Classic and Novel Histopathologic Risk Factors for Lymph Node Metastasis in T1 Colorectal Cancer: A Systematic Review and Meta-analysis

BACKGROUND

Treatment of endoscopically resected T1 colorectal cancers is based on the risk of lymph node metastasis. Risk is based on histopathologic features, although there is lack of consensus as to what constitutes high-risk features.

OBJECTIVE

The purpose of this study was to conduct a systematic review and meta-analysis of histopathologic risk factors for lymph node metastasis.

DATA SOURCES

A search of MEDLINE, Embase, Scopus, and Cochrane controlled register of trials for risk factors for lymph node metastasis was performed from inception until August 2018.

STUDY SELECTION

Included patients must have had an oncologic resection to confirm lymph node status and reported at least 1 histopathologic risk factor.

INTERVENTION

Rates of lymph node positivity were compared between patients with and without risk factors.

MAIN OUTCOME MEASURES

We report the results of the meta-analysis as ORs.

RESULTS

Of 8592 citations, 60 met inclusion criteria. Pooled analyses found that lymphovascular invasion, vascular invasion, neural invasion, and poorly differentiated histology were significantly associated with lymph node metastasis, as were depths of 1000 µm (OR = 2.76), 1500 µm (OR = 4.37), 2000 µm (OR = 2.37), submucosal level 3 depth (OR = 3.08), and submucosal level 2/3 (OR = 3.08) depth. Depth of 3000 µm, Haggitt level 4, and widths of 3000 µm and 4000 µm were not significantly associated with lymph node metastasis. Tumor budding (OR = 4.99) and poorly differentiated clusters (OR = 14.61) were also significantly associated with lymph node metastasis.

LIMITATIONS

Included studies reported risk factors independently, making it impossible to examine the additive metastasis risk in patients with numerous risk factors.

CONCLUSIONS

We identified 1500 μm as the depth most significantly associated with lymph node metastasis. Novel factors tumor budding and poorly differentiated clusters were also significantly associated with lymph node metastasis. These findings should help inform guidelines regarding risk stratification of T1 tumors and prompt additional investigation into the exact contribution of poorly differentiated clusters to lymph node metastasis.

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.

Tumor budding as a risk factor for nodal metastasis in pT1 colorectal cancers: a meta-analysis

Worldwide, colorectal cancer (CRC) screening programs have significantly increased the detection of submucosal (pT1) adenocarcinoma. Completion surgery may be indicated after endoscopic excision of these potentially metastasizing early cancers. However, the postsurgical prevalence of nodal implants does not exceed 15%, leading to questions concerning the clinical appropriateness of any post-endoscopy surgery. Eastern scientific societies (Japanese Society for Cancer of the Colon-Rectum, in particular) include tumor budding (TB), defined as the presence of isolated single cancer cells or clusters of fewer than 5 cancer cells at the tumor invasive front, among the variables that must be included in histologic reports. In Western countries, however, no authoritative endorsements recommend the inclusion of TB in the histology report because of the heterogeneity of definitions and measurement methods as well as its apparent poor reproducibility. To assess the prognostic value of TB in pT1 CRCs, this meta-analysis evaluated 41 studies involving a total of 10137 patients. We observed a strong association between the presence of TB and risk of nodal metastasis in pT1 CRC. In comparing TB-positive (684/2401; 28.5%) versus TB-negative (557/7736; 7.2%) patients, the prevalence of nodal disease resulted in an odds ratio value of 6.44 (95% confidence interval, 5.26-7.87; P<.0001; I² = 30%). This increased risk of regional nodal metastasis was further confirmed after accounting for potential confounders. These results support the priority of histologically reporting TB in any endoscopically removed pT1 CRC to direct more appropriate patient management.

Patient gender as a factor associated with lymph node metastasis in T1 colorectal cancer: A systematic review and meta-analysis

Approximately 10% of patients with T1 colorectal cancer have lymph node metastases (LNM), requiring node dissection along with surgical resection. Patient gender was recently reported to affect the occurrence of LNM. The aim of the present study was to assess whether patient gender was predictive of LNM in T1 colorectal cancer. Public databases, including PubMed, EMBASE and the Cochrane Central Register of Controlled Trials were searched, using key terms related to 'T1 colorectal cancer' and 'lymph node'. All relevant studies reporting the adjusted odds ratio or risk ratio of LNM in relation to patient gender were included. The quality of the studies was classified according to the Quality in Prognostic Studies tool. A random-effects model was used and the quality of the evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation approach. The initial database search identified 2,492 publications; of those, 36 studies reported unadjusted results. Of the 36 studies, 4 reported adjusted results and fulfilled the inclusion criteria for this meta-analysis: 3 studies were graded as having a moderate risk of bias, and 1 had a low risk of bias. The present meta-analysis demonstrated that female gender was associated with increased risk of LNM (risk ratio=2.45, 95% confidence interval: 1.03-3.88). The I² statistic was 0.901, classified as very low (+OOO) and was downgraded by the risk of bias, inconsistency and publication bias. In conclusion, female gender was found to be correlated with LNM in patients with T1 colorectal cancer.

Evaluation of the correlation of KAI1/CD82, CD44, MMP7 and β-catenin in the prediction of prognosis and metastasis in colorectal carcinoma

BACKGROUND

To investigate the relationship of KAI1/CD82, CD44, matrix metalloproteinase 7 (MMP7) and β-catenin, and examine its association with clinicopathological features, metastasis and prognosis in colorectal carcinoma (CRC).

METHODS

Immunohistochemical (IHC) analysis was used to detect the expression of KAI1/CD82, CD44, MMP7 and β-catenin in 174 archival surgical specimens of human CRC. Furthermore, clinicopathological features such as age, sex and so on were also collected retrospectively.

RESULTS

CD44, MMP7 and β-catenin expression was positively associated with distant metastasis, lymph node metastasis and tumor-node-metastasis (TNM) stage. However, decreased KAI1/CD82 expression correlated significantly with distant metastasis, lymph node metastasis and TNM stage. KAI1/CD82 expression showed a negative correlation with CD44, MMP7 and β-catenin. Furthermore, β-catenin expression showed a positive correlation with CD44 and MMP7. Multivariate logistic regression analysis showed that KAI1/CD82 and β-catenin expression were significantly associated with lymph node metastasis and KAI1/CD82 was significantly associated with distant metastasis. Kaplan-Meier analysis revealed that CD44, MMP7 and β-catenin expression was negatively correlated with overall survival (OS), while KAI1/CD82 expression was positively correlated with OS. Low KAI1/CD82 expression and high expression of CD44, MMP7 and β-catenin was associated with a poor prognosis in CRC. Multivariate Cox regression analysis indicated that the expression of KAI1/CD82, MMP7 and β-catenin were independent predictors of OS in CRC.

CONCLUSION

The expression of KAI1/CD82, CD44, MMP7 and β-catenin is related to tumor metastasis and prognosis in CRC. Combined detection of these factors may be of significant value in predicting the prognosis and metastasis in CRC patients.

Tumor budding in colorectal cancer--ready for diagnostic practice?

Tumor budding is an important additional prognostic factor for patients with colorectal cancer (CRC). Defined as the presence of single tumor cells or small clusters of up to 5 cells in the tumor stroma, tumor budding has been likened to an epithelial-mesenchymal transition. Based on well-designed retrospective studies, tumor budding is linked to adverse outcome of CRC patients in 3 clinical scenarios: (1) in malignant polyps, detection of tumor buds is a risk factor for lymph node metastasis indicating the need for colorectal surgery; (2) tumor budding in stage II CRC is a highly adverse prognostic indicator and may aid patient selection for adjuvant therapy; (3) in the preoperative setting, presence of tumor budding in biopsy material may help to identify high-risk rectal cancer patients for neoadjuvant therapy. However, lack of consensus guidelines for standardized assessment still limits reporting in daily diagnostic practice. This article provides a practical and comprehensive overview on tumor budding aimed at the practicing pathologist. First, we review the prognostic value of tumor budding for the management of colon and rectal cancer patients. Second, we outline a practical, evidence-based proposal for the assessment of tumor budding in the daily sign-out. Last, we summarize the current knowledge of the molecular characteristics of high-grade budding tumors in the context of personalized treatment approaches and biomarker discovery.

Immunohistochemical assessment of E-cadherin and β-catenin in the histological differentiations of oral squamous cell carcinoma

The aim of this study was to establish the expression and localization of E-cadherin and β-catenin in oral squamous cell carcinomas (OSCC) so that we could correlate the findings with prognostic-relevant histopathological variables. E-cadherin and β-catenin expression in normal oral epithelia and in oral squamous cell carcinomas was examined immunohistochemically, and associations with histopathological differentiation and prognosis were then analyzed in 33 patients who had been operated on for OSCC. E-cadherin expression was found in (82%) of the squamous cells of well differentiated OSCC, (61%) of moderately differentiated and (39%) of poorly differentiated. E-cadherin expression was significantly associated with histological grade (p=0.000). No nuclear staining was detected. In (19.5%) of the cells E-cadherin localized in the cytoplasm, with no correlation to the histological grade (p=0.106). β-Catenin expression was found in 87% of the squamous cells of well differentiated OSCC, 67% of moderately differentiated and 43% of poorly differentiated, the expression was significantly associated with histological grade (p=0.000). the nuclear β-Catenin expression appeared in 3.3% of the cells and it was correlated to the histological grade (p=0.000). In (23.5%) of the cells β-Catenin localized in the cytoplasm, with correlation to the histological grade (p=0.002). According to this study the expression of β-catenin and E-cadherin were independent prognostic factors for histological grade. E-cadherin was closely linked to β-catenin expression in OSCC (p=0.000) and to tumor differentiation. That reflects a structural association and the role of both in tumor progression.

Risk assessment in early colorectal cancer: histological and molecular markers

The pathological examination of early colorectal cancer specimens, in particular 'malignant polyps', provides important prognostic information. The depth of invasion into the submucosal layer assessed according to the Haggitt (for pedunculated lesions) or Kikuchi (for nonpolypoid lesions) classification systems or by direct measurement has been associated with the risk of lymph node metastasis. Angioinvasion, in particular lymphatic invasion, budding, tumor differentiation or grade, and resection margin status have been identified as further risk factors. The combination of these parameters allows the stratification of affected individuals into low- and high-risk categories, which is pivotal for clinical management. For low-risk cancers, defined as a completely excised Haggitt level 1-3/Kikuchi sm1 tumor with no evidence of poor differentiation or angioinvasion, local excision is generally regarded as adequate treatment. Oncological surgical resection is, however, indicated for high-risk cancers, which show at least one of the following features: Haggitt level 4/Kikuchi sm3 invasion, the presence of lymphatic (or vascular) invasion, poor differentiation, or positive resection margin. The inclusion of molecular markers such as tumor suppressor genes and their products, markers involved in tumor vascularization, and markers related to tumor cell adhesion and invasion may help to refine risk stratification, but data on molecular markers are still limited in this regard.

Expression of RUNX3 and β-catenin in the carcinogenesis of sporadic colorectal tubular adenoma

The aim of this study is to investigate the possible roles of runt-related transcription factor 3 (RUNX3) and β-catenin in the carcinogenesis of sporadic colorectal tubular adenomas. The expression of the RUNX3 and β-catenin proteins was evaluated by immunohistochemistry in 23 normal colorectal mucosa (NCM), 81 sporadic colorectal tubular adenomas with different dysplasias (SCTA-D) (mild n=33, moderate n=23, and severe n=25 dysplasia), and 48 sporadic colorectal tubular adenomas with cancerous changes (SCTA-Ca). RUNX3 methylation was assessed by methylation-specific polymerase chain reaction (MSP), combined with laser capture microdissection (LCM), in 17 NCM, 41 SCTA-D (mild n=15, moderate n=12, and severe n=14 dysplasia), and 17 SCTA-Ca tissues. Compared to NCM (82.6 %), RUNX3 in SCTA-D (54.3 %) and SCTA-Ca (27.1 %) was significantly downregulated (P<0.05). In NCM, SCTA-D, and SCTA-Ca, the incidence of positive expression for β-catenin was 13.0, 60.5, and 79.2 %, respectively. A statistically significant difference was observed (P<0.05). RUNX3 levels were markedly higher in adenoma with mild dysplasia (75.8 %) and moderate dysplasia (60.9 %) than in adenoma with severe dysplasia (20.0 %) (both with P<0.05). Likewise, the expression of β-catenin in severe dysplasia adenoma was 84.0 %, which was significantly higher than that in mild dysplasia adenoma (39.4 %). An inverse correlation was found between the protein expression of RUNX3 and β-catenin in SCTA-D and SCTA-Ca (P<0.05). MSP results showed that RUNX3 methylation in NCM, SCTA-D, and SCTA-Ca was 5.9, 17.1, and 41.2 %, respectively, with a statistically significant difference between NCM and SCTA-Ca (P<0.05). However, no significant difference of RUNX3 methylation was observed among different dysplasia groups. RUNX3 and β-catenin play important roles in the carcinogenesis of sporadic colorectal tubular adenomas. In addition, hypermethylation of RUNX3 can downregulate its expression.