Macroscopic features at the deepest site of tumor penetration predicting liver metastases of colorectal cancer

Japanese multicenter prospective study investigating laparoscopic surgery for locally advanced rectal cancer with evaluation of CRM and TME quality (PRODUCT trial)

Aim

In Japan, we have not been able to validate the results of laparoscopic surgery for locally advanced rectal cancer using the universal index "circumferential resection margin (CRM)." Previously, we established a semi-opened circular specimen processing method and validated its feasibility. In the PRODUCT trial, we aimed to assess CRM in patients with locally advanced rectal cancer who underwent laparoscopic rectal resection.

Methods

This was a multicenter, prospective, observational study. Eligible patients had histologically confirmed rectal adenocarcinoma located at or below 12 cm above the anal verge with clinical stage II or III and were scheduled for laparoscopic or robotic surgery. The primary endpoint was pathological CRM. CRM ≤1 mm was defined as positive.

Results

A total of 303 patients operated on between August 2018 and January 2020 were included in the primary analysis. The number of patients with clinical stage II and III was 139 and 164, respectively. Upfront surgery was performed for 213 patients and neoadjuvant therapy for 90 patients. The median CRM was 4.0 mm (IQR, 2.1-8.0 mm), and CRM was positive in 26 cases (8.6%). Univariate and multivariate analyses demonstrated that a predicted CRM from the mesorectal fascia of ≤1 mm on MRI was the significant factor for positive CRM (P = .0012 and P = .0045, respectively).

Conclusion

This study showed the quality of laparoscopic rectal resection based on the CRM in Japan. Preoperative MRI is recommended for locally advanced rectal cancer to prevent CRM positivity.

Nomograms predicting survival and recurrence in colonic cancer in the era of complete mesocolic excision

Background

More extensive lymphadenectomy may improve survival after resection of colonic cancer. Nomograms were created predicting overall survival and recurrence for patients who undergo D2-D3 lymph node dissection, and their validity determined.

Methods

This was a multicentre study of patients with colonic cancer who underwent resection with D2-D3 lymph node dissection in Japan. Inclusion criteria included R0 resection. A training cohort of patients operated on from 2007 to 2008 was analysed to construct prognostic models predicting survival and recurrence. Discrimination and calibration were performed using an external validation cohort from the Japanese colorectal cancer registry (procedures in 2005-2006).

Results

The training cohort consisted of 2746 patients. Predictors of survival were: age (hazard ratio (HR) 1·04), female sex (HR 0·71), depth of tumour invasion (HR 1·15, 1·22, 2·96 and 3·14 for T2, T3, T4a and T4b respectively versus T1), lymphatic invasion (HR 1·11, 1·15 and 2·95 for ly1, ly2 and ly3 versus ly0), preoperative carcinoembryonic antigen (CEA) level (HR 1·21, 1·59 and 1·99 for 5·1-10·0, 10·1-20·0 and 20·1 and over versus 0-5·0 ng/ml), number of metastatic lymph nodes (HR 1·07), number of lymph nodes examined (HR 0·98) and extent of lymphadenectomy (HR 0·23, 0·13 and 0·11 for D1, D2 and D3 versus D0). Predictors of recurrence were: female sex (HR 0·82), macroscopic type (HR 3·82, 4·56, 6·66, 7·74 and 3·22 for types I, II, III, IV and V versus type 0), depth of invasion (HR 1·25, 2·66, 5·32 and 6·43 for T2, T3, T4a and T4b versus T1), venous invasion (HR 1·43, 3·05 and 4·79 for v1, v2 and v3 versus v0), preoperative CEA level (HR 1·39, 1·43, 1·56 and 1·85 for 5·1-10·0, 10·1-20·0, 20·1-40·0 and 40·1 or more versus 0-5 ng/ml), number of metastatic lymph nodes (HR 1·07) and number of lymph nodes examined (HR 0·98). The validation cohort comprised 4446 patients. The internal and external validated Harrell's C-index values for the nomogram predicting survival were 0·75 and 0·74 respectively. Corresponding values for recurrence were 0·78 and 0·75.

Conclusion

These nomograms could predict survival and recurrence after curative resection of colonic cancer.

Establishment of new predictive markers for distant recurrence of colorectal cancer using lectin microarray analysis

We evaluated the clinical benefits of novel predictive markers for distant recurrence with colorectal cancer using lectin microarray analysis of cell surface glycan modifications. Glycoproteins were extracted from formalin-fixed, paraffin-embedded tumor specimens and normal epithelium from 53 consecutive curatively resected stage I–III colorectal cancer cases and then subjected to lectin microarray to obtain lectin–glycan interaction (LGI) values. In addition, clinicopathological factors associated with distant recurrence were identified. LGI values that were associated with distant recurrence were validated with an additional 55 curatively resected stage II colorectal cancer cases. LGI values for Agaricus bisporus (ABA) lectin, prominent in cancer tissues, were statistically associated with distant recurrence. ABA lectin staining exhibited strikingly intense signals in the cytoplasm and apical surfaces of cancer cells, while weak staining was observed in the supranuclear regions of normal epithelium. This ABA tumor/normal LGI ratio may be a new predictive biomarker for distant recurrence of curatively resected colorectal cancer.

Histopathologic factors affecting tumor recurrence after hepatic resection in colorectal liver metastases

Purpose

Hepatic resection is a standard method of treatment for colorectal liver metastases (CRLM). However, the pathologic factors of metastatic lesions that affect tumor recurrence are less well defined in CRLM. The aim of this study was to evaluate the risk factors for recurrence of CRLM, focusing on histopathologic factors of metastatic lesions of the liver.

Methods

From January 2003 to December 2008, 117 patients underwent curative hepatic resection for CRLM were reviewed. Tumor size and number, differentiation, tumor budding, angio-invasion, dedifferentiation and tumor infiltrating inflammation of metastatic lesions were investigated.

Results

The mean number of hepatic tumors was 2 (range, 1-8). The mean size of the largest tumor was 2.9 cm (range, 0.3-18.5 cm) in diameter. The moderate differentiation of the hepatic tumor was the most common in 86.3% of the patients. Tumor budding, angio-invasion, and dedifferentiation were observed in 81%, 34%, and 12.8% of patients. Inflammation infiltrating tumor was detected in 6.8% of patients. Recurrence after hepatic resection appeared in 69 out of 117 cases (58.9%). Recurrence-free survival at 1, 2 and 5 years were 62.4%, 43.6%, and 34.3%. The multivariate analysis showed the number of metastases ≥3 (P = 0.007), the tumor infiltrating inflammation (P = 0.047), and presence of dedifferentiation (P = 0.020) to be independent risk factors for tumor recurrence.

Conclusion

Histopathological factors, i.e., dedifferentiation and tumor infiltrating inflammation of the metastatic lesion, could be one of the risk factors of aggressive behavior as well as the number of metastases even after curative resection for CRLM.

Elastic laminal invasion in colon cancer: diagnostic utility and histological features

Primary tumors of the colorectal cancers are assessed pathologically based on the tumor spread into the bowel wall. The assessment of serosal involvement, which may be relevant to pT4, can be challenging for pathologists, making the consistency of diagnoses questionable. As solutions to this problem, the following two strategies could be adopted. One would be to use special staining or immunohistochemical staining techniques for diagnostic assistance. The other would be to construct recommendations for the assessment of tumor spreading and to obtain a world-wide consensus on the criteria used to assess tumor spreading. Using elastic staining, we previously reported that peritoneal elastic laminal invasion (ELI) could be objectively determined and would likely contribute to a simplified and more objective stratification of deep tumor invasion around the peritoneal surface. We also noted the importance of sampling, staining, and histo-anatomical knowledge in the application of elastic staining during routine pathological diagnosis. Here we review the history of primary tumor stratification leading to the present TNM classification and report on the current status of pathological assessments made at our hospital to summarize what has been established and what is further required for the pathological diagnosis of tumor spreading in patients with colorectal cancer.

Peritoneal elastic laminal invasion of colorectal cancer: the diagnostic utility and clinicopathologic relationship

To determine whether the peritoneal elastic lamina can be a useful pathologic hallmark to classify the level of tumor spreading in colorectal cancer, we performed elastica staining in 564 pT3 and pT4a colorectal cancer cases. Associations between peritoneal elastic laminal invasion of the tumor and clinicopathologic features were evaluated. Next, morphology of tumor was compared between cases with and those without peritoneal elastic laminal invasion to estimate the morphologic alteration that occurs when tumor invades beyond the peritoneal elastic lamina. Morphometric analysis of tumor area beyond the peritoneal elastic lamina was performed and compared with other tumor area to elucidate morphologic characteristics of the tumor area beyond the peritoneal elastic lamina. Clinicopathologic analysis revealed that peritoneal elastic laminal invasion was associated with higher tumor stage, palliative resection, deeper tumor invasion, deeper ulceration, over 5 mm of muscular layer elevation and peritoneal surface retraction with fibro-inflammation, higher budding grade, and high grade of lymphovascular invasion (P<0.01). Peritoneal elastic laminal invasion was associated with recurrence and prognosis in colon cancer and was an independent risk factor for the recurrence of stage II colon cancer. Furthermore, morphometric analysis revealed that tumor area in subserosal invasive front beyond peritoneal elastic lamina exhibited significantly more prominent fibrosis and tumor budding than other tumor area (P<0.01). Peritoneal elastic lamina was useful hallmark to determine the level of tumor invasion, and was powerful indicator to predict prognosis in colon cancer. Tumor area beyond the elastic lamina is characterized by extensive tumor budding and fibrosis.

Thin section MRI in multidisciplinary pre-operative decision making for patients with rectal cancer

High spatial resolution MRI of the rectum is an accurate method of staging rectal cancer. The technique requires attention to detail so that correct planes and scan parameters are used to obtain the best images. A detailed understanding of the pathological features of these tumours is required for image interpretation so that prognostic information beyond the basic T and N staging of the tumour can be obtained. Use of standardized criteria for reporting is reproducible in the multicentre setting and pre-operative multidisciplinary discussion of the MRI features increases the number of operations performed with tumour-free resection margins.

Actinin-4 increases cell motility and promotes lymph node metastasis of colorectal cancer

BACKGROUND & AIMS

Enhanced motility of cancer cells by remodeling of the actin cytoskeleton seems crucial in the process of cancer invasion and metastasis. We previously identified an actin-binding protein, actinin-4, as a new biomarker of cancer invasion and an indicator of prognosis for patients with breast cancer. However, its involvement in the mechanisms of cancer invasion and metastasis remains undetermined. The current study tested the role of actinin-4 in the motility and metastatic potential of colorectal cancer cells.

METHODS & RESULTS

Quantitative immunofluorescence histochemistry showed that the expression level of the actinin-4 protein was increased in 73.1% (19/26) of the cases of colorectal cancer over the corresponding normal intestinal epithelium. The increased expression of actinin-4 was most significant in dedifferentiated cancer cells at the invasive front. A colorectal cancer cell clone capable of inducing actinin-4 using the tetracycline-regulatory system (designated DLD1 Tet-off ACTN-4) was established. Upon the induction of actinin-4, DLD1 Tet-off ACTN-4 cells spread filopodia and significantly increased their motility ( P = .00027); actinin-4 protein was concentrated at the leading edges of these actin-rich podia. When injected into the mesocecum of severe combined immunodeficient mice, DLD1 Tet-off ACTN4 cells, but not the control cells, metastasized into regional mesenteric lymph nodes, resembling the behavior of clinical cancers. The expression of actinin-4 in focally dedifferentiated cancer cells at the invasive front was significantly correlated with the frequency of lymph node metastasis of colorectal cancer ( P = .038).

CONCLUSIONS

Actinin-4 actively increases cell motility and promotes lymph node metastasis of colorectal cancer.

Prospective evaluation of prognostic factors in patients with colorectal cancer undergoing curative resection

BACKGROUND AND OBJECTIVES

Streak type, defined by the presence of white streaks at the advancing margin of tumor invasion; focal dedifferentiation, seen as undifferentiated cancer cells with an infiltrative pattern at the invasive front; and perineural invasion have been demonstrated to be prognostic factors in patients with colorectal cancer. We performed a prospective study to examine the usefulness of these features as prognostic factors.

METHODS

We reviewed a total of 391 patients who underwent curative surgery for colorectal cancer between May 1997 and June 1999. Of these, 50 patients with multiple cancers were excluded, and a total of 341 patients were finally entered into the study.

RESULTS

Of the prognostic factors investigated, depth of invasion, lymph node status, lymphatic invasion, venous invasion, growth type, streak type, focal dedifferentiation, and perineural invasion were significant prognostic factors in univariate analysis. In multivariate analysis, lymph node status, depth of invasion, and perineural invasion were significant prognostic factors. The survival of patients with perineural invasion was significantly poorer than that of patients without perineural invasion in both stage II and III cancer.

CONCLUSIONS

Perineural invasion status can be used to facilitate the selection of colorectal cancer patients for adjuvant chemotherapy and should be described in routine pathology reports.

Cell adhesion system and human cancer morphogenesis

Cell-cell adhesion determines the polarity of cells and participates in the maintenance of the cell societies called tissues. Cell-cell adhesiveness is generally reduced in human cancers. Reduced intercellular adhesiveness allows cancer cells to disobey the social order, resulting in destruction of histological structure, which is the morphological hallmark of malignant tumors. Reduced intercellular adhesiveness is also indispensable for cancer invasion and metastasis. A tumor-suppressor gene product, E-cadherin, and its undercoat proteins, catenins, which connect cadherins to actin filaments, are located at lateral borders, concentrating on adherens junctions, of epithelial cells and establish firm cell-cell adhesion. The E-cadherin cell adhesion system in cancer cells is inactivated by various mechanisms that reflect the morphological and biological characteristics of the tumor. Silencing of the E-cadherin gene by DNA hypermethylation around the promoter region occurs frequently, even in precancerous conditions. In diffuse infiltrating cancers, mutations are found in the genes for E-cadherin and alpha- and beta-catenins. At the invading front of cancers, the E-cadherin cell adhesion system is inactivated by tyrosine phosphorylation of beta-catenin; an oncogene product, c-erbB-2 protein, is found to associate directly with beta-catenin. The E-cadherin cell adhesion system cross-talks with the Wingless/Wnt signaling pathway through beta-catenin, and expression of genes, which participate in cancer morphogenesis, may be regulated in conjunction with the Wingless/Wnt signaling pathway. Dysadherin, a newly identified cancer-associated cell membrane glycoprotein, down-regulates E-cadherin and promotes cancer metastasis. In conclusion, inactivation of the E-cadherin cell adhesion system by both genetic and epigenetic mechanisms plays a significant role during multistage human carcinogenesis.

Less aggressive features of colorectal cancer with liver metastases showing macroscopic intrabiliary extension

We have previously reported the frequent occurrence of bile duct invasion by liver metastases from colorectal cancer. We found that patients with macroscopic intrabiliary cancer growth survive longer after hepatectomy than those without this feature. In the present study, we analyzed the clinicopathological features of primary colorectal cancer showing macroscopic intrabiliary extension of liver metastases. We reviewed 217 patients who underwent initial hepatic resection for colorectal liver metastasis between 1992 and 1998, and analyzed the corresponding primary colorectal cancers clinicopathologically. Microscopic bile duct invasion was found in 89 of 217 cases (40.6%) and, of these cases, 23 (10.6%) had macroscopic intrabiliary extension. Histological sections of the corresponding primary colorectal cancer were available in eight (group A) of these 23 cases. These were compared with 20 cases, selected randomly, of colorectal cancer that did not show bile duct invasion and were diagnosed as liver metastases. These patients underwent hepatectomy during the same period as group A and were used as a control (group B). The histology of the primary tumors revealed well-differentiated adenocarcinoma in 100% of group A and in 25% of group B. The average maximum diameter of the primary tumor was 5.32 cm in group A and 3.61 cm in group B. Venous invasion was detected in 25% of group A and in 90% of group B (P < 0.01), while the incidences of lymphatic vessel invasion and lymph node metastases were similar between the groups. These data suggest that macroscopic intrabiliary extension could be a good indicator of a unique subgroup of colorectal cancers showing less aggressive features even though they develop liver metastases. Careful histological evaluation is important even for metastatic tumors.

Clinicopathological significance of tumor nest configuration in patients with esophageal squamous cell carcinoma

BACKGROUND

Cancer-stromal interactions are an important mediator of cancer invasion and metastasis.

METHODS

The authors investigated the clinicopathological significance of tumor nest configuration and the surrounding stroma in 159 patients with advanced esophageal squamous cell carcinoma (ESCC). The tumors were classified microscopically into two types. Type A tumors had oval-shaped or sheet-like tumor nests (with > 80% of the tumor area showing these features). Type B tumors had asteroid-shaped or scattered small tumor nests (with > 20% of the tumor area showing these features).

RESULTS

Of the 159 tumors examined, 38 (24%) were type A and 121 (76%) were type B. Type B tumors had a significantly deeper invasion depth, more frequent lymphatic permeation and lymph node metastasis, more prominent active fibroblastic stroma, and less frequent inflammatory cell infiltration (P < 0.05). Both univariate (P < 0.05) and multivariate (P < 0.05) analysis of the patients' survival showed that the prognosis for patients with type B tumors was significantly worse than for patients with type A tumors.

CONCLUSIONS

This study showed that tumor nest configuration, which corresponded to the behavior of tumor cells against stromal cells, correlated well with the aggressiveness of the tumor.

Tumor thickness is a histopathologic predictive parameter of tumor metastasis and prognosis in patients with Dukes stage C ulcerative-type colorectal carcinoma. A two-hospital-based study

BACKGROUND

Metastasis to the liver or lymph nodes is an important prognostic factor in patients with colorectal carcinoma. The purpose of the current study was to estimate the power of tumor thickness in predicting metachronous liver metastasis (MLM), lymph node metastasis (LNM), or overall survival (OS) in patients at two hospitals (the National Cancer Center Hospital [NCCH] and the National Cancer Center Hospital East [NCCHE]) to confirm the reproducibility of the study.

METHODS

The subjects of this study were 74 and 186 consecutive patients with ulcerative-type colorectal carcinoma treated at the NCCH and NCCHE, respectively. Tumor thickness was measured in three areas: 1) the marginal elevated area (MEA), 2) the central depressed area (CDA), and 3) the most thickened area (MTA). Studies were performed with well known histologic parameters to compare the predictive power of tumor thickness on MLM, LNM, and OS using the Cox proportional hazards regression model or analysis of variance.

RESULTS

A significant correlation between tumor thickness and MLM was observed only in the CDA in the NCCH patients (P = 0.005). The authors applied a tumor thickness cutoff value in the CDA of 10 mm (</= 10 mm and > 10 mm) for further study. Multivariate analyses demonstrated that a tumor CDA thickness > 10 mm was associated significantly with MLM, multiple LNMs, and OS in NCCH patients with Dukes Stage C disease (P = 0.002, P = 0.023, and P = 0.002, respectively). A significant predictive power for tumor CDA thickness for MLM, multiple LNMs, and OS was confirmed by multivariate analysis in NCCHE patients with Dukes Stage C disease (P = 0.008, P = 0.021, and P = 0.010, respectively).

CONCLUSIONS

The CDA thickness of the tumor was found to be a useful predictive parameter for MLM, multiple LNMs, and OS in patients with Dukes Stage C ulcerative-type colorectal carcinoma who were being treated in two independent hospitals.

Inactivation of the E-cadherin-mediated cell adhesion system in human cancers

It has long been known that cell-cell adhesiveness is generally reduced in human cancers. Tumor cells are dissociated throughout the entire tumor masses of diffuse-type cancers, whereas those of solid tumors with high metastatic potentials are often focally dissociated or dedifferentiated at the invading fronts. Thus, both irreversible and reversible mechanisms for inactivating the cell adhesion system appear to exist. This paper focuses on the cadherin system, which mediates Ca2+-dependent homophilic cell-cell adhesion. The E (epithelial)-cadherin-mediated cell adhesion system in cancer cells is inactivated by multiple mechanisms corresponding to the pathological features described above. Mutations have been found in the genes for E-cadherin and its undercoat proteins, alpha- and beta-catenins, which connect cadherins to actin filaments and establish firm cell-cell adhesion. Transcriptional inactivation of E-cadherin expression was shown to occur frequently in tumor progression. E-cadherin expression in human cancer cells is regulated by CpG methylation around the promoter region. The cadherin system interacts directly with products of oncogenes, eg, cerbB-2 protein and the epidermal growth factor receptor, and of the tumor suppressor gene, adenomatous polyposis coli (APC) protein, through beta-catenin, which may be important in signal transduction pathways contributing to the determination of the biological properties of human cancers. In conclusion, inactivation of the E-cadherin system by multiple mechanisms, including both genetic and epigenetic events, plays a significant role in multistage carcinogenesis.