Gustavo Baretton

HER2 diagnostics in gastric cancer—guideline validation and development of standardized immunohistochemical testing

Trastuzumab-based therapy has been shown to confer overall survival benefit in HER2-positive patients with advanced gastric cancer in a large multicentric trial (ToGA study). Subgroup analysis identified adenocarcinomas of the stomach and gastroesophageal (GE) junction with overexpression of HER2 according to immunohistochemistry (IHC) as potential responders. Due to recent approval of trastuzumab for HER2 positive metastatic gastric and GE-junction cancer in Europe (EMEA) HER2 diagnostics is now mandatory with IHC being the primary test followed by fluorescence in situ hybridization (FISH) in IHC2+ cases. However, in order to not miss patients potentially responding to targeted therapy determination of a HER2-positive status for gastric cancer required modification of scoring as had been proposed in a pre-ToGA study. To validate this new HER2 status testing procedure in terms of inter-laboratory and inter-observer consensus for IHC scoring a series of 547 gastric cancer tissue samples on a tissue microarray (TMA) was used. In the first step, 30 representative cores were used to identify specific IHC HER2 scoring issues among eight French and German laboratories, while in the second step the full set of 547 cores was used to determine IHC HER2 intensity and area score concordance between six German pathologists. Specific issues relating to discordance were identified and recommendations formulated which proved to be effective to reliably determine HER2 status in a prospective test series of 447 diagnostic gastric cancer specimens.

Overexpression of the insulin-like growth factor I receptor in human colon carcinomas

High concentrations of insulin‐like growth factor (IGF)‐I and IGF‐II have been demonstrated in human colonic adenocarcinomas and exert mitogenic effects through paracrine/autocrine interactions with the IGF‐I receptor (IGF‐IR). However, definitive studies of IGF‐IR expression in these tissues have not been performed.

The APC/beta-catenin pathway in ulcerative colitis-related colorectal carcinomas: a mutational analysis.

Although the APC/β‐catenin pathway is known to play a crucial role in sporadic colorectal carcinogenesis, its influence on ulcerative colitis (UC)–related neoplastic progression is unknown. To elucidate the role of the APC‐/β‐catenin pathway in UC‐related carcinogenesis, the authors identified APC and β‐catenin mutations in a set of UC‐related and sporadic colorectal carcinomas.

FISH analysis of gene aberrations (MYC, CCND1, ERBB2, RB, and AR) in advanced prostatic carcinomas before and after androgen deprivation therapy

Genetic mechanisms leading to androgen-independent growth in advanced prostatic carcinomas (PC) are still poorly understood. Analysis of genes potentially involved in the regulation of tumor cell proliferation and apoptosis might confer better insight into this process and might lead to improved therapeutic strategies. Fluorescence in situ hybridization (FISH) analysis of dissociated nuclei with DNA probes for MYC (8q24)/#8, cyclin D1 gene (CCND1; 11q13)/#11, ERBB2 (17q13)/#17, the androgen receptor gene (AR; Xq12)/#X, and the retinoblastoma gene (RB; 13q14) was applied to formalin-fixed tissue from 63 patients with advanced PC after androgen deprivation therapy (ADT); matched tumor tissue before ADT was also available in 22 of these cases. The cut-points used were: “increased copy number,” ≥ 30% of all nuclei with increased FISH signals (centromere and/or gene); “amplification,” ≥ 15% of nuclei with “increased gene copy number.” CCND1 and MYC gene “amplifications” were present before ADT in 25% and 33% of the cases, respectively; the frequency of these “amplifications” increased to 37% and 57% after ADT. Loss of the RB gene was nearly four times more frequent after ADT than before therapy (22% versus 6%). AR and ERBB2 gene “amplifications” occurred only after ADT in 36% and 30% of cases, respectively. With the exception of the AR gene, the copy number increase was low. After treatment, MYC and AR gene “amplifications” correlated with the proliferation rate (Ki-67/MIB1 index; p = 0.01 and p = 0.04), whereas ERBB2 “amplifications” were associated with increased apoptotic index (PCD/TUNEL; p = 0.016). However, no correlation between FISH results and clinical follow-up could be established. FISH analysis of genes putatively involved in PC progression revealed characteristic patterns of aberrations in advanced PC before and after ADT. Distinct changes in gene copy number before and after therapy suggests possible involvement of these genes in the escape from androgen control.

Lymph Node Status and TS Gene Expression Are Prognostic Markers in Stage II/III Rectal Cancer After Neoadjuvant Fluorouracil-Based Chemoradiotherapy

PURPOSE According to the CAO/ARO/AIO-94 trial of the German Rectal Cancer Study Group, preoperative combined fluorouracil (FU) -based long-term chemoradiotherapy (CT/RT) is recommended for patients with International Union Against Cancer (UICC) stage II/III rectal cancer. However, despite the local benefit of neoadjuvant treatment, the overall prognostic value remains uncertain in comparison with adjuvant CT/RT. Furthermore, the prognostic value of molecular biomarkers, such as thymidylate synthase (TS), thymidine phosphorylase (TP), and dihydropyrimidine dehydrogenase (DPD), all of which are involved in the FU metabolism, is unknown in neoadjuvant settings. We assessed the impact of standardized preoperative CT/RT and intratumoral TS, TP, and DPD levels on patient outcome. PATIENTS AND METHODS Forty patients with rectal cancer pretherapeutic UICC stage II/III, receiving preoperative FU-based CT/RT (CAO/ARO/AIO-94 trial) followed by standardized surgery, including total mesorectal excision, were investigated. Downsizing, downstaging, tumor regression, as well as TS, TP, and DPD gene expression of post-treatment surgical specimens were correlated with disease-free survival (DFS) and overall survival (OS). RESULTS Significant downsizing (P < .001) and downstaging (P = .001) were achieved with preoperative CT/RT. During a median follow-up of 49 months (95% CI, 43 to 58 months), the cancer recurrence rate was 28.2%. DFS and OS were significantly increased in patients with downstaging (P < .001 and P = .003, respectively), compared with patients without downstaging. All patients who developed cancer recurrence had a persistent positive lymph node status after preoperative CT/RT (P < .001) and a significantly higher TS gene expression (P = .035) compared with those patients without recurrence. CONCLUSION Persistent positive lymph node status and high intratumoral TS expression after preoperative CT/RT are predictive of an unfavorable prognosis in rectal cancer UICC stage II/III.

Oral Budesonide for Maintenance Treatment of Collagenous Colitis: A Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND & AIMS Oral budesonide effectively induces clinical remission in patients with collagenous colitis, a debilitating illness characterized by chronic watery/loose diarrhea, but there is a high rate of relapse after treatment cessation. METHODS This randomized, double-blind, placebo-controlled, multicenter study evaluated the efficacy and safety of long-term therapy with oral budesonide (Entocort CIR capsules) for maintenance of clinical remission of collagenous colitis. Patients were aged >18 years with histologically proven collagenous colitis and >3 watery/loose stools per day on >or=4 of the prior 7 days. Open-label oral budesonide 9 mg/d was administered to all patients for 6 weeks. Patients in clinical remission (<or=3 stools per day) at week 6 were subsequently randomized to double-blind oral treatment with budesonide 6 mg/d or matching placebo for 6 months. Relapse was defined as >3 stools per day on >or=4 consecutive days (and included patients withdrawn because of adverse events). RESULTS Of 48 enrolled patients, 46 (96%) achieved clinical remission at week 6 and were randomized to maintenance budesonide or placebo. There were 21 relapses during maintenance therapy, and almost all occurred during the first 2 months. Budesonide therapy was associated with a significantly lower cumulative rate of relapse compared with placebo (6/23 [26%] and 15/23 [65%], respectively; P = .022), and high correlation between clinical remission and histologic improvement was observed. Budesonide was well tolerated with no serious adverse events. CONCLUSIONS Oral budesonide 6 mg/d is efficacious and well tolerated for long-term maintenance of clinical remission in patients with collagenous colitis.

Serrated polyps of the colon and rectum (hyperplastic polyps, sessile serrated adenomas, traditional serrated adenomas, and mixed polyps)—proposal for diagnostic criteria

Until recently, two major types of colorectal epithelial polyps were distinguished: the adenoma and the hyperplastic polyp. While adenomas—because of their cytological atypia—were recognized as the precursor lesions for colorectal carcinoma, hyperplastic polyps were perceived as harmless lesions without any potential for malignant progression mainly because hyperplastic polyps are missing cytological atypia. Meanwhile, it is recognized that the lesions, formerly classified as hyperplastic, represent a heterogeneous group of polyps with characteristic serrated morphology some of which exhibit a significant risk of neoplastic progression. These serrated lesions show characteristic epigenetic alterations not commonly seen in colorectal adenomas and progress to colorectal carcinoma via the so-called serrated pathway (CpG-island-methylation-phenotype pathway). This group of polyps is comprised not only of hyperplastic polyps, but also of sessile serrated adenomas, traditional serrated adenomas and mixed polyps, showing serrated and “classical” adenomatous features. Diagnostic criteria and nomenclature for these lesions are not uniform and, therefore, somewhat confusing. In a consensus conference of the Working Group of Gastroenterological Pathology of the German Society of Pathology, standardization of nomenclature and diagnostic criteria as well as recommendations for clinical management of these serrated polyps were formulated and are presented herein.

Budesonide Is Effective in Treating Lymphocytic Colitis: A Randomized Double-Blind Placebo-Controlled Study

BACKGROUND & AIMS Budesonide is effective in treating collagenous colitis, but no treatment is established for lymphocytic colitis. We performed a randomized, double-blind, placebo-controlled study to evaluate the effects of budesonide in patients with lymphocytic colitis. METHODS Forty-two patients (median age, 61 years) with lymphocytic colitis and chronic diarrhea were randomly assigned to groups that were given oral doses of budesonide (9 mg/d) or placebo for 6 weeks. Nonresponders at week 6 were given open-label budesonide (9 mg/d) for 6 additional weeks. A complete colonoscopy and histologic and quality-of-life analyses were performed at baseline and at week 6. The primary end point was clinical remission at 6 weeks, with last observation carried forward (LOCF). All patients who left the study in clinical remission were followed for relapse. RESULTS At week 6, 86% of patients given budesonide were in clinical remission (with LOCF) compared with 48% of patients given placebo (P = .010). Furthermore, open-label budesonide therapy induced clinical remission in 7 of 8 patients given placebo. Histologic remission was observed in 73% of patients given budesonide compared with 31% given placebo (P = .030). Only 1 patient discontinued budesonide therapy prematurely. During a mean follow-up period of 14 months, 15 patients (44.1%) experienced a clinical relapse (after a mean of 2 months); 8 of the relapsing patients were retreated with and responded again to budesonide. CONCLUSIONS Budesonide effectively induces clinical remission in patients with lymphocytic colitis and significantly improves histology results after 6 weeks. Clinical relapses occur but can be treated again with budesonide.

A Subset of Human Dendritic Cells in the T Cell Area of Mucosa-Associated Lymphoid Tissue with a High Potential to Produce TNF-α

Recently, a new class of human dendritic cell (DC) precursors has been described in the peripheral blood recognized by the mAb M-DC8. These cells represent ∼1% of PBMC and acquire several characteristics of myeloid DC upon in vitro culture. In this report we show that M-DC8+ monocytes secrete in response to LPS >10 times the amount of TNF-α as M-DC8− monocytes, but produce significantly less IL-10. Consistent with a role in inflammatory responses, we found that M-DC8+ cells localized in the T cell area of inflamed human tonsils and in the subepithelial dome region of Peyer’s patches. In patients with active Crohn’s disease, abundant M-DC8+ cells were detectable in inflamed ileal mucosa, which were entirely depleted after systemic steroid treatment. Our results indicate that M-DC8+ cells are cells of DC phenotype in inflamed mucosa-associated lymphoid tissue that may contribute to the high level of TNF-α production in Crohn’s disease. We infer that selective elimination of M-DC8+ cells in inflammatory diseases has therapeutic potential.

Altered Distribution of β-Catenin, and Its Binding Proteins E-Cadherin and APC, in Ulcerative Colitis–Related Colorectal Cancers

The β-catenin pathway plays a central role in transcriptional signaling and cell–cell interactions in colonic epithelium. Alterations of the expression of β-catenin, and its binding partners E-cadherin and the adenomatous polyposis coli protein (APC), are frequent events in sporadic colorectal cancer. Ulcerative colitis (UC)–related cancers originate in a field of chronic inflammation and therefore may have different alterations in the β-catenin pathway than sporadic cancers. To test this hypothesis, expres-sion and subcellular localization of β-catenin, E-cadherin, and APC were detected by immunohistochemistry in paraffin sections from 33 UC-related and 42 sporadic colorectal cancers. Although β-catenin and E-cadherin expression were predominantly limited to the lateral cell membrane in normal colonic epithelium, both tumor groups showed an overall shift from membranous to cytoplasmic expression for these proteins. An increase in nuclear localization of β-catenin and a decrease in cytoplasmic APC expression also were seen in both cancer groups compared with normal epithelium. Abnormal β-catenin expression was more closely linked to E-cadherin alterations in UC-related cancers than in sporadic cancers. In contrast, abnormal β-catenin expression was more closely linked to APC alterations in sporadic cancers than in UC-related cancers. These data suggest that alterations of the β-catenin pathway are important in both UC-related and sporadic colorectal cancers. However, differences in the expression patterns of β-catenin, E-cadherin, and APC between UC-related and sporadic colorectal cancers suggest that the specific alterations in this pathway may differ in these two cancer groups.