Tumor budding and evidence-based treatment of T2 rectal carcinomas

Challenges in Implementing Endoscopic Resection for T2 Colorectal Cancer

The current standard treatment for muscularis propria-invasive (T2) colorectal cancer is surgical colectomy with lymph node dissection. With the advent of new endoscopic resection techniques, such as endoscopic full-thickness resection or endoscopic intermuscular dissection, T2 colorectal cancer, with metastasis to 20%-25% of the dissected lymph nodes, may be the next candidate for endoscopic resection following submucosal-invasive (T1) colorectal cancer. We present a novel endoscopic treatment strategy for T2 colorectal cancer and suggest further study to establish evidence on oncologic and endoscopic technical safety for its clinical implementation.

Is High-Grade Tumor Budding an Independent Prognostic Factor in Stage II Colon Cancer?

BACKGROUND

Risk factors, including lymphatic, vascular, and perineural invasion, are considered indications for adjuvant treatment in stage II colon cancer. However, tumor budding is not included in the above risk factors.

OBJECTIVE

This study aimed to assess the value of tumor budding as a prognostic factor in stage II colon cancer.

DESIGN

This is a retrospective cohort study.

SETTINGS

This study was conducted in a tertiary referral center.

PATIENTS

This study examined 1390 patients with stage II colon cancer who received curative resection from 2007 to 2013 at an institution.

INTERVENTIONS

These patients were classified according to tumor budding status: low-grade tumor budding (less than 10 buds) and high-grade tumor budding (10 buds or more). Differences between the 2 groups were corrected by propensity score matching.

MAIN OUTCOME MEASURES

Disease-free survival and overall survival were the primary end points.

RESULTS

Among 1390 patients, 146 (10.5%) had high-grade tumor budding. The high-grade tumor budding group showed adverse histological characteristics such as advanced T stage, histological grade of differentiation, and presence of lymphatic/perineural invasion. After matching, the 5-year disease-free survival rate for the high-grade tumor budding group was significantly lower than for the low-grade group. We also compared survival outcomes according to tumor budding grade for patients who did not have risk factors and did not receive adjuvant treatment. The 5-year overall survival was similar between the 2 groups. However, the 5-year disease-free survival decreased significantly in the high-grade tumor budding group than in the low-grade tumor budding group.

LIMITATIONS

This was a retrospective study with a single-center design.

CONCLUSIONS

High-grade tumor budding is a poor prognostic factor in stage II colon cancer and is considered one of the risk factors for adjuvant treatment. See Video Abstract at http://links.lww.com/DCR/B962 .

ES LA GEMACIN TUMORAL UN FACTOR PRONSTICO INDEPENDIENTE EN EL CNCER DE COLON EN ESTADIO II

ANTECEDENTES:Los factores de riesgo, incluida la invasión linfática/vascular/perineural, se consideran indicaciones para el tratamiento adyuvante en el cáncer de colon en estadio II. Sin embargo, la gemación tumoral (desdiferenciación tumoral aislada), no está incluida en los factores de riesgo anteriores.OBJETIVO:El objeto de este estudio fue evaluar el valor de la gemación tumoral como factor pronóstico en el cáncer de colon en estadio II.DISEÑO:Este es un estudio de cohorte retrospectivo.ENTORNO CLÍNICO:Este estudio se realizó en un centro de referencia terciario.PACIENTES:Este estudio analizó 1390 pacientes con cáncer de colon en estadio II que recibieron una resección curativa entre 2007 y 2013 en una institución.INTERVENCIONES:Estos pacientes se clasificaron según el estado de gemación tumoral: gemación tumoral de bajo grado (<10 yemas) y gemación tumoral de alto grado (≥10 yemas). Las diferencias entre los dos grupos se corrigieron mediante el emparejamiento por puntaje de propensión.PRINCIPALES MEDIDAS DE VALORACIÓN:La supervivencia libre de enfermedad y la supervivencia global fueron los puntos finales primarios.RESULTADOS:Entre 1.390 pacientes, 146 (10,5%) tenían brotes tumorales de alto grado. El grupo de gemación tumoral de alto grado mostró características histológicas adversas como estadio T avanzado, grado histológico de diferenciación y presencia de invasión linfática/perineural. Después del emparejamiento, la tasa de supervivencia libre de enfermedad a cinco años para el grupo de brotes de tumores de alto grado fue significativamente menor que para el grupo de bajo grado. También comparamos los resultados de supervivencia según el grado de gemación del tumor para pacientes que no tenían factores de riesgo y que no recibieron tratamiento adyuvante. La supervivencia global a cinco años fue similar entre los dos grupos. Sin embargo, la supervivencia libre de enfermedad a cinco años disminuyó significativamente en el grupo de brotes de tumores de alto grado que en el grupo de brotes de tumores de bajo grado.LIMITACIONES:Este fue un estudio retrospectivo con un diseño de centro único.CONCLUSIÓNES:La gemación tumoral de alto grado es un factor de mal pronóstico en el cáncer de colon estadio II y se considera uno de los factores de riesgo para el tratamiento adyuvante. Consulte Video Resumen en http://links.lww.com/DCR/B962 . (Traducción-Dr. Ingrid Melo ).

Prognostic significance of tumor budding in melanoma

Cutaneous melanoma is an aggressive neoplasm with growing incidence and continuous research is undertaken for novel prognostic factors. This current research aims to determine if tumor budding is an independent factor that correlates with the survival of patients with melanoma. A total of 742 cases of melanoma were evaluated. A receiver operating curve (ROC) was performed to analyze tumor budding impact on survival, identifying a cutoff point associated with death. Subsequently, two groups of participants were created based on that result. Participants within the two groups were compared for clinicopathologic characteristics and survival analysis. Also, a multivariate analysis was performed. Of the total, 447 (60.2%) melanomas occurred in women and 295 in men. The mean age was 57.5 years + 15.75. The most common location was in acral areas (68.2%) followed by trunk (16.7%) and head and neck (15.1%). At presentation, 142 cases (19.1%) presented as stage I, 307 (41.4%) as stage II, 269 (36.3%) as stage III, and 24 (3, 2%) in stage IV. Regarding tumor budding, 586 (79%) cases showed tumor budding (at least one bud in 0.785 mm2), with a median of 5. From the ROC curve, 4.5 tumor buds/0.785 mm2 was the best cutoff point for correlation with death, grouping the series in low budding (0-4 buds/0.785 mm2) and high budding (>5 buds/0.785 mm2). Cases with high tumor budding were associated with older age, acral location, advanced clinical stages, ulceration, recurrence, and death. High tumor budding was associated with a significant decrease in 5-year overall survival (94.4% vs. 55.5%, P < 0.001). In the multivariate analysis, the factors remaining as independent predictors of survival were acral location, clinical stage IV, recurrence during clinical follow-up, and high tumor budding. High tumor budding (>5 buds in 0.785 mm2) independently correlates with 5-year overall survival rates and is associated with older age, acral location, advanced clinical stages, ulceration, recurrence, and death.

Tumor Budding as a Prognostic Marker in Rectal Cancer Patients on Propensity Score Analysis

BACKGROUND

Tumor budding is associated with adverse histology. It is a predictor of poor oncologic outcomes in colorectal cancer. However, it remains unclear whether tumor budding is a predictor of poor prognosis for rectal cancer patients regardless of neoadjuvant chemoradiotherapy (nCRT).

PATIENTS AND METHODS

This study analyzed 2888 rectal cancer patients who underwent radical surgery from 2007 to 2014. Among these patients, 939 underwent nCRT while 1949 did not receive nCRT. Tumor budding was defined as positive if the number of isolated tumor cells or small clusters of up to five tumor cells at the invasive front of the tumor was five or more. If the number was less than five, it was defined as negative. Patients were categorized according to tumor budding status. We used 1:1 propensity score matching to adjust for potential baseline confounders between the two groups.

RESULTS

Among 2888 patients, 939 received nCRT while 1949 did not receive nCRT. A total of 418 patients who received nCRT were matched (209 in each group). A total of 1024 patients without nCRT were also matched (512 in each group). In matched patients, 5-year overall survival (OS) and 5-year disease-free survival (DFS) rates for the positive budding group were significantly lower than those in the negative budding group regardless of nCRT. On multivariate analysis of prognostic factors, positive budding was associated with poorer disease-free survival independent of nCRT.

CONCLUSION

Tumor budding positivity is a prognostic indicator of poor outcomes in rectal cancer patients regardless of neoadjuvant chemoradiotherapy.

Evaluation of risk factors for lymph node metastasis in T2 lower rectal cancer to perform chemoradiotherapy after local resection

The oncological outcome of chemoradiotherapy (CRT) after local excision (LE) for T2 lower rectal cancer has demonstrated a high local recurrence (LR) rate. The aim of the present study was to determine the risk factors for lymph node metastasis (LNM) in order to reduce LR in T2 lower rectal cancer after LE and CRT. Specimens were collected from 95 consecutive patients with T2 lower rectal adenocarcinoma who underwent R0 resection by total mesenteric excision or tumor-specific mesenteric excision between January 2008 and December 2018 at Osaka International Cancer Institute. All specimens were checked and evaluated to determine the risk factors for LNM. LNM was observed in 26 patients (27%), including 2 patients (2%) with lateral pelvic lymph node metastasis. Univariate analysis indicated lymphovascular invasion (LVI; P=0.008), tumor budding (P=0.012) and histology other than well-differentiated adenocarcinoma (P=0.08) were associated with LNM; multivariate analysis revealed that LVI (P=0.03) was the only independent risk factor for LNM. LNM was confirmed in 0% (0/8) of patients without LVI, tumor budding and histological type. LVI, tumor budding and histological type can be risk factors for LNM in lower rectal cancer. The present study may be helpful to select patients for performing LE and CRT with good oncological outcome.

The prognostic value of tumor budding in patients who had surgery for rectal cancer with and without neoadjuvant therapy

BACKGROUND

The aim of this study was to investigate the prognostic value of tumor budding (TB) in rectal cancer patients. TB in the specimens of patients who received neoadjuvant chemoradiotherapy was specifically analyzed.

METHODS

This study was conducted on rectal cancer patients treated at Dokuz Eylul University Hospital, Turkey, between January 2000 and June 2010. Prospectively recorded clinicopathological data and the oncological outcomes of patients who received neoadjuvant chemoradiotherapy (CRT) (n = 117) and also patients who did not receive it (n = 113) were analyzed. TB was defined as an isolated single cancer cell or a cluster of cells composed of less than 5 cells of a "budding focus". Budding intensity was scored as follows: none (0), mild (1-5 buds), moderate (6-10 buds), and severe (> 10 buds). Two tumor budding intesity groups were created, TB-1 (none, few) and TB-2 (moderate, severe) for statistical analysis.

RESULTS

The median follow-up time was 40.12 ± 27.5 months. The 5-year overall and disease-free survival (DFS) rates were 66% and 62%, respectively. Multivariate analysis of overall survival in all patients showed that TB intensity (HR 2.64; 95% CI 1.46-4.77) and radial margin status (HR 2.16; 95% CI 1.18-3.96) were independent predictors of decreased overall survival. In patients who received CRT, TB (HR 4.87; 95% CI 2.10-11.28) and distant metastasis (HR 4.31; 95% CI 1.81-10.22) were predictive of survival while in patients who did not receive CRT, TB (HR 4.28; 95% CI 1.60-11.49), distant metastasis (HR 2.33; 95% CI 1.19-4.60), radial margin status (HR 2.53; 95% CI 1.09-5.91), and venous invasion (HR 4.48; 95% CI 2.14-9.39) were significantly independent predictors of survival. In multivariate analysis of all patients decreased DFS was correlated with lymph node involvement (HR 2.78; 95% CI 1.60-4.87), venous invasion (HR 1.76; 95% CI 1.00-3.09), and with radial margin status (HR 2.31; 95% CI 1.27-4.22). In multivariate analysis in the CRT group, decreased DFS was significantly associated with lymph node involvement (HR 4.39; 95% CI 1.70-11.33) and radial margin status (HR 2.56; 95% CI 1.12-5.90) while only lymph node involvement (HR 2.33; 95% CI 1.16-4.66) was a significant predictor of decreased DFS in patients who did not receive CRT.

CONCLUSIONS

TB has prognostic value as important as lymph node involvement and radial margin status and it may be a helpful prognostic indicator even after CRT. TB should be included in the TNM classification and may be used in planning adjuvant therapy.

Tumour budding in rectal cancer. A comprehensive review

A unique and fundamental characteristic of malignant neoplastic cells is their ability to invade other tissues and metastasise. The first step in this process is the dissociation of some of these cells from the tumour invasion front, named tumour budding (TB). This phenomenon has become increasingly relevant in recent years due to its association with adverse clinicopathological characteristics and with the epithelial-mesenchymal transition. TB has been studied by mixing colon with rectal tumours, but it is clinically important to differentiate these types of tumours. A review in two databases without language restriction was performed from 1950 to 2017 about TB with an emphasis on rectal cancer. We present various aspects of TB, from its terminology and evaluation to its molecular aspects, through its clinical associations. TB is associated with adverse clinicopathological features, like lymphovascular invasion, lymph node metastasis, and decreased survival. More studies of the clinicopathological, molecular, and epidemiological characteristics of TB in rectal cancer are needed.

Tumour Budding and Survival in Stage II Colorectal Cancer: a Systematic Review and Pooled Analysis

PURPOSE

Tumour budding is defined as the presence of isolated or small clusters of malignant cells at the invasive edge of the tumour. It is considered a negative prognostic factor in colorectal cancer (CRC) and is associated with a poor outcome and adverse pathological features. Here, we report a meta-analysis of the association of tumour budding and survival in stage II CRC patients.

METHODS

PubMed, EMBASE, Web of Science and SCOPUS were searched for studies that assessed the relationship between tumour budding and 5-year overall survival (OS) in stage II CRC patients. Published data were extracted and used to compute odds ratios (ORs) for death at 5 years and hazard ratios (HRs) for survival amongst patients with respect to the extent of tumour budding, using multivariate analysis. Data were pooled using the Mantel-Haenszel random effect model.

RESULTS

We analysed 12 studies that included a total of 1652 patients. High-grade budding was associated with worse OS at 5 years (OR for death, 6.25; 95 % confidence interval [CI], 4.04-9.67; P < 0.00001). The absolute difference in 5-year OS was -25 % (95 % CI, -18- - 33 %, P < 0.00001). It was particularly noteworthy that the presence of high-grade budding was associated with an increased risk of death (HR for death, 3.68; 95 % CI, 2.16-6.28, P < 0.00001).

CONCLUSIONS

Tumour budding is associated with worse survival in stage II CRC, in particular in pT3N0M0 patients. It could therefore potentially be used when deciding whether to administer adjuvant chemotherapy in high-risk node negative 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.

Tumor budding is associated with an increased risk of lymph node metastasis and poor prognosis in superficial esophageal adenocarcinoma

The treatment approach for superficial (stage T1) esophageal adenocarcinoma critically depends on the pre-operative assessment of metastatic risk. Part of that assessment involves evaluation of the primary tumor for pathologic characteristics known to predict nodal metastasis: depth of invasion (intramucosal vs submucosal), angiolymphatic invasion, tumor grade, and tumor size. Tumor budding is a histologic pattern that is associated with poor prognosis in early-stage colorectal adenocarcinoma and a predictor of nodal metastasis in T1 colorectal adenocarcinoma. In a retrospective study, we used a semi-quantitative histologic scoring system to categorize 210 surgically resected, superficial (stage T1) esophageal adenocarcinomas according to the extent of tumor budding (none, focal, and extensive) and also evaluated other known risk factors for nodal metastasis, including depth of invasion, angiolymphatic invasion, tumor grade, and tumor size. We assessed the risk of nodal metastasis associated with tumor budding in univariate analyses and controlled for other risk factors in a multivariate logistic regression model. In all, 41% (24 out of 59) of tumors with extensive tumor budding (tumor budding in ≥3 20X microscopic fields) were metastatic to regional lymph nodes, compared with 10% (12 out of 117) of tumors with no tumor budding, and 15% (5 out of 34) of tumors with focal tumor budding (P<0.001). When controlling for all pathologic risk factors in a multivariate analysis, extensive tumor budding remains an independent risk factor for lymph node metastasis in superficial esophageal adenocarcinoma associated with a 2.5-fold increase (95% CI=1.1-6.3, P=0.039) in the risk of nodal metastasis. Extensive tumor budding is also a poor prognostic factor with respect to overall survival and time to recurrence in univariate and multivariate analyses. As an independent risk factor for nodal metastasis and poor prognosis after esophagectomy, tumor budding should be evaluated in superficial (T1) esophageal adenocarcinoma as a part of a comprehensive pathologic risk assessment.

Local resection of early rectal cancer

The introduction of the National Danish screening programme for colorectal cancer will result in the detection of more early rectal cancers (ERC), which may be considered for local excision. For the low risk≤T1 cancer, the oncological outcome at local excision in smaller patient series has shown similar results to conventional surgery, but with a significantly lower rate of serious complications, morbidity and mortality. The challenge is correct preoperative staging, and a meticulous systematic histopathological staging of the excised specimen to distinguish the low risk from high-risk cases, where rescue surgery may be considered. The establishment of a regional or national clinical database is necessary to improve the local treatment of ERC.

Tumor budding in upper gastrointestinal carcinomas

The basis of personalized medicine in oncology is the prediction of an individual's risk of relapse and death from disease. The presence of tumor budding (TB) at the tumor-host interface of gastrointestinal cancers has been recognized as a hallmark of unfavorable disease biology. TB is defined as the presence of dedifferentiated cells or small clusters of up to five cells at the tumor invasive front and can be observed in aggressive carcinomas of the esophagus, stomach, pancreas, ampulla, colon, and rectum. Presence of TB reproducibly correlates with advanced tumor stage, frequent lymphovascular invasion, nodal, and distant metastasis. The UICC has officially recognized TB as additional independent prognostic factor in cancers of the colon and rectum. Recent studies have also characterized TB as a promising prognostic indicator for clinical management of esophageal squamous cell carcinoma, adenocarcinoma of the gastro-esophageal junction, and gastric adenocarcinoma. However, several important issues have to be addressed for application in daily diagnostic practice: (1) validation of prognostic scoring systems for TB in large, multi-center studies, (2) consensus on the optimal assessment method, and (3) inter-observer reproducibility. This review provides a comprehensive analysis of TB in cancers of the upper gastrointestinal tract including critical appraisal of perspectives for further study.

Tumor budding in the clinical management of colon and rectal cancer

SUMMARY 

Morphological features of the tumor microenvironment are emerging as powerful prognostic indicators for colorectal cancer (CRC). The presence of peritumoral budding (PTB), defined as the presence of single tumor cells or small clusters of up to five cells in the tumor stroma ahead of the invasive front, is a hallmark of aggressive disease biology. Presence of PTB strongly correlates with adverse clinicopathological features and is recognized as an additional adverse prognostic factor by the Union for International Cancer Control. Recent studies have also characterized intratumoral budding (ITB) in biopsy material as a prognostic indicator in the preoperative setting. This paper provides a comprehensive overview on the role of PTB and ITB in the clinical management of colon and rectal cancer.

Tumor budding in colorectal carcinoma: time to take notice

Tumor 'budding', loosely defined by the presence of individual cells and small clusters of tumor cells at the invasive front of carcinomas, has received much recent attention, particularly in the setting of colorectal carcinoma. It has been postulated to represent an epithelial-mesenchymal transition. Tumor budding is a well-established independent adverse prognostic factor in colorectal carcinoma that may allow for stratification of patients into risk categories more meaningful than those defined by TNM staging, and also potentially guide treatment decisions, especially in T1 and T3 N0 (Stage II, Dukes' B) colorectal carcinoma. Unfortunately, its universal acceptance as a reportable factor has been held back by a lack of definitional uniformity with respect to both qualitative and quantitative aspects of tumor budding. The purpose of this review is fourfold: (1) to describe the morphology of tumor budding and its relationship to other potentially important features of the invasive front; (2) to summarize current knowledge regarding the prognostic significance and potential clinical implications of this histomorphological feature; (3) to highlight the challenges posed by a lack of data to allow standardization with respect to the qualitative and quantitative criteria used to define budding; and (4) to present a practical approach to the assessment of tumor budding in everyday practice.

Intra-tumoral budding in preoperative biopsy specimens predicts lymph node and distant metastasis in patients with colorectal cancer

Tumor budding, a histological hallmark of epithelial-mesenchymal transition in colorectal cancer, is a parameter of tumor progression and according to the International Union Against Cancer/American Joint Committee on Cancer an 'additional' prognostic factor. The current definition of tumor budding is reserved for the invasive tumor front of colorectal cancer (so called peri-tumoral budding), but tumor buds can also be observed in small preoperative biopsy specimens. Whereas the prognostic value of peri-tumoral budding assessed in resection specimens has found wide acceptance, the value of budding in preoperative biopsies, which normally do not encompass the invasive tumor margin and hence can be called intra-tumoral budding, has not been systematically investigated yet. Therefore, the aim of this study is to assess the predictive value of intra-tumoral budding for lymph node and distant metastasis in preoperative biopsies. Preoperative biopsy samples and consecutive resection specimens from 72 patients with pathological information on TNM stage, vascular, lymphatic and perineural invasion, and tumor border configuration were used to evaluate intra-tumoral budding and peri-tumoral budding. Both parameters were scored semiquantitatively as 'high' (detectable at low power magnification × 2.5) and 'low' (occasional budding at intermediate magnification × 10, difficult to find or absent). In biopsy samples high intra-tumoral budding was observed in 12/72 patients (17%) and associated with high peri-tumoral budding in the corresponding resection specimens (P=0.008). Additionally, there was a correlation between high intra-tumoral budding and lymph node metastasis (P=0.034), distant metastasis (P=0.007) and higher tumor grade (P=0.025). Peri-tumoral budding was associated with higher N stage (P=0.004), vascular (P=0.046) and lymphatic invasion (P=0.019) as well as with an infiltrating tumor border (P<0.001), reflecting the predictive power of peri-tumoral budding for tumor progression. High intra-tumoral budding in preoperative biopsy samples of colorectal cancer patients predicts high peri-tumoral budding at the invasive margin and lymph node metastasis in the corresponding resection specimens as well as distant metastasis.

Meta-analysis of histopathological features of primary colorectal cancers that predict lymph node metastases

BACKGROUND

Treatment decisions for colorectal cancer vary based on lymph node status. While some histopathological features of the primary tumor correlate with lymph node spread, the relative influences of these risk factors are not well quantified.

OBJECTIVE

This study aims to systematically review published studies relating histopathological features of primary colorectal cancer to the presence of lymph node metastases and to determine how reliable certain factors might be at predicting nodal metastasis when only the primary lesion is available for study.

DATA SOURCES

Inclusive literature search using EMBASE and Ovid MEDLINE databases plus manual reference checks of all articles correlating lymphatic spread with colorectal cancer (any T stage) from 1984 to mid-2008 was performed.

STUDY SELECTION

This search generated two levels of screening utilized on 602 citations, yielding 123 articles for full review. Data reported from 76 articles were chosen.

MAIN OUTCOME MEASURES

The relative influence of each histopathological feature on the likelihood of lymphatic metastases was determined. Fixed-effects meta-analysis was performed, and results were reported as Mantel-Haenszel odds ratios (OR).

RESULTS

Of 42 histopathological features analyzed, only 40.4% were reported in >2 articles. The positive predictive values for the top quartile of most frequently reported risk factors were 25.5-86.4%. Among the commonly reported histopathological findings, lymphatic invasion (OR, 8.62) significantly outperformed tumor depth (T2 vs. T1; OR, 2.62) and overall differentiation (OR, 2.38) in predicting nodal spread. For the rectal cancer subset, risk factors differed from the overall colorectal group in predictive ability; poor differentiation at the invasive front (OR, 6.08) and tumor budding (OR, 5.82) were the most predictive.

LIMITATIONS

This literature search is limited by the small number of studies examining only rectal cancers and the potential changes in histological and/or surgical techniques over the study period.

CONCLUSIONS

No single histopathological feature of colorectal cancer reliably predicted lymph node metastases. Several risk factors that correlate highly with nodal disease are not routine components of standard pathology reports. Until further research establishes histopathological or molecular patterns for predicting lymph node spread, caution should be exercised when basing treatment decisions solely on these factors.

Risk factors for lymph node metastasis in pT1 and pT2 rectal cancer: a single-institute experience in 943 patients and literature review

BACKGROUND

Local excision has become an alternative for radical resection in rectal cancer for selected patients. The purpose of this study was to assess the clinicopathologic factors determining lymph node metastasis (LNM) in patients with T1-2 rectal cancer.

METHODS

Between January 1995 and December 2009, a total of 943 patients with pT1 or pT2 rectal adenocarcinoma received radical resection at a single institution. Clinicopathologic factors were evaluated by univariate and multivariate analyses to identify risk factors for LNM.

RESULTS

A total of 943 patients (544 men and 399 women) treated for T1-2 rectal cancer were included in this study. LNM was found in 188 patients (19.9%). In multivariate analysis, lymphovascular invasion (LVI; P < 0.001, hazard ratio 11.472), poor differentiation (PD; P = 0.007, hazard ratio 3.218), and depth of invasion (presence of pT2; P = 0.032, hazard ratio 1.694) were significantly related to nodal involvement. The incidence for LNM lesions in the presence of LVI, PD, and pT2 was 68.8, 50.0, and 23.1%, respectively, while that for pT1 carcinomas with no LVI or PD was 7.5%.

CONCLUSIONS

LVI, PD, and pT2 are independent risk factors predicting LNM in pT1-2 rectal carcinoma.

Morphology and prognostic value of tumor budding in rectal cancer after neoadjuvant radiotherapy

Tumor budding is an acknowledged prognostic marker in colorectal cancer. This study was conducted to investigate the morphology and prognostic significance of budding in rectal cancer after neoadjuvant radiotherapy. Surgical specimens from 96 consecutive patients who underwent neoadjuvant radiotherapy and curative resection were retrieved to assess budding and other clinicopathologic factors. The morphology and prognostic significance of postirradiation tumor budding were closely associated with tumor regression grade. In the tumor regression grade 1 group, tumor budding presented as "false budding" and did not have a significant association with prognosis. In the tumor regression grade 2 and 3 groups, budding was observed surrounded by radiation-induced fibrosis and large populations of infiltrating inflammatory cells, and budding intensity was significantly associated with histologic differentiation, ypN stage, and lymphovascular invasion (P < .05). Moreover, the low-grade budding subgroup showed a significantly higher rate of 5-year disease-free survival than the high-grade budding subgroup (87.5% versus 55.6%, P < .0001). Multivariate analysis showed that pretreatment serum carcinoembyronic antigen, tumor regression grade, and tumor budding were the major independent factors affecting long-term disease-free survival. In conclusion, postirradiation budding has distinct morphology and prognostic significance in rectal cancer after neoadjuvant radiotherapy.

Epithelial mesenchymal transition and tumor budding in aggressive colorectal cancer: tumor budding as oncotarget

Epithelial mesenchymal transition (EMT) is proposed as a critical mechanism for the acquisition of malignant phenotypes by epithelial cells. In colorectal cancer, tumor cells having undergone EMT are histologically represented by the presence of tumor buds defined as single cells or small clusters of de-differentiated tumor cells at the invasive front. Tumor budding is not a static, histological feature rather it represents a snap-shot of a dynamic process undertaken by an aggressive tumor with the potential to disseminate and metastasize. Strong, consistent evidence shows that tumor budding is a predictor of lymph node metastasis, distant metastatic disease, local recurrence, worse overall and disease-free survival time and an independent prognostic factor. Moreover, the International Union against Cancer (UICC) recognizes tumor budding as a highly relevant, additional prognostic parameter. The aim of this review is to summarize the evidence supporting the implementation of tumor budding into diagnostic pathology and patient management and additionally to illustrate its worthiness as a potential therapeutic target.

Tumor budding predicts response to anti-EGFR therapies in metastatic colorectal cancer patients

AIM: To investigate whether the evaluation of tumor budding can complement K-RAS analysis to improve the individualized prediction of response to anti-epidermal growth factor receptor based therapies in metastatic colorectal cancer (mCRC) patients.

METHODS: Forty-three patients with mCRC treated with cetuximab or panitumumab were entered into this study. According to the Response Evaluation Criteria in Solid Tumors criteria, 30 patients had stable or progressive disease (non-responsive), while 13 patients had a partial response. Tumor buds were evaluated from whole tissue sections stained for pan-cytokeratin, evaluated in the densest region using a 40 × objective and “high-grade” tumor budding was defined as 15 buds/high-power field.

RESULTS: Tumor buds and K-RAS mutation both correctly classified 68% of patients. All patients with K-RAS mutation (n = 7) or high-grade tumor budding (n = 11) were non-responsive, of which 4 patients had both features. All 13 partial responders were K-RAS wild-type with low-grade tumor budding. Combined, the predictive value of K-RAS and tumor budding was 80%. Additionally, high-grade tumor budding was significantly related to worse progression-free survival [HR (95% CI): 2.8 (1.3-6.0, P = 0.008)].

CONCLUSION: If confirmed in larger cohorts, the addition of tumor budding to K-RAS analysis may represent an effective approach for individualized patient management in the metastatic setting.

Risk factors of nodal involvement in T2 colorectal cancer

PURPOSE

Because of the adverse consequences of radical resection of T2 colorectal cancer, criteria are needed for selection of patients who can safely undergo local excision without requiring additional radical surgery. We therefore conducted a retrospective study of patients with T2 colorectal cancer to identify risk factors for nodal involvement that might be used in selecting patients for local excision.

METHODS

We reviewed records from consecutive patients who had undergone curative resection of T2 colorectal cancer at the Department of Surgery, National Defense Medical College, Saitama, Japan, between 1985 and 2005. Data on conventional clinicopathologic variables were retrieved from pathology reports at the time of surgery, and archived slides were evaluated regarding potential risk factors such as extent of poorly differentiated component (grade I-III), myxoid cancer stroma, tumor budding, and growth pattern and invasion depth in the muscularis propria.

RESULTS

A total of 244 patients (139 men and 105 women) treated for T2 colorectal cancer were included. Nodal involvement was found in 7 (8.4%) of 83 patients classified as grade I on the poorly differentiated component vs. 47 (29.2%) of 161 patients classified as grade II or III (P < .001). Of 148 patients negative for myxoid cancer stroma, 30 (16.9%) had nodal involvement vs. 24 (36.4%) of 42 patients who were positive for myxoid cancer stroma (P = .0011). According to multiple variable logistic analysis, significant independent risk factors for nodal involvement included poorly differentiated component (P = .002), myxoid cancer stroma (P = .032), and lymphovascular invasion (P = .022).

CONCLUSIONS

Poorly differentiated component, myxoid cancer stroma, and lymphovascular invasion are significant independent risk factors for nodal involvement in T2 colorectal cancer. We need further study to validate these results on another data set, especially in patients with rectal cancer, and to confirm whether local resection of T2 rectal cancer is able to predict the nodal involvement before laparotomy.

Invasive front of colorectal cancer: Dynamic interface of pro-/anti-tumor factors

Tumor-host interaction at the invasive front of colorectal cancer represents a critical interface encompassing a dynamic process of de-differentiation of colorectal carcinoma cells known as epithelial mesenchymal transition (EMT). EMT can be identified histologically by the presence of “tumor budding”, a feature which can be highly specific for tumors showing an infiltrating tumor growth pattern. Importantly, tumor budding and tumor border configuration have generated considerable interest as additional prognostic factors and are also recognized as such by the International Union Against Cancer. Evidence seems to suggest that the presence of tumor budding or an infiltrating growth pattern is inversely correlated with the presence of immune and inflammatory responses at the invasive tumor front. In fact, several tumor-associated antigens such as CD3, CD4, CD8, CD20, Granzyme B, FOXP3 and other immunological or inflammatory cell types have been identified as potentially prognostic in patients with this disease. Evidence seems to suggest that the balance between pro-tumor (including budding and infiltrating growth pattern) and anti-tumor (immune response or certain inflammatory cell types) factors at the invasive front of colorectal cancer may be decisive in determining tumor progression and the clinical outcome of patients with colorectal cancer. On one hand, the infiltrating tumor border configuration and tumor budding promote progression and dissemination of tumor cells by penetrating the vascular and lymphatic vessels. On the other, the host attempts to fend off this attack by mounting an immune response to protect vascular and lymphatic channels from invasion by tumor buds. Whereas standard pathology reporting of breast and prostate cancer involves additional prognostic features, such as the BRE and Gleason scores, the ratio of pro- and anti-tumor factors could be a promising approach for the future development of a prognostic score for patients with colorectal cancer which could complement tumor node metastasis staging to improve the clinical management of patients with this disease.

Clinicopathologic factors of lymph node metastasis in T2 colorectal carcinoma

AIM: To explore the related clinicopathologic factors of lymph nodes metastasis (LNM) in T₂ colorectal carcinoma and to provide reasonable and highly efficient indicators for individualized treatment.

METHODS: A total of 324 patients with T₂ colorectal carcinoma who underwent curative resection in our hospital from Jan 1991 to Aug 2006 were collected. The relationship between its clinicopathologic factors and LNM was analyzed retrospectively.

RESULTS: Single factor and multifactor Logistic regression analysis demonstrated that the depth of tumor invasion (OR = 3.841, 95% CI: 1.581-9.329, P = 0.003) and histological type (OR = 1.451, 95% CI: 1.059-1.989, P = 0.023) were the major factors in T₂ colorectal carcinoma of LNM. A significant difference of LNM rates was observed between lower muscular layer (mp₁) and deeper muscular layer (mp₂) of tumor invasion. However, gender, age, tumor site, tumor size, growth pattern, lymph-vascular and venous invasion were not related to LNM.

CONCLUSION: The depth of tumor invasion and histological type are the major relevant factors of LNM in T₂ colorectal carcinoma. The depth of tumor invasion is particularly important and mp1 as a barrier may prevent tumor cells from metastasis. Once the depth of tumor invasion goes beyond mp1, the risk of LNM would increase significantly.