Venous invasion detectable only by elastic stain shows weak prognostic value in colon cancer

AIMS

Large venous invasion (VI) is prognostically significant in colon cancer. The increased use of elastic stains by pathologists results in higher VI detection rates compared to routine stains alone. This study assesses the prognostic value of VI detected by elastic versus routine stains.

METHODS AND RESULTS

Colon cancers resected between 2014 and 2017 underwent pathology slide review for VI. Cases without VI on routine stain were stained by elastic trichrome and re-examined. Demographic, clinical, pathological and outcome data were gathered by retrospective review. Kaplan-Meier curves with log-rank tests were performed for survival categorised by VI status. Cox regression was performed for multivariate analysis. Of 277 cases, 97 (35%) showed VI by routine stain alone, with an additional 58 (21%) discovered by subsequent elastic stains. Thus, elastic trichrome increased VI detection by 60%. However, only VI detected by routine stain showed worse overall survival (P < 0.001). VI detected by elastic stain only was not prognostically different from cases without VI (P = 0.428). For stage 2 cancers, VI was not prognostically significant regardless of method of detection. For stage 3 cases, only VI detected by routine stain was prognostic for overall survival (P = 0.002) with a hazard ratio of 4.04 by multivariate regression (P = 0.028).

CONCLUSIONS

VI detectable only by elastic stains do not show prognostic significance for survival in colon cancer. For pathologists with high baseline VI detections rates on routine stain, reflexive use of elastic stain may be of limited value.

Response to Marabotto et al

Biopsies have important value in assessing for nonerosive reflux disease.

The role of histology in the diagnosis of non-erosive reflux disease: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Non-erosive reflux disease (NERD) accounts for over half of all gastroesophageal reflux cases and is characterized by reflux symptoms with pathologic acid exposure on pH monitoring but no evidence of erosions on upper endoscopy. Ambulatory pH monitoring is limited by availability and patient tolerance. The utility of performing esophageal mucosal biopsies in diagnosing NERD is unclear. We conducted a systematic review and meta-analysis to determine the sensitivity of esophageal mucosal biopsies in diagnosing NERD.

METHODS

Data were obtained from Embase and Ovid MEDLINE from inception to April 2021. Studies were included if esophageal mucosal biopsies were taken and analyzed using conventional histopathologic analysis in symptomatic NERD patients. Relevant data was including histologic abnormalities and location of the biopsy. Sensitivity and specificity were calculated against healthy controls or those with functional heartburn.

RESULTS

The search yielded 2871 studies, of which 10 studies met our inclusion criteria and contained raw data. Histological abnormalities included histologic sum scores, papillary elongation, basal cell hyperplasia, and dilated intraepithelial spaces. When assessing for the presence of any abnormality, biopsies taken <3 cm from the lower esophageal sphincter (LES) had a pooled sensitivity of 0.71 (95% CI 0.64-0.77) and specificity of 0.64 (95% 0.54-0.73); however, analysis of individual histologic features such as the presence of eosinophils improved the sensitivity.

CONCLUSIONS

Although esophageal mucosal biopsies had poor sensitivity at diagnosing NERD, biopsies taken within 3 cm of the LES had higher sensitivity when pathologists reported upon eosinophils and dilated intraepithelial spaces.

Feasibility and Performance of Elastin Trichrome as a Primary Stain in Colorectal Cancer Resection Specimens: Results of an Interobserver Variability Study

Venous invasion (VI) is a powerful prognostic factor in colorectal cancer (CRC) that is widely underreported. The ability of elastin stains to improve VI detection is now recognized in several international CRC pathology protocols. However, concerns related to the cost and time required to perform and evaluate these stains in addition to routine hematoxylin and eosin (H&E) stains remains a barrier to their wider use. We therefore sought to determine whether an elastin trichrome (ET) stain could be used as a "stand-alone" stain in CRC resections, by comparing the sensitivity, accuracy, and reproducibility of detection of CAP-mandated prognostic factors using ET and H&E stains. Representative H&E- and ET-stained slides from 50 CRC resections, including a representative mix of stages and prognostic factors, were used to generate 2 study sets. Each case was represented by H&E slides in 1 study set and by corresponding ET slides from the same blocks in the other study set. Ten observers (3 academic gastrointestinal [GI] pathologists, 4 community pathologists, 3 fellows) evaluated each study set for CAP-mandated prognostic factors. ET outperformed H&E in the assessment of VI with respect to detection rates (50% vs. 28.6%; P<0.0001), accuracy (82% vs. 59%, P<0.0001), and reproducibility (k=0.554 vs. 0.394). No significant differences between ET and H&E were observed for other features evaluated. In a poststudy survey, most observers considered the ease and speed of assessment at least equivalent for ET and H&E for most prognostic factors, and felt that ET would be feasible as a stand-alone stain in practice. If validated by others, our findings support the use of ET, rather than H&E, as the primary stain for the evaluation of CRC resections.

Prognostic and Predictive Value of Tumor Budding in Colorectal Cancer

BACKGROUND

Tumor budding (TB) is an adverse prognostic factor in colorectal cancer (CRC). International consensus on a standardized assessment method has led to its wider reporting. However, uncertainty regarding its clinical value persists. This study aimed to (1) confirm the prognostic significance of TB, particularly in stage II CRC; (2) to determine optimum thresholds for TB risk grouping; and (3) to determine whether TB influences responsiveness to chemotherapy.

METHODS

TB was assessed in CRC sections from 1575 QUASAR trial patients randomized between adjuvant chemotherapy and observation. Optimal risk group cutoffs were determined by maximum likelihood methods, with their influence on recurrence and mortality investigated in stratified log-rank analyses on exploratory (n = 504), hypothesis-testing (n = 478), and final (n = 593) data sets.

RESULTS

The optimal threshold for high-grade TB (HGTB) was ≥ 10 buds per 1.23 mm². High-grade TB tumors had significantly worse outcomes than those with lower TB: 10-year recurrence 36% versus 22% (risk ratio, 2.00 [95% CI, 1.62-2.45]; 2P < .0001) and 10-year mortality 50% vs. 37% (risk ratio, 1.53 [95% CI, 1.34-1.76]; 2P < .0001). The prognostic significance remained equally strong after allowance for other pathological risk factors, including stage, grade, lymphovascular invasion, and mismatch repair status. There was a nonsignificant trend toward increasing chemotherapy efficacy with increasing bud counts.

CONCLUSIONS

TB is a strong independent predictor of recurrence. Chemotherapy efficacy is comparable in patients with higher and lower TB; hence, absolute reductions in recurrence and death with chemotherapy should be about twice as large in patients with ≥ 10 than < 10 TB counts.

Canadian Consensus for Biomarker Testing and Treatment of TRK Fusion Cancer in Adults

The tyrosine receptor kinase (TRK) inhibitors larotrectinib and entrectinib were recently approved in Canada for the treatment of solid tumours harbouring neurotrophic tyrosine receptor kinase (NTRK) gene fusions. These NTRK gene fusions are oncogenic drivers found in most tumour types at a low frequency (<5%), and at a higher frequency (>80%) in a small number of rare tumours (e.g., secretory carcinoma of the salivary gland and of the breast). They are generally mutually exclusive of other common oncogenic drivers. Larotrectinib and entrectinib have demonstrated impressive overall response rates and tolerability in Phase I/II trials in patients with TRK fusion cancer with no other effective treatment options. Given the low frequency of TRK fusion cancer and the heterogeneous molecular testing landscape in Canada, identifying and optimally managing such patients represents a new challenge. We provide a Canadian consensus on when and how to test for NTRK gene fusions and when to consider treatment with a TRK inhibitor. We focus on five tumour types: thyroid carcinoma, colorectal carcinoma, non-small cell lung carcinoma, soft tissue sarcoma, and salivary gland carcinoma. Based on the probability of the tumour harbouring an NTRK gene fusion, we also suggest a tumour-agnostic consensus for NTRK gene fusion testing and treatment. We recommend considering a TRK inhibitor in all patients with TRK fusion cancer with no other effective treatment options.

Hot avulsion may be effective as salvage treatment for focal Barrett's esophagus remaining after endoscopic therapy for dysplasia or early cancer: a preliminary study

BACKGROUND AND STUDY AIM

Both endoscopic mucosal resection (EMR) and radiofrequency ablation (RFA) are used to treat Barrett's esophagus (BE) complicated by dysplasia and intramucosal cancer. However, focal areas of BE can remain after otherwise successful application of these techniques. We report the results of hot avulsion using a hot biopsy forceps to resect these residual focal areas.

PATIENTS AND METHODS

This was a retrospective study from a prospective database in a tertiary reference center from August 2013 to May 2015. All included patients had undergone hot avulsion for eradication of residual focal areas of BE that were ≤ 1 cm and not suspicious for dysplasia, following at least one previous endoscopic treatment for dysplasia or intramucosal cancer.

RESULTS

35 patients harboring 124 residual areas of 1 - 7 mm were treated with hot avulsion. After a mean follow-up of 17.4 months, all patients achieved complete eradication of residual focal BE. One of the patients required a second hot avulsion treatment. Hot avulsion provided samples in all cases but limited the assessment of dysplasia (cautery artifact) in 20.2 % of them. The only complication was bleeding in two patients, which was easily stopped by soft coagulation.

CONCLUSIONS

Hot avulsion appears to be effective and safe in removing focal BE ≤ 1 cm at its greatest length remaining after endoscopic treatment for dysplasia or early cancer. Further studies are required before this technique can be considered the standard of care.

Cytokeratin-based assessment of tumour budding in colorectal cancer: analysis in stage II patients and prospective diagnostic experience

Tumour budding in colorectal cancer is an important prognostic factor. A recent consensus conference elaborated recommendations and key issues for future studies, among those the use of pan‐cytokeratin stains, especially in stage II patients. We report the first prospective diagnostic experience using pan‐cytokeratin for tumour budding assessment. Moreover, we evaluate tumour budding using pan‐cytokeratin stains and disease‐free survival (DFS) in stage II patients. To this end, tumour budding on pan‐cytokeratin‐stained sections was evaluated by counting the number of tumour buds in 10 high‐power fields (0.238 mm²), then categorizing counts as low/high‐grade at a cut‐off of 10 buds, in two cohorts. Cohort 1: prospective setting with 236 unselected primary resected colorectal cancers analysed by 17 pathologists during diagnostic routine. Cohort 2: retrospective cohort of 150 stage II patients with information on DFS. In prospective analysis of cohort 1, tumour budding counts correlated with advanced pT, lymph node metastasis, lymphovascular invasion, perineural invasion (all p < 0.0001), and distant metastasis (p = 0.0128). In cohort 2, tumour budding was an independent predictor of worse DFS using counts [p = 0.037, HR (95% CI): 1.007 (1.0–1.014)] and the low‐grade/high‐grade scoring approach [p = 0.02; HR (95% CI): 3.04 (1.2–7.77), 90.7 versus 73%, respectively]. In conclusion, tumour budding assessed on pan‐cytokeratin slides is feasible in a large pathology institute and leads to expected associations with clinicopathological features. Additionally, it is an independent predictor of poor prognosis in stage II patients and should be considered for risk stratification in future clinical studies.

HtrA3 stromal expression is correlated with tumor budding in stage II colorectal cancer

Tumor budding is a well-established adverse prognostic factor in colorectal carcinoma (CRC). It may represent a form of epithelial-to-mesenchymal transition (EMT), although the underlying mechanisms remain unclear. High-temperature requirement A3 (HtrA3) is an inhibitor of the bone morphogenetic protein pathway, the suppression of which has been linked to EMT. Since HtrA3 is highly expressed in the desmoplastic stroma at the CRC invasive front, we sought to evaluate the relationship between tumor budding and HtrA3 expression in 172 stage II CRC resection specimens. All tumors were evaluated for tumor budding, with the highest budding slide selected for pan-keratin (CK) and HtrA3 immunohistochemistry. Representative areas of tumor core and invasive front, including budding and non-budding areas, were marked on CK stained slides, and then evaluated on HtrA3 stained slides. HtrA3 expression in tumor cells (tHtrA3) and peritumoral stroma (sHtrA3) was assessed for staining percentage and intensity (the product yielding a final score). Tumors with high-grade tumor budding (HGTB) showed increased expression of sHtrA3 in budding areas compared to non-budding areas at the invasive front (P<0.001). In addition, sHtrA3 expression at the invasive front was significantly higher in HGTB tumors compared to minimally budding tumors (P<0.05). tHtrA3 expression at the invasive front was significantly associated with high histological grade (P<0.05). Higher sHtrA3 expression in the tumor core (but not invasive front) was significantly associated with decreased 5-year overall survival on univariate analysis (P<0.05), but not multivariate analysis. HtrA3 expression in the peritumoral stroma of patients with stage II CRC is associated with HGTB and may be a novel marker of poor outcome.

Gastric foveolar dysplasia: a survey of reporting habits and diagnostic criteria

This study aimed to ascertain views, incidence of reporting and diagnostic criteria for gastric foveolar dysplasia. A questionnaire, a post-questionnaire discussion and microscopic assessment of selected cases was conducted by gastrointestinal pathologists to explore the above-stated aims. Fifty-four percent of respondents never or rarely diagnosed gastric foveolar-type dysplasia. The general consensus was that round nuclei, lack of nuclear stratification, presence of inflammation/damage and surface maturation favoured reactive change; while architectural abnormalities/complexity and nuclear enlargement mainly were used to separate low-grade from high-grade foveolar dysplasia. Immunohistochemistry was rarely used to make the diagnosis of dysplasia and was thought not to be of help in routine practice. Inter-observer agreement in grading of dysplasia versus reactive, and the type of dysplasia (foveolar versus adenomatous), was substantial/almost perfect amongst 35.7% and 21.4% of participants, respectively. This reflects low reproducibility in making these diagnoses. In conclusion, foveolar dysplasia was a rarely made diagnosis among 14 gastrointestinal pathologists, there are no uniform criteria for diagnosis and there is poor inter-observer agreement in separating low-grade foveolar dysplasia from reactive gastric mucosa and low-grade adenomatous dysplasia. Greater awareness and agreed criteria will prevent misdiagnosis of low-grade foveolar dysplasia as reactive, and vice versa.

HER2 Genetic Heterogeneity in Gastric Cancer: Evaluation According to the College of American Pathologists Breast Cancer Criteria

Gastric and gastroesophageal junction (GEJ) adenocarcinomas have been shown to display significant HER2 genetic heterogeneity (GH). This is typically seen as a cluster of HER2-positive cells but can also take the form of intermingled cells, referred to a "mosaic" pattern. GH is not well defined in gastric/GEJ tumors and the "mosaic" pattern has never been studied. We sought to evaluate the frequency and distribution of the "mosaic" pattern of GH in gastric/GEJ tumors using the College of American Pathologists-endorsed breast criteria of 5% to <50% amplified nuclei. We also postulated that the lower limit of this GH definition might be seen by chance in normal gastric epithelium. A total of 360 consecutive gastric/GEJ tumors were tested for HER2 by immunohistochemistry and in situ hybridization. Individual tumor cell HER2:CEP17 ratios were calculated for each case and the percentage of tumor cells with a ratio ≥2.0 determined. In addition, 300 normal gastric epithelial cells were scored for HER2 and CEP17 signals. Overall, 265 cases (73.4%) showed GH. The percentage of amplified cells in GH cases linearly correlated with the overall HER2:CEP17 ratio. In normal gastric epithelium, a cell with an "amplified" 2:1 ratio was seen in 9.7% (29/300) of cells, thus reaching GH. The chance of "GH" in scoring 20 normal epithelial cells was 87%. We conclude that GH is very common in gastric/GEJ tumors when College of American Pathologists breast criteria are applied and the lower threshold is likely of little clinical significance due to the finding "amplified" 2:1 nuclei in normal cells.

Neuroendocrine tumors of the luminal gastrointestinal tract

CONTEXT

Neuroendocrine tumors (NETs) of the gastrointestinal tract have been recognized for more than a century. Despite histologic similarities between different sites in the tract, behavior varies between areas. All of these tumors have malignant potential, but determination of exact risk is difficult.

OBJECTIVES

To review the diagnosis of luminal gastrointestinal NETs, including a discussion of grading. Grading by mitotic index/activity, in conjunction with tumor size/stage, has been found to be the strongest predictor of behavior.

DATA SOURCES

Literature review of luminal gastrointestinal NETs was performed and the results summarized.

CONCLUSIONS

Our understanding of these lesions is incomplete and continues to evolve.

Esophagitis: Old Histologic Concepts and New Thoughts

Context

Inflammatory lesions of the esophagus are a diverse group, often with nonspecific histologic findings. These benign changes can produce diagnostic difficulties for pathologists.

Objective

To discuss the typical histologic findings of a variety of the most common causes of esophagitis (reflux, eosinophilic esophagitis, infections, medications) along with less common issues such as sloughing esophagitis and skin disorders involving the squamous mucosa.

Data Sources

The literature has been reviewed to discuss histologic definitions of current and developing issues in the area of esophagitis.

Conclusions

Histologic features are not entirely sensitive and specific for inflammatory esophageal disorders. Awareness of these problems is essential; clinical and endoscopic information can be very useful in distinguishing among the various lesions.

Evaluation of human tissue kallikrein-related peptidases 6 and 10 expression in early gastroesophageal adenocarcinoma

Kallikreins are a family of serine proteases that are linked to malignancy of different body organs with potential clinical utility as tumor markers. In this study, we investigated kallikrein-related peptidase 6 (KLK6) and KLK10 expression in early gastroesophageal junction adenocarcinoma and Barrett esophagus (BE) with and without dysplasia. Immunohistochemistry revealed significantly increased KLK6 expression in early invasive cancer compared with dysplastic (P = .009) and nondysplastic BE (P = .0002). There was a stepwise expression increase from metaplasia to dysplasia and invasive tumors. Significantly higher KLK10 was seen in dysplastic lesions compared with metaplasia but not between dysplastic lesions and invasive cancers. KLK6 staining intensity was increased at the invasive front (P = .006), suggesting its role in tumor invasiveness. Neither KLK6 nor KLK10 was significantly associated with other prognostic markers, including depth of invasion, indicating their potential as independent biomarkers. Our results should be interpreted with caution due to limited sample size. There was a significant correlation between KLK6 and KLK10 expression both at the invasive front and within the main tumor, indicating a collaborative effect. We then compared KLK6 and KLK10 messenger RNA expression between metaplastic and cancerous tissues in an independent data set of esophageal carcinoma from The Cancer Genome Atlas. KLK6 and KLK10 may be useful markers and potential therapeutic targets in gastroesophageal junction tumors.

Expression patterns of bone morphogenetic protein antagonists in colorectal cancer desmoplastic invasion fronts

Bone morphogenetic proteins (BMPs) are a group of growth factors with dual functions in cancer development and progression. Recently, certain tumor-promoting roles have been identified for selected antagonists/inhibitors (BMPIs) of this developmental pathway. A recent focus on the implication of BMP in colorectal cancer progression has emerged, mainly due to the presence of inactivating mutations in several members of the canonical signaling cascade. However, the detailed expression profiles of BMPIs remain largely unknown. Based on our previous work, whereby three specific BMPIs, gremlin-1 (GREM1), high-temperature requirement A3 (HTRA3) and follistatin (FST) were collectively overexpressed in desmoplastic cocultures of colorectal cancer (CRC), here, we undertook an immunohistochemical approach to describe the patterns of their expression in CRC patients. Two major characteristics described the BMPI expression signature: First, the synchronous and coordinated stromal and epithelial overexpression of individual BMPIs in desmoplastic lesions, which demonstrated that all three of them contribute to increasing levels of BMP antagonism in such areas. Second, the presence of microenvironmental polarity in the BMPI pattern of expression, which was indicated through the preferential expression of HTRA3 in the stromal, and the parallel FST/GREM1 expression in the epithelial component of the investigated sections. In addition, expression of HTRA3 in the epithelial compartment of the tumors demonstrated a significant predictive power to discriminate between tumor-budding-bearing and tumor-budding-free desmoplastic microenvironments. Together, these findings contribute to the understanding of signaling dynamics of BMP antagonism in the colorectal cancer desmoplastic invasion front.

Histopathology in barrett esophagus and barrett esophagus-related dysplasia

Pathologic specimens, both biopsies and endoscopic mucosal resections, for Barrett esophagus and Barrett-associated dysplasia and malignancy are common for pathologists in North America, and the incidence in South Asian countries seems to be increasing. Dysplasia and malignancy arising in intestinalized gastric-type mucosa raises issues in the interpretation of dysplasia and the evaluation of the depth of invasion of malignancies that are not seen in squamous dysplasia and squamous cell carcinoma. We review the North American approach to these lesions.

Correlation of peripheral blood lymphocyte counts with outcome and histopathologic features of lymphocytic inflammation in patients with stage II colorectal carcinoma

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Background: The prognostic importance of the local antitumor immune response in colorectal carcinoma (CRC) is well established. Recent studies suggest that systemic antitumor immunity may also impact on survival. This study aimed to determine the relationship between peripheral blood lymphocyte counts (PBLCs), reactive features in regional lymph nodes, local tumoral/peri-tumoral lymphocytic inflammation and survival in stage II CRC. Methods: Resection specimens from 185 patients with stage II CRC were assessed for peri-tumoral lymphocytic inflammation, tumor-infiltrating lymphocytes, lymph node yield, lymph node size, and reactive changes in individual lymph nodes. Reactive changes were scored semi-quantitatively and given a reactivity [R] score of 1-4 based on the presence and size of germinal centers. Pre-operative PBLCs and neutrophil counts were recorded. Results: Lower peripheral lymphocyte counts were associated with advanced age (p = 0.016), T4 disease (p = 0.006), venous invasion (p = 0.006), lymph node yields <12 (p = 0.024), smaller mean nodal diameters (p = 0.021), absence of tumor-infiltrating lymphocytes (p = 0.002) and fewer highly-reactive lymph nodes (R score 4) per case (p = 0.032). Cox regression analysis revealed that advanced age (Hazard Ratio, 1.03 per year [95% confidence interval, 1.01-1.05]; p = 0.015) and higher peripheral lymphocyte counts (HR, 0.52 per 1x109cells/L [95% CI, 0.31-0.86]; p = 0.011) were independently predictive of disease-free survival. Neutrophil counts were not associated with outcome. A higher neutrophil to lymphocyte ratio was associated with worse survival on univariate, but not multivariable analysis. Conclusions: The PBLC is an independent predictor of survival in stage II CRC, and is significantly associated with the immune status of regional lymph nodes and the local lymphocytic immune response.

Matched biopsy and resection specimens of gastric and gastroesophageal adenocarcinoma show high concordance in HER2 status

In advanced gastric and gastroesophageal junction (GEJ) adenocarcinomas that overexpress human epidermal growth factor receptor 2 (HER2), treatment with trastuzumab confers a survival benefit. To select patients for treatment, HER2 status is evaluated by immunohistochemistry (IHC) and in situ hybridization. Gastric and GEJ adenocarcinomas demonstrate heterogeneity in HER2 expression. Nonetheless, testing is often performed on biopsies alone, which raises the issue of nonrepresentative sampling. We investigated the correlation of HER2 status between matched biopsy and resection specimens and the role of tumor heterogeneity in contributing to discrepancy. A total of 128 patients with gastric or GEJ adenocarcinoma had tissue available from a biopsy and subsequent resection. HER2 IHC was performed and evaluated by the criteria used in the Trastuzumab for Gastric Cancer clinical trial. In situ hybridization was performed if IHC was equivocal (2+) in either the biopsy or resection and in discrepant cases. Tumor heterogeneity was defined as 3+ or 2+ staining in 10% to 60% of tumor cells. Overall, HER2 was overexpressed in 18 tumors (14%), with a biopsy-resection concordance of 96.1%. Five cases were discrepant; 2 were positive on biopsy only, and 3 were positive on resection only. Tumor heterogeneity was seen in 80% of discrepant biopsies and resections, compared with 24% of concordant cases (P = .016). Our study demonstrates strong concordance between biopsy and resection specimens for HER2 overexpression in gastric cancer. Discordance was correlated with tumor heterogeneity. Overall, both biopsy and resection specimens are appropriate for HER2 testing, but generous sampling for biopsy specimens is necessary to ensure accurate assessment.

Collective migration of cancer-associated fibroblasts is enhanced by overexpression of tight junction-associated proteins claudin-11 and occludin

It has been suggested that cancer-associated fibroblasts (CAFs) positioned at the desmoplastic areas of various types of cancer are capable of executing a migratory program, characterized by accelerated motility and collective configuration. Since CAFs are reprogrammed derivatives of normal progenitors, including quiescent fibroblasts, we hypothesized that such migratory program could be context-dependent, thus being regulated by specific paracrine signals from the adjacent cancer population. Using the traditional scratch assay setup, we showed that only specific colon cancer cell lines (i.e. HT29) were able to induce collective CAF migration. By performing quantitative proteomics (SILAC), we identified a 2.7-fold increase of claudin-11, a member of the tight junction apparatus, in CAFs that exerted such collectivity in their migratory pattern. Further proteomic investigations of cancer cell line secretomes revealed a specific signature, involving TGF-β, as potential mediator of this effect. Normal colonic fibroblasts stimulated with TGF-β exerted myofibroblastic differentiation, occludin (OCLN) and claudin-11 (CLDN11) overexpression and cohort formation. Subsequently, inhibition of TGF-β attenuated all the previous effects. Immunohistochemistry of the universal tight junction marker occludin in a cohort of 30 colorectal adenocarcinoma patients defined a CAF subpopulation expressing tight junctions. Overall, these data suggest that cancer cells may induce CLDN11 overexpression and subsequent collective migration of peritumoral CAFs via TGF-β secretion.

Peritoneal elastic lamina invasion: limitations in its use as a prognostic marker in stage II colorectal cancer

Peritoneal involvement in colorectal cancer (CRC) is an adverse prognostic feature, which may prompt consideration of adjuvant chemotherapy in stage II disease. Controversies and challenges surrounding its assessment have led to consideration of peritoneal elastic lamina invasion (ELI) as an alternative marker of advanced local spread. The objectives of this study were (1) to evaluate the prognostic significance of peritoneal ELI in stage II CRC and (2) to determine the feasibility of ELI assessment in routine practice with the use of an elastic stain. Two hundred seventeen patients with stage II CRC (186, pT3; 31, pT4) were assessed for ELI and other established adverse histologic features. Of the pT3 tumors, 31 (16.7%) were ELI positive, 121 (65%) were ELI negative, and 34 (18.3%) lacked an identifiable elastic lamina. There were no significant differences in disease-free survival between pT3 ELI-negative and ELI-positive tumors (P = .517). The disease-free survival of pT4 tumors was significantly lower than that of pT3 ELI-negative tumors (P = .024) and pT3 ELI-positive tumors (P = .026), respectively. The elastic lamina was detected less frequently in right-sided pT3 tumors compared with left-sided tumors (65/91 [71.4%] versus 87/95 [91.6%], P < .001). Right-sided tumors were also associated with a reduction in the staining intensity of the elastic lamina (P < .001). In conclusion, peritoneal ELI was not an adverse prognostic factor in this study. The frequent absence of an identifiable elastic lamina, particularly in right-sided tumors, may limit the use of ELI as a prognostic marker in CRC.

A role for mucosal IL-22 production and Th22 cells in HIV-associated mucosal immunopathogenesis

Interleukin-22 (IL-22) is a cytokine with epithelial reparative and regenerative properties that is produced by Th22 cells and by other immune cell subsets. Therefore, we explored the hypothesis that disruption of the gut barrier during HIV infection involves dysregulation of these cells in the gastrointestinal mucosa. Sigmoid IL-22-producing T cell and Th22 cells were dramatically depleted during chronic HIV infection, epithelial integrity was compromised, and microbial translocation was increased. These alterations were reversed after long-term antiretroviral therapy. While all mucosal IL-22-producing T-cell subsets were also depleted very early during HIV infection, at these early stages IL-22 production by non-T-cell populations (including NKp44+ cells) was increased and gut epithelial integrity was maintained. Circulating Th22 cells expressed a higher level of the HIV co-receptor/binding molecules CCR5 and α4β7 than CD4+ T-cell subsets in HIV-uninfected participants, but this was not the case after HIV infection. Finally, recombinant IL-22 was protective against HIV and tumor necrosis factor-α-induced gut epithelial damage in a validated in vitro gut epithelial system. We conclude that reduced IL-22 production and Th22 depletion in the gut mucosa are important factors in HIV mucosal immunopathogenesis.

Intestinal metaplasia and the risk of gastric cancer in an immigrant asian population

The development of intestinal metaplasia (IM) has been purported to be a critical step in the pathogenesis of gastric cancer. However, the natural history of IM in migrant human populations has not been well elucidated. The purpose of this study was to determine the risk of gastric cancer posed by IM in Asian immigrants undergoing gastric cancer screening. A retrospective review of Asian immigrants found to have IM during screening was conducted over an 18-month period. In total, 222 patients were found to have IM. Altogether, 24% had a history of smoking, 48% had a family history of gastric cancer, and 52% had a history of Helicobacter pylori (H. pylori) infection with a 96% eradication rate. Patients with stable IM (SIM) were then compared with those who developed high risk pathology (HRP), specifically dysplasia and/or adenocarcinoma. Thirty-five patients (16%) were included in the HRP group, 31 with dysplasia (14%) and 4 with adenocarcinoma (2%). Of those with dysplasia, 55% demonstrated regression to IM over the course of follow-up. Patients in the SIM group were more likely to be female (60% vs. 31%, P = 0.002) and more likely to have had a normal biopsy during follow-up (32% vs. 9%, P = 0.005). Odds ratios for IM stability were 3.3 (95% CI 1.5-7.0) and 5.0 (95% CI 1.5-17.1) for female gender and presence of a normal biopsy, respectively. Intestinal metaplasia in immigrant Asian populations is predominantly a stable histologic finding associated with a low rate of persistent dysplasia and adenocarcinoma.

Mantle cell lymphoma as a rare cause of intussusception: a report of 2 cases

Intussusception is uncommon in adults and is only very rarely caused by malignant lymphoma. To our knowledge, there are only 2 previously reported cases of mantle cell lymphoma causing intussusception. We present 2 additional cases of intussusception at the ileocecal valve in patients being treated for mantle cell lymphoma, and a review of the pertinent literature is presented.

Measuring extent of ductal carcinoma in situ in breast excision specimens: a comparison of 4 methods

CONTEXT

Measuring the extent of nonpalpable ductal carcinoma in situ (DCIS) in a breast specimen is challenging but important because it influences patient management. There is no standardized method for estimating the extent of DCIS, although serial sequential sampling with mammographic correlation is considered an accurate method.

OBJECTIVE

To estimate the extent of DCIS using various methods and to compare these estimations with the extent as determined by the serial sequential sampling method.

DESIGN

A total of 78 primary breast excisions with DCIS were retrospectively reviewed. All specimens had been sampled using the serial sequential sampling method, which involved mapping the location of each block on the sliced specimen radiograph and calculating the extent through 3-dimensional reconstruction. The other measures for estimating extent included (1) calculating size based on areas of calcification, (2) recording the number of blocks involved by DCIS and multiplying that number by 0.3 cm, and (3) measuring the largest extent of DCIS on a single slide.

RESULTS

All 3 alternative methods tended to underestimate the DCIS. Discrepancies became more pronounced as size increased. The percentage of cases estimated to within 1 cm of the serial sequential sampling method were 81%, 72%, and 50%, respectively, for the calcification, blocks, and single-slide methods; differences of more than 2 cm were seen in 9%, 8%, and 30% of cases, respectively.

CONCLUSIONS

The single-slide method performed poorly and should be used only when DCIS is limited to a single slide. Although the calcification and the blocks methods gave better estimates, both produced substantial underestimates and/or overestimates that could affect clinical decision making.

Falling estradiol levels as a result of intentional reduction in gonadotrophin dose are not associated with poor IVF outcomes, whereas spontaneously falling estradiol levels result in low clinical pregnancy rates

BACKGROUND

Although estradiol levels remain an integral part of monitoring in most IVF programmes, the effect of falling estradiol on IVF outcome has not been adequately quantified. The objective of this study was to evaluate the effect of falling estradiol levels prior to hCG on IVF outcome.

METHODS

This was a retrospective cohort study carried out in a university-based fertility clinic. A total of 112 IVF patients in whom estradiol levels fell prior to the administration of hCG were matched for age and year of treatment with 112 control IVF patients. IVF outcomes including oocytes retrieved, fertilization rate, embryos for transfer, and pregnancy rates were compared between the groups.

RESULTS

Seventy per cent of women in the falling estradiol group experienced spontaneously falling estradiol levels. Spontaneously falling estradiol was associated with fewer oocytes retrieved (median 5 versus 8, P=0.001), increased rates of failed fertilization (18 versus 6%, P=0.018) and lower clinical pregnancy rates (12 versus 26%, P=0.012) compared to controls. Despite marked decreases in estradiol levels, IVF outcomes for patients whose estradiol levels fell as a result of deliberate protocol modification had similar fertilization and clinical pregnancy rates as controls.

CONCLUSIONS

Subtle (<10%) spontaneous decreases in estradiol levels are associated with very poor IVF outcomes.