The prognostic value of lymph node ratio after neoadjuvant chemoradiation and rectal cancer surgery

Re-evaluating Lymph Node Yield, Lymph Node Ratio, and the number of metastatic nodes as prognostic factors in oral cavity squamous cell carcinoma

OBJECTIVE

Previous studies of Lymph Node Yield (LNY) for neck dissection in Oral Cavity Squamous Cell Carcinoma (OCSCC) have shown LNY of 18 or more lymph nodes to be of prognostic value. This study aims to evaluate the prognostic implications of LNY, number of metastatic nodes, and Lymph Node Ratio (LNR) in clinical N0 OCSCC.

METHODS

We retrospectively analyzed 118 patients who underwent elective neck dissection for OCSCC at Rabin Medical Center (2000-2020). Demographic, clinical, pathological, and surgical data were collected. We examined the prognostic significance of LNY cutoffs (18 and 13), number of positive nodes, and LNR on disease-free and overall survival.

RESULTS

The mean LNY was 19.5 ± 11.3 nodes, with a lymph node metastasis rate of 31.3 %. Statistical analysis showed that neither 18 nor 13 lymph nodes had significant prognostic value for recurrence or survival. The mean LNR was 4.52 % ± 11.3 %, with higher LNR values (>3.4 %) significantly associated with increased recurrence (p = 0.003) and reduced survival intervals (p = 0.003). Cox regression analysis further confirmed that both elevated LNR and the presence of more than two metastatic lymph nodes were independently associated with increased mortality.

CONCLUSIONS

Our findings challenge the commonly cited LNY threshold of 18, as no specific LNY cutoff conferred significant survival benefits. Instead, LNR emerged as a superior prognostic marker, correlating strongly with overall survival and locoregional control. Incorporating LNR into prognostic models may enhance risk stratification and guide clinical decision-making in OCSCC management.

Developing and validation a prognostic model for predicting prognosis among synchronous colorectal cancers patients using combined log odds ratio of positive lymph nodes: a SEER database study

PURPOSE

The aim of the study is to identify risk factors for the prognosis and survival of synchronous colorectal cancer and to create and validate a functional Nomogram for predicting cancer-specific survival in patients with synchronous colorectal cancer.

METHODS

Synchronous colorectal cancers cases were retrieved from the Surveillance, Epidemiology, and End Results database retrospectively, then they were randomly divided into training (n = 3371) and internal validation (n = 1440) sets, and a set of 100 patients from our group was used as external validation. Risk factors for synchronous colorectal cancer were determined using univariate and multivariate Cox regression analyses, and two Nomograms were established to forecast the overall survival and cancer-specific survival, respectively. We assessed the Nomogram performance in terms of discrimination and calibration. Bootstrap resampling was used as an internal verification method, and we select external data from our hospital as independent validation sets.

RESULTS

Two Nomograms are established to predict the overall survival and cancer-specific survival. In OS Nomogram, sex, age, marital status, ttumor pathological grade, AJCC TNM stage, preoperative serum CEA level, LODDS, radiotherapy and chemotherapy were determined as prognostic factors. In CSS Nomogram, age and marital status, AJCC TNM stage, tumor pathological grade, preoperative serum CEA level, LODDS, radiotherapy and chemotherapy were determined as prognostic factors.The C-indexes for the forecast of overall survival were 0.70, and the C-index was 0.68 for the training and internal validation cohort, respectively. The C-indexes for the forecast of cancer-specific survival were 0.75, and the C-index was 0.74 for the training and internal validation cohort, respectively. The Nomogram calibration curves showed no significant deviation from the reference line, indicating a good level of calibration. Both C-index and calibration curves indicated noticeable performance of newly established Nomograms.

CONCLUSIONS

Those Nomograms with risk rating system can identify high risk patients who require more aggressive therapeutic intervention and longer and more frequent follow-up scheme, demonstrated prognostic efficiency.

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.

Prognostic value of lymph node ratio in resectable rectal cancer after preoperative short-course radiotherapy-results from randomized clinical trial

PURPOSE

The value of the lymph node ratio (LNR) in patients with rectal cancer has not yet been unequivocally established. This study aims to assess the effect of the lymph node ratio on the prognosis of rectal cancer in patients operated after short-course preoperative 25 Gy radiotherapy, at 10-year follow-up.

METHODS

This is a substudy based on data from a prospective randomized clinical trial. A total of 141 patients with resectable rectal cancer were included. Lymph node yield was compared in patients with short and long time intervals between radiotherapy and surgery. Survival curves were compared between patients with different ypN and LNR categories. Univariate and multivariate analyses were performed to identify independent prognostic factors for overall survival and disease-free survival.

RESULTS

Survival and recurrence data were available for a median follow-up of 11.6 years. The lymph node yield did not differ significantly between the patients in the short- and long-interval groups. A greater difference in 10-year survival was observed in patients with LNR ≤ 0.41 and > 0.41 when compared to the ypN categories. Separate prognostic factor analyses were performed for the entire population and for subgroups that had < 12 and 12 lymph nodes resected. LNR was identified as an independent prognostic factor for overall survival, in multivariate analyses, for all patients and those with less than 12 retrieved lymph nodes.

CONCLUSION

The lymph node yield is comparable in patients with different time intervals between radiation therapy and surgery. LNR better discriminates patients in terms of overall survival than ypN categories.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT01444495, date of registration: September 30, 2011.

Assessment of Textbook Oncologic Outcomes Following Proctectomy for Rectal Cancer

BACKGROUND

Outcomes of rectal adenocarcinoma vary considerably. Composite "textbook oncologic outcome" (TOO) is a single metric that estimates optimal clinical performance for cancer surgery.

METHODS

Patients with stage II/III rectal adenocarcinoma who underwent single-agent neoadjuvant chemoradiation and proctectomy within 5-12 weeks were identified in the National Cancer Database (NCDB). TOO was defined as achievement of negative distal and circumferential resection margin (CRM), retrieval of ≥ 12 nodes, no 90-day mortality, and length of stay (LOS) < 75th percentile of corresponding year's range. Multivariable logistic regression was used to identify predictors of TOO.

RESULTS

Among 318,225 patients, 8869 met selection criteria. Median age was 62 years (IQR 54-71), and 5550 (62.6%) were males. Low anterior resection was the most common procedure (LAR, 6,037 (68.1%) and 3084 (34.8%) were treated at a high-volume center (≥ 20 rectal resections/year). TOO was achieved in 3967 patients (44.7%). Several components of TOO were achieved commonly, including negative CRM (87.4%), no 90-day mortality (98.0%), no readmission (93.0%), and no prolonged hospitalization (78.8%). Logistic regression identified increasing age, non-private insurance, low-volume centers, open approach, Black race, Charlson score ≥ 3, and abdominoperineal resection (APR) as predictors of failure to achieve TOO. Over time, TOOs were attained more commonly which correlated with increased minimally invasive surgery (MIS) adoption. TOO achievement was associated with improved survival.

CONCLUSIONS

Rectal adenocarcinoma patients achieve TOO uncommonly. Treatment at high-volume centers and MIS approach were among modifiable factors associated with TOO in this study.

Is there a relationship between length of resection and lymph-node ratio in colorectal cancer?

BACKGROUND

The prognosis of colorectal cancer depends on the number of positive lymph nodes (LN+) and the total number of lymph nodes resected (rLN). This represents the lymph-node ratio (LNR). The aim of our study is to assess how the length of the resected specimen (RL) influences the prognostic values of the LNR.

METHODS

We conducted a retrospective study of all the patients operated on for colorectal cancer from 2000 to 2015 at our institution. Pathology details were analysed. The total number of rLN, the number of LN+, and the LNR were calculated and measured against the RL. The receiver-operating characteristic (ROC) curve of patients with LN+ was calculated.

RESULTS

Of the 670 patients included in our study, 337 were men (50.3%) and the mean age was 69.2 years. The correlation with prognosis of the LNR is greater than that of the LNR adjusted to RL (LNR/RL), both in subjects with positive nodes (n = 312) and in all cases (n = 670). The LNR presents a higher prognostic value than LNR/RL and RL in patients with LN+ except for metastatic recurrence, for which the predictive value appears slightly higher for LNR/RL. The statistical significance of the maximal divergence in Kaplan-Meier survival plots was demonstrated for the LNR (P = 0.043), not for LNR/RL (P = 0.373) and RL alone (P = 0.314).

CONCLUSION

An increase in RL causes an increase in the number of harvested lymph nodes without affecting the number of LN+, thus representing a confounding factor that could alter the prognostic value of the LNR. Prospective larger-scale studies are needed to confirm these findings.

Log odds of positive lymph nodes is an excellent prognostic factor for patients with rectal cancer after neoadjuvant chemoradiotherapy

Background

Neoadjuvant chemoradiotherapy (NCRT) results in fewer lymph nodes harvested and causes staging migration. Therefore, we compared the prognostic value of the logarithmic odds of positive lymph nodes (LODDS) with the lymph node ratio (LNR) and the American Joint Committee on Cancer (AJCC) ypN stage in patients with locally advanced rectal cancer (LARC) after NCRT.

Methods

A total of 445 patients with LARC who received NCRT and underwent radical surgery between January 2004 and December 2015 were recruited, and data from 4881 patients included in the Surveillance, Epidemiology and End Results (SEER) database between 2010 and 2013 were analyzed to verify our results. The time-dependent area under the receiver operating characteristic curve (TimeROC) was used to evaluate the discriminative ability of the different lymph node staging systems.

Results

ypN staging failed to satisfactorily stratify the patients treated with NCRT [the 3-year disease-free survival (DFS) rates were 65.7% and 55.4% for the ypN1 and ypN2 groups, respectively, P=0.252]. The LODDS classification was significantly associated with DFS, and the 3-year DFS rates for the LODDS0, LODDS1, and LODDS2 groups were 89.9%, 72.4%, and 53.9%, respectively (P<0.05 across all groups). Furthermore, the LODDS classification system was able to subclassify patients with ypN0 stage tumors regardless of whether ≥12 or <12 total lymph nodes (TLNs) were harvested. TimeROC analysis showed that the LODDS classification (AUC, median: 0.722, range: 0.692–0.754) had a higher accuracy for determining the prognosis than the ypN stage (AUC, median: 0.691, range: 0.684–0.712) or the LNR (AUC, median: 0.703, range: 0.685–0.730) classification, regardless of lymph node status. These results were verified using the SEER database.

Conclusions

The LODDS was a better prognostic factor for DFS than ypN staging or the LNR-based approach in patients with LARC after NCRT, particularly those with <12 TLNs harvested or ypN0 stage disease.

Lymph node ratio is an independent prognostic factor for rectal cancer after neoadjuvant therapy: A meta-analysis

OBJECTIVE

With neoadjuvant therapy increasingly used in advanced rectal cancer, the lymph node ratio (LNR) has been strongly considered to indicate cancer-specific survival in recent years, and a comprehensive evaluation of a large number of studies is deficient. The objective of our study is to pool enough eligible studies to assess the relationship between LNR and prognosis of advanced rectal cancer after neoadjuvant therapy.

METHODS

A systematic search was done in the PubMed and EmBase databases (through 1 March 2017) that reported LNR in colorectal cancer after neoadjuvant therapy. The first two authors independently conducted the study selection and data extraction. All statistical analyses were conducted using STATA 13.0 (College Station, Texas).

RESULTS

Thirteen studies with 4023 participants were included in the meta-analysis, and all were published after 2011. A high LNR was assessed to be a predictor of poor overall survival in rectal cancer after neoadjuvant therapy (HR: 2.94, 95% CI:1.97 to 3.91, P < 0.001). Similarly, a high LNR was related to poor disease-free survival (HR: 2.83, 95% CI: 1.82 to 3.85, P < 0.001). With respect to recurrence, the HRs of 3.25, 1.93, and 2.11 also showed a strong relationship between high LNR and poor local, distant, and total recurrences.

CONCLUSIONS

Our present study demonstrates that a high LNR can predict poor survival in advanced rectal cancer. We suggest well-designed clinical trials to prospectively assess LNR as an independent predictor of rectal cancer survival.

The prognostic value of lymph node ratio in colon cancer is independent of resection length

BACKGROUND

Lymph node ratio (LNR), the ratio of tumor-positive lymph nodes (+LN) to the total number of resected lymph nodes (rLN), predicts recurrence and survival in colon cancer. Variations in colonic resection length (RL) may influence rLN, +LN, or both, thereby potentially impacting LNR and its prognostic value in colon cancer.

METHODS

All colon cancer patients treated surgically at our center from 2004 to 2011 were included in an institutional review board-approved data repository (n = 1,039).

RESULTS

Larger RL was associated with increased rLN (ρ = .22; P < .001) but not with +LN (P = .21). In node-positive patients (n = 411), RL-adjusted LNR had weaker correlations with death (ρ = .338 vs .373, both P < .001) or metastatic disease (ρ = .303 vs .345; both P < .001) and a smaller area under the curve (death: .695 vs .715, metastasis: .675 vs .699). Findings were similar in segmental, extended segmental, and total colectomy subgroups.

CONCLUSIONS

Provided that resections are performed following standard oncologic principles, our analysis shows that RL does not significantly impact the prognostic value of LNR in colon cancer. Correcting LNR for RL seems redundant and may even act as noise distorting LNR values.

Prognostic Value of Lymph Node Ratio in Locally Advanced Rectal Cancer Patients After Preoperative Chemoradiotherapy Followed by Total Mesorectal Excision

Although the absolute number of positive lymph nodes (LNs) has been established as 1 of the most important prognostic factors in rectal cancers, many researchers have proposed that the lymph node ratio (LNR) may have better predicted outcomes. We conducted a retrospective study to compare the predictive ability of LNR and ypN category in rectal cancer. A total of 264 locally advanced rectal cancer (LARC) patients who underwent preoperative chemoradiotherapy (CRT) followed by total mesorectal excision (TME) between 2005 and 2012 were reviewed. All patients were categorized into 3 groups or patients with metastatic LNs were categorized into 2 groups according to the LNR. The prognostic effect on overall survival (OS) and disease-free survival (DFS) was evaluated. With a median follow-up of 45 months, the OS and DFS were 68.4% and 59.3% for the entire cohort, respectively. The respective 5-year OS and DFS rates for the 3 groups (LNR = 0, 0 < LNR ≤ 0.20, and 0.20 < LNR ≤ 1.0) were as follows: 83.2%, 72.6%, and 49.4% (P < 0.001) and 79.5%, 57.3%, and 33.5% (P < 0.001), respectively. Multivariate analysis revealed that LNR and differentiation, but not the number of positive LNs, had independent prognostic value for OS (hazard ratio [HR] = 2.328, 95% confidence interval [CI]: 1.850-4.526, P < 0.001) and DFS (HR = 3.004, 95% CI: 1.616-5.980, P < 0.001). As for patients with positive LNs, the respective 5-year OS and DFS rates for the 2 groups (0 < LNR ≤ 0.20, and 0.20 < LNR ≤ 1.0) were 72.6% and 49.4% (P < 0.001) and 57.3% and 33.5% (P < 0.001), respectively. Multivariate analysis revealed that only LNR was an independent factor for OS (HR = 3.214, 95% CI: 1.726-5.986, P < 0.001) and DFS (HR = 4.230, 95% CI: 1.825-6.458, P < 0.001). Subgroups analysis demonstrated that the ypN category had no impact on survival whereas increased LNR was a significantly prognostic indicator for worse survival in the LNs < 12 subgroup. LNR is an independent prognostic factor in LARC patients treated with preoperative CRT followed by TME. It may be a better independent staging method than the number of metastatic LNs when <12 LNs are harvested after preoperative CRT.

Prognostic value of lymph node ratio in survival of patients with locally advanced rectal cancer

BACKGROUND

The lymph node ratio (LNR) has been shown to be an important prognostic factor in patients with gastric, breast, pancreatic and colorectal cancer. We investigated the prognostic impact of the LNR in addition to TNM classification in patients with locally advanced rectal cancer.

METHODS

We retrospectively analyzed patients who underwent curative resection for locally advanced rectal cancer between July 2005 and December 2010. We determined the LNR cutoff value using a receiver operating characteristic curve. The Kaplan-Meier method was used to estimate survival curves, while Cox regression analyses were used to evaluate the relationship between LNR and survival.

RESULTS

We included 180 patients aged 28-83 years with median follow-up of 41.8 months. The median number of lymph nodes examined and lymph nodes involved were 11.5 and 4, respectively, and the median LNR was 0.366. An LNR of 0.19 (19%) was the cutoff point to separate patients with regard to median overall survival. Median overall survival was 64.2 months for patients with an LNR of 0, 59.1 for an LNR of 0.19 or less and 37.6 for an LNR greater than 0.19 (p = 0.004). The median disease-free survival was 32.9 months for patients with an LNR of 0, 30.4 for an LNR of 0.19 or less and 17.8 for an LNR greater than 0.19 (p = 0.002).

CONCLUSION

Our results suggest that LNR should be considered an additional prognostic factor in patients with locally advanced rectal cancer.

Pathologic Assessment of Rectal Carcinoma after Neoadjuvant Radio(chemo)therapy: Prognostic Implications

Neoadjuvant radio(chemo)therapy is increasingly used in rectal cancer and induces a number of morphologic changes that affect prognostication after curative surgery, thereby creating new challenges for surgical pathologists, particularly in evaluating morphologic changes and tumour response to preoperative treatment. Surgical pathologists play an important role in determining the many facets of rectal carcinoma patient care after neoadjuvant treatment. These range from proper handling of macroscopic specimens to accurate microscopic evaluation of pathological features associated with patients' prognosis. This review presents the well-established pathological prognostic indicators and discusses challenging features in order to provide both surgical pathologists and treating physicians with a checklist that is useful in a neoadjuvant setting.

Impact of Lymph Node Ratio on Oncologic Outcomes in ypStage III Rectal Cancer Patients Treated with Neoadjuvant Chemoradiotherapy followed by Total Mesorectal Excision, and Postoperative Adjuvant Chemotherapy

PURPOSE

To evaluate the prognostic impact of the lymph node ratio (LNR) in ypStage III rectal cancer patients who were treated with neoadjuvant chemoradiotherapy (NCRT).

MATERIALS AND METHODS

We retrospectively reviewed the data of 638 consecutive patients who underwent NCRT followed by total mesorectal excision, and postoperative adjuvant chemotherapy for rectal cancer from 2004 to 2011. Of these, 125 patients were positive for lymph node (LN) metastasis and were analyzed in this study.

RESULTS

The median numbers of examined and metastatic LNs were 17 and 2, respectively, and the median LNR was 0.143 (range, 0.02-1). Median follow-up time was 55 months. In multivariate analyses, LNR was an independent prognostic factor for overall survival (OS) (hazard ratio [HR] 2.17, p = 0.041), disease-free survival (DFS) (HR 2.28, p = 0.005), and distant metastasis-free survival (DMFS) (HR 2.30, p = 0.010). When ypN1 patients were divided into low (low LNR ypN1 group) and high LNR (high LNR ypN1 group) according to a cut-off value of 0.152, the high LNR ypN1 group had poorer OS (p = 0.043) and DFS (p = 0.056) compared with the low LNR ypN1 group. And there were no differences between the high LNR ypN1 group and the ypN2 group in terms of the OS (p = 0.703) and DFS (p = 0.831).

CONCLUSIONS

For ypN-positive rectal cancer patients, the LNR was a more effective prognostic marker than the ypN stage, circumferential resection margin, or tumor regression grade after NCRT, and could be used to discern the high-risk group among ypN1 patients.

Total number of lymph nodes harvested is associated with better survival in stages II and III colorectal cancer

BACKGROUND

Lymph node status is important in staging colorectal cancer (CRC). Presence of metastatic nodes differentiates stage III from stage II. The role of adjuvant therapy is still unclear in stage II CRC. Inadequate node sampling may result in inaccurate staging.

METHOD

Records of 131 patients with stages II and III CRC who underwent curative resection, having five or more lymph nodes harvested from the specimen, were prospectively followed up and analyzed. The Kaplan-Meier method was used to analyze survival, based on groups of serially ascending values of lymph nodes harvested. Regression analysis was performed by Cox proportional hazards ratio model with right-censored CRC survival data at a 10 % significance level. The effect of nodal harvest on survival was adjusted for age, sex, preoperative carcinoembryonic antigen (CEA) level, neoadjuvant chemoradiation, pathological tumor stage, histological type, differentiation, margin positivity, angioinvasion, perineural invasion, and lymphovascular infiltration.

RESULTS

The total population showed improved survival with 14 or more nodes harvested (p= 0.005). For both rectal (n= 83; p= 0.03) and colon cancers (n= 46; p= 0.08), most significant survival benefits were seen with over 14 nodes harvested, irrespective of the stage. With multiple regression analysis, advanced age (p= 0.003), male sex (p= 0.017), lymphovascular infiltration (p= 0.015), and preoperative CEA levels (p= 0.096) were found to be other significant factors. The lymph node effect remained significant (HR = 0.19, p= 0.004) after adjusting for the above factors.

CONCLUSION

A lymph node harvest of 14 or more resulted in better survival outcome from CRC in this population. Staging of the disease could be accurate with increased nodal harvesting.

The prognostic value of lymph node ratio and updated TNM classification in rectal cancer patients with adequate versus inadequate lymph node dissection

BACKGROUND

The aim of this study was to clarify whether the lymph node ratio (LNR) is superior to the updated TNM classification regarding the prognosis of stage III rectal cancer patients who have not undergone neoadjuvant therapy. The TNM system is based on the absolute number of lymph nodes involved, and the LNR takes into account involved and examined nodes.

METHODS

In 237 patients with stage III rectal cancer, we evaluated prognostic factors for 5-year overall survival (OS), disease-free survival (DFS), and risk of distant metastases (DM) using the Kaplan-Meier method, with patients divided based on adequate versus inadequate lymph node dissection (≥12 vs. <12 lymph nodes examined). The updated TNM divides patients into four groups (1, 2-3, 4-6, and ≥7 involved nodes), while LNR divides patients into quartiles. Multivariate Cox regression analyses were performed.

RESULTS

Among patients with adequate lymph node dissection, the distributions within the two systems were in agreement in 141/178 (79.2 %, kappa 0.721), and the predictive values for OS, DFS, and DM were similar. In patients with inadequate lymph node dissection, the classifications of both systems were concordant in only 13/59 (22 %, kappa 0.021). The pN system significantly under-staged patients, while the LNR classification was a better predictor of OS, DFS, and DM.

CONCLUSIONS

In patients with adequate lymph node dissection, LNR staging does not add substantial information to the predictions of updated TNM lymph node staging. However, in patients with inadequate lymph node harvesting, the LNR compensates for the under-staging of the TNM classification and provides a better estimation of prognosis than the updated TNM system.

Routine defunctioning stoma after chemoradiation and total mesorectal excision: A single-surgeon experience

AIM: To investigate the 10-year results of treating low rectal cancer by a single surgeon in one institution.

METHODS: From Oct 1998 to Feb 2009, we prospectively followed a total of 62 patients with cT2-4 low rectal cancer with lower tumor margins measuring at 3 to 6 cm above the anal verge. All patients received neoadjuvant chemoradiation (CRT) for 6 wk. Among them, 85% of the patients received 225 mg/m²/d 5-fluorouracil using a portable infusion pump. The whole pelvis received a total dose of 45 Gy of irradiation in 25 fractions over 5 wk. The interval from CRT completion to surgical intervention was planned to be approximately 6-8 wk. Total mesorectal excision (TME) and routine defunctioning stoma construction were performed by one surgeon. The distal resection margin, circumferential resection margin, tumor regression grade (TRG) and other parameters were recorded. We used TRG to evaluate the tumor response after neoadjuvant CRT. We evaluated anal function outcomes using the Memorial Sloan-Kettering Cancer Center anal function scores after closure of the defunctioning stoma.

RESULTS: The median distance from the lower margin of rectal cancer to the anal verge was 5 cm: 6 cm in 9 patients, 5 cm in 32 patients, 4 cm in 10 patients, and 3 cm in 11 patients. Before receiving neoadjuvant CRT, 45 patients (72.6%) had a cT3-4 tumor, and 21 (33.9%) patients had a cN1-2 lymph node status. After CRT, 30 patients (48.4%) had a greater than 50% clinical reduction in tumor size. The final pathology reports revealed that 33 patients (53.2%) had a ypT3-4 tumor and 12 (19.4%) patients had ypN1-2 lymph node involvement. All patients completed the entire course of neoadjuvant CRT. Most patients developed only Grade 1-2 toxicities during CRT. Thirteen patients (21%) achieved a pathologic complete response. Few post-operative complications occurred. Nearly 90% of the defunctioning stomas were closed within 6 mo. The local recurrence rate was 3.2%. Pathologic lymph node involvement was the only prognostic factor predicting disease recurrence (36.5% vs 76.5%, P = 0.006). Nearly 90% of patients recovered sphincter function within 2 year after closure of the defunctioning stoma.

CONCLUSION: Neoadjuvant CRT followed by TME, combined with routine defunctioning stoma construction and high-volume surgeon experience, can provide excellent surgical quality and good local disease control.

Treatment of locally advanced rectal cancer: Controversies and questions

Rectal cancers extending through the rectal wall, or involving locoregional lymph nodes (T3/4 or N1/2), have been more difficult to cure. The confines of the bony pelvis and the necessity of preserving the autonomic nerves makes surgical extirpation challenging, which accounts for the high rates of local and distant relapse in this setting. Combined multimodality treatment for rectal cancer stage II and III was recommended from National Institute of Health consensus. Neoadjuvant chemoradiation using fluoropyrimidine-based regimen prior to surgical resection has emerged as the standard of care in the United States. Optimal time of surgery after neoadjuvant treatment remained unclear and prospective randomized controlled trial is ongoing. Traditionally, 6-8 wk waiting period was commonly used. The accuracy of studies attempting to determine tumor complete response remains problematic. Currently, surgery remains the standard of care for rectal cancer patients following neoadjuvant chemoradiation, whereas observational management is still investigational. In this article, we outline trends and controversies associated with optimal pre-treatment staging, neoadjuvant therapies, surgery, and adjuvant therapy.

Reduced lymph node harvest after neoadjuvant chemotherapy in gastric cancer

This retrospective study investigated the impact of neoadjuvant chemotherapy on the number of lymph nodes harvested in patients with T(3)/T(4) gastric cancer. Lymph node counts in 58 patients who received preoperative neoadjuvant chemotherapy were compared with those in 168 patients who received surgery alone. Significantly more patients (n = 14, 24.1%) treated with neoadjuvant chemotherapy had < 15 lymph nodes harvested compared with patients (n = 13, 7.7%) treated with surgery alone. A significant correlation between the total number of harvested lymph nodes and the number of metastatic lymph nodes (mLNs) existed in both groups. Neoadjuvant chemotherapy was the only factor associated with the retrieval of < 15 lymph nodes. The number of mLNs was an independent predictive factor for overall survival. Although neoadjuvant chemotherapy decreased the number of lymph nodes harvested, the number of mLNs may still be an acceptable prognostic factor in patients with gastric cancer, following neoadjuvant chemotherapy.

Lymph node ratio is an independent prognostic factor in patients with rectal cancer treated with preoperative chemoradiotherapy and curative resection

PURPOSE

To evaluate the prognostic effect of lymph node ratio (LNR) in patients with locally advanced rectal cancer who were treated with curative resection after preoperative chemoradiotherapy (CRT).

METHODS

Between October 2001 and December 2007, 519 patients who had undergone curative resection of primary rectal cancer after preoperative CRT were enrolled. Of these, 154 patients were positive for lymph node (LN) metastasis and were divided into three groups according to the LNR (≤ 0.15 [n=80], 0.16-0.3 [n=44], >0.3 [n=30]) to evaluate the prognostic effect on overall survival (OS) and disease-free survival (DFS).

RESULTS

LNR (≤ 0.15, 0.16-0.3, and >0.3) was significantly associated with 5-year OS (90.3%, 75.1%, and 45.1%; p<0.001) and DFS (66.7%, 55.8%, and 21.9%; p<0.001) rates. In a multivariate analysis, LNR (≤ 0.15, 0.16-0.3, and >0.3) was a significant independent prognostic factor for OS (hazard ratios [HRs], 1, 3.609, and 8.197; p<0.001) and DFS (HRs, 1, 1.699, and 3.960; p<0.001). LNR had a prognostic impact on OS and DFS in patients with <12 harvested LNs, as well as in those with ≥ 12 harvested LNs (p<0.05).

CONCLUSION

LNR was a significant independent prognostic predictor for OS and DFS in patients with locally advanced rectal cancer who were treated with curative resection after preoperative CRT.

Dukes C colorectal cancer: is the metastatic lymph node ratio important?

PURPOSE

Although the regional lymph node status is essential for staging of colorectal cancer, the importance of the total number of collected nodes remains controversial. Our aim was to examine the impact of the metastatic lymph node ratio (LNR) on the survival of patients with Dukes C colorectal cancer.

METHODS

All patients with Dukes C histology were selected from a prospectively collected database of all colorectal cancers resected between 1997 and 2007 at our institution. Demographic, histopathological and adjuvant treatment data were collected. The total number of positive lymph nodes was divided by the total number of lymph nodes examined to calculate the LNR. Patients were categorised into LNR groups 1 to 5 according to cut-off points: ≤0.1, 0.21, 0.36, 0.6 and ≥0.61. Survival from the date of operation was calculated using Kaplan-Meier estimates. Multivariate analysis was performed to identify those factors influencing survival.

RESULTS

Of 1,098 patients who underwent colorectal cancer resections, 41% were staged as Dukes C. Sixty-four percent of patients received chemotherapy. The median number of lymph nodes harvested and positive for tumour were 11 (range 1-52) and 4 (range 1-28), respectively. In patients who received chemotherapy, 5-year survival was 69.3% for LNR 1 and 23.6% for LNR 5. When no chemotherapy was given, the 5-year survival was 43.1% for LNR 1 and 8.7% for LNR 5.

CONCLUSIONS

Current evaluation of positive lymph nodes may not accurately stage Dukes C colorectal cancer. The assessment of the LNR is a useful prognostic method in this heterogenous group of patients.

Dukes C colorectal cancer: is the metastatic lymph node ratio important?

PURPOSE

Although the regional lymph node status is essential for staging of colorectal cancer, the importance of the total number of collected nodes remains controversial. Our aim was to examine the impact of the metastatic lymph node ratio (LNR) on the survival of patients with Dukes C colorectal cancer.

METHODS

All patients with Dukes C histology were selected from a prospectively collected database of all colorectal cancers resected between 1997 and 2007 at our institution. Demographic, histopathological and adjuvant treatment data were collected. The total number of positive lymph nodes was divided by the total number of lymph nodes examined to calculate the LNR. Patients were categorised into LNR groups 1 to 5 according to cut-off points: ≤0.1, 0.21, 0.36, 0.6 and ≥0.61. Survival from the date of operation was calculated using Kaplan-Meier estimates. Multivariate analysis was performed to identify those factors influencing survival.

RESULTS

Of 1,098 patients who underwent colorectal cancer resections, 41% were staged as Dukes C. Sixty-four percent of patients received chemotherapy. The median number of lymph nodes harvested and positive for tumour were 11 (range 1-52) and 4 (range 1-28), respectively. In patients who received chemotherapy, 5-year survival was 69.3% for LNR 1 and 23.6% for LNR 5. When no chemotherapy was given, the 5-year survival was 43.1% for LNR 1 and 8.7% for LNR 5.

CONCLUSIONS

Current evaluation of positive lymph nodes may not accurately stage Dukes C colorectal cancer. The assessment of the LNR is a useful prognostic method in this heterogenous group of patients.