Histological changes in the cervical lymph nodes after radiotherapy

Detectability and intra-fraction motion of individual elective lymph nodes in head and neck cancer patients on the Magnetic Resonance Image guided linear accelerator

Background and purpose

Individual elective lymph node irradiation instead of elective neck irradiation is a new concept for head-and-neck cancer (HNC) patients developed for the Magnetic Resonance Image guided linear accelerator (MR-linac). To prepare this, the detectability, volume changes and intra-fraction motion of elective lymph nodes on the MR-linac was assessed.

Materials and methods

A total of 15 HNC patients underwent diagnostic pre-treatment MRI. Additionally, two MR-linac scans were obtained with a 10-minute time difference in the first week of radiation treatment. Elective lymph node contours inside lymph node levels (Ib-V) were segmented on the pre-treatment MRI and the MR-linac scans and compared on number and maximal transversal diameter. Intra-fraction motion of elective lymph nodes on the MR-linac was estimated using Center of Mass (COM) distances and incremental isotropic expansion of lymph node segmentations.

Results

Of all 679 detected lymph nodes on the pre-treatment MRI, eight lymph nodes were not detectable on the first MR-linac scan and 16 new lymph nodes were detected. Lymph node diameters between the pre-treatment MRI scan and the MR-linac scan varied from -0.19 to + 0.13 mm. COM distances varied from 1.2 to 1.7 mm and lymph node contours had to be expanded with 3 mm.

Conclusions

Nearly all elective lymph nodes were detectable on the 1.5T MR-linac scan with no major changes in target volumes compared to the pre-treatment MRI. Simulated intra-fraction motion during the MR-linac scans was smaller than the 5-mm margin that will be used in the first elective lymph node radiation treatment.

Prognostic significance of lymph node yield on oncologic outcomes according to tumor response after preoperative chemoradiotherapy in rectal cancer patients

PURPOSE

This study aimed to evaluate the predictive value of lymph node yield (LNY) for survival outcomes according to tumor response after preoperative chemoradiotherapy (PCRT) in patients with rectal cancer.

METHODS

This study was a retrospective study conducted in a tertiary center. A total of 1,240 patients with clinical stage II or III rectal cancer who underwent curative resection after PCRT between 2007 and 2016 were included. Patients were categorized into the good response group (tumor regression grade [TRG], 0-1) or poor response group (TRG, 2-3). Propensity score matching was performed for age, sex, and pathologic stage between LNY of ≥12 and LNY of <12 within tumor response group. The primary outcome was 5-year disease-free survival (DFS) and overall survival (OS).

RESULTS

LNY and positive lymph nodes were inversely correlated with TRG. In good responders, 5-year DFS and 5-year OS of patients with LNY of <12 were better than those with LNY of ≥12, but there was no statistical significance. In poor responders, the LNY of <12 group had worse survival outcomes than the LNY of ≥12 group, but there was also no statistical significance. LNY of ≥12 was not associated with DFS and OS in multivariate analysis.

CONCLUSION

LNY of <12 showed contrasting outcomes between the good and poor responders in 5-year DFS and OS. LNY of 12 may not imply adequate oncologic surgery or proper staging in rectal cancer patients treated by PCRT. Furthermore, a decrease in LNY should be comprehended differently according to tumor response.

Lymph node yield less than 12 is not a poor predictor of survival in locally advanced rectal cancer after laparoscopic TME following neoadjuvant chemoradiotherapy

Purpose

Previous studies have confirmed that neoadjuvant chemoradiotherapy (nCRT) may reduce the number of lymph nodes retrieved in rectal cancer. However, it is still controversial whether it is necessary to harvest at least 12 lymph nodes for locally advanced rectal cancer (LARC) patients who underwent nCRT regardless of open or laparoscopic surgery. This study was designed to evaluate the relationship between lymph node yield (LNY) and survival in LARC patients who underwent laparoscopic TME following nCRT.

Methods

Patients with LARC who underwent nCRT followed by laparoscopic TME were retrospectively analyzed. The relationship between LNY and survival of patients was evaluated, and the related factors affecting LNY were explored. To further eliminate the influence of imbalance of clinicopathological features on prognosis between groups, propensity score matching was conducted.

Results

A total of 257 consecutive patients were included in our study. The median number of LNY was 10 (7 to 13) in the total cohort. There were 98 (38.1%) patients with 12 or more lymph nodes harvested (LNY ≥12 group), and 159 (61.9%) patients with fewer than 12 lymph nodes retrieved (LNY <12 group). There was nearly no significant difference between the two groups in clinicopathologic characteristics and surgical outcomes except that the age of LNY <12 group was older (P<0.001), and LNY <12 group tended to have more TRG 0 cases (P<0.060). However, after matching, when 87 pairs of patients obtained, the clinicopathological features were almost balanced between the two groups. After a median follow-up of 65 (54 to 75) months, the 5-year OS was 83.9% for the LNY ≥12 group and 83.6% for the LNY <12 group (P=0.893), the 5-year DFS was 78.8% and 73.4%, respectively (P=0.621). Multivariate analysis showed that only patient age, TRG score and ypN stage were independent factors affecting the number of LNY (all P<0.05). However, no association was found between LNY and laparoscopic surgery-related factors.

Conclusions

For LARC patients who underwent nCRT followed by laparoscopic TME, the number of LNY less than 12 has not been proved to be an adverse predictor for long-term survival. There was no correlation between LNY and laparoscopic surgery-related factors.

MRI visibility and displacement of elective lymph nodes during radiotherapy in head and neck cancer patients

Background and purpose

To decrease the impact of radiotherapy to healthy tissues in the head and neck region, we propose to restrict the elective neck irradiation to elective lymph nodes at risk of containing micro metastases instead of the larger lymph node volumes. To assess whether this new concept is achievable in the clinic, we determined the number, volume changes and displacement of elective lymph nodes during the course of radiotherapy.

Materials and methods

MRI scans of 10 head and neck cancer (HNC) patients were acquired before radiotherapy and in week 2, 3, 4 and 5 during radiotherapy. The weekly delineations of elective lymph nodes inside the lymph node levels (Ib/II/III/IVa/V) were rigidly registered and analyzed regarding number and volume. The displacement of elective lymph nodes was determined by center of mass (COM) distances, vector-based analysis and the isotropic contour expansion of the lymph nodes of the pre-treatment scan or the scan of the previous week in order to geographically cover 95% of the lymph nodes in the scans of the other weeks.

Results

On average, 31 elective lymph nodes in levels Ib-V on each side of the neck were determined. This number remained constant throughout radiotherapy in most lymph node levels. The volume of the elective lymph nodes reduced significantly in all weeks, up to 50% in week 5, compared to the pre-treatment scan. The largest median COM displacements were seen in level V, for example 5.2 mm in week 5 compared to the pre-treatment scan. The displacement of elective lymph nodes was mainly in cranial direction. Geographical coverage was obtained when the lymph node volumes were expanded with 7 mm in case the pre-treatment scan was used and 6.5 mm in case the scan of the previous week was used.

Conclusion

Elective lymph nodes of HNC patients remained visible on MRI and decreased in size during radiotherapy. The displacement of elective lymph nodes differ per lymph node level and were mainly directed cranially. Weekly adaptation does not seem to improve coverage of elective lymph nodes. Based on our findings we expect elective lymph node irradiation is achievable in the clinic.

Lymph Node Yield in Gastrointestinal Cancer Surgery With or Without Prior Neoadjuvant Therapy: Protocol for a Systematic Review and Meta-analysis

BACKGROUND

Lymph node yield is the number of lymph nodes retrieved during oncological resection and histopathologically identified in the resection specimen. It is an important surrogate parameter for assessing the oncological radicality of the resection of gastrointestinal carcinomas, as well as a prognostic factor in these diseases. It remains unclear if and to what extent neoadjuvant chemotherapy, radiotherapy, or chemoradiotherapy, which have become established treatments for carcinoma of the esophagus, stomach, and rectum and are increasingly used in pancreatic carcinoma, affect the lymph node yield.

OBJECTIVE

This systematic review with meta-analysis is conducted with the aim of summarizing the available evidence regarding the lymph node yield, an oncological surrogate marker, in patients with gastrointestinal carcinomas undergoing surgery after neoadjuvant therapy compared to those undergoing surgery without neoadjuvant therapy.

METHODS

Randomized and nonrandomized studies comparing oncological resection of esophageal, stomach, pancreatic, and rectal carcinoma with and without prior neoadjuvant therapy are eligible for inclusion regardless of study design. Publications will be identified with a defined search strategy in 2 electronic databases: PubMed and Cochrane Library. The primary endpoint of the analysis is the number of lymph nodes identified in the resected specimen. Secondary endpoints include the number of harvested metastatic lymph nodes, operation time, postoperative complications, pathological TNM staging, and overall and recurrence-free survival time. Using suitable statistical methods, the endpoints between patients with and without neoadjuvant therapy, as well as in defined subgroups (neoadjuvant chemotherapy, radiotherapy, or chemoradiotherapy; and patients with esophageal, gastric, pancreatic, or rectal cancer), will be compared.

RESULTS

The literature search and data collection started in October 2021. Results are expected to be published in mid-2022.

CONCLUSIONS

This meta-analysis will provide the most up-to-date and complete summary of the evidence on an association between neoadjuvant therapy and lymph node yield in gastrointestinal cancer surgery. The underlying hypothesis is that neoadjuvant therapy decreases the number and size of lymph nodes through lymphocyte depletion and radiation-induced fibrosis, thus leading to a lower possible lymph node yield. The findings of the meta-analysis will show if this hypothesis is supported by evidence.

TRIAL REGISTRATION

PROSPERO CRD218459; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021218459.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/35243.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Diagnostic performance of core needle biopsy for nodal recurrences in patients with head and neck squamous cell carcinoma

This study investigated the diagnostic accuracy and affecting factors of ultrasound (US)-guided core-needle biopsy (CNB) in patients with treated head and neck squamous cell carcinoma (HNSCC). We retrospectively reviewed patients with treated HNSCC who received US-guided CNB from January 2011 to December 2018 with corresponding imaging. Pathological necrosis and fibrosis of targeted lymph nodes (LNs) were evaluated. We analyzed the correlation between CNB accuracy and clinical and pathological characteristics. In total, 260 patients were included. The overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of CNB for nodal recurrence were 84.47%, 100%, 100%, 54.67%, and 86.92%, respectively. CNB of fibrotic LNs had significantly worse sensitivity, NPV, and accuracy than that of non-fibrotic LNs. Similarly, CNB of necrotic LNs had significantly worse sensitivity, NPV, and accuracy than non-necrotic LNs. Multivariate regression revealed that fibrotic LN was the only independent factor for a true positive rate, whereas both necrotic LN and fibrotic LN were independent factors for a false negative rate. The diagnostic accuracy of CNB in treated HNSCC patients is affected by LN necrosis and fibrosis. Therefore, CNB results, particularly for necrotic or fibrotic LNs, should be interpreted carefully.

Adequate Lymphadenectomy as a Quality Measure in Esophageal Cancer: Is there an Association with Treatment Approach?

BACKGROUND

The national comprehensive cancer network defines adequate lymphadenectomy as evaluation of ≥ 15 lymph nodes in esophageal cancer. However, varying thresholds have been suggested following neoadjuvant therapy.

OBJECTIVES

Our objectives were to (1) explore trends in adequate lymphadenectomy rates over time; (2) evaluate unadjusted lymphadenectomy yield by treatment characteristics; and (3) identify independent factors associated with adequate lymphadenectomy.

METHODS

The National Cancer Data Base was used to identify patients who underwent esophagectomy for cancer from 2004 to 2015. Adequate lymphadenectomy trends over time were evaluated using the Cochrane-Armitage test, and lymph node yield by treatment approach was compared using the Mann-Whitney U and Kruskal-Wallis tests. Associations with treatment factors were assessed by multivariable logistic regression.

RESULTS

Among 24,413 patients, 9919 (40.6%) had adequate lymphadenectomy. Meeting the nodal threshold increased over time (52.6% in 2015 vs. 26.0% in 2004; p < 0.01). Lymph node yield did not differ based on neoadjuvant therapy (median 12 [interquartile range 7-19] with and without neoadjuvant therapy; p = 0.44). Adequate lymphadenectomy was not associated with neoadjuvant therapy (40.5% vs. 40.8%, odds ratio [OR] 0.94, 95% confidence interval [CI] 0.82-1.07), but was associated with surgical approach (52.7% of laparoscopic cases, OR 1.28, 95% CI 1.06-1.56; 61.2% of robotic cases, OR 1.71, 95% CI 1.34-2.19, vs. 43.5% of open cases), and increasing annual esophagectomy volume (55.6% in the fourth quartile vs. 32.6% in the first quartile; OR 3.57, 95% CI 2.35-5.43).

CONCLUSIONS

Despite increases over time, only 50% of patients undergo adequate lymphadenectomy during esophageal cancer resection. Adequate lymphadenectomy was not associated with neoadjuvant therapy. Focusing on surgical approach and esophagectomy volume may further improve adequate lymphadenectomy rates.

Increased lymph node yield indicates improved survival in locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

PURPOSE

It is recommended for colorectal cancer to harvest at least 12 lymph nodes (LNs) during surgery to avoid understaging of the disease. However, it is still controversial whether it is necessary to harvest from locally advanced rectal cancer (LARC) patients who underwent neoadjuvant chemoradiotherapy (neo-CRT). The impact of lymph node yield (LNY) on prognosis in LARC patients was analyzed.

MATERIALS/METHODS

In total, 495 LARC patients who underwent neo-CRT in 2006-2015 were analyzed. After examining clinicopathological distribution differences between the LNY subgroups (with the threshold of 12), univariate and multivariate Cox survival analyses were performed. Survival plots were obtained from Kaplan-Meier analyses. Similar subgroup analyses were performed according to the tumor regression grade (TRG) and metastatic status of post-operational LNs.

RESULTS

Of the 495 patients, 287 (57.98%) had an LNY of less than 12. Nearly no significant clinicopathological difference was found between the LNY subgroups, including the TRG scores. Multivariate survival analysis demonstrated that at least 12 LNs examined was an independent prognostic feature of good overall survival (OS), disease-free survival (DFS), and distant metastasis free survival (DMFS), but not local recurrence free survival (LRFS). However, in the subgroup analyses, no association was found between LNY and prognosis in patients with good TRG scores (0-1) or negative LNs.

CONCLUSIONS

For LARC patients treated with neo-CRT, an LNY of at least 12 indicated an improved survival. Decreased LNY was not related to better tumor regression. It suggests that a sufficiently high LNY is still required, especially in those with a potentially poor tumor response.

Therapeutic effects of oxaliplatin-based neoadjuvant chemotherapy and chemoradiotherapy in patients with locally advanced rectal cancer: a single-center, retrospective cohort study

BACKGROUND

Neoadjuvant chemoradiotherapy (NACRT) has now become the standard treatment for locally advanced rectal cancer (LARC). NACRT has decreased local relapse (LR) rate in patients with LARC; however, distant relapse has recently attracted much attention. This study aimed to assess the feasibility and efficiency of neoadjuvant chemotherapy (NAC) for LARC.

METHODS

Data on patients with cT3/4 and N+ rectal cancer who were treated in our institution from April 2010 to February 2016 were reviewed retrospectively. Twenty-seven patients who received 2-9 cycles of oxaliplatin-based NAC and 28 patients who received NACRT (45 Gy delivered in 25 fractions and 5-fluorouracil-based oral chemotherapy) were analyzed. The primary and secondary endpoints of the present study were the 3-year relapse-free survival (RFS) and the local and distant relapse rates, respectively.

RESULTS

Regardless of the kind of neoadjuvant therapy, no patient experienced any grade 3-4 therapy-related adverse events. The frequent toxic events were grade 1 diarrhea in patients with NACRT and neutropenia in patients with NAC. A significantly higher proportion of patients with NAC underwent laparoscopic surgery and anterior resection (p = 0.037 and p = 0.003, respectively). The percentages of patients with lymph node yield less than 12 in the NAC group, and those in the NACRT group were 26 and 68%, respectively (p = 0.002). Comparing the NAC with the NACRT groups, the local relapse and distant relapse rates were 7.4 and 7.1% and 7.4 and 18%, respectively. There were no significant differences in 3-year RFS and 4-year overall survival (OS) between NAC and NACRT (3-year RFS 85.2 vs. 70.4%, p = 0.279; 4-year OS 96.3 vs. 89.1%, p = 0.145, respectively). With an analysis excluding patients who received postoperative adjuvant chemotherapy, no patients who received NAC had a distant relapse, and there was a significant difference in 3-year RFS compared with the NACRT groups (94.4 vs. 63.2%, p = 0.043).

CONCLUSION

These outcomes suggest that the therapeutic effect of oxaliplatin-based NAC is at least equal to that of NACRT and that NAC is a feasible and promising option for LARC.

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

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

Contributing factors on lymph node yield after surgery for mid-low rectal cancer

PURPOSE

The purpose of the present study was to evaluate the contributing factors to the lymph node status as well as to define the impact of preoperative concurrent chemoradiotherapy (CCRT) on the number of lymph nodes retrieved in mid-low rectal cancer.

MATERIALS AND METHODS

We retrospectively analyzed 277 patients who underwent curative surgical resection for mid-low rectal cancer between 1998 and 2007. Eighty-two patients received long course preoperative CCRT followed by surgery.

RESULTS

A mean of 13.12±9.28 lymph nodes was retrieved. In a univariate analysis, distance from the anal verge, pT stage, pN stage, lymphovascular invasion, preoperative CCRT had significant influence on the number of lymph nodes retrieved. In a multivariate model, patients in the CCRT group had fewer retrieved lymph nodes than the non-CCRT group (p<0.001). Both univariate and multivariate analyses showed that the ypN0 group had fewer retrieved lymph nodes than the ypN1-2 group (p=0.027) in the CCRT group.

CONCLUSION

Preoperative CCRT was an independent risk factor for failure to harvest an appropriate number of lymph nodes, and node-negative patients who received CCRT had fewer lymph nodes harvested.

Lymph node retrieval after preoperative chemoradiotherapy for rectal cancer

BACKGROUND

Current guidelines recommend the assessment of at least 12 lymph nodes for rectal cancer staging. Preoperative chemoradiotherapy may affect lymph node yield in this malignancy. This study investigated the impact of neoadjuvant chemoradiotherapy on the number of lymph nodes retrieved from rectal cancer patients.

METHODS

An analysis of 162 rectal cancer patients who underwent curative surgery between 2005 and 2010. Seventy-one patients with stage II or III tumors received preoperative chemoradiotherapy. Using multivariate analysis, we assessed the correlation between clinicopathologic variables and number of retrieved lymph nodes. We also evaluated the association between survival and number of lymph nodes obtained.

RESULTS

On multivariate analysis, preoperative chemoradiotherapy was the only variable to independently affect the number of lymph nodes obtained. The mean number of lymph nodes was 14.2 in patients treated with preoperative chemoradiotherapy and 19.4 in those not treated (P < 0.001). In the chemoradiotherapy group, 29.6 % of patients had fewer than 12 lymph nodes obtained compared with 9.9 % in the primary surgery group (P = 0.003). After chemoradiation, the number of retrieved lymph nodes was inversely correlated with tumor regression grade. Results showed that 5-year overall and disease-free survival were similar whether the patient had 12 or more nodes retrieved or not.

CONCLUSIONS

Preoperative chemoradiotherapy reduces the lymph node yield in rectal cancer. The number of retrieved lymph nodes is affected by degree of histopathologic response of the tumor to chemoradiation. Thus, number of lymph nodes should not be used as a surrogate for oncologic adequacy of resection after neoadjuvant chemoradiotherapy for rectal cancer.

Challenging the feasibility and clinical significance of current guidelines on lymph node examination in rectal cancer in the era of neoadjuvant therapy

PURPOSE

We sought to examine the feasibility and clinical significance of current guidelines on nodal assessment in patients with rectal cancer (RC) treated with neoadjuvant radiation.

METHODS

All patients with RC treated with curative surgery from 1991 to 2003 were included. Number of lymph nodes (LNs) assessed was compared between patients who received neoadjuvant therapy and surgery (NEO) and patients who underwent surgery alone (SURG). Impact of node retrieval on node positivity and disease-specific survival (DSS) in NEO patients was assessed.

RESULTS

In total, 708 patients were identified, of whom 429 (61%) were in the NEO group. These patients had significantly fewer nodes assessed than SURG patients (unadjusted mean, 10.8 v 15.5; adjusted mean difference, -5.0 nodes; P < .001). In the NEO group, 63% of patients had fewer than 12 nodes retrieved (P < .001 v SURG). The proportion of patients diagnosed with node-positive disease in the NEO group was significantly and monotonically associated with the number of lymph nodes retrieved, with no plateau in the relationship. Fewer nodes retrieved was not associated with inferior DSS.

CONCLUSION

In a tertiary cancer center, the 12-LN threshold was not relevant and often not achievable in patients with RC treated with neoadjuvant therapy. Lower LN count after neoadjuvant treatment was not associated with understaging or inferior survival. Although we support the critical importance of careful pathologic examination and adequate nodal staging, we challenge the relevance of LN count both in clinical practice and as a quality indicator in RC.

Reduced lymph node yield in rectal carcinoma specimen after neoadjuvant radiochemotherapy has no prognostic relevance

BACKGROUND

In colorectal surgery UICC/AJCC criteria require a yield of 12 or more locoregional lymph nodes for adequate staging. Neoadjuvant radiochemotherapy for rectal carcinoma reduces the number of lymph nodes in the resection specimen; the prognostic impact of this reduced lymph node yield has not been determined.

METHODS

One hundred two patients with uT3 rectal carcinoma who were receiving neoadjuvant radiochemotherapy were compared with 114 patients with uT3 rectal carcinoma who were receiving primary surgery followed by adjuvant radiochemotherapy. Total lymph node yield and number of tumor-positive lymph nodes were determined and correlated with survival.

RESULTS

After neoadjuvant radiochemotherapy both total lymph node yield (12.9 vs. 21.4, p < 0.0001) and number of tumor-positive lymph nodes (1.0 vs. 2.3, p = 0.014) were significantly lower than after primary surgery plus adjuvant radiochemotherapy. Reduced total lymph node yield in neoadjuvantly treated patients had no prognostic impact, with overall survival of patients with 12 or more lymph nodes the same as that of patients with less than 12 lymph nodes. Overall survival of neoadjuvantly treated patients was significantly influenced by the number of tumor-positive lymph nodes with 5-year-survival rates of 88, 63, and 39% for 0, 1-3, and more than 3 positive lymph nodes (p < 0.0001).

CONCLUSION

The UICC/AJCC criterion of a total lymph node yield of 12 or more should be revised for rectal carcinoma patients.