The clinicopathologic relevance and prognostic value of tumor deposits and the applicability of N1c category in rectal cancer with preoperative radiotherapy

Risk Factors for Recurrence After Surgery for Rectal Cancer in a Modern, Nationwide Population-Based Cohort

BACKGROUND

The success of modern multimodal treatment in rectal cancer is dependent on risk prediction. Better knowledge of the risk of locoregional and distant recurrence, in relation to preoperative treatment, pathological stage, and commonly used risk factors, is needed when deciding on adjuvant therapy and surveillance.

METHODS

The Swedish ColoRectal Cancer Registry was used to identify patients diagnosed with rectal adenocarcinoma between 2011 and 2018. Readily available variables, including patient, tumor, and treatment factors were exposures. Cox proportional hazard models were used to identify important risk factors for recurrence and calculate recurrence risks.

RESULTS

A total of 9428 curatively resected patients were included and followed for a median of 72 months. Eighteen percent had distal recurrence and 3% had locoregional recurrence at 5 years. Risk factors with major impact on distal recurrence were pT4a (hazard ratio [HR] 5.1, 95% confidence interval [CI] 3.3-8.0), pN2b (HR 3.4, 95% CI 2.7-4.2), tumor deposit (HR 1.7, 95% CI 1.5-1.9), lymph node yield (HR 1.5, 95% CI 1.3-1.8), and tumor level 0-5 cm (HR 1.5, 95% CI 1.3-1.8). Pathologic stage and number of risk factors identified groups with markedly different recurrence risks in all neoadjuvant treatment groups.

CONCLUSIONS

Readily available risk factors, as a complement to stage, are still valid and robust in all neoadjuvant treatment groups. Tumor deposit is important, while circumferential resection margin might no longer be important with improved oncological treatments and high-quality TME surgery. Tailored surveillance is possible in selected groups using risk stratification based on stage and risk factors.

Prognosis of Mesorectal Tumor Deposits in Patients with Rectal Cancer Treated with Neoadjuvant Chemoradiotherapy and Total Mesorectal Excision

BACKGROUND

Tumor deposits (TDs) are associated with adverse prognostic factors and decreased survival in colon cancer. However, there is no information of their survival impact in rectal cancer with neoadjuvant chemoradiotherapy (n-CRT).

METHODS

Retrospective study in 223 patients with rectal cancer with n-CRT. A survival analysis of factors associated with decreased overall survival (OS) including TDs was performed.

RESULTS

From 223 patients, 131 (58.7%) were men, mean age 59.8 (± 13.06) years, and 42 (18.8%) of them revealed TDs. Survival analysis of TDs showed no association with mortality. Factors associated with decreased 5-year OS were the histologic grade (p = 0.42), perineural invasion (p = 0.001), and mesorectal quality (p = 0.067). Perineural invasion (HR = 2.335, 95% CI = 1.198-4.552) remained as independent factor in the multivariate analysis.

CONCLUSIONS

TDs were not associated with mortality in rectal cancer patients treated with n-CRT. Factors associated with decreased survival were inadequate mesorectal quality and perineural invasion.

Adverse impact of tumor deposits in lymph node negative rectal cancer - a national cohort study

PURPOSE

This study aimed to investigate the prognostic effect of tumor deposits (TDs) in lymph node negative rectal cancer.

METHODS

Patients who had undergone surgery for rectal cancer with curative intention between 2011 and 2014 were extracted from the Swedish Colorectal Cancer Registry. Patients with positive lymph nodes, undisclosed TD status, stage IV disease, non-radical resections, or any outcome (local recurrence (LR), distant metastasis (DM) or mortality) within 90 days after surgery were excluded. TDs status was based on histopathological reports. Cox-regression analyses were used to examine the prognostic impact of TDs on LR, DM, and overall survival (OS) in lymph node-negative rectal cancer.

RESULTS

A total of 5455 patients were assessed for inclusion of which 2667 patients were analyzed, with TDs present in 158 patients. TD-positive patients had a lower 5-year DM-free survival (72.8%, p < 0.0001) and 5-year overall survival (75.9%, p = 0.016), but not 5-year LR-free survival (97.6%) compared to TD-negative patients (90.2%, 83.1% and 95.6%, respectively). In multivariable regression analysis, TDs increased the risk of DM [HR 4.06, 95% CI 2.72-6.06, p < 0.001] and reduced the OS [HR 1.83, 95% CI 1.35-2.48, p < 0.001]. For LR, only univariable regression analysis was performed which showed no increased risk of LR [HR 1.88, 95% CI 0.86-4.11, p = 0.11].

CONCLUSION

TDs are a negative predictor of DM and OS in lymph node-negative rectal cancer and could be taken into consideration when planning adjuvant treatment.

The Prognostic Value of Adjuvant Chemotherapy in Colon Cancer With Solitary Tumor Deposit

Purpose

The aim of this study is to investigate the survival benefit of adjuvant chemotherapy in patients with colon cancer with the solitary tumor deposit (TD).

Methods

The primary study outcomes used in this study were colon cancer–specific survival (CSS) and overall survival (OS). The differences of the distribution of categorical variables in patients with colon cancer with the solitary TD according to adjuvant chemotherapy administration were tested using the Pearson’s chi-square test. The Kaplan–Meier method was utilized to evaluate CSS and OS. Hazard ratio (HR) and 95% confidence interval (CI) were calculated on the basis of Cox regression models to assess the prognostic value of different demographic and clinicopathological characteristics.

Results

A total of 877 patients with TanyN1cM0 colon cancer with solitary TD were identified in our analysis. It was found that OS (75.4% vs. 42.8% for 5-year OS rate, p < 0.001) and CSS (82.9% vs. 69.3% for 5-year CSS rate, p < 0.001) of patients with colon cancer with adjuvant chemotherapy administration were significantly better than those without adjuvant chemotherapy administration. Multivariate Cox survival analyses revealed that the overall and colon cancer–specific mortality risks of patients with adjuvant chemotherapy administration were decreased by 64.4% (HR = 0.356, 95% CI = 0.265–0.479, p < 0.001) and 57.4% (HR = 0.426, 95% CI = 0.286–0.634, p < 0.001) compared with those without adjuvant chemotherapy administration, respectively.

Conclusions

Adjuvant chemotherapy administration could significantly improve OS and CSS in patients with colon cancer with the solitary TD. This is the first study to investigate and demonstrate the survival benefit of adjuvant chemotherapy in patients with colon cancer with the solitary TD.

Prognostic and staging value of tumor deposits in patients with rectal cancer after neoadjuvant chemoradiotherapy

Background

The presence of tumor deposits (TDs) is only considered in the absence of lymph node metastases (LNMs) in the current TNM staging system. However, the prognostic value of TDs when concomitant with LNM for rectal cancer after neoadjuvant chemoradiotherapy (NCRT) remains unclear. This study aimed to evaluate the prognostic value of TDs and when concomitant with LNMs in rectal cancer after NCRT.

Methods

Patients with rectal cancer who had received NCRT between 2010 and 2016 were obtained from the Surveillance, Epidemiology and End Results (SEER) 18 (year range, 1975–2016) database. Data were extracted on the following: age, sex, race, TNM stage, total LNs harvested, positive LNs, histologic type, perineural invasion, grade, carcinoma embryonic antigen status, TD number, and cancer-specific survival (CSS) rates. The primary objective was to determine the prognostic impact of TDs on CSS. The effect of the addition of TD to the LNM count for a novel N stage was also evaluated. Univariate and multivariate analyses were performed using the Kaplan-Meier method and Cox models.

Results

Of 9,620 patients, 865 (9.0%) had TDs. TD-positive patients showed a worse prognosis than TD-negative patients (HR =2.39, 95% CI: 2.04–2.80, P<0.001), and multivariate analysis showed that the presence of TDs was an independent poor prognostic factor (HR =1.41, 95% CI: 1.19–1.67, P<0.001). Regarding the LN status, TDs were associated with a higher risk of cancer-specific death in the LNM- group (HR =2.43, 95% CI: 1.86–3.18, P<0.001), M1 group (HR =1.51, 95% CI: 1.08–2.10, P<0.001), and ypN1 group (HR =2.08, 95% CI: 1.61–2.70, P<0.001), but not in the ypN2 group (HR =0.97, 95% CI: 0.69–1.36, P=0.84). Patients with concomitant TDs and LNM showed significantly worse survival than those with TDs or LNM alone (5-year CSS: 48.2%, 72.2%, and 67.8%, respectively). The 5-year CSS rates were 86.2%, 77.4%, 65.1%, 53.8%, and 46.5% for the novel N0, N1a, N1b, N2a, and N2b groups, respectively (P<0.05 across all groups). Time dependent receiver operating characteristic curve analysis and decision curve analysis showed that the novel N stage was superior to the current ypN stage.

Conclusions

The presence of TDs is an independent poor prognostic factor for LARC patients after NCRT. The concomitant presence of TDs and LNM indicates a significantly worse survival, and the addition of TD to LNM may help to better prompt appropriate risk stratification.

Computed Tomography-Based Radiomics for Preoperative Prediction of Tumor Deposits in Rectal Cancer

Objective

To develop and validate a computed tomography (CT)-based radiomics model for predicting tumor deposits (TDs) preoperatively in patients with rectal cancer (RC).

Methods

This retrospective study enrolled 254 patients with pathologically confirmed RC between December 2017 and December 2019. Patients were divided into a training set (n = 203) and a validation set (n = 51). A large number of radiomics features were extracted from the portal venous phase images of CT. After selecting features with L1-based method, we established Rad-score by using the logistic regression analysis. Furthermore, a combined model incorporating Rad-score and clinical factors was developed and visualized as the nomogram. The models were evaluated by the receiver operating characteristic curve (ROC) analysis and area under the ROC curve (AUC).

Results

One hundred and seventeen of 254 patients were eventually found to be TDs⁺. Rad-score and clinical factors including carbohydrate antigen (CA) 19-9, CT-reported T stage (cT), and CT-reported peritumoral nodules (+/-) were significantly different between the TDs⁺ and TDs^- groups (all P < 0.001). These factors were all included in the combined model by the logistic regression analysis (odds ratio = 2.378 for Rad-score, 2.253 for CA19-9, 2.281 for cT, and 4.485 for peritumoral nodules). This model showed good performance to predict TDs in the training and validation cohorts (AUC = 0.830 and 0.832, respectively). Furthermore, the combined model outperformed the clinical model incorporating CA19-9, cT, and peritumoral nodules (+/-) in both training and validation cohorts for predicting TDs preoperatively (AUC = 0.773 and 0.718, P = 0.008 and 0.039).

Conclusions

The combined model incorporating Rad-score and clinical factors could provide a preoperative prediction of TDs and help clinicians guide individualized treatment for RC patients.

Prognostic value of tumor deposits in locally advanced rectal cancer: a retrospective study with propensity score matching

BACKGROUND

The actual risks posed by tumor deposits (TDs) in colorectal cancer are still incompletely assessed. We explored the prognostic value of TDs in locally advanced rectal cancer (LARC) patients using propensity score matching (PSM) method.

METHODS

Consecutive LARC patients in Peking University First Hospital between 2011 and 2015 were retrospectively analyzed. Kaplan-Meier methods and Cox proportional hazard regression analysis were conducted to explore prognostic values of TDs. PSM method was conducted to minimize selection bias. The correlation between TDs number and prognosis was explored.

RESULTS

Four hundred and fifty-one LARC patients were recruited, and 78 (17.3%) patients were with TDs. Multivariate Cox analysis identified that the presence of TDs was an independent prognostic risk factor for overall survival (OS) (P = 0.044). PSM identified 76 matched pairs of LARC patients, and Kaplan-Meier curves revealed that patients with TDs experienced worse  OS (log-rank P = 0.0220) and relapse-free survival (RFS) (log-rank P = 0.0117). Subgroup analysis of 50 pairs extracted by PSM from 246 LARC patients with lymph node metastasis (LNM) further proved that TDs were significantly associated with worse OS (log-rank P = 0.0415), and the association was barely significant for RFS (log-rank P = 0.0527). There were non-significant tendencies towards higher mortality in TDs ≥ 2 than TD = 1 group (log-rank P = 0.348 for OS, log-rank P = 0.087 for RFS).

CONCLUSION

Our study manifested that the presence of TDs was an independent risk factor for LARC patients. The prognostic value of TDs for LARC patients with LNM should not be ignored.

The prognostic significance of tumor deposits in patients with head and neck squamous cell carcinomas

Background

A tumor deposit (TD) is a phenomenon that has not been well studied in head and neck squamous cell carcinoma (HNSCC) but might have prognostic significance. The present study was conducted to explore the presence and the prognostic significance of TDs in patients with HNSCCs.

Methods

Six hundred forty-two pathologically confirmed HNSCC patients with neck dissection samples were enrolled in this retrospective study. Patients were followed up and evaluated every 3 months in the first 3 years after surgery, and every 6 months thereafter by physical examination and computed tomography (CT)/magnetic resonance imaging (MRI) scans. The five-year overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) were compared in the TD and non-TD groups using multivariable analyses and propensity score matching (PSM) methodology (1:1).

Results

The 5-year OS, DSS, and RFS rate of all patients was 77.3%, 80.6%, and 71.9%, respectively. In the multivariable analyses, poorer rates of OS (HR =2.345, P<0.001), DSS (HR =2.818, P<0.001), and RFS (HR =2.536, P<0.001) were observed in the TD versus the non-TD group. In the PSM cohort, eighty-one patients who had TDs were paired with 70 patients without TDs. Significantly diminished rates of DSS (P=0.040) and RFS (P=0.004) were found in the TD versus the non-TD group.

Conclusions

In response to sparse reports regarding TDs in HNSCCs, the present study proposes the TD as an independent poor prognostic factor meriting further research because of its association with diminished OS, DSS, and RFS rates.

Utility of texture analysis on T2-weighted MR for differentiating tumor deposits from mesorectal nodes in rectal cancer patients, in a retrospective cohort

OBJECTIVE

The purpose of the study was to evaluate the utility of MR texture analysis for differentiating tumor deposits from mesorectal nodes in rectal cancer.

MATERIALS AND METHODS

Pretreatment MRI of 40 patients performed between 2006 and 2018 with pathologically proven tumor deposits and/or malignant nodes in the setting of rectal cancer were retrospectively reviewed. In total, 25 tumor deposits (TDs) and 71 positive lymph nodes (LNs) were analyzed for morphological and first-order texture analysis features on T2-weighted axial images. MR morphological features (lesion shape, size, signal heterogeneity, contrast enhancement) were analyzed and agreed in consensus by two experienced radiologists followed by assessment with Fisher's exact test. Texture analysis of the lesions was performed using TexRAD, a proprietary software algorithm. First-order texture analysis features (mean, standard deviation, skewness, entropy, kurtosis, MPP) were obtained after applying spatial scaling filters (SSF; 0, 2, 3, 4, 5, 6). Univariate analysis was performed with non-parametric Mann-Whitney U test. The results of univariate analysis were reassessed with generalized estimating equations followed by multivariate analysis. Using histopathology as a gold standard, diagnostic accuracy was assessed by obtaining area under the receiver operating curve.

RESULTS

MR morphological parameter, lesion shape was a strong discriminator between TDs and LNs with a p value of 0.02 (AUC: 0.76, 95% CI of 0.66 to 0.84, SE: 0.06) and sensitivity, specificity of 90% and 68%, respectively. Skewness extracted at fine filter (SSF-2) was the only significant texture analysis parameter for distinguishing TDs from LNs with p value of 0.03 (AUC: 0.70, 95% CI of 0.59 to 0.79, SE: 0.06) and sensitivity, specificity of 70% and 72%, respectively. When lesion shape and skewness-2 were combined into a single model, the diagnostic accuracy was improved with AUC of 0.82 (SE: 0.05, 95% CI of 0.72 to 0.88 with p value of < 0.01). This model also showed a high sensitivity of 91% with specificity of 68%.

CONCLUSION

Lesion shape on MR can be a useful predictor for distinguishing TDs from positive LNs in rectal cancer patients. When interpreted along with MR texture parameter of skewness, accuracy is further improved.

A Modified Pathological N Stage Including Status of Tumor Deposits in Colorectal Cancer With Nodal Metastasis

Background

The American Joint Committee on Cancer 8th classification states that colorectal cancer (CRC) is classified as N1c stage when regional lymph nodes (LNs) are negative and tumor deposits (TDs) are positive. However, how to classify TDs when regional LNs are positive remains unclear. The current study aimed to investigate the possibility of combining positive LNs and positive TDs to develop a modified pathological N (mpN) stage for CRC.

Methods

We retrospectively analyzed 9,198 patients with stage III CRC from the Surveillance, Epidemiology, and End Results program who underwent surgery (6,440 in the training cohort and 2,758 the validation cohort). The combination of positive LNs and TD status was defined as mpN stage. Overall survival (OS) according to mpN and pathological N (pN) stages was analyzed by the Kaplan–Meier method. The area under the curves (AUCs) and Akaike’s information criterion (AIC) were applied to assess the predictive discrimination abilities and goodness-of-fit of the model. The clinical benefits were measured using decision curve analyses. The validation cohort was used to validate the results.

Results

AUC analysis showed that the prognostic discrimination of mpN stage (AUC = 0.628, 95% confidence interval (CI), 0.616–0.640) was better than that of pN stage (AUC = 0.618, 95% CI, 0.606–0.630, p = 0.006) for OS. The AIC demonstrated that mpN stage (AIC = 30,217) also showed superior model-fitting compared with pN stage (AIC = 30,257) and decision curve analyses revealed that mpN stage had better clinical benefits than pN stage. Similar results were found in the validation cohort.

Conclusions

Among patients with CRC and LN metastasis, mpN stage might be superior to pN stage for assessing prognosis and survival, suggesting that TD status should be included in the pN stage.

Prognostic value of tumor deposits in rectal cancer: A monocentric series of 505 patients

BACKGROUND AND OBJECTIVES

It has been suggested that tumor deposits (TDs) may have a worse prognosis in rectal cancer compared with colonic cancer. The aim of this study was to assess TDs prognosis in rectal cancer.

METHODS

Patients who underwent total mesorectum excision for rectal adenocarcinoma (2011-2016) were included. A case-matched analysis was performed to assess the accurate impact of TDs for each pN category after exclusion of synchronous metastasis.

RESULTS

A total of 505 patients were included. TDs were observed in 99 (19.6%) patients, (pN1c = 37 [7.3%]). TDs were associated with pT3-T4 stage (P = .037), synchronous metastasis (P = .003), lymph node (LN) invasion (P = .041), vascular invasion (P = .001), and perineural invasion (P < .001). TD was associated with a worse 3-year disease-free survival (DFS) among pN0 (51.2% vs 79.8%; P < .001); pN1 patients (35.2% vs 70.1%; P = .004) but not among pN2 patients (37.5% vs 44.7%; P = .499). After matching, pN1c patients had a worse 3-year DFS compared with pN0 patients (58.6% vs 82.4%; P = .035) and a tendency toward a worse DFS among N1 patients (40.1% vs 64.2%; P = .153). DFS was worse when one TD was compared with one invaded LN (40.8% vs 81.3%; P < .001).

CONCLUSION

In rectal cancer, TDs have a metastatic risk comparable to a pN2 stage which may lead to changes in adjuvant treatment.

Preoperative prediction of tumour deposits in rectal cancer by an artificial neural network-based US radiomics model

OBJECTIVE

To develop a machine learning-based ultrasound (US) radiomics model for predicting tumour deposits (TDs) preoperatively.

METHODS

From December 2015 to December 2017, 127 patients with rectal cancer were prospectively enrolled and divided into training and validation sets. Endorectal ultrasound (ERUS) and shear-wave elastography (SWE) examinations were conducted for each patient. A total of 4176 US radiomics features were extracted for each patient. After the reduction and selection of US radiomics features , a predictive model using an artificial neural network (ANN) was constructed in the training set. Furthermore, two models (one incorporating clinical information and one based on MRI radiomics) were developed. These models were validated by assessing their diagnostic performance and comparing the areas under the curve (AUCs) in the validation set.

RESULTS

The training and validation sets included 29 (33.3%) and 11 (27.5%) patients with TDs, respectively. A US radiomics ANN model was constructed. The model for predicting TDs showed an accuracy of 75.0% in the validation cohort. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and AUC were 72.7%, 75.9%, 53.3%, 88.0% and 0.743, respectively. For the model incorporating clinical information, the AUC improved to 0.795. Although the AUC of the US radiomics model was improved compared with that of the MRI radiomics model (0.916 vs. 0.872) in the 90 patients with both ultrasound and MRI data (which included both the training and validation sets), the difference was nonsignificant (p = 0.384).

CONCLUSIONS

US radiomics may be a potential model to accurately predict TDs before therapy.

KEY POINTS

• We prospectively developed an artificial neural network model for predicting tumour deposits based on US radiomics that had an accuracy of 75.0%. • The area under the curve of the US radiomics model was improved than that of the MRI radiomics model (0.916 vs. 0.872), but the difference was not significant (p = 0.384). • The US radiomics-based model may potentially predict TDs accurately before therapy, but this model needs further validation with larger samples.

Tumor-infiltrating lymphocytes in primary tumors of colorectal cancer and their metastases

The presence of tumor cells in the large intestine stimulates hypoxia and local inflammatory mediators that activate numerous inflammatory cells, including a diverse lymphoid tumor cell population. The aim of the present study was to evaluate tumor-infiltrating lymphocytes (TILs) located in the invasive primary tumor, surrounding deposits of tumor cells and those present in distal metastatic cells in the liver of patients with colorectal cancer. Furthermore, the correlation of TILs with anatomical parameters was assessed. The study group included 123 patients with primary tumor colorectal cancer without distant metastasis, 25 cases with deposits of colorectal cancer cells and 15 cases of colorectal cancer liver metastasis. TILs were assessed in tissues stained with hematoxylin-eosin using light microscopy and evaluated by two independent pathologists blinded to the clinical information. Infiltration of TILs in the invasive front of primary tumor was stronger compared with those surrounding deposits of cancer cells and liver metastases (P<0.001). TILs in the invasive front of primary tumor masses were associated with various variables linked with tumor progression and inflammatory cell infiltrate. TILs distributed around the deposits of cancer cells were associated with postoperative treatment; however, those localized in the invasive front of liver metastases were correlated with preoperative therapy. In conclusion, TILs assessment in primary tumors of colorectal cancer, surrounding deposits of tumor cells and in the metastatic cells in the liver may be helpful in understanding the role of these cells in the organization of immune response.

Tumor deposit indicates worse prognosis than metastatic lymph node in gastric cancer: a propensity score matching study

Background

The prognostic value of tumor deposit (TD) in gastric cancer is controversial. This study aims to investigate the prognostic value of TD.

Methods

The consecutive patients diagnosed with gastric cancer from October 2007 to October 2012 were selected. The patients were divided by whether they suffered TD into two groups. The basic data were comparable between the two groups after propensity score matching (PSM), then survival analysis [overall survival (OS) and cancer-specific survival (CSS)] was applied in two groups. After that, all the patients were divided by pN staging and survival analysis were applied in each subgroup. At last, all patients were divided into TD group, pN1 stage group, pN2 stage group, pN3a, and pN3b stage group, OS and CSS were compared between them. Multivariable competing risk analyses tested association of TD with OS and CSS, before and after PSM.

Results

Eight hundred and three patients were concluded. After PSM, 137 patients with TD and 274 patients without TD were selected, the 5-year OS and CSS rates of patients with TD were significantly worse than patients without TD (OS: 19.7% vs. 42.0%, P<0.001; CSS: 22.6% vs. 45.6%, P<0.001). In all patients' survival analysis, the 5-year OS and CSS rates of TD group were comparable with pN3a group (OS: 19.7% vs. 25.3%, P=0.221, CSS: 22.6% vs. 30.1%, P=0.092) and pN3b group (OS: 19.7% vs. 19.6% P=0.349, CSS: 22.6% vs. 23.5%, P=0.452). Meanwhile, on multivariable cox regression analyses, the presence of TD significantly reduces the OS and CSS of patients in gastric cancer.

Conclusions

TD has a marked impact on the prognosis of gastric cancer. Even patients with TD had the same prognosis with pN3 stage.

Prognostic value of N1c in colorectal cancer: a large population-based study using propensity score matching

PURPOSE

We conducted this large population-based study to investigate the prognostic significance of N1c.

METHODS

Patients diagnosed with colorectal cancer from the surveillance, epidemiology, and end results (SEER) database between January 1, 2010, and December 31, 2010, were included in the sample. The primary outcome of interest used in our study was cause-specific survival (CSS). Cox proportional hazards models and Kaplan-Meier methods were used to evaluate the prognostic value of N1c. Propensity score matching (PSM) was implemented to reduce the possibility of selection bias using a logistic regression model.

RESULTS

A total of 19,991 patients diagnosed with colorectal cancer were identified from the SEER database. The median follow-up time of the whole cohort was 60 months (0-71 months). Multivariate Cox analysis showed that N1c was associated with significantly higher risk of colorectal cancer-specific mortality compared with N0 (HR = 1.962, 95%CI = 1.642 to 2.343, P < 0.001) and N1a (HR = 0.818, 95%CI = 0.678 to 0.987, P = 0.036); N1c was associated with significantly lower risk of colorectal cancer-specific mortality compared with N2a (HR = 1.296, 95%CI = 1.081 to 1.554, P = 0.005) and N2b (HR = 1.663, 95%CI = 1.391 to 1.989, P < 0.001). Yet the CSS difference between N1b and N1c did not achieve statistical difference (HR = 1.089, 95%CI = 0.909 to 1.304, P = 0.354).

CONCLUSIONS

The large population-based and propensity score-matched study with long follow-up time provides the first evidence that CSS difference between N1b and N1c does not achieve a statistical difference.

Poor prognostic and staging value of tumor deposit in locally advanced rectal cancer with neoadjuvant chemoradiotherapy

Tumor deposit (TD) was associated with poor survival in colorectal cancer. However, its prognostic and staging value in locally advanced rectal cancer (LARC) patients following neoadjuvant chemoradiotherapy (neo‐CRT) is controversial. Four hundred and ninety‐five LARC patients following neo‐CRT and surgery were retrospectively analyzed. Univariate and multivariate analyses were performed using Kaplan‐Meier method and Cox proportional hazards regression in all lymph node (LN) ‐negative and LN‐positive patients. Next, we used three methods to classify the counts of LNs and TDs (oN, only LN counts; n1N, counts according to the N1c standards; n2N, total counts of LNs and TDs) to evaluate the impact of TD on N staging. TD‐positive patients were associated with more aggressive clinicopathological features. In multivariate analyses, TD was an independent poor prognostic factor of overall survival (OS), disease‐free survival (DFS), and local recurrence‐free survival in all patients. In LN‐negative patients, TD was an independent poor prognostic factor of OS, DFS and distant metastasis‐free survival (DMFS). In LN‐positive patients, TD has poor prognostic value only in patients with one positive LN. Three multivariate analyses according to three N staging methods showed that oN was not an independent prognostic factor, whereas n1N and n2N were independently associated with poor survival in OS, DFS and DMFS. The n2N method seemed to be better than n1N method. TD is an independent poor prognostic factor in LARC patients following neo‐CRT, especially in patients with no more than one positive LN. TD probably should be considered as one positive LN when performing N staging.

Prognostic value and characteristics of N1c colorectal cancer

AIM

The presence of tumour deposits (TDs) in colorectal cancer (CRC) is associated with poor prognosis. The seventh edition of TNM subclassified a new nodal stage, N1c, characterized by the presence of TDs without any concurrent positive lymph node (LN). It is not clear if the N1c category is or is not equal to LN metastasis. We aimed to examine the prevalence, characteristics and prognostic significance of this new subcategory.

METHOD

Consecutive patients who underwent surgery for CRC in two centres (2011-2014) were analysed. N1 cM0 patients were matched against non-N1 cM0 (N0, N1a and N1b) patients for 3-year overall survival (OS) and disease-free survival (DFS).

RESULTS

We identified 1122 patients with 648 (57.8%) colonic cancers. In 57 patients (5.1%), N1c status was associated with rectal cancers [rectum = 33/57 (57.9%) vs colon = 24/57 (42.1%); P = 0.029], a higher pathological tumour stage [pT3-T4 N1c = 55/843 (6.5% vspT3-T4 non-N1c = 2/279 (0.7%); P < 0.0001] and vascular emboli [n = 35 (61.4%) vs n = 552 (51.8%); P = 0.0305]. Synchronous metastasis was observed in 23 cases (40%). After a mean follow-up of 31 months, 3-year OS for M0 patients, was 89.4%, 89.1%, 86.6% and 81.8% for N0, N1a, N1b and N1c tumours, respectively. DFS was significantly worse for N1c than for N0 (P = 0.0169), with N1c status having a significant effect on DFS in colonic cancers (P = 0.014). The presence of more than one TD was associated with a significantly worse DFS (P = 0.021).

CONCLUSION

Our results indicate that N1c CRC patients should be included among high-risk patients for whom it is widely accepted that adjuvant chemotherapy should be considered.

Newly recognized extratumoral features of colorectal cancer challenge the current tumor-node-metastasis staging system

One of the most common malignant tumors in humans, colorectal cancer has been extensively studied during the past few decades. Staging colorectal cancer allows clinicians to obtain precise prognostic information and apply specific treatment procedures. Apart from remote metastases, the depth of tumor infiltration and lymph node involvement have traditionally been recognized as the most important factors predicting outcome. Variations in the molecular signature of colorectal cancer have also revealed differences in phenotypic aggressiveness and therapeutic response rates. This article presents a review of the extratumoral environment in colorectal surgery.

Beyond T, N and M: The impact of tumor deposits on the staging and treatment of colorectal and gastric carcinoma

This review aims to describe the results of the most recent studies on the prognostic value of TDs and highlight the impact of TDs on the staging and treatment of colorectal and gastric carcinoma. For colorectal carcinoma TDs have an adverse prognostic effect that is at least similar to that of positive regional lymph nodes. However, support is growing in favor of including of TDs in the M category, rather than the N or T categories of the TNM classification. Moreover, TDs seem to have an adverse effect on outcomes not only in patients without lymph node involvement but also in patients with nodal involvement. Although the prognostic impact of TDs in gastric cancer appears to be undeniable, the actual prognostic determinants of TDs, particularly in relation to the number, size and histological types, remain to be established. Although the 7th and 8th Edition of the TNM classification of colorectal and gastric carcinoma includes TDs in the N category, no current procedures or methods to assess preoperative or intraoperative N-status allow TD detection. After neoadjuvant treatment for advanced rectal carcinoma, the presence of TDs may indicate incomplete eradication of the main tumor and not discontinuous tumor foci. TDs have an undeniable prognostic impact but no algorithm of staging and strategy of treatment has been conformed to this prognostic factor to overcome the classical T,N, and M prognostic categories. Staging and treatment of colorectal and gastric cancers should be reconsidered in light of the emerging prognostic value of TDs.