[Diagnosis of Helicobacter pylori infection on gastric biopsies: Standard stain, special stain or immunohistochemistry?] / Diagnostic d'infection à Helicobacter pylori sur biopsies gastriques : coloration standard, coloration spéciale ou immunohistochimie ?

INTRODUCTION: There is no consensus on the benefit of performing a systematic complementary technique for the diagnosis of Helicobacter pylori infection. In our laboratory, a cresyl violet was carried out systematically until July 2014; since that date, a cresyl violet or immunohistochemistry is only made on request. We evaluated the value of cresyl violet staining of gastric biopsies to diagnose H. pylori infection by comparing a period of systematic staining to a time when it was made on demand. MATERIAL AND METHODS: We retrospectively studied the gastric biopsy of 786 consecutive patients from April to November 2014, taken in the absence of focal endoscopic lesion. During the first period, hematoxylin-eosin and cresyl violet were performed on all biopsies. During the second period, hematoxylin-eosin was performed and then, if necessary, cresyl violet or immunohistochemistry. All hematoxylin-eosin stained slides were revised to identify H. pylori. We performed immunohistochemistry in cases of active chronic gastritis without H. pylori identified on hematoxylin-eosin or cresyl violet. RESULTS: We have shown that gastric biopsy performed in the absence of focal mucosal lesion are normal in 55% of cases. The percentage of H. pylori infection was similar in both groups. In cases of active chronic gastritis, H. pylori infection is visible, in most cases, on hematoxylin-eosin (94%). Immunohistochemistry should be prescribed only in case of chronic active gastritis without H. pylori identified on standard staining, with bacteria rare or atypically located. CONCLUSION: In our experiment, H. pylori is present only in case of active gastritis (33% of the biopsies in our series) and being almost always identifiable on the standard staining with H-E (in 94% of the cases), it is not It is not necessary to systematically perform, on all gastric biopsies, a complementary histo- or immunohistochemical technique.

Adjuvant Fluorouracil, Leucovorin, and Oxaliplatin in Stage II to III Colon Cancer: Updated 10-Year Survival and Outcomes According to BRAF Mutation and Mismatch Repair Status of the MOSAIC Study.

PURPOSE: The MOSAIC (Multicenter International Study of Oxaliplatin/Fluorouracil/Leucovorin in the Adjuvant Treatment of Colon Cancer) study has demonstrated 3-year disease-free survival (DFS) and 6-year overall survival (OS) benefit of adjuvant oxaliplatin in stage II to III resected colon cancer. This update presents 10-year OS and OS and DFS by mismatch repair (MMR) status and BRAF mutation. METHODS: Survival actualization after 10-year follow-up was performed in 2,246 patients with resected stage II to III colon cancer. We assessed MMR status and BRAF mutation in 1,008 formalin-fixed paraffin-embedded specimens. RESULTS: After a median follow-up of 9.5 years, 10-year OS rates in the bolus/infusional fluorouracil plus leucovorin (LV5FU2) and LV5FU2 plus oxaliplatin (FOLFOX4) arms were 67.1% versus 71.7% (hazard ratio [HR], 0.85; P = .043) in the whole population, 79.5% versus 78.4% for stage II (HR, 1.00; P = .980), and 59.0% versus 67.1% for stage III (HR, 0.80; P = .016) disease. Ninety-five patients (9.4%) had MMR-deficient (dMMR) tumors, and 94 (10.4%) had BRAF mutation. BRAF mutation was not prognostic for OS (P = .965), but dMMR was an independent prognostic factor (HR, 2.02; 95% CI, 1.15 to 3.55; P = .014). HRs for DFS and OS benefit in the FOLFOX4 arm were 0.48 (95% CI, 0.20 to 1.12) and 0.41 (95% CI, 0.16 to 1.07), respectively, in patients with stage II to III dMMR and 0.50 (95% CI, 0.25 to 1.00) and 0.66 (95% CI, 0.31 to 1.42), respectively, in those with BRAF mutation. CONCLUSION: The OS benefit of oxaliplatin-based adjuvant chemotherapy, increasing over time and with the disease severity, was confirmed at 10 years in patients with stage II to III colon cancer. These updated results support the use of FOLFOX in patients with stage III disease, including those with dMMR or BRAF mutation.

Patients with colorectal tumors with microsatellite instability and large deletions in HSP110 T17 have improved response to 5-fluorouracil­based chemotherapy.

BACKGROUND & AIMS: Patients with colorectal tumors with microsatellite instability (MSI) have better prognoses than patients with tumors without MSI, but have a poor response to 5-fluorouracil­based chemotherapy. A dominant-negative form of heat shock protein (HSP)110 (HSP110DE9) expressed by cancer cells with MSI, via exon skipping caused by somatic deletions in the T(17) intron repeat, sensitizes the cells to 5-fluorouracil and oxaliplatin.We investigated whether HSP110 T(17) could be used to identify patients with colorectal cancer who would benefit from adjuvant chemotherapy with 5-fluorouracil and oxaliplatin. METHODS: We characterized the interaction between HSP110 and HSP110DE9 using surface plasmon resonance. By using polymerase chain reaction and fragment analysis, we examined how the size of somatic allelic deletions in HSP110 T(17) affected the HSP110 protein expressed by tumor cells. We screened 329 consecutive patients with stage II­III colorectal tumors with MSI who underwent surgical resection at tertiary medical centers for HSP110 T(17). RESULTS: HSP110 and HSP110DE9 interacted in a1:1 ratio. Tumor cells with large deletions in T(17) had increased ratios of HSP110DE9:HSP110, owing to the loss of expression of full-length HSP110. Deletions in HSP110 T(17) were mostly biallelic in primary tumor samples with MSI. Patients with stage II­III cancer who received chemotherapy and had large HSP110 T(17) deletions (≥5 bp; 18 of 77 patients, 23.4%) had longer times of relapse-free survival than patients with small or no deletions (≤4 bp; 59 of 77 patients, 76.6%) in multivariate analysis (hazard ratio, 0.16; 95% confidence interval, 0.012­0.8; P = .03). We found a significant interaction between chemotherapy and T17 deletion (P =.009). CONCLUSIONS: About 25% of patients with stages II­III colorectal tumors with MSI have an excellent response to chemotherapy, due to large, biallelic deletions in the T(17) intron repeat of HSP110 in tumor DNA.

Extensive characterization of sphere models established from colorectal cancer cell lines.

Links between cancer and stem cells have been proposed for many years. As the cancer stem cell (CSC) theory became widely studied, new methods were developed to culture and expand cancer cells with conserved determinants of "stemness". These cells show increased ability to grow in suspension as spheres in serum-free medium supplemented with growth factors and chemicals. The physiological relevance of this phenomenon in established cancer cell lines remains unclear. Cell lines have traditionally been used to explore tumor biology and serve as preclinical models for the screening of potential therapeutic agents. Here, we grew cell-forming spheres (CFS) from 25 established colorectal cancer cell lines. The molecular and cellular characteristics of CFS were compared to the bulk of tumor cells. CFS could be isolated from 72 % of the cell lines. Both CFS and their parental CRC cell lines were highly tumorigenic. Compared to their parental cells, they showed similar expression of putative CSC markers. The ability of CRC cells to grow as CFS was greatly enhanced by prior treatment with 5-fluorouracil. At the molecular level, CFS and parental CRC cells showed identical gene mutations and very similar genomic profiles, although microarray analysis revealed changes in CFS gene expression that were independent of DNA copy-number. We identified a CFS gene expression signature common to CFS from all CRC cell lines, which was predictive of disease relapse in CRC patients. In conclusion, CFS models derived from CRC cell lines possess interesting phenotypic features that may have clinical relevance for drug resistance and disease relapse.

What is the incidence of metastatic lymph node involvement after significant pathologic response of primary tumor following neoadjuvant treatment for locally advanced rectal cancer?

BACKGROUND: In locally advanced rectal cancer (LARC) patients, major response to neoadjuvant radiotherapy (NR) has been associated with favorable long-term outcomes. Positive pathologic nodal status was recently proven to be associated with poor prognosis even after total regression of primary tumor (ypT0). The aim of this study was to evaluate the rate of lymph node (LN) involvement in patients with complete (ypT0) or major (TRG1: very few viable tumor cells) response. METHODS: Included were patients with complete or major response after radiotherapy followed by surgery and histological examination of the whole specimen. RESULTS: From 1996 to 2010, 245 patients with LARC were treated by NR. We collected clinical data for 53 patients (21.6 %) with ypT0 (n = 26, 49 %) or TRG1 (n = 27, 51 %) response. Sphincter-preserving surgery was performed in 40 patients (75 %). Overall, nine patients (16.9 %) presented LN involvement: 2 (7.7 %) in the ypT0 group and 7 (25.9 %) in the TRG1 group (NS). Patients with ypT3 tumors had significantly more invaded LN than patients with ypT1-T2 tumors (6 of 13 [46 %] vs 1 of 14 [7 %], p = .032). After median follow-up of 30 months (range, 1-160 months), 5-year disease-free and overall survivals were 88.2 and 89.0 %, respectively. CONCLUSIONS: There was a clear cutoff between patients with ypT0-T2 (3 of 40, 7.5 %) and ypT3 (6 of 13, 46 %) concerning the incidence of metastatic LN in patients achieving pathologic complete or major response after NR. In patients with good clinical response, local full-thickness resection of the residual tumor could be a first step, followed by standard rectal resection in cases of ypT3.

Defective mismatch repair status as a prognostic biomarker of disease-free survival in stage III colon cancer patients treated with adjuvant FOLFOX chemotherapy.

PURPOSE: Adding oxaliplatin to adjuvant 5-fluorouracil (5-FU) chemotherapy improves 3-year disease-free survival (DFS) after resection of stage III colon cancer. Several studies suggest that patients with tumors exhibiting defective mismatch repair (MMR) do not benefit from adjuvant 5-FU chemotherapy, but there are few data on 5-FU-oxaliplatin (FOLFOX) adjuvant chemotherapy in this setting. The aim of this study was to evaluate the prognostic value of MMR status for DFS in patients with stage III colon cancer receiving adjuvant FOLFOX chemotherapy. EXPERIMENTAL DESIGN: MMR status was determined by microsatellite instability testing or immunohistochemistry in 303 unselected patients with stage III colon cancer receiving adjuvant FOLFOX chemotherapy in 9 centers. Cox proportional hazards models were used to examine the association between MMR status and 3-year DFS. RESULTS: The 3-year DFS rate was significantly higher in the 34 patients (11.2% of the study population) with defective MMR tumors (90.5%) than in patients with proficient MMR tumors (73.8%; log-rank test; HR = 2.16; 95% CI, 1.09-4.27; P = 0.027). In multivariate analysis, MMR status remained an independent significant prognostic factor for DFS (HR = 4.48; 95% CI, 1.34-14.99; P = 0.015). CONCLUSION: MMR status is an independent prognostic biomarker for DFS in patients with stage III colon cancer receiving adjuvant FOLFOX chemotherapy.

Expression of a mutant HSP110 sensitizes colorectal cancer cells to chemotherapy and improves disease prognosis.

Heat shock proteins (HSPs) are necessary for cancer cell survival. We identified a mutant of HSP110 (HSP110ΔE9) in colorectal cancer showing microsatellite instability (MSI CRC), generated from an aberrantly spliced mRNA and lacking the HSP110 substrate-binding domain. This mutant was expressed at variable levels in almost all MSI CRC cell lines and primary tumors tested. HSP110ΔE9 impaired both the normal cellular localization of HSP110 and its interaction with other HSPs, thus abrogating the chaperone activity and antiapoptotic function of HSP110 in a dominant-negative manner. HSP110ΔE9 overexpression caused the sensitization of cells to anticancer agents such as oxaliplatin and 5-fluorouracil, which are routinely prescribed in the adjuvant treatment of people with CRC. The survival and response to chemotherapy of subjects with MSI CRCs was associated with the tumor expression level of HSP110ΔE9. HSP110 may thus constitute a major determinant for both prognosis and treatment response in CRC.

Acute and subchronic toxicity of Anacardium occidentale Linn (Anacardiaceae) leaves hexane extract in mice.

These studies focus on the toxicity leaf hexane extract of A. occidentale L (Anacardiaceae) used in Cameroon traditional medicine for the treatment of diabetes and hypertension. Previous findings on antidiabetic and anti-inflammatory have given support to the ethnopharmacological applications of the plant. After acute oral administration, it was found that doses of the extract less than 6 g/kg are not toxic. Signs of toxicity at high doses were asthenia, anorexia, diarrhoea, and syncope. The LD(50) of the extract, determined in mice of both sexes after oral administration was 16 g/kg. In the subchronic study, mice received A. occidentale at doses of 6, 10 and 14 g/kg (by oral route) for 56 days. At doses of 2, 6 and 10 g/kg of extract, repeated oral administration to mice produced a reduction in food intake, weight gain, and behavioural effects. Liver or the kidney function tests were assessed by determining serum parameters like, creatinine, transaminases, and urea. All these parameters were significantly (p<0.01) abnormal. Histopathological studies revealed evidence of microscopic lesions either in the liver or in the kidney which may be correlated with biochemical disturbances. We conclude that toxic effects of A. occidentale L hexane leaf extract occurred at higher doses than those used in Cameroon folk medicine.

Conservative treatment of primary gastric low-grade B-cell lymphoma of mucosa-associated lymphoid tissue: predictive factors of response and outcome.

OBJECTIVES: Primary gastric low-grade B-cell lymphoma of mucosa-associated lymphoid tissue may regress with conservative treatment such as anti-Helicobacterpylori therapy or monochemotherapy. The aims of the present study were to analyze the predictive factors of response to anti-H. pylori treatment, to assess the effects of an adjuvant therapy in responding patients, and to evaluate an alternative therapy in nonresponding patients. METHODS: From 1995 to 2000, 48 H. pylori-infected patients with localized primary gastric low-grade B-cell lymphoma of mucosa-associated lymphoid tissue were treated with anti-H. pylori therapy. Endoscopic and endoscopic ultrasonography features and histological grading of large cells' proportion were analyzed. Eradication of H. pylori and tumoral response were assessed at 2 and 6 months, respectively. From 1996, patients in remission at 6 months were randomized to receive either chlorambucil p.o. for 6 months or no treatment. Patients who did not respond to H. pylori eradication received chlorambucil p.o. for 1 yr. RESULTS: Among the 48 treated patients, 33 (69%) were in complete (n = 28) or in partial (n = 5) remission, and 15 (31%) were in treatment failure at 6 months. H. pylori was eradicated in 47 patients. The response was not correlated with the endoscopic features or with the histological grade. In contrast, it was related to ultrasonographic features: remission was achieved in 76% of patients when no perigastric lymph node was detected versus only 33% when endoscopic ultrasonography showed presence of lymph nodes (p = 0.025). All responding patients remained in remission (median 34 months) whatever the treatment they received (no treatment or chlorambucil). Remission could be achieved with chlorambucil in 58% of the nonresponding patients to anti-H. pylori treatment. CONCLUSIONS: The major negative predictive factor of the tumoral response to anti-H. pylori treatment in patients with primary gastric low-grade B-cell lymphoma of mucosaassociated lymphoid tissue was the presence of perigastric lymph nodes on endoscopic ultrasonography. In responding patients, remission remained stable, suggesting that adjuvant chemotherapy was not useful. In patients who failed to respond to H. pylori eradication, monochemotherapy with chlorambucil proved to be efficient, but new therapeutic modalities should be evaluated to improve the control of the tumoral process.