Prognostic implications of the number of retrieved lymph nodes of patients with rectal cancer treated with preoperative chemoradiotherapy

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

Background

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

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

Results

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

Conclusions

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

Supplementary Information

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

Comparison of Four Lymph Node Staging Systems in Gastric Adenocarcinoma after Neoadjuvant Therapy – A Population-Based Study

Introduction

Neoadjuvant treatment leads in a reduction in positive lymph nodes and examined lymph nodes (ELN), which may affect assessment of lymph node staging and postoperative treatment. We aimed to compare the staging systems of lymph node ratio (LNR), the positive logarithm ratio of lymph nodes (LODDS), negative lymph nodes (NLN), and the 8th AJCC ypN stage for patients with gastric adenocarcinoma after neoadjuvant therapy.

Materials and Methods

Data was collected from the Surveillance, Epidemiology, and End Results database and 1,551 patients with gastric adenocarcinoma who underwent neoadjuvant therapy and radical surgery were enrolled. Harrell’s concordance index, the Receiver Operative Curve, the likelihood ratio test, and the Akaike information criterion were used to compare the predictive abilities of the different staging systems.

Results

Among the 1,551 patients, 689 (44.4%) had ELN < 16 and node-negative patients accounted for 395 (25.5%). When regarded as the categorical variable, LNR had better discrimination power, higher homogeneity, and better model fitness for CSS and OS compared to other stage systems, regardless of the status of ELN. When regarded as the continuos variable, LODDS outperformed others for CSS. Furthermore, the NLN staging system performed superior to others in node-negative patients.

Conclusions

LNR had a better predictive performance than ypN, LODDS and NLN staging systems regardless of the status of ELN when regarded as the categorical variable, whereas LOODS became the better predictive factor for CSS when regarded as the continuos variable. In node-negative patients, NLN might be a feasible option for evaluating prognosis. A combination of LNR and NLN should be considered as user-friendly method in the clinical prognostic assessment.

Pathological Features and Prognostication in Colorectal Cancer

The prognostication of colorectal cancer (CRC) has traditionally relied on staging as defined by the Union for International Cancer Control (UICC) and American Joint Committee on Cancer (AJCC) TNM staging classifications. However, clinically, there appears to be differences in survival patterns independent of stage, suggesting a complex interaction of stage, pathological features, and biomarkers playing a role in guiding prognosis, risk stratification, and guiding neoadjuvant and adjuvant therapies. Histological features such as tumour budding, perineural invasion, apical lymph node involvement, lymph node yield, lymph node ratio, and molecular features such as MSI, KRAS, BRAF, and CDX2 may assist in prognostication and optimising adjuvant treatment. This study provides a comprehensive review of the pathological features and biomarkers that are important in the prognostication and treatment of CRC. We review the importance of pathological features and biomarkers that may be important in colorectal cancer based on the current evidence in the literature.

Downstaged ypT0-2N0 rectal cancer after neoadjuvant chemoradiation therapy may not need adjuvant chemotherapy: a retrospective cohort study

PURPOSE

Current guidelines suggest that adjuvant chemotherapy (AC) be administered to all locally advanced (clinically T3-4 or N-positivity) rectal cancer patients undergoing neoadjuvant chemoradiotherapy (nCRT) and radical surgical resection regardless of the final pathological staging (yp staging). This study aimed to evaluate the necessity of AC for ypT0-2N0 rectal cancer.

METHODS

Patients with ypT0-2N0 rectal cancer, who received nCRT and radical surgical resection, were recruited retrospectively at a university hospital. The main outcome was to evaluate the 5-year overall survival (OS) and disease-free survival (DFS) between ypT0-2N0 rectal cancer patients with AC and those without AC. We also identified potential independent prognostic factors associated with poor outcomes.

RESULTS

One hundred and ten ypT0-2N0 rectal cancer patients (ypT0: n = 6; ypT1: n = 44; ypT2: n = 60) were followed up for a median of 60 months. No significant difference was observed in DFS and 5-year OS between patients with AC and those without AC. The risk of recurrence was associated with the postoperative pathological staging (0% with ypT0, 2.4% with ypT1, and 10% with ypT2). In the multivariate analysis, retrieval of < 12 lymph nodes was an independent favorable prognostic factor, which correlated with a higher OS (HR: 2.263; 95% CI: 1.093-4.687, P = 0.028). Intra-tumor lymphovascular and perineural invasion were poor prognostic markers for shorter DFS (HR: 5.940; 95% CI: 1.150-30.696, P = 0.033).

CONCLUSION

Postoperative AC is not required for patients with ypT0-2N0 rectal cancer downstaged by nCRT, especially in those without poor prognostic factors.

Large negative lymph nodes - a surrogate for immune activation in rectal cancer patients?

AIM

The size of regional, tumor draining lymph nodes without metastasis (LNneg) found in rectal cancer resection specimens varies and seems to be related to patient survival. Yet, the histopathological features influencing LNneg size in rectal cancer have not been studied in detail. Our pilot study focused on investigating the relationship between lymph node (LN) size and LNneg microarchitecture in rectal cancer (RC) resection specimens.

METHOD

In this retrospective cohort study, resection specimens from 146 RC patients, treated with either surgery alone (n = 29) or neoadjuvant therapy followed by resection (n = 117), were included in the study. Histology of LNnegs was reviewed to establish number of lymphoid follicles and presence of intranodal fat. Longest long axis and area of each LN were measured digitally.

RESULTS

1830 LNnegs were measured. The microarchitecture was analyzed in a subset of 680 LNnegs. 153 (22.5 %) LNnegs contained intranodal fat. After neoadjuvant treatment, presence of intranodal fat was related to smaller LNneg area (median (range) area of LNneg without intranodal fat: 4.51 mm² (0.15-46.89 mm²), with intranodal fat: 3.46 mm² (0.12-27.22 mm²), p = 0.048). A higher number of lymphoid follicles was related to a larger LNneg area in both patient groups (p < 0.001).

CONCLUSION

Our pilot data suggest that in rectal cancer the presence of large regional LNnegs may reflect increased immune activation due to tumor related antigens. Further studies are warranted to investigate whether histologically visible microarchitectural features of LNnegs such as lymphoid follicles translate to particular features in radiological images and hence could potentially help to identify LNneg with more certainty at the time of pre-treatment disease staging.

Short-term outcomes of a multicentre randomized clinical trial comparing D2 versus D3 lymph node dissection for colonic cancer (COLD trial)

BACKGROUND

It remains unclear whether extended lymphadenectomy provides oncological advantages in colorectal cancer. This multicentre RCT aimed to address this issue.

METHODS

Patients with resectable primary colonic cancer were enrolled in four hospitals registered in the COLD trial, and randomized to D2 or D3 dissection in a 1 : 1 ratio. Data were analysed to assess the safety of D3 dissection.

RESULTS

The study included the first 100 patients randomized in this ongoing trial. Ninety-nine patients were included in the intention-to-treat (ITT) analysis (43 D2, 56 D3). Ninety-two patients received the allocated treatment and were included in the per-protocol (PP) analysis: 39 of 43 in the D2 group and 53 of 56 in the D3 group. There were no deaths. The 30-day postoperative morbidity rate was 47 per cent in the D2 group and 48 per cent in the D3 group, with a risk ratio of 1·04 (95 per cent c.i. 0·68 to 1·58) (P = 0·867). There were two anastomotic leaks (5 per cent) in the D2 group and none in the D3 group. Postoperative recovery, complication and readmission rates did not differ between the groups in ITT and PP analyses. Mean lymph node yield was 26·6 and 27·8 in D2 and D3 procedures respectively. Good quality of complete mesocolic excision was more frequently noted in the D3 group (P = 0·048). Three patients in the D3 group (5 per cent) had metastases in D3 lymph nodes. D3 was never the only affected level of lymph nodes. N-positive status was more common in the D3 group (46 per cent versus 26 per cent in D2), with a risk ratio of 1·81 (95 per cent c.i. 1·01 to 3·24) (P = 0·044).

CONCLUSION

D3 lymph node dissection is feasible and may be associated with better N staging. Registration number: NCT03009227 ( http://www.clinicaltrials.gov).

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

Background

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

Methods

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

Results

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

Conclusion

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

Impact of adjuvant chemotherapy on patients with ypT0-2 ypN0 rectal cancer after neoadjuvant chemoradiation: a cohort study from a tertiary referral hospital

Background

To investigate the importance of adjuvant chemotherapy in locally advanced rectal cancer (≥ cT3 or N+) staged ypT0–2 ypN0 on final histological work-up after neoadjuvant chemoradiation and radical resection.

Methods

The clinical course of patients with rectal cancer and ypT0–2 ypN0 stages after neoadjuvant chemoradiation and radical resection was analyzed from 1999 to 2012. Patients were divided into two groups depending on whether adjuvant chemotherapy was administered or not. Overall survival, distant metastases, and local recurrence were compared between both groups.

Results

Fifty-four patients with adjuvant (ACT) and 50 patients without adjuvant chemotherapy (NACT) after neoadjuvant chemoradiation followed by radical resection for rectal cancer were included in the analysis. Mean follow-up was 68 ± 33.7 months. One patient without adjuvant chemotherapy and none in the ACT group developed a local recurrence. Five patients in the NACT group and three patients in the ACT group had distant recurrences. Median disease-free survival for all patients was 65.5 ± 34.5 months. Multivariate analysis showed adjuvant chemotherapy to be the most relevant factor for disease-free and overall survival. Patients staged ypT2 ypN0 showed a significantly better disease-free survival after application of adjuvant chemotherapy. Disease-free survival in ypT0–1 ypN0 patients showed no correlation to the administration of adjuvant chemotherapy.

Conclusion

Administration of adjuvant chemotherapy after neoadjuvant chemoradiation and radical resection in rectal cancer improved disease-free and overall survival of patients with ypT0–2 ypN0 tumor stages in our study. In particular, ypT2 ypN0 patients seem to profit from adjuvant treatment.

Survival analysis in rectal carcinoma after neoadjuvant chemoradiation: various methods with different results

PURPOSE

Survival is an important indicator of outcome quality in rectal carcinoma. The 5-year survival rate is the typical outcome measurement. In patients with neoadjuvant chemoradiation followed by curative surgery, 7 years of follow-up is recommended. Different methods of survival analysis lead to different results. Here, we compared four different methods.

METHODS

The data of 439 patients with rectal carcinoma treated with neoadjuvant chemoradiation followed by curative total mesorectal excision (TME) surgery between 1995 and 2010 were analysed. After stratifying by stage, relative survival (RS), cancer-related survival (CRS), overall survival (OS) and disease-free survival (DFS) were compared. In particular, the 3-year disease-free survival rate was compared to the 5- and 7-year overall survival rates.

RESULTS

In the total cohort, the 5-year survival rates ranged from 90% (RS), over 84% (CRS) and 83% (OS) to 72% (DFS). Depending on the stage of disease, the differences between the 5-year survival rates varied between 10 and 32 percentage points. The differences were lowest in UICC stage y0 and highest in UICC stage yIV. The 3-year DFS-rate was always lower (worse) than the 5-year OS rate and higher (better) than the 7-year OS rate, with the exception of stage yIV.

CONCLUSIONS

Comparisons of survival are only meaningful if the same methods are applied. The 3-year rate of DFS was always worse than the rate of 5-year OS. Therefore, the 3-year rate of DFS appears to be a useful surrogate indicator in rectal carcinoma treatment studies.

Tattooing improves the detection of small lymph nodes and increases the number of retrieved lymph nodes in patients with rectal cancer who receive preoperative chemoradiotherapy: A randomized controlled clinical trial

BACKGROUND

In rectal cancer who received chemoradiotherapy, the number of Lymph nodes (LNs) required remains unclear. We conducted a randomized controlled trial to determine whether preoperative tattooing increases the number of LNs and enhances the detection rate of metastatic LNs.

METHODS

Eighty patients with rectal cancer who received chemoradiotherapy were randomly assigned to receive no tattooing (C group) or to receive tattooing (T group).

RESULTS

The number of LNs was significantly higher in the T group (13.3 ± 7.4, mean ± SD) than in the C group (8.8 ± 5.9, p < 0.001), however, the number of positive LNs did not differ (0.5 ± 1.3 vs. 0.5 ± 1.1, p = 0.882). The long-axis diameter of LNs was significantly smaller in the T group than in the C group (3.4 ± 1.8 vs. 3.9 ± 2.3 mm, p < 0.001), however, the long-axis diameter of positive LNs did not differ.

CONCLUSIONS

Tattooing increased the number of retrieved LNs by 51%, however, there was no increase in the number of positive LNs.

Effect of Neoadjuvant Radiation Dose and Schedule on Nodal Count and Its Prognostic Impact in Stage II-III Rectal Cancer

BACKGROUND

It is unknown how neoadjuvant treatment schedule affects lymph node count (LNC) and lymph node ratio (LNR) and how these correlate with overall survival (OS) in rectal cancer (RC).

METHODS

Data were used from the Belgian PROCARE rectal cancer registry on RC patients treated with surgery alone, short-term radiotherapy with immediate surgery (SRT), or chemoradiation with deferred surgery (CRT). The effect of neoadjuvant therapy on LNC was examined using Poisson log-linear analysis. The association of LNC and LNR with overall survival (OS) was studied using Cox proportional hazards models.

RESULTS

Data from 4037 patients were available. Compared with surgery alone, LNC was reduced by 12.3 % after SRT and by 31.3 % after CRT (p < 0.001). In patients with surgery alone, the probability of finding node-positive disease increased with LNC, while after SRT and CRT no increase was noted for more than 12 and 18 examined nodes, respectively. Per node examined, we found a decrease in hazard of death of 2.7 % after surgery alone and 1.5 % after SRT, but no effect after CRT. In stage III patients, the LNR but not (y)pN stage was significantly correlated with OS regardless of neoadjuvant therapy. Specifically, a LNR > 0.4 was associated with a significantly worse outcome.

CONCLUSIONS

Nodal counts are reduced in a schedule-dependent manner by neoadjuvant treatment in RC. After chemoradiation, the LNC does not confer any prognostic information. A LNR of >0.4 is associated with a significantly worse outcome in stage III disease, regardless of neoadjuvant therapy type.

Importance of Adequate Lymphadenectomy in Gastrointestinal Cancer

One of the most important factors influencing cancer-specific survival in the field GI oncology is the presence of positive lymph nodes. Although it remains controversial, adequate lymph node examination is required for accurate staging such that patients can receive correct adjuvant treatments and for stratification in clinical trials. Nevertheless, wide variation in the quality of lymph node examination exists in the US and many centers are not meeting guideline treatment recommendations.

Role of Adjuvant Chemotherapy in ypT0-2N0 Patients Treated with Preoperative Chemoradiation Therapy and Radical Resection for Rectal Cancer

OBJECTIVE

To explore the role of adjuvant chemotherapy for patients with ypT0-2N0 rectal cancer treated by preoperative chemoradiation therapy (PCRT) and radical resection.

PATIENTS AND METHODS

A national consortium of 10 institutions was formed, and patients with ypT0-2N0 mid- and low-rectal cancer after PCRT and radical resection from 2004 to 2009 were included. Patients were categorized into 2 groups according to receipt of additional adjuvant chemotherapy: Adj CTx (+) versus Adj CTx (-). Propensity scores were calculated and used to perform matched and adjusted analyses comparing relapse-free survival (RFS) between treatment groups while controlling for potential confounding.

RESULTS

A total of 1016 patients, who met the selection criteria, were evaluated. Of these, 106 (10.4%) did not receive adjuvant chemotherapy. There was no overall improvement in 5-year RFS as a result of adjuvant chemotherapy [91.6% for Adj CTx (+) vs 87.5% for Adj CTx (-), P=.18]. There were no differences in 5-year local recurrence and distant metastasis rate between the 2 groups. In patients who show moderate, minimal, or no regression in tumor regression grade, however, possible association of adjuvant chemotherapy with RFS would be considered (hazard ratio 0.35; 95% confidence interval 0.14-0.88; P=.03). Cox regression analysis after propensity score matching failed to show that addition of adjuvant chemotherapy was associated with improved RFS (hazard ratio 0.81; 95% confidence interval 0.39-1.70; P=.58).

CONCLUSIONS

Adjuvant chemotherapy seemed to not influence the RFS of patients with ypT0-2N0 rectal cancer after PCRT followed by radical resection. Thus, the addition of adjuvant chemotherapy needs to be weighed against its oncologic benefits.

Total number of lymph nodes in oncologic resections, is there more to be found?

Pathologic staging of oncologic specimens includes the identification of the accurate lymph node status. Retrieving more lymph nodes leads to a more reliable N0 status in the TNM classification. The aim of this prospective study was to evaluate whether more lymph nodes can be retrieved from oncologic resection specimens when more time is invested in the search and if this contributes to a more reliable N-status in the individual patient. A total of 67 gastrointestinal oncologic specimens were reexamined for additional lymph nodes. The mean number of lymph nodes collected in the prospective group was compared against two retrospective groups, one before minima for lymph node counts were set (retrospective group 1) and one after (retrospective group 2). More lymph nodes were dissected per specimen in the prospective group (24.1 lymph nodes), compared to the retrospective group (14.3 lymph nodes, P = <0.001). During the study period, more patients were diagnosed as pN+ compared to the two retrospective groups (62.7 vs. 47.8 % respectively, P = 0.082). Significantly more lymph nodes can be found in oncologic specimens when more time is invested in the search. This will result in more accurate staging of the tumor.