05) with no significance difference. There is no significant difference in the number of lymph nodes obtained in group A and group B, while in group C the number of the harvested lymph nodes was higher (p < 0.05). The indicators for intestinal / defecation dysfunction, as well as for urinary/sexual dysfunction, according to our data, are significantly more favorable in patients with LT, in contrast to the other two groups.

CONCLUSION

HT vascular ligation attempts to achieve tension-free anastomosis and more harvested lymph nodes. However, LT could be a preferred option, based on the lack of significant evidence for a difference in specific oncological survival and due to more accurate preservation of proximal intestinal segment microperfusion to prevent anastomosis dehiscence, also for its lower risk of damage to the hypogastric plexus. Splenic flexure mobilization provides elongation of the proximal intestinal segment, but has no proven effect on anastomotic leakage incidence. It increases surgical duration and is in fact necessary in up to 30% of the cases. At the present moment there is no precise data whether LT has an advantage in terms of prevention of autonomic nervous and urogenital dysfunction. New prospective randomized and highly probative studies are needed to standardize the procedures in specific clinical situations.

Association of certification, improved quality and better oncological outcomes for rectal cancer in a specialized colorectal unit

PURPOSE

Centralization of cancer care is expected to yield superior results. In Germany, the national strategy is based on a voluntary certification process. The effect of centre certification is difficult to prove because quality data are rarely available prior to certification. This observational study aims to assess outcomes for rectal cancer patients before and after implementation of a certified cancer centre.

PATIENTS AND METHODS

All consecutive patients treated for rectal cancer in our certified centre from 2009 to 2017 were retrieved from a prospective database. The dataset was analyzed according to a predefined set of 19 quality indicators comprising 36 quality goals. The results were compared to an identical cohort of patients, treated from 2000 to 2008 just before centre implementation.

RESULTS

In total, 1059 patients were included, 481 in the 2009-2017 interval and 578 in the 2000-2008 interval. From 2009 to 2017, 25 of 36 quality goals were achieved (vs. 19/36). The proportion of anastomotic leaks in low anastomoses was improved (13.5% vs. 22.1%, p = 0.018), as was the local 5-year recurrence rate for stage (y)pIII rectal cancers (7.7% vs. 17.8%, p = 0.085), and quality of mesorectal excision (0.3% incomplete resections vs. 5.5%, p = 0.002). Furthermore, a decrease of abdominoperineal excisions was noted (47.1% vs. 60.0%, p = 0.037). For the 2009-2017 interval, local 5-year recurrence rate in stages (y)p0-III was 4.6% and 5-year overall survival was 80.2%.

CONCLUSIONS

Certification as specialized centre and regular audits were associated with an improvement of various quality parameters. The formal certification process has the potential to enhance quality of care for rectal cancer patients.

Prognostic Impact of Lymph Node Ratio in Patients Undergoing Preoperative Chemoradiotherapy Followed by Curative Resection for Locally Advanced Rectal Cancer

BACKGROUND/AIM

To analyze the prognostic significance of nodal status in patients undergoing preoperative chemoradiotherapy (CRT) followed by curative resection for locally advanced rectal cancer.

PATIENTS AND METHODS

Between 2000 and 2015, 80 consecutive patients with rectal cancer underwent preoperative CRT followed by curative resection. The lymph node ratio (LNR) was defined as the number of positive lymph nodes (LNs) divided by the examined LNs, and log odds of positive lymph nodes (LODDS) was the log of the ratio between positive and negative LNs. The prognostic value of these indicators was evaluated in terms of overall (OS) and disease-free (DFS) survival.

RESULTS

The median follow-up period for patients overall was 59 months (range=11-190 months). The median number of examined LNs and number of positive LNs were 10 (range=1-29) and 2 (range=1-27), respectively, and the median LNR and LODDS values were 0.0 (range=0.0-0.96) and -1.0 (range=-1.7-1.3), respectively. The 5-year OS and DFS were 83% and 64%, respectively. In multivariate analysis, LNR was an independent prognostic factor in terms OS (p=0.041) but not for DFS (p=0.075). LODDS was not significantly associated with OS or DFS. In patients with clinical stage III rectal cancer, LNR was significantly associated with OS and DFS when the number of evaluated LNs was greater than 12 (p=0.038 for OS, p=0.006 for DFS).

CONCLUSION

Our study suggests that LNR is a more effective prognostic factor than LODDS in terms of predicting survival. LNR was a significant predictor for survival for patients with clinical stage III rectal cancer with >12 harvested LNs.

Incorporating the Number of PLN into the AJCC Stage Could Better Predict the Survival for Patients with NSCLC: A Large Population-Based Study

Purpose

This study aimed to investigate the application of the number of positive lymph nodes (PLNs) in tumor, node, metastasis (TNM) staging system of non-small cell lung cancer (NSCLC) patients. Patients and Methods. We screened a total of 15820 patients with resected NSCLC between 2004 and 2015 from SEER database. The X-tile model was used to determine the cutoff values of the number of PLNs. Overall survival (OS) curves were plotted using the Kaplan–Meier method, and the differences among the individual groups were defined using the log-rank test. Cox regression model was used to perform univariate and multivariate analyses and to assess the association between the number of PLNs and OS.

Results

In this study, using the X-tile model, we screened three different cutoff values, including nN0, nN1–3, and nN4-. Survival curves demonstrated that our defined nN stage had a significant predictive value for OS (P < 0.001). In the univariate and multivariate Cox analyses, the result showed that nN stage was a significant prognostic factor of OS for NSCLC patients (P < 0.001). Subsequently, we classified the patients into five subgroups based on the combination of pN and nN stages, including pN0 + nN0, pN1 + nN1-3, pN2 + nN1-3, pN1 + nN4-, and pN2 + nN4-. Moreover, survival curves revealed significant differences among these five groups (P < 0.001).

Conclusion

A combination of pathological LNs (pN) and the number of LN (nN) involvement in NSCLC patients had a better prognostic value than the current TNM staging system based on only pN stage.

Prognostic significance of lymph node yield in patients with synchronous colorectal carcinomas

BACKGROUND

The National Comprehensive Cancer Network (NCCN) guidelines recommend examination of a minimum of 12 lymph nodes (LNs) for accurate staging of a single case of colorectal cancer. However, the guidelines do not support the examination of LNs in synchronous colorectal carcinoma (SCC). This study aimed to investigate the association between lymph node yield and the prognosis of SCC patients.

METHODS

Synchronous colorectal carcinoma patients were selected from the Surveillance, Epidemiology, and End Results (SEER) database over a 10-year interval (2004 to 2013). Systematic dichotomization for optimal cut-off point identification was performed using X-tile. The baseline for the two LNs groups generated was balanced using the propensity score matching (PSM) method.

RESULTS

A total of 4616 patients met the inclusion criteria. The cut-off number for lymph node retrieved from a single patient was 15 and 12 for the first- and second-time diagnosis of SCC, respectively. Age, T category, N category, tumor grade, tumor site, tumor size, and radiation sequence were not balanced in the two groups. After adjusting the baseline in the two groups, the same results were observed. Age, T category, N category, tumor site had a partial effect on lymph node yield. There might be some biological characteristics of the tumor that influence lymph node yield.

CONCLUSIONS

Retrieval of fewer than 15 LNs at the first time of SCC diagnosis indicates worse SCC prognosis. Because factors such as manner of surgical examination influence SCC prognosis, specimens should be preserved for at least 6 months to enable reevaluation should there be a need. Irb: IRB approval is not required because the SEER data are freely accessible.

A retrospective study on the impact of the number of resected lymph nodes on the survival outcome of stage IV rectal cancer patients after preoperative therapy

Background

There is no consensus on the optimal number of examined LNs for stage IV rectal cancer patients after preoperative therapy. We aimed to explore the impact of the number of resected lymph nodes (LNs) on the survival outcomes of stage IV rectal cancer patients after preoperative therapy.

Methods

Clinicopathologic data of 556 patients diagnosed with stage IV rectal cancer between 1st January, 2010 and 31st December, 2015 from the Surveillance, Epidemiology, and End Results (SEER) database after preoperative therapy were reviewed. The patients were further divided into two groups: the ≥15 resected LNs group and <15 resected LNs group based on the X-tile software analysis results of the number of resected LNs.

Results

Both univariate and multivariate regression analyses revealed that the number of resected LNs and N status were significantly positively correlated with the survival outcome of the patients. Patients in the ≥15 resected LNs group had a significant better cancer-specific survival (CSS) (P=0.003) than those in the <15 resected LNs group. The 3-year CSS rate was 63.2% for patients with ≥15 resected LNs compared with 55.7% for those with <15 resected LNs. The 5-year CSS rate was 50.2% and 30.5% for patients in the ≥15 resected LNs group and those in the <15 resected LNs group, respectively.

Conclusions

The number of resected LNs is an important independent prognostic factor that influences the survival outcome of stage IV rectal cancer patients after receiving preoperative therapy.

The quality of lymph node harvests in extralevator abdominoperineal excisions

Background

Lymph node (LN) harvest in colorectal cancer resections is a well-recognised prognostic factor for disease staging and determining survival, particularly for node-negative (N0) diseases. Extralevator abdominoperineal excisions (ELAPE) aim to prevent “waisting” that occurs during conventional abdominoperineal resections (APR) for low rectal cancers, and reducing circumferential resection margin (CRM) infiltration rate. Our study investigates whether ELAPE may also improve the quality of LN harvests, addressing gaps in the literature.

Methods

This retrospective observational study reviewed 2 sets of 30 consecutive APRs before and after the adoption of ELAPE in our unit. The primary outcomes are the total LN counts and rates of meeting the standard of 12-minimum, particularly for those with node-negative disease. The secondary outcomes are the CRM involvement rates. Baseline characteristics including age, sex, laparoscopic or open surgery and the use of neoadjuvant chemoradiotherapy were accounted for in our analyses.

Results

Median LN counts were slightly higher in the ELAPE group (16.5 vs. 15). Specimens failing the minimum 12-LN requirements were almost significantly fewer in the ELAPE group (OR 0.456, P = 0.085). Among node-negative rectal cancers, significantly fewer resections failed the 12-LN standard in the ELAPE group than APR group (OR 0.211, P = 0.044). ELAPE led to a near-significant decrease in CRM involvement (OR 0.365, P = 0.088). These improvements were persistently observed after taking into account baselines and potential confounders in regression analyses.

Conclusion

ELAPE provides higher quality of LN harvests that meet the 12-minimal requirements than conventional APR, particularly in node-negative rectal cancers. The superiority is independent of potential confounding factors, and may implicate better clinical outcomes.

Short- and long-term outcomes of laparoscopic versus open lateral lymph node dissection for locally advanced middle/lower rectal cancer using a propensity score-matched analysis

BACKGROUND

There are few reports on large-scale trials for the long-term outcomes regarding laparoscopic lateral lymph node dissection (LLND). We evaluated the short- and long-term outcomes of laparoscopic versus open LLND for locally advanced middle/lower rectal cancer using a propensity score-matched analysis.

METHODS

From January 2005 to December 2016, consecutive clinical stage II to III middle/lower rectal cancer patients who underwent total mesorectal excision (TME) plus LLND were retrospectively collected at three institutions. Laparoscopic LLND was compared with open LLND for the surgical and oncological outcomes, including the long-term survival, using a propensity score-matched analysis.

RESULTS

A total of 325 patients were collected. There were 142 patients who underwent open TME plus LLND (open group) and 183 patients who underwent laparoscopic TME plus LLND (laparoscopic group). A total of 93 patients each were matched to each group. Compared to the open group, the laparoscopic group had a significantly longer operative time (327 vs. 377 min; p = 0.002) but significantly less blood loss (540 vs. 50 ml; p < 0.001), fewer Clavian-Dindo grade ≥ 2 postoperative complications (49.5% vs. 34.4%; p = 0.037) and shorter postoperative hospital stay (18 vs. 14 days; p = 0.008). Furthermore, the rate of urinary retention was significantly lower in the laparoscopic group than in the open group (16.1% vs. 6.5%; p = 0.037). The estimated 3-year overall survival, relapse-free survival, and cumulative incidence of local recurrence were 91.4%, 73.1%, and 3.4% in the open group and 90.3%, 74.2%, and 4.3% in the laparoscopic group (p = 0.879, 0.893, 0.999), respectively.

CONCLUSIONS

This study showed that laparoscopic LLND had advantages over an open approach, such as less blood loss, fewer postoperative complications, and a shorter postoperative hospital stay, and the oncologic outcomes were similar to the open approach. Laparoscopic LLND could be a viable standard approach to LLND for advanced middle/lower rectal cancer surgery.

Laparoscopic Curative Resection for Right-Sided Colonic Tumors: Initial Experience From a Specialized Cancer Hospital of a Developing Country

Introduction

Laparoscopic colonic resection is increasingly becoming popular worldwide and aims to provide curative resection in addition to the inherent benefits of laparoscopic surgery. The aim of this study was to evaluate the long-term outcomes of laparoscopic right hemicolectomy in a Pakistani cohort of patients.

Methods and procedures

We retrospectively analyzed the medical records of all patients who presented to our hospital with the diagnosis of right-sided colon carcinoma from January 2010 to December 2018 and underwent laparoscopic right or extended right hemicolectomy. Demographics, operative findings, histopathology report, and follow-up of patients were recorded and the analysis was performed on Statistical Packages for the Social Sciences (SPSS) Version 20 (IBM Corp, Armonk, NY).

Results

Seventy-five patients were included, 56 (74.7%) of whom were males and 19 (25.3%) were females. The median age was 52 years (range 25-82 years). The median hospital stay was five days (Range 3-13 days). The median blood loss was 70 milliliters and the mean operative time was 195.5±77.6 minutes. Laparoscopic extended right hemicolectomy was performed in 23 (16.67%) patients and standard right hemicolectomy in 52 (83.33%) patients. Most (72%) of the patients had a pathological T3 tumor, and the majority (61.3%) of the patients had no nodal involvement (pN0). The mean number of lymph nodes removed was 20+8. The median numbers of involved lymph nodes were 1.14+2.19. All the patients had R0 resection. Postoperatively, two patients had pelvic collection, and there was no 30-day mortality. Local recurrence occurred in four patients and distant metastases were observed in nine patients. The median follow-up in our study was 40.5±18.35 months. The median disease-free survival was 42±2.17 months and the median overall survival was 44±2.16 months.

Conclusion

Our experience with laparoscopic right colon resections has confirmed the safety and feasibility of the procedure.

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 safety and effectiveness of carbon nanoparticles suspension in tracking lymph node metastases of colorectal cancer: a prospective randomized controlled trial

OBJECTIVE

This study was to evaluate the safety and effectiveness of carbon nanoparticles suspension in tracking lymph node metastases of colorectal cancer.

METHODS

Eligible patients diagnosed with stages I-III colorectal cancer in Fudan University Shanghai Cancer Center between 1 May 2017 and 31 May 2018 fulfilling the inclusion criteria were included in this prospective randomized controlled study. All the patients were randomly allocated to two groups: the nanocarbon group and the control group. Patients' clinicopathological characteristics were compared between the nanocarbon group and the control group. For continuous variables, data were presented as mean (±SD) and differences between the two groups were compared by the Mann-Whitney U test; for categorical variables, data was presented as frequency (%) and the Pearson's chi-squared test was used to compare the differences between two groups.

RESULTS

All the patients' characteristics between two groups did not achieve statistical significance (P > 0.05). Patients in nanocarbon group were more likely to be associated with more lymph nodes retrieved totally compared with control group (19.84 ± 6.428 vs. 17.41 ± 7.229, P < 0.001). The number of lymph nodes retrieved in nanocarbon group were more likely to be ≥12 than that in the control group (P = 0.005).

CONCLUSIONS

Our study confirmed the safety of using carbon nanoparticles suspension as a tracer in colorectal cancer. More importantly, nanocarbon could significantly increase the detected number of lymph nodes in colorectal cancer, which can help improve the accuracy of lymph node staging and even improve patients' survival.

Pathology protocol increases lymph node yield in neck dissection for oral cavity squamous cell carcinoma

BACKGROUND

Lymph node yield (LNY) is a proposed quality indicator in neck dissection for oral cavity squamous cell carcinoma (OCSCC).

METHODS

Retrospective series including 190 patients with OCSCC undergoing neck dissection between 2016 and 2018. A change in pathologic grossing protocol was initiated during the study period to assess residual adipose tissue. A generalized linear model was used to assess the impact of multiple variables on LNY.

RESULTS

Mean LNY was 28.59 (SD = 17.65). The protocol identified a mean of 10.32 lymph nodes per case. Multivariable analysis identified associations between LNY and use of the pathology protocol (P = .02), number of dissected lymph node levels (P < .001), presence of pathologic lymph nodes (P = .002), body mass index (P = .02), prior neck surgery (P = .001), and prior neck radiation (P = .001).

CONCLUSIONS

Assessment of residual adipose tissue within neck dissection specimens improves accuracy of LNY. LNY in neck dissection is influenced by multiple factors including methods of pathologic assessment.

Prognostic Impact of the Number of Examined Lymph Nodes in Stage II Colorectal Adenocarcinoma: A Retrospective Study

BACKGROUND

Evaluation of lymph node status is critical in colorectal carcinoma (CRC) treatment. However, as patients with node involvement may be incorrectly classified into earlier stages if the examined lymph node (ELN) number is too small and escape adjuvant therapy, especially for stage II CRC. The aims of this study were to assess the impact of the ELN on the survival of patients with stage II colorectal cancer and to determine the optimal number.

METHODS

Data from the US Surveillance, Epidemiology, and End Results (SEER) database on stage II resected CRC (1988-2013) were extracted for mathematical modeling as ELN was available since 1988. Relationship between ELN count and stage migration and disease-specific survival was analyzed by using multivariable models. The series of the mean positive LNs, odds ratios (ORs), and hazard ratios (HRs) were fitted with a LOWESS (Locally Weighted Scatterplot Smoothing) smoother, and the structural break points were determined by the Chow test. An independent cohort of cases from 2014 was retrieved for validation in 5-year disease-specific survival (DSS).

RESULTS

An increased ELN count was associated with a higher possibility of metastasis LN detection (OR 1.010, CI 1.009-1.011, p < 0.001) and better DSS in LN negative patients (OR 0.976, CI 0.975-0.977, p < 0.001). The cut-off point analysis showed a threshold ELN count of 21 nodes (HR 0.692, CI 0.667-0.719, p < 0.001) and was validated with significantly better DSS in the SEER 2009 cohort CRC (OR 0.657, CI 0.522-0.827, p < 0.001). The cut-off value of the ELN count in site-specific surgeries was analyzed as 20 nodes in the right hemicolectomy (HR 0.674, CI 0.638-0.713, p < 0.001), 19 nodes in left hemicolectomy (HR 0.691, CI 0.639-0.749, p < 0.001), and 20 nodes in rectal resection patients (HR 0.671, CI 0.604-0.746, p < 0.001), respectively.

CONCLUSIONS

A higher number of ELNs are associated with more-accurate node staging and better prognosis in stage II CRCs. We recommend that at least 21 lymph nodes be examined for accurate diagnosis of stage II colorectal cancer.

Postoperative radio-chemotherapy for rectal cancer: A retrospective analysis from a tertiary referral hospital

Aim

To report results of postoperative radio-chemotherapy (RT-CHT) for rectal cancer (RC).

Background

Total mesorectal excision (TME) is an essential treatment method in rectal cancer (RC). Perioperative radiotherapy in locally advanced RC improves loco-regional free survival (LRFS). Preoperative radiotherapy is a preferred option; however, some patients are not referred for it. In case of the risk of loco-regional failure postoperative radio-chemotherapy (RT-CHT) is indicated.

Material and methods

Between 2004 and 2010, 182 patients with pathological stage II-III RC (TME performed - 41%, resection R0 - 88%, circumferential resection margin evaluated - 55.5% and was above 2 mm in 66% of them) received postoperative RT-CHT in our institution. Overall survival (OS) and LRFS were estimated with the Kaplan-Meier method. Univariate and multivariate analysis were performed to compare the impact of prognostic factors on survival.

Results

Five-year OS and LRFS rates were 63% and 85%, respectively. Loco-regional recurrence and isolated distant metastases rates were 11.5% and 19%, respectively. Multivariate analysis showed stage (III vs. II), HR: 2.3 (95% confidence interval [CI]: 1.4-3.8), p = 0.0001; extent of resection (R1-2 vs. R0), HR: 2.14 (95%CI: 1.14-3.99), p = 0.017, and age (>65 vs. ≤65 years), HR: 1.66 (95%CI: 1.06-2.61), p = 0.027 as prognostic factors for OS. Extent of resection (R1-2 vs. R0), HR: 3.65 (95%CI: 1.41-9.43), p = 0.008 had significant impact on LRFS.

Conclusion

Despite a suboptimal quality of surgery and pathological reports, the outcome in our series is close to that reported in the literature. We confirm a strong impact of the extent of resection on patient's outcome, which confirms the pivotal role of surgery in the management of RC.

Synoptic Operative Reporting: Documentation of Quality of Care Data for Rectal Cancer Surgery

Operative reports can be used to evaluate quality of care indicators in surgical patients. This study evaluated documentation of preoperative and intraoperative quality of care indicators for rectal cancer surgery in synoptic reports and traditional dictated reports. Two surgeons independently reviewed 40 prospectively collected synoptic operative reports from rectal cancer cases and a case-matched historical cohort of 40 dictated reports. Rectal cancer–specific quality measures were scored in both report groups using two separate, previously validated checklists. Synoptic reports had significantly higher overall scores on both checklists 1 (mean adjusted score ± SD 76 ± 4 vs 41 ± 19, P < 0.01) and 2 (54 ± 3 vs 24 ± 11, P < 0.01; maximum score of 100 for both checklists). Synoptic reports scored significantly higher in reporting preoperative and intraoperative care indicators. Data were extracted quickly from synoptic reports (mean 3:46 vs 6:21, minutes:seconds to complete checklists, P < 0.05). Synoptic reports are associated with accurate documentation of quality of care data for rectal cancer surgery. Refining the synoptic templates used will further enhance the collection of quality indicators and reporting in complex oncologic procedures.

Quality Indicators of Central Compartment Neck Dissection in Thyroid Surgery

OBJECTIVES

Quality metrics are an increasingly important means of improving patient care. Variability in the number of lymph nodes removed during central compartment lymph node dissection (CCLND) at the time of thyroidectomy has not been studied.

STUDY DESIGN

A retrospective cohort study was performed using American College of Surgeons National Quality Improvement Program (ACS-NSQIP) data.

SETTING

Centers in North America and worldwide contributing data to ACS-NSQIP and performing thyroidectomy on adults in inpatient and outpatient settings were included.

SUBJECTS AND METHODS

Adult patients undergoing thyroidectomy with or without CCLND were included. Outcomes of interest were number of nodes removed during CCLND and risks of postoperative hypocalcemia.

RESULTS

In total, 6108 patients met inclusion criteria (1565 with CCLND). The median number of lymph nodes removed during CCLND was 2. There was no statistically significant association between postoperative hypocalcemia and CCNLD, regardless of number of nodes removed. However, we were underpowered to detect this association based on the overall low nodal yield of many CCLNDs performed.

CONCLUSION

In many cases where CCLND is documented as part of thyroidectomy, very few lymph nodes are removed. Our ability to draw conclusions regarding the effect of CCLND on postoperative hypocalcemia is restricted due to the limited nature of many CCLNDs performed.

Harvest of at least 18 lymph nodes is associated with improved survival in patients with pN0 colon cancer: a retrospective cohort study

PURPOSE

To investigate the correlation between number of retrieved lymph nodes (rLNs) and prognosis and further ascertain the optimal number of rLNs with a beneficial survival impact in patients with pN0 colon cancer.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was searched for pN0 colon cancer cases. X-Tile software and Kaplan-Meier survival analysis were applied to determine the optimal number of rLNs based on the minimal probability (P) value and the largest χ² value. Univariate analyses and Cox proportional hazard regression model were used to investigate the relationship between rLN number and overall survival. Multiple analyses were conducted to assess the prognostic predictive ability of the identified optimal rLN cut-off value under different stratifications. Nomograms were established based on the independent prognostic factors selected by the multivariate analysis to predict 3- and 5-year overall survival rates of pN0 patients.

RESULTS

A total of 6269 pN0 colon cancer patients who underwent surgical therapy were finally included for analysis. Harvest of at least 18 lymph nodes was determined as the optimal rLN number. This cut-off rLN value (< 18 versus ≥ 18) was identified as an independent prognostic factor (P < 0.001) of overall survival via multivariate analysis. Similar findings were obtained in patients with retrieval of at least 12 lymph nodes (18 > rLNs ≥ 12 versus rLNs ≥ 18) stratified into several groups.

CONCLUSIONS

The number of rLNs was identified as an independent prognostic factor for pN0 colon cancer. Retrieval of at least 18 lymph nodes was associated with favorable prognosis in patients with pN0 colon cancer, and should, therefore, be regarded as an alternative cut-off value for survival analysis.

Prognosis of colorectal cancer patients is associated with the novel log odds of positive lymph nodes scheme: derivation and external validation

Background and aim: To construct proper and externally validate cut-off points for log odds of positive lymph nodes scheme (LODDS) staging scheme in colorectal cancer (CRC). Patients and methods: The X-tile approach was used to find the cut-off points for the novel LODDS staging scheme in 240,898 patients from the Surveillance, Epidemiology and End Results (SEER) database and externally validated in 1,878 from the international multicenter cohort. Kaplan-Meier plot and multivariate Cox proportional hazard models were performed to investigate the role of the novel LODDS classification. Results: The prognostic cut-off values were determined as -2.18, and -0.23 (P< 0.001). Patients had 5-year cancer-specific survival rates of 83.8%, 57.4% and 24.4% with increasing LODDS (P< 0.001) in the SEER database. Five-year overall survival rates were 77.2%, 55.0% and 26.7% with increasing LODDS (P< 0.001) in the external international multicenter cohort. Multivariate survival analysis identified both the LODDS classification, the patient's age, the T category, the M status, and the tumor grade as independent prognostic factors in both two independent databases. The analyses of the subgroup of patients stratified by tumor location (colon or rectum), number of retrieved lymph node (< 12 or ≥ 12), TNM stage III, lymph node-negative also confirmed the LODDS as independent prognostic factors (P< 0.001) in both two independent databases. Conclusions: The novel LODDS classification was an independent prognostic factor for patients with CRCs and should be calculated for additional risk group stratification with pN scheme.

Oncologic and Perioperative Outcomes of Laparoscopic, Open, and Robotic Approaches for Rectal Cancer Resection: A Multicenter, Propensity Score-Weighted Cohort Study

BACKGROUND

Minimally invasive approaches have been shown to reduce surgical site complications without compromising oncologic outcomes.

OBJECTIVE

The primary aim of this study is to evaluate the rates of successful oncologic resection and postoperative outcomes among laparoscopic, open, and robotic approaches to rectal cancer resection.

DESIGN

This is a multicenter, quasiexperimental cohort study using propensity score weighting.

SETTINGS

Interventions were performed in hospitals participating in the American College of Surgeons National Surgical Quality Improvement Program.

PATIENTS

Adult patients who underwent rectal cancer resection in 2016 were included.

MAIN OUTCOME MEASURES

The primary outcome was a composite variable indicating successful oncologic resection, defined as negative distal and radial margins with at least 12 lymph nodes evaluated.

RESULTS

Among 1028 rectal cancer resections, 206 (20%) were approached laparoscopically, 192 (18.7%) were approached robotically, and 630 (61.3%) were open. After propensity score weighting, there were no significant sociodemographic or preoperative clinical differences among subcohorts. Compared to the laparoscopic approach, open and robotic approaches were associated with a decreased likelihood of successful oncologic resection (ORadj = 0.64; 95% CI, 0.43-0.94 and ORadj = 0.60; 95% CI, 0.37-0.97), and the open approach was associated with an increased likelihood of surgical site complications (ORadj = 2.53; 95% CI, 1.61-3.959). Compared to the laparoscopic approach, the open approach was associated with longer length of stay (6.8 vs 8.6 days, p = 0.002).

LIMITATIONS

This was an observational cohort study using a preexisting clinical data set. Despite adjusted propensity score methodology, unmeasured confounding may contribute to our findings.

CONCLUSIONS

Resections that were approached laparoscopically were more likely to achieve oncologic success. Minimally invasive approaches did not lengthen operative times and provided benefits of reduced surgical site complications and decreased postoperative length of stay. Further studies are needed to clarify clinical outcomes and factors that influence the choice of approach. See Video Abstract at http://links.lww.com/DCR/B70. RESULTADOS ONCOLÓGICOS Y PERIOPERATORIOS DE LOS ABORDAJES LAPAROSCÓPICOS, ABIERTOS Y ROBÓTICOS PARA LA RESECCIÓN DEL CÁNCER RECTAL: UN ESTUDIO DE COHORTE MULTICÉNTRICO Y PONDERADO DEL PUNTAJE DE PROPENSIÓN: Se ha demostrado que los enfoques mínimamente invasivos reducen las complicaciones del sitio quirúrgico sin comprometer los resultados oncológicos.El objetivo principal de este estudio es evaluar las tasas de resección oncológica exitosa y los resultados postoperatorios entre los abordajes laparoscópico, abierto y robótico para la resección del cáncer rectal.Este es un estudio de cohorte cuasi-experimental multicéntrico que utiliza la ponderación de puntaje de propensión.Las intervenciones se realizaron en hospitales que participan en el Programa Nacional de Mejora de la Calidad Quirúrgica del Colegio Americano de Cirujanos.Se incluyeron pacientes adultos que se sometieron a resección de cáncer rectal en 2016.El resultado primario fue una variable compuesta que indicaba una resección oncológica exitosa, definida como márgenes negativos distales y radiales con al menos 12 ganglios linfáticos evaluados.Entre 1,028 resecciones de cáncer rectal, 206 (20%) fueron abordadas por vía laparoscópica, 192 (18.7%) robóticamente y 630 (61.3%) abiertas. Después de ponderar el puntaje de propensión, no hubo diferencias sociodemográficas o clínicas preoperatorias significativas entre las subcohortes. En comparación con el abordaje laparoscópico, los abordajes abiertos y robóticos se asociaron con una menor probabilidad de resección oncológica exitosa (ORadj = 0.64; IC 95%, 0.43-0.94 y ORadj = 0.60; IC 95%, 0.37-0.97), y el abordaje abierto se asoció con una mayor probabilidad de complicaciones del sitio quirúrgico (ORadj = 2.53; IC 95%, 1.61-3.959). En comparación con el abordaje laparoscópico, el abordaje abierto se asoció con una estadía más prolongada (6.8 frente a 8.6 días, p = 0.002).Este fue un estudio de cohorte observacional que utilizó un conjunto de datos clínicos preexistentes. A pesar de la metodología de puntuación de propensión ajustada, la confusión no medida puede contribuir a nuestros hallazgos.Las resecciones que se abordaron por vía laparoscópica tuvieron más probabilidades de lograr el éxito oncológico. Los enfoques mínimamente invasivos no alargaron los tiempos quirúrgicos y proporcionaron beneficios de la reducción de las complicaciones del sitio quirúrgico y la disminución de la duración de la estadía postoperatoria. Se necesitan más estudios para aclarar los resultados clínicos y los factores que influyen en la elección del enfoque. Vea video resumen en http://links.lww.com/DCR/B70.

Pathological Tumor Regression Grade Classifications in Gastrointestinal Cancers: Role on Patients' Prognosis

Preoperative chemotherapy or combined radiotherapy and chemotherapy (CRT), followed by surgery, represents the standard approach for locally advanced esophageal, gastric, and rectal carcinomas. To adequately evaluate the effects of neoadjuvant CRT in the resection specimens, several histopathologic tumor regression grade (TRG) scoring systems have been introduced into clinical practice. The primary goal of these TRG systems relies on a correct prognostic stratification of patients in the attempt to help clinical decision-making and influence surgical strategies, postoperative adjuvant therapies, and surveillance intensity. However, most TRG systems suffer from poor reproducibility and low interobserver concordance rates. Many efforts have been made in the identification of alternative, robust, simple, and universally accepted TRG scoring systems, which would help in the comparison of different treatment strategies and in the standardization of multimodal therapies. The aim of this review is to analyze the most commonly used TRG systems in gastrointestinal cancers highlighting their pitfalls and usefulness, depending on the tumor type.

"Caudal-to-cranial" plus "artery first" technique with beyond D3 lymph node dissection on the right midline of the superior mesenteric artery for the treatment of right colon cancer: is it more in line with the principle of oncology?

OBJECTIVE

To explore the feasibility and application value of a "caudal-to-cranial" plus "artery first" technique with beyond D3 lymph node dissection on the right midline of the superior mesenteric artery (SMA) for the treatment of right colon cancer METHODS: Clinical data consisting of 168 right colon cancer cases under going laparoscopic D3 radical resection, including 84 cases of "caudal-to-cranial" plus "artery first" technique with beyond D3 lymph node dissection on the right midline of the SMA (CC + SMA group) and 84 cases of conventional medial approach plus dissection around the superior mesenteric vein (MA + SMV group), from January 2017 to March 2018 were retrospectively analyzed. For CC + SMA group, our surgical method was to isolate the mesocolon using a caudal-to-cranial pathway and ligate blood vessels along the midline of the SMA.

RESULTS

The baseline data was not significantly different between the two groups (all p > 0.05). The mean operation time and intraoperative blood loss in the CC + SMA and the MA + SMV groups were 170.04 ± 43.10 versus 172.33 ± 41.84 min and 91.07 ± 55.12 versus 77.38 ± 40.21 ml, respectively, which has no significant difference (p > 0.05). The mean number of total and positive harvested lymph nodes in the two groups were 29.44 ± 5.90 versus 26.21 ± 6.64 (p < 0.05) and 2.57 ± 1.93 versus 2.51 ± 1.05, respectively (p > 0.05). Compared with the MA + SMV group, there was no significant difference in total postoperative complication rate in the CC + SMA group. The time to pull out drainage tube in the CC + SMA group was longer than MA + SMV group (4.05 ± 1.79 versus 3.38 ± 1.99 day; p = 0.022).

CONCLUSION

It is safe and feasible for the "caudal-to-cranial" plus "artery first" technique with beyond D3 lymph node dissection on the right midline of the SMA in right colon cancer. It may have some advantages in the number of lymph nodes dissection, and the long-term prognosis remains to be expected.

What is the Optimal Number of Lymph Nodes to be Dissected in Colorectal Cancer Surgery?

Background

Regional lymph node (LN) involvement in colorectal cancer (CRC) identifies the stage and the subset of patients who would benefit from adjuvant chemotherapy. We performed a retrospective analysis to determine if the number of recovered LNs was associated with long-term outcome in patients operated on for stage II and III CRC.

Patients and methods

Hospital records of 179 patients with CRC followed in our unit from 1997 to April 2003 were reviewed.

Results

On average 11.68 ± 7.3 LNs were sampled per surgical specimen. Sampling of at least nine LNs appeared to be the minimum number required for accurately predicting LN involvement ( P = 0.002). Three-year rates of disease-free survival (DFS), local recurrence-free survival (LRFS) and overall survival (OS) were lower in patients with fewer than nine LNs sampled ( P = 0.032, P = 0.006 and P = 0.04, respectively). However, this had no impact on the three-year distant metastasis-free survival rate (DMFS) ( P = 0.472). In stage II disease, patients with nine or more LNs dissected had significantly higher three year DFS and LRFS rates than the subgroup with fewer than nine LNs dissected ( P = 0.024 and P = 0.015, respectively), but this did not have any effect on DMFS or OS ( P = 0.406 and P = 0.353, respectively).

Conclusion

Current protocols provide adjuvant treatment in stage III patients; the problem is to correctly determine stage by recovering as many LNs as possible.

A hypothesized TNM staging system based on the number and location of positive lymph nodes may better reflect the prognosis for patients with NSCLC

Background

This study aimed to evaluate the feasibility and prognostic accuracy of incorporating the number of positive lymph nodes (PLN) into the TNM staging system for non-small cell lung cancer (NSCLC) patients.

Methods

We screened a total of 9539 patients with resected stage IA-IIIB non-small cell cancer between 2010 and 2015 from SEER database. The chi-square test was used to compare patient baseline characteristics and the X-tile model was applied to determine cut-off values for the number of PLN (nN). The X-tile model was used to screen three different cut-off values including nN = 0, nN1–3 and nN4-. Univariate and multivariate Cox proportional hazards regression models were used to analyze the influence of different variables on overall survival (OS). Kaplan-Meier and log-rank test were used to compare survival differences.

Results

Based on the nN cutoffs, we conducted the univariate and multivariate Cox proportional hazards regression. The result showed that nN stage was a significant prognostic factor affecting patients' OS (all P <  0.001). We reclassified the seventh edition TNM stages of the enrolled patients with stage IA-IIIB NSCLC according to the 5-year OS rate. Hypothesized TNM substage based on the location and the number of PLN was further calculated. Then we drew survival curves for each substage, including for the current TNM stage and the hypothesized TNM stage. From the comparison of survival curves, we found that the survival curve of each substage of the hypothesized TNM classification was proportional and well distributed compared with the current TNM classification (P <  0.001).

Conclusion

Revised TNM staging integrating locational pN stage and numerical nN stage was a more accurate prognostic determinant in patients with NSCLC.

Including positive lymph node count in the AJCC N staging may be a better predictor of the prognosis of NSCLC patients, especially stage III patients: a large population-based study

BACKGROUND

The study was designed to explore the value of including positive lymph node count in the TNM staging system of non-small cell lung cancer.

PATIENTS AND METHODS

The X-tile model was applied to determine the cutoff values of positive lymph node count. Survival curves were generated using the Kaplan-Meier method and differences in survival among subgroups were examined using the log-rank test. The influence of different variables on overall survival and lung cancer-specific survival was further evaluated using univariate and multivariate Cox proportional hazard models. All statistical analyses were performed using SPSS version 22.0 (SPSS, Chicago, IL, USA). All p values were 2-sided and p < 0.05 was considered statistically significant.

RESULTS

The overall survival and lung cancer-specific survival between stage IIIA and IIIB classified by the sixth edition TNM staging system show no statistically significant difference (p = 0.479 for overall survival; p = 0.081 for lung cancer specific survival). The X-tile model was used to screen three different cutoff values including nN = 0, nN1-3 and nN4-. The nN value is a significant independent prognostic factor that affects overall survival and lung cancer-specific survival of non-small cell lung cancer patients (all, p < 0.001). We obtained the hypothesized TNM sub-stages based on location and the number of PLN. There were significant differences between the hypothesized stage IIIA and IIIB regarding overall survival and lung cancer-specific survival (all, p < 0.001).

CONCLUSIONS

It needs to be considered that N stage in combination with positive lymph node count may be used to predict the prognosis of non-small cell lung cancer for stage III cases with increased accuracy than category location-based stage.

Carnoy's solution fixation with compression significantly increases the number of lymph nodes yielded from colorectal cancer specimens

BACKGROUND AND OBJECTIVES

Carnoy's fixation and compression represents a novel technique to enhance lymph node evaluation and accuracy of staging after colorectal cancer resection.

METHODS

This study was performed in all adults undergoing colorectal cancer operations by Kaiser Permanente surgeons at two separate facilities. Patients were assigned to either location based upon surgeon and patient availability. One group of patients had their lymph nodes examined with current standard manual technique (MT). The other group had their specimens fixed with Carnoy's solution and then compressed (CT) to assess for lymph nodes.

RESULTS

A total of 157 patients were enrolled. Seventy-eight patient specimens underwent MT and 79 patient specimens underwent the new compression technique (CT). CT resulted in a significant increase in total lymph node yield per specimen (37.6 ± 18.5 nodes with CT vs 18.9 ± 8.8 nodes with MT; P < 0.0001). CT also resulted in sufficient lymph node sampling (>12 nodes) in all 79 patients in the group compared with 13 of 78 patients (17%) with an insufficient lymph node evaluation in the MT group ( P = 0.0002).

CONCLUSION

This study demonstrated that Carnoy's fixation with compression can significantly increase lymph node yields in colorectal cancer specimens and allow for a higher rate of adequate lymph node sampling.

Neoadjuvant chemoradiation and rectal cancer

Neoadjuvant chemoradiation (NACR) is now standard of care in stage II and III rectal cancer. The advent of this modality of treatment has impacted on the way the pathological evaluation of resection specimens that have been subjected to preoperative chemoradiation is conducted. The gross description, sectioning and microscopic examination have had to be adapted to accommodate the changes induced by NACR. Attempts at introducing a uniform approach to the gross triaging and reporting of these specimens have been met with muted response. There still exists much variation in approach. The purpose of this overview is to highlight some of the newer developments and issues around NACR-treated rectal cancers from a pathological point of view. The NACR-treated resection specimens should be handled in a consistent manner, at least within individual institutions, if not universally. There should be generous sampling with multiple sections taken as tumour is often sequestered deep in the bowel wall. Microscopic examination should be extra vigilant as residual cancer can be present as single cells or small clusters, often deep in the muscularis propria or serosa. Acellular pools of mucin or non-viable tumour cells in mucin within the bowel wall or lymph nodes are not regarded as positive and do not upstage the tumour. The issue of grading of regression has been the subject of much debate, and several approaches have been published. It is recommended that a system that has clinical meaning and use to oncologists be used. Lymph node counts will be reduced after NACR, but reasonable attempts to accrue 12 nodes should be made.

A case-control study of using carbon nanoparticles to trace decision-making lymph nodes around inferior mesenteric artery in rectal cancer

BACKGROUND

Accurate identification of lymph nodes localized around inferior mesenteric artery (IMA), with or without metastasis, is of crucial importance for surgeons when dissecting D2 or D3 lymph nodes in patients with rectal cancer (RC). The following study evaluates whether carbon nanoparticles can be used for detection of decision-making lymph nodes (DLNs) in station 253 lymph nodes found around IMA during RC surgery.

METHODS

A total of 66 patients with rectal adenocarcinomas were recruited between January 2014 and August 2017. Patients were divided into carbon nanoparticle (CN) group and control (CL) group; for the CN group, 1 ml nanoparticles were endoscopically injected into submucosal layer of primary tumor 1 day before surgery. DLNs were defined as black-dyed nodes in CN group or macroscopic lymph nodes in CL group localized along the IMA, proximal to the origin of the left colic artery. D3 lymph nodes were dissected using laparoscopic radical resection, and then examined using pathological approach. Intra-operative and post-operative data were compared between the two groups.

RESULTS

In CN group, black-dyed DLNs were easily found under laparoscopy; the median number of DLNs was 3 (range 1-9). In CL group, the median number of DLNs was 0 (range 0-3). Consistency between intra-operative DLNs and post-operative station 253 nodes were confirmed by pathological examination. Significant higher number of DLNs in station 253 nodes (2.91 ± 2.47 vs 0.58 ± 0.75, p < 0.001), number of station 251 nodes (12.85 ± 8.99 vs 8.09 ± 5.85, p = 0.014), number of station 253 nodes (5.21 ± 5.26 vs 3.15 ± 2.32, p = 0.045), and the number of total lymph nodes (24.06 ± 13.20 vs 16.21 ± 9.09, p = 0.007) were found in the CN group compared to CL group.

CONCLUSIONS

Carbon nanoparticles are useful for identifying DLNs in station 253 LNs around IMA in RC. It is not necessary to perform D3 lymph node dissection if there are no intra-operative DLNs metastases in RC.

Role of lymph node yield and lymph node ratio in predicting outcomes in non-metastatic colorectal cancer

Background

Lymph node yield (LNY) of 12 or more in resection of colorectal cancer is recommended in current international guidelines. Although a low LNY (less than 12) is associated with poorer outcome in some studies, its prognostic value is unclear in patients with early‐stage colorectal or rectal cancer with a complete pathological response following neoadjuvant therapy. Lymph node ratio (LNR), which reflects the proportion of positive to total nodes obtained, may be more accurate in predicting outcome in stage III colorectal cancer. This study aimed to identify factors correlating with LNY and evaluate the prognostic role of LNY and LNR in colorectal cancer.

Methods

An observational study was performed on patients with colorectal cancer treated at three hospitals in Melbourne, Australia, from January 2010 to March 2016. Association of LNY and LNR with clinical variables was analysed using linear regression. Disease‐free (DFS) and overall (OS) survival were investigated with Cox regression and Kaplan–Meier survival analyses.

Results

Some 1585 resections were analysed. Median follow‐up was 27·1 (range 0·1–71) months. Median LNY was 16 (range 0–86), and was lower for rectal cancers, decreased with increasing age, and increased with increasing stage. High LNY (12 or more) was associated with better DFS in colorectal cancer. Subgroup analysis indicated that low LNY was associated with poorer DFS and OS in stage III colonic cancer, but had no effect on DFS and OS in rectal cancer (stages I–III). Higher LNR was predictive of poorer DFS and OS.

Conclusion

Low LNY (less than 12) was predictive of poor DFS in stage III colonic cancer, but was not a factor for stage I or II colonic disease or any rectal cancer. LNR was a predictive factor in DFS and OS in stage III colonic cancer, but influenced DFS only in rectal cancer.

A statistical tool for risk assessment as a function of the number of lymph nodes retrieved from rectal cancer patients

AIM

Although a minimum of 12 lymph nodes (LNs) has been recommended for examination in colorectal cancer patients there remains considerable debate with regard to rectal cancer. Inadequacy of examined LNs could lead to understaging and inappropriate treatment as a consequence. We describe a statistical tool that allows an estimate of the probability of false-negative nodes.

METHOD

A total of 26 778 patients diagnosed between 2004 and 2013 with rectal adenocarcinoma [tumour stage (T stage) 1-3] who did not receive neoadjuvant therapies and had at least one histologically assessed LN were extracted from the Surveillance, Epidemiology and End Results (SEER) database. A statistical tool using beta-binomial distribution was developed to estimate the probability of missing a positive node as a function of the total number of LNs examined and T stage.

RESULTS

The probability of falsely identifying a patient as node-negative decreased with increasing number of nodes examined for each stage. It was estimated to be 72%, 66% and 52% for T1, T2 and T3 patients, respectively, with a single node examined. To confirm an occult nodal disease with 90% confidence, 5, 9 and 29 nodes need to be examined for patients from stages T1, T2 and T3, respectively.

CONCLUSION

The false-negative rate of the examined LNs in rectal cancer was verified to be dependent preoperatively on the clinical T stage. A more accurate nodal staging score was developed to recommend a threshold for the minimum number of examined nodes with regard to the favoured level of confidence.