Number of lymph nodes assessed has no prognostic impact in node-negative rectal cancers after neoadjuvant therapy. Results of the "Italian Society of Surgical Oncology (S.I.C.O.) Colorectal Cancer Network" (SICO-CCN) multicentre collaborative study

Neoadjuvant treatment of colorectal cancer: comprehensive review

BACKGROUND

Neoadjuvant therapy has an established role in the treatment of patients with colorectal cancer. However, its role continues to evolve due to both advances in the available treatment modalities, and refinements in the indications for neoadjuvant treatment and subsequent surgery.

METHODS

A narrative review of the most recent relevant literature was conducted.

RESULTS

Short-course radiotherapy and long-course chemoradiotherapy have an established role in improving local but not systemic disease control in patients with rectal cancer. Total neoadjuvant therapy offers advantages over short-course radiotherapy and long-course chemoradiotherapy, not only in terms of increased local response but also in reducing the risk of systemic relapses. Non-operative management is increasingly preferred to surgery in patients with rectal cancer and clinical complete responses but is still associated with some negative impacts on functional outcomes. Neoadjuvant chemotherapy may be of some benefit in patients with locally advanced colon cancer with proficient mismatch repair, although patient selection is a major challenge. Neoadjuvant immunotherapy in patients with deficient mismatch repair cancers in the colon or rectum is altering the treatment paradigm for these patients.

CONCLUSION

Neoadjuvant treatments for patients with colon or rectal cancers continue to evolve, increasing the complexity of decision-making for patients and clinicians alike. This review describes the current guidance and most recent developments.

Association between the number of retrieved lymph nodes and demographic/tumour-related characteristics in colorectal cancer: a systematic review and meta-analysis

OBJECTIVE

Clinical practice guidelines recommend retrieving at least 12 lymph nodes for correct staging in colorectal cancer. However, it is difficult to retrieve adequate lymph nodes because of various factors. We aimed to evaluate the association between the number of retrieved lymph nodes and demographic/tumour-related characteristics in colorectal cancer.

DESIGN

Systematic review and meta-analysis of primary studies.

DATA SOURCES

PubMed, Embase, Cochrane and Web of Science were searched from January 2016 to June 2023.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies that evaluated the association between retrieved lymph nodes and demographic/tumour-related characteristics in colorectal cancer were included.

DATA EXTRACTION AND SYNTHESIS

OR with 95% conference intervals was extracted and pooled.

RESULTS

A total of 54 studies containing 2 05 821 patients were included in this meta-analysis. The results showed that fewer nodes were retrieved from elderly patients (OR=0.70, 95% CI (0.54 to 0.90), p=0.005), and from tumours located in the left colon than in the right colon (OR=0.43, 95% CI (0.33 to 0.56), p<0.001). More lymph nodes were obtained from females than males (OR=1.15, 95% CI (1.04 to 1.28), p=0.006), from the advanced T stage (T3+T4) than T1+T2 stage (OR=1.57, 95% CI (1.25 to 1.97), p<0.001) and from the N2 stage than N0 stage (OR=1.32, 95% CI (1.15 to 1.51), p<0.001). Body mass index, ethnicity, N1 stage, M stage, tumour differentiation and lymph-vascular invasion were not significantly associated with the lymph node yield.

CONCLUSIONS

The study results suggest that clinicians have an increased opportunity to retrieve sufficient lymph nodes for accurate pathological staging to guide treatment decisions in patients with colorectal cancer who are young, female, with tumours located in the right colon, advanced T stage and N2 stage.

Robotic Rectal Resection for Rectal Cancer in Elderly Patients: A Systematic Review and Meta-Analysis

Rectal cancer is estimated to increase due to an expanding aging population, thus affecting elderly patients more frequently. The optimal surgical treatment for this type of patient remains controversial because they are often excluded from or underrepresented in trials. This meta-analysis aimed to evaluate the feasibility and the safety of robotic surgery in elderly patients (>70 years old) undergoing curative treatment for rectal cancer. Studies comparing elderly (E) and young (Y) patients submitted to robotic rectal resection were searched on PubMed, Embase, and the Cochrane Library. Data regarding surgical oncologic quality, post-operative, and survival outcomes were extracted. Overall, 322 patients underwent robotic resection (81 in the E group and 241 in the Y group) for rectal cancer. No differences between the two groups were found regarding distal margins and the number of nodes yielded (12.70 in the E group vs. 14.02 in the Y group, p = 0.16). No differences were found in conversion rate, postoperative morbidity, mortality, and length of stay. Survival outcomes were only reported in one study. The results of this study suggest that elderly patients can be submitted to robotic resection for rectal cancer with the same oncologic surgical quality offered to young patients, without increasing postoperative mortality and morbidity.

Metastatic lymph nodes and prognosis assessed by the number of retrieved lymph nodes in gastric cancer

BACKGROUND

The prognostic value of quantitative assessments of the number of retrieved lymph nodes (RLNs) in gastric cancer (GC) patients needs further study.

AIM

To discuss how to obtain a more accurate count of metastatic lymph nodes (MLNs) based on RLNs in different pT stages and then to evaluate patient prognosis.

METHODS

This study retrospectively analyzed patients who underwent GC radical surgery and D2/D2+ LN dissection at the Cancer Hospital of Harbin Medical University from January 2011 to May 2017. Locally weighted smoothing was used to analyze the relationship between RLNs and the number of MLNs. Restricted cubic splines were used to analyze the relationship between RLNs and hazard ratios (HRs), and X-tile was used to determine the optimal cutoff value for RLNs. Patient survival was analyzed with the Kaplan-Meier method and log-rank test. Finally, HRs and 95% confidence intervals were calculated using Cox proportional hazards models to analyze independent risk factors associated with patient outcomes.

RESULTS

A total of 4968 patients were included in the training cohort, and 11154 patients were included in the validation cohort. The smooth curve showed that the number of MLNs increased with an increasing number of RLNs, and a nonlinear relationship between RLNs and HRs was observed. X-tile analysis showed that the optimal number of RLNs for pT1-pT4 stage GC patients was 26, 31, 39, and 45, respectively. A greater number of RLNs can reduce the risk of death in patients with pT1, pT2, and pT4 stage cancers but may not reduce the risk of death in patients with pT3 stage cancer. Multivariate analysis showed that RLNs were an independent risk factor associated with the prognosis of patients with pT1-pT4 stage cancer (P = 0.044, P = 0.037, P = 0.003, P < 0.001).

CONCLUSION

A greater number of RLNs may not benefit the survival of patients with pT3 stage disease but can benefit the survival of patients with pT1, pT2, and pT4 stage disease. For the pT1, pT2, and pT4 stages, it is recommended to retrieve 26, 31 and 45 LNs, respectively.

Determination of the extent of dissection in early gastric cancer based on lymph node station power index

Background

The relative prognostic value of each lymph node (LN) station remains undefined in the treatment of gastric cancer. This study aimed to develop a new method to evaluate LN station ranking and define the optimal extent of lymphadenectomy for early gastric cancer.

Methods

Clinical and histopathological information from patients who underwent curative gastrectomy with lymphadenectomy between 1989 and 2018 was reviewed. The LN station power index (LNPI) of each station was estimated using a LN retrieval frequency and the 5-year overall survival of patients with absence of LN at each station. External validation was conducted to evaluate the relevance of the LNPI.

Results

A training set was developed from examination of 7009 patient records. For most nodal stations, the absence of LN was significantly associated with a poor prognosis. For the perigastric stations, the prognostic value assessed using the LNPI was in the following order: LN 4 (LNPI = 19.68), LN 3 (LNPI = 17.58), LN 6 (LNPI = 15.16), LN 1 (LNPI = 6.71), LN 2 (LNPI = 4.64) and LN 5 (LNPI = 2.86). The value rank of the extra-gastric stations was in the following order: LN 8a (LNPI = 12.93), LN 7 (LNPI = 10.51) and LN 9 (LNPI = 9.70), but the index of LN 12a (LNPI = 4.79) was higher than that of LN 11 (LNPI = 4.78). These trends in the LNPI were similar in the validation patient cohort.

Conclusions

The LNPI is a simple tool to rank the priority of each LN station dissection. The optimal extent of D1 + lymphadenectomy using LNPI was determined to be D1 with LNs 7, 8a and 9.

Number of Examined Lymph Nodes as a Risk Factor for Recurrence in pT1N+ or pT2-3N0 Gastric Cancer

BACKGROUND/AIM

Japanese Gastric Cancer Treatment Guidelines do not recommend adjuvant chemotherapy after radical gastrectomy for pathological stage (p) T1N+ or pT2~3N0 gastric cancer. However, some patients experience disease recurrence. This study aimed to identify the risk factors for recurrence in pT1N+ or pT2-3N0 gastric cancer.

PATIENTS AND METHODS

The study included 157 patients with diagnosed pT1N+ or pT2-3N0 gastric cancer who underwent radical gastrectomy at our institution between January 2001 and December 2020. Clinicopathological data and surgical data were obtained. Independent prognostic factors were analyzed using a Cox proportional hazards regression model.

RESULTS

Thirteen patients (8.3%) experienced disease recurrence. Multivariate analysis revealed that the number of examined lymph nodes was an independent prognostic factor for recurrence-free survival (hazard ratio=10.90; 95% confidence interval=1.39-85.86; p=0.023). The group with ≤35 examined lymph nodes had significantly worse recurrence-free survival compared with the group with ≥36 examined lymph nodes (80.7% versus 98.7%; p=0.0005).

CONCLUSION

The number of examined lymph nodes (≤35) was an independent risk factor for recurrence after radical gastrectomy with pT1N+ or pT2-3N0 gastric cancer.

The assessment of risk factors for long-term survival outcome in ypN0 patients with rectal cancer after neoadjuvant therapy and radical anterior resection

BACKGROUND

The main negative prognostic factors in patients with rectal cancer after radical treatment include regional lymph node involvement, lymphovascular invasion, and perineural invasion. However, some patients still develop cancer recurrence despite the absence of the above risk factors. The aim of the study was to assess clinicopathological factors influencing long-term oncologic outcomes in ypN0M0 rectal cancer patients after neoadjuvant therapy and radical anterior resection.

METHODS

A retrospective survival analysis was performed on a group of 195 patients. We assessed clinicopathological factors which included tumor regression grade, number of lymph nodes in the specimen, Charlson comorbidity index (CCI), and colorectal anastomotic leakage (AL).

RESULTS

In the univariate analysis, AL and CCI > 3 had a significant negative impact on disease-free survival (DFS), disease-specific survival (DSS), and overall survival (OS). After the division of ALs into early and late ALs, it was found that only patients with late ALs had a significantly worse survival. The multivariate Cox regression analysis showed that CCI > 3 was a significant adverse risk factor for DFS (HR 5.78, 95% CI 2.15-15.51, p < 0.001), DSS (HR 7.25, 95% CI 2.25-23.39, p < 0.001), and OS (HR 3.9, 95% CI 1.72-8.85, p = 0.001). Similarly, late ALs had a significant negative impact on the risk of DFS (HR 5.05, 95% CI 1.97-12.93, p < 0.001), DSS (HR 10.84, 95% CI 3.44-34.18, p < 0.001), and OS (HR 4.3, 95% CI 1.94-9.53, p < 0.001).

CONCLUSIONS

Late AL and CCI > 3 are the factors that may have an impact on long-term oncologic outcomes. The impact of lymph node yield on understaging was not demonstrated.

Effects of neoadjuvant chemotherapy plus chemoradiotherapy on lymph nodes in rectal adenocarcinoma

The pathological nodal stage, determination of which requires examination of ≥ 12 lymph nodes, is one of the main prognostic factors in rectal cancer. Neoadjuvant chemoradiotherapy (CRT) may reduce the number of both lymph nodes retrieved and positive lymph nodes. Induction chemotherapy before CRT aimed at reducing the rate of distant metastases. However, the impact of this new treatment on number of lymph nodes retrieved and positive lymph nodes is unknown. This study was performed to evaluate the effects of neoadjuvant chemotherapy on lymph nodes in locally advanced rectal cancer treated by CRT. We retrospectively included patients with T2 - 4 Nx M0 rectal cancer and compared those receiving neoadjuvant chemotherapy plus CRT with those receiving CRT alone. From 2012 to 2019, 85 patients were treated with neoadjuvant chemotherapy + CRT and 189 with CRT alone. The number of lymph nodes retrieved (19 vs. 17, respectively, P = 0.434), the rate of specimens with ≥ 12 lymph nodes (92% vs. 88%, respectively, P = 0.397), and the median number of positive lymph nodes (1 vs. 2, respectively, P = 0.878) were similar between the two groups. However, the rate of pN0 was higher after neoadjuvant chemotherapy + CRT compared to CRT (75% vs. 62%, respectively, P = 0.030). Neoadjuvant chemotherapy before CRT for locally advanced rectal cancer did not modify the number of lymph nodes retrieved or the number of positive lymph nodes compared to CRT alone. However, it significantly increased the rate of tumors without any positive lymph nodes (ypN0).

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.

Impact of examined lymph node count on staging and long-term survival of patients with node-negative stage III gastric cancer: a retrospective study using a Chinese multi-institutional registry with Surveillance, Epidemiology, and End Results (SEER) data validation

Background

Accumulating evidence has confirmed the potential prognostic value of examined lymph nodes (ELNs) in patients with gastric cancer (GC). However, there is currently no consensus on the threshold ELN number for predicting both stage migration and long-term survival, especially in patients with stage III GC. This study aimed to validate the need to increase the ELN count to improve its prognostic accuracy in node-negative patients with stage III GC after curative gastrectomy.

Methods

This retrospective, population-based study analyzed the clinical data of 84 patients with node-negative stage III GC from three high-volume institutions in China and 196 cases from the Surveillance, Epidemiology and End Results (SEER) program registry. The optimal number of ELNs was determined by receiver operating characteristic (ROC) curve analysis. Clinicopathological characteristics significantly related to survival were evaluated using the Kaplan-Meier method and Cox proportional hazards analysis. Stratified analyses were adopted to assess the prognostic predictive ability of the identified optimal number of ELNs in different populations. Survival differences among subgroups were analyzed to assess the impact of ELN count on stage migration according to overall survival (OS) among GC patients.

Results

The optimal number of ELNs was >31 according to ROC analysis of patients with node-negative stage III GC who underwent gastrectomy. Multivariate analysis identified ELNs as an independent predictor of postoperative OS in patients with node-negative stage III GC in both the Chinese cohort [hazard ratio (HR) 0.235; P<0.001] and the SEER cohort (HR 0.421; P<0.010). Stratified analysis demonstrated that >31 ELNs was a prerequisite for accurate prognostic evaluation of patients with node-negative stage III GC, regardless of sex, tumor size, and other factors. Stage migration between pT4bN0M0 and pT4bN1M0 was detected in patients with >31 ELNs. A nomogram was created to predict OS among patients with node-negative stage III GC. These results were validated using data from the SEER cohort.

Conclusions

The number of ELNs was significantly associated with prognosis in patients with stage III GC after gastrectomy with systemic lymphadenectomy in both the Chinese and SEER cohorts. The results suggest that >31 ELNs are required for an accurate prognostic evaluation in patients with GC, especially those with node-negative stage III GC.

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

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

Impact of negative lymph nodes on colon cancer survival and exploring relevant transcriptomics differences through real-world data analyses

Background

The prognostic role and underlying heterogeneity of negative lymph nodes (NLNs) on colon cancer is not well understood. The purpose of this study was to construct NLN-based prognostic models and reveal relevant mechanisms affecting NLNs by analyzing omic data.

Methods

This inception cohort study included 314,398 colon cancer patients from the US Surveillance, Epidemiology, and End Results (SEER) database. Receiver operating characteristic (ROC) curve was used to determine the cut-off of NLNs. Nomograms were constructed and validated using SEER data and the Cancer Genome Atlas (TCGA) data, respectively. The differentially expressed genes (DEGs) were analyzed using edgeR. Enrichment analyses were performed by Metascape.

Results

Multivariate analysis confirmed the high NLN had improved cancer-specific survival (CSS) and overall survival (OS) compared to low NLN [hazard ratio (HR) =0.610, 95% confidence interval (CI), 0.601-0.620] for CSS and (HR =0. 682, 95% CI, 0.674-0.690) for OS. Nomograms were established for CSS and OS with the c-statistic 0.790 (95% CI, 0.788-0.792) for CSS and 0.734 (95% CI, 0.732-0.736) for OS. High NLN was associated with less B cell (P=0.002) and macrophage infiltration (P<0.0001), high microsatellite instability (MSI) (OR =4.325, P=0.001), and hypermutation (OR =4.285, P=0.001; high vs. low). Transcriptomics analysis demonstrated histone modifiers were the most significant different biological processes between the high and low NLN group.

Conclusions

The NLN-based models can aid in personalized risk stratification for colon cancer. This study postulates that high NLN may represent a biological subtype with less macrophage infiltration, high MSI status, hypermutation, and histone modifier gene enriched expression, and thus warrants further investigation.

Number of retrieved lymph nodes is an independent prognostic factor after total gastrectomy for patients with stage III gastric cancer: propensity score matching analysis of a multi-institution dataset

BACKGROUND

The prognostic significance of the number of retrieved lymph nodes (RLNs) in gastric cancer remains controversial. Therefore, we designed a multicenter collaborative database to investigate the correlation between the number of RLNs and prognosis of patients with advanced gastric cancer after curative resection.

METHODS

We retrospectively analyzed 1103 patients who underwent gastrectomy for stage II/III gastric cancer between 2010 and 2014. Lymph nodes, which were retrieved by surgeons from surgically resected specimens, were validated by pathologists. A target population and the optimal cutoff were determined using receiver operating characteristic (ROC) curve analysis. After propensity score matching of eight variables, including splenectomy and adjuvant chemotherapy, the prognostic significance of RLNs was evaluated.

RESULTS

According to ROC curve analysis, the optimum cutoff score for predicting postoperative survival was 40. After matching, the backgrounds of patients in the RLN < 40 and RLN ≥ 40 groups (n = 87 each) became well-balanced. The RLN < 40 group experienced significantly shorter relapse-free and overall survival. The prevalence of peritoneal recurrence was significantly increased in the RLN < 40 group. RLN < 40 was an independent prognostic factor in multivariable analysis, although pathological N status was not. A forest plot revealed that the RLN < 40 group was at greater risk of recurrence in most subgroups.

CONCLUSIONS

RLN < 40 was associated with an adverse prognosis of patients with stage III gastric cancer who underwent total gastrectomy.

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.

Progress in neoadjuvant drug therapy of rectal cancer

Rectal cancer is one of the most common malignant tumors of the digestive system. A portion of patients have had locally advanced disease at the time of diagnosis and have lost the chance of radical surgery. How to increase the R0 resection rate has always been a major difficulty in clinical practice. Some studies have shown that for some patients, neoadjuvant drug therapy can achieve reduction of clinical stage, increase the R0 resection rate and anus-preserving rate, reduce the local recurrence and micro-metastasis, and prolong the survival time of patients. This article mainly reviews the progress in neoadjuvant drug therapy of rectal cancer.