Tumor deposits: markers of poor prognosis in patients with locally advanced rectal cancer following neoadjuvant chemoradiotherapy

MRI-detected tumor deposits in cT3 and cT4 rectal cancer following neoadjuvant chemoradiotherapy

OBJECTIVES

To evaluate the identification of tumor deposits (TDs) and the prognostic significance of an MRI tumor regression grade for TDs in patients with rectal cancer treated with neoadjuvant chemoradiotherapy (nCRT).

METHODS

Ninety-one patients with cT3 or cT4 rectal cancer who underwent surgery following nCRT between August 2014 and June 2020 were retrospectively analyzed. Changes in pre-nCRT MRI-detected TDs (mrTDs) were described as mrTD regression grade. The diagnostic performance of post-nCRT MRI-detected TDs (ymrTDs) was compared with histopathological reference standard. The correlation between ymrTDs, mrTD regression grade, and disease-free survival (DFS) was assessed.

RESULTS

The sensitivity and specificity of ymrTDs were 88.00% and 89.39%, respectively. The area under the receiver operating characteristic curve was 0.887 (95% confidence interval [CI]: 0.803-0.944). The 3-year DFS of patients with positive ymrTDs was significantly lower than of the negative group (44.83% vs 82.73%, p < 0.001). The 3-year DFS was 33.33% for patients with poor regression of mrTDs following nCRT and 55.56% for those with moderate regression, compared to 69.23% in good responders and 83.97% in patients without mrTDs (p < 0.001). On multivariable Cox regression, mrTD regression grade was the only independent MRI factor associated with DFS (p = 0.042).

CONCLUSIONS

Diagnostic performance of ymrTDs was moderate. The mrTD regression grade was independently correlated with DFS, which may have a prognostic implication for treatment and follow-up.

CLINICAL RELEVANCE STATEMENT

Patients with poor regression of MRI-detected tumor deposits may benefit from more aggressive treatments, such as chemoradiation therapy plus induction or consolidation chemotherapy.

KEY POINTS

• MRI provides a preoperative and noninvasive way to visualize tumor deposits (TDs) after neoadjuvant chemoradiotherapy (nCRT). • Post-nCRT MRI-detected TDs are a poor prognostic marker in cT3 and cT4 rectal cancer patients. • The regression of MRI-detected TDs after nCRT is associated with an improved disease-free survival.

The Relationship between Tumor Budding and Tumor Deposits in Patients with Stage III Colorectal Carcinoma

Background/Objectives: Recently, some new morphological features of colorectal cancer have been discovered as important prognostic factors; in this paper, we study the relationship between tumor budding (TB) and tumor deposits (TDs). Methods: The retrospective cohort study included 90 patients with pathohistologically confirmed stage III CRC who were treated with radical surgical resection. All hematoxylin and eosin (H and E)-stained slides from each patient were reviewed, and histological parameters were recorded. The samples were divided into two groups with similar sizes: a group without TDs (N = 51) and a control group with TDs (N = 39). The presence and TB grade were further analyzed in these groups and compared with other clinical and histological features. Results: The prevalence of TB in the investigated cohort was unexpectedly high (94.4%). Overall, there were 23 (25.6%) Bd1, 20 (22.2%) Bd2, and 47 (52.2%) Bd3 cases. The presence of TDs was significantly associated with a higher number of TB (p < 0.001, OR 16.3) and, consequently, with a higher TB grade (p = 0.004, OR 11.04). A higher TB grade (p = 0.001, HR 2.28; 95% CI 1.93-4.76) and a growing number of TDs (p = 0.014, HR 1.52; 95% CI 1.09-2.1) were statistically significantly associated with shorter survival. Conclusions: TDs appear more often in patients with higher TB grades in stage III CRC. A higher TB grade and a growing number of TDs were statistically significantly associated with shorter overall survival. These results could give additional emphasis to the importance of TB as an adverse prognostic factor since a strong relationship with TDs has been demonstrated.

Negative Prognostic Impact of Tumor Deposits in Rectal Cancer: A National Study Cohort

OBJECTIVE

To investigate whether tumor deposits (TDs) in rectal cancer are associated with increased recurrence risk and decreased survival.

BACKGROUND

Tumor deposits (TDs) are considered a risk factor for recurrence after colon cancer resection, and the presence of TDs prompts adjuvant chemotherapy. The prognostic relevance of TDs in rectal cancer requires further exploration.

METHODS

All patients treated with abdominal resection surgery for rectal cancer in Sweden between 2011 and 2014 were eligible for inclusion in this retrospective cohort study based on prospectively collected data from the Swedish Colorectal Cancer Registry. The primary endpoint was local recurrence or distant metastasis. Secondary outcomes were overall and relative survival.

RESULTS

Five thousand four hundred fifty-five patients were identified of which 3769 patients were analyzed after exclusion. TDs were found in 404 (10.7%) patients, including 140 (3.7%) patients with N1c-status. In TD-positive patients, local recurrence and distant metastasis rates at 5 years were 6.3% [95% CI 3.8-8.8%] and 38.9% [95% CI, 33.6-43.5%] compared with 2.7% [95% CI, 2.1-3.3%] and 14.3% [95% CI, 13.1-15.5%] in TD-negative patients. In multivariable regression analysis, the risk of local recurrence and distant metastasis were increased; HR 1.86 [95% CI, 1.09-3.19; P =0.024] and 1.87 [95% CI, 1.52-2.31; P =<0.001], respectively. Overall survival at 5 years was 68.8% [95% CI, 64.4-73.4%] in TD-positive patients and 80.7% [95% CI, 79.4-82.1%] in TD-negative patients. pN1c-patients had similar outcomes regarding local recurrence, distant metastasis, and survival as pN1a-b stage patients. TD-positive pN1a-b patients had significantly worse outcomes whereas TDs did not affect outcomes in pN2a-b patients.

CONCLUSION

This study suggests that TDs have a negative impact on the prognosis in rectal cancer. Thus, efforts should be made to diagnose TD-positive rectal cancer patients preoperatively.

Computed Tomography-based Radiomics Nomogram for the Preoperative Prediction of Tumor Deposits and Clinical Outcomes in Colon Cancer: a Multicenter Study

RATIONALE AND OBJECTIVES

To develop and validate a computed tomography (CT)-based radiomics nomogram for the preoperative prediction of tumor deposits (TDs) and clinical outcomes in patients with colon cancer.

MATERIALS AND METHODS

This retrospective study included 383 consecutive patients with colon cancer from two centers. Radiomics features were extracted from portal venous phase CT images. Least absolute shrinkage and selection operator regression was applied for feature selection and radiomics signature construction. The multivariate logistic regression model was used to establish a radiomics nomogram. The performance of the nomogram was assessed by using receiver operating characteristic curves, calibration curves and decision curve analysis. Kaplan‒Meier survival analysis was used to assess the difference of the overall survival (OS) in the TDs-positive and TDs-negative groups.

RESULTS

The radiomics signature was composed of 11 TDs status related features. The AUCs of the radiomics model in the training cohort, internal validation and external validation cohorts were 0.82, 0.78 and 0.78, respectively. The radiomics nomogram that incorporated the radiomics signature and clinical independent predictors (CT-N, CEA and CA199) showed good calibration and discrimination with AUCs of 0.88, 0.80 and 0.81 in the training cohort, internal validation and external validation cohorts, respectively. The radiomics nomogram-predicted high-risk groups had a worse OS than the low-risk groups (p < 0.001). The radiomics nomogram-predicted TDs was an independent preoperative predictor of OS.

CONCLUSION

The radiomics nomogram based on CT radiomics features and clinical independent predictors could effectively predict the preoperative TDs status and OS of colon cancer.

IMPORTANT FINDINGS

CT-based radiomics nomogram may be applied in the individual preoperative prediction of TDs status in colon cancer. Additionally, there was a significant difference in OS between the high-risk and low-risk groups defined by the radiomics nomogram, in which patients with high-risk TDs had a significantly worse OS, compared with those with low-risk TDs.

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.

Tumor deposits in colorectal cancer: Refining their definition in the TNM system

Tumor deposits (TDs) are discontinuous tumor spread in the mesocolon/mesorectum which is found in approximately 20% of colorectal cancer (CRC) and negatively affects survival. We have a history of repeated revisions on TD definition and categorization in the tumor-node-metastasis (TNM) system leading to stage migration. Since 1997, TDs have been categorized as T or N factors depending on their size (TNM5) or contour (TNM6). In 2009, TNM7 provided the category of N1c for TDs in a case without positive lymph nodes (LNs), which is also used in TNM8. However, increasing evidence suggests that these revisions are suboptimal and only "partially" successful. Specifically, the N1c rule is certainly useful for oncologists who are having difficulty with TDs in a case with no positive LNs. However, it has failed to maximize the value of the TNM system because of the underused prognostic information of individual TDs. Recently, the potential value of an alternative staging method has been highlighted in several studies using the "counting method." For this method, all nodular type TDs are individually counted together with positive LNs to derive the final pN, yielding a prognostic and diagnostic value that is superior to existing TNM systems. The TNM system has long stuck to the origin of TDs in providing its categorization, but it is time to make way for alternative options and initiate an international discussion on optimal treatment of TDs in tumor staging; otherwise, a proportion of patients end up missing an opportunity to receive the optimal 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.

Histopathological diagnosis of tumour deposits in colorectal cancer: a Delphi consensus study

AIMS

Tumour deposits (TDs) are an important prognostic marker in colorectal cancer. However, the classification, and inclusion in staging, of TDs has changed significantly in each tumour-node-metastasis (TNM) edition since their initial description in TNM-5, and terminology remains controversial. Expert consensus is needed to guide the future direction of precision staging.

METHODS AND RESULTS

A modified Delphi consensus process was used. Statements were formulated and sent to participants as an online survey. Participants were asked to rate their agreement with each statement on a five-point Likert scale and also to suggest additional statements for discussion. These responses were circulated together with anonymised comments, and statements were modified prior to carrying out a second online round. Consensus was set at 70%. Overall, 32 statements reached consensus. There were concerns that TDs were currently incorrectly placed in the TNM system and that their prognostic importance was being underestimated. There were concerns regarding interobserver variation and it was felt that a clearer, more reproducible definition of TDs was needed.

CONCLUSIONS

Our main recommendations are that the number of TDs should be recorded even if lymph node metastases (LNMs) are also present and that nodules with evidence of origin [extramural venous invasion (EMVI), perineural invasion (PNI), lymphatic invasion (LI)] should still be categorised as TDs and not excluded, as TNM-8 specifies. Whether TDs should continue to be included in the N category at all is controversial, and did not achieve consensus; however, participants agreed that TDs are prognostically worse than LNMs and the N1c category is suboptimal, as it does not reflect this.

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.

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.

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.

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.

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.

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

The clinicopathologic relevance and prognostic value of tumor deposits in colorectal cancer has been widely demonstrated. However, there are still debates in the prognostic value of tumor deposits and the applicability of N1c category in rectal cancer with preoperative radiotherapy. In this study, rectal cancer with preoperative radiotherapy followed by resection of primary tumors registered in Surveillance, Epidemiology and End Results (SEER) database from 2010-2012 were analyzed. There were 4,813 cases eligible for this study, and tumor deposits were found in 514 (10.7%) cases. The presence of tumor deposits was significantly associated with some aggressive characteristics, including poorer tumor differentiation, more advanced ypT category, ypN category and ypTNM stage, distant metastasis, elevated carcinoembryonic antigen, higher positive rates of circumferential resection margin and perineural invasion (all P < = 0.001). Tumor deposit was also an independent negative prognostic factor for cancer-specific survival in rectal cancer with preoperative radiotherapy (adjusted HR and 95% CI: 2.25 (1.51 - 3.35)). N1c category had significant worse survival compared with N0 category (adjusted HR and 95% CI: 2.41 (1.24 - 4.69)). In conclusion, tumor deposit was a significant and independent prognostic factor, and the N1c category by the 7th edition of AJCC/TNM staging system was applicable in rectal cancer with preoperative radiotherapy.