Screening for precancerous anal lesions linked to human papillomaviruses: French recommendations for clinical practice.

In France, about 2000 new cases of anal cancer are diagnosed annually. Squamous cell carcinoma is the most common histological type, mostly occurring secondary to persistent HPV16 infection. Invasive cancer is preceded by precancerous lesions. In addition to patients with a personal history of precancerous lesions and anal cancer, three groups are at very high risk of anal cancer: (i) men who have sex with men and are living with HIV, (ii) women with a history of high-grade squamous intraepithelial lesions (HSILs) or vulvar HPV cancer, and (iii) women who received a solid organ transplant more than 10 years ago. The purpose of screening is to detect HSILs so that they can be treated, thereby reducing the risk of progression to cancer. All patients with symptoms should undergo a proctological examination including standard anoscopy. For asymptomatic patients at risk, an initial HPV16 test makes it possible to target patients at risk of HSILs likely to progress to cancer. Anal cytology is a sensitive test for HSIL detection. Its sensitivity is greater than 80% and exceeds that of proctological examination with standard anoscopy. It is indicated in the event of a positive HPV16 test. In the presence of cytological abnormalities and/or lesions and a suspicion of dysplasia on clinical examination, high-resolution anoscopy is indicated. Performance is superior to that of proctological examination with standard anoscopy. However, this technique is not widely available, which limits its use. If high-resolution anoscopy is not possible, screening by a standard proctological examination is an alternative. There is a need to develop high-resolution anoscopy and triage tests and to evaluate screening strategies.

Prediction of response to immune checkpoint blockade in patients with metastatic colorectal cancer with microsatellite instability.

BACKGROUND: Mismatch repair-deficient (dMMR) tumors displaying microsatellite instability (MSI) represent a paradigm for the success of immune checkpoint inhibitor (ICI)-based immunotherapy, particularly in patients with metastatic colorectal cancer (mCRC). However, a proportion of patients with dMMR/MSI mCRC exhibit resistance to ICI. Identification of tools predicting MSI mCRC patient response to ICI is required for the design of future strategies further improving this therapy. PATIENTS AND METHODS: We combined high-throughput DNA and RNA sequencing of tumors from 116 patients with MSI mCRC treated with anti-programmed cell death protein 1 ± anti-cytotoxic T-lymphocyte-associated protein 4 of the NIPICOL phase II trial (C1, NCT03350126, discovery set) and the ImmunoMSI prospective cohort (C2, validation set). The DNA/RNA predictors whose status was significantly associated with ICI status of response in C1 were subsequently validated in C2. Primary endpoint was progression-free survival by immune RECIST (iRECIST) (iPFS). RESULTS: Analyses showed no impact of previously suggested DNA/RNA indicators of resistance to ICI, e.g. MSIsensor score, tumor mutational burden, or specific cellular and molecular tumoral contingents. By contrast, iPFS under ICI was shown in C1 and C2 to depend both on a multiplex MSI signature involving the mutations of 19 microsatellites hazard ratio cohort C2 (HRC2) = 3.63; 95% confidence interval (CI) 1.65-7.99; P = 1.4 × 10-3] and the expression of a set of 182 RNA markers with a non-epithelial transforming growth factor beta (TGFB)-related desmoplastic orientation (HRC2 = 1.75; 95% CI 1.03-2.98; P = 0.035). Both DNA and RNA signatures were independently predictive of iPFS. CONCLUSIONS: iPFS in patients with MSI mCRC can be predicted by simply analyzing the mutational status of DNA microsatellite-containing genes in epithelial tumor cells together with non-epithelial TGFB-related desmoplastic RNA markers.

Discordance between immunochemistry of mismatch repair proteins and molecular testing of microsatellite instability in colorectal cancer.

BACKGROUND: DNA mismatch repair system deficiency (dMMR) is found in 15% of colorectal cancers (CRCs). Two methods are used to determine dMMR, immunohistochemistry (IHC) of MMR proteins and molecular testing of microsatellite instability (MSI). Only studies with a low number of patients have reported rates of discordance between these two methods, ranging from 1% to 10%. MATERIALS AND METHODS: Overall, 3228 consecutive patients with CRCs from two centers were included. Molecular testing was carried out using the Pentaplex panel and IHC evaluated four (MLH1, MSH2, MSH6, and PMS2; cohort 1; n = 1085) or two MMR proteins (MLH1 and MSH2; cohort 2; n = 2143). The primary endpoint was the rate of discordance between MSI and MMR IHC tests. RESULTS: Fifty-one discordant cases (1.6%) were initially observed. Twenty-nine out of 51 discordant cases were related to IHC misclassifications. In cohort 1, after re-reading IHC and/or carrying out new IHC, 16 discordant cases were reclassified as nondiscordant. In cohort 2, after the addition of MSH6/PMS2 IHC and re-examination, 13 were reclassified as nondiscordant. In addition, 10 misclassifications of molecular tests were identified. Finally, only 12 discordant cases (0.4%) remained: 5 were proficient MMR/MSI and 7 were dMMR/microsatellite stable. CONCLUSIONS: Our study confirmed the high degree of concordance between MSI and MMR IHC tests. Discordant cases must be reviewed, and if needed, tests must be repeated and analyzed by an expert team.

Tumor regression grading after neoadjuvant treatment of esophageal and gastroesophageal junction adenocarcinoma: results of an international Delphi consensus survey.

Complete histopathologic tumor regression after neoadjuvant treatment is a well-known prognostic factor for survival among patients with adenocarcinomas of the esophagus and gastroesophageal junction. The aim of this international Delphi survey was to reach a consensus regarding the most useful tumor regression grading (TRG) system that could represent an international standard for histopathologic TRG grading of gastroesophageal carcinomas. Fifteen pathologists with special interest in esophageal and gastric pathology participated in the online survey. The initial questionnaire contained of 43 statements that addressed the following topics: (1) specimen processing, (2) gross examination, (3) cross sectioning, (4) staining, (5) Barrett's esophagus, (6) TRG systems, and (7) TRG in lymph node (LN). Participants rated the items using a 5-point Likert style scale and were encouraged to write comments for each statement. The expert panel recommended a 4-tiered TRG system for assessing the primary tumor: grade 1: No residual tumor (complete histopathologic tumor regression), grade 2: less than 10% residual tumor (near-complete regression), grade 3: 10%-50% residual tumor (partial regression), grade 4: greater than 50% residual tumor (minimal/no regression), combined with a 3-tiered system for grading therapeutic response in metastatic LNs: grade a: no residual tumor (complete histopathologic TRG), grade b: partial regression (tumor cells and regression), grade c: no regression (no sign of tumor response). This TRG grading system can be recommended as an international standard for histopathologic TRG grading in esophageal and gastroesophageal junction adenocarcinoma.

Correction to: Assessment of individual tumor buds using keratin immunohistochemistry: moderate interobserver agreement suggests a role for machine learning.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Assessment of individual tumor buds using keratin immunohistochemistry: moderate interobserver agreement suggests a role for machine learning.

Tumor budding is a promising and cost-effective biomarker with strong prognostic value in colorectal cancer. However, challenges related to interobserver variability persist. Such variability may be reduced by immunohistochemistry and computer-aided tumor bud selection. Development of computer algorithms for this purpose requires unequivocal examples of individual tumor buds. As such, we undertook a large-scale, international, and digital observer study on individual tumor bud assessment. From a pool of 46 colorectal cancer cases with tumor budding, 3000 tumor bud candidates were selected, largely based on digital image analysis algorithms. For each candidate bud, an image patch (size 256 × 256 µm) was extracted from a pan cytokeratin-stained whole-slide image. Members of an International Tumor Budding Consortium (n = 7) were asked to categorize each candidate as either (1) tumor bud, (2) poorly differentiated cluster, or (3) neither, based on current definitions. Agreement was assessed with Cohen's and Fleiss Kappa statistics. Fleiss Kappa showed moderate overall agreement between observers (0.42 and 0.51), while Cohen's Kappas ranged from 0.25 to 0.63. Complete agreement by all seven observers was present for only 34% of the 3000 tumor bud candidates, while 59% of the candidates were agreed on by at least five of the seven observers. Despite reports of moderate-to-substantial agreement with respect to tumor budding grade, agreement with respect to individual pan cytokeratin-stained tumor buds is moderate at most. A machine learning approach may prove especially useful for a more robust assessment of individual tumor buds.

Operative start time may impact the quality of mesorectal excision in minimally invasive rectal surgery: retrospective analysis of 137 patients.

INTRODUCTION: Timing of major elective operations is a potentially important outcome variable. This study examined the impact of operative start time (OST) on pathologic and short-term outcomes of minimally invasive rectal surgery (MIRS). METHODS: All rectal tumors patients who underwent MIRS from May 2012 to April 2016 were identified. Peroperative outcomes and the oncological quality of surgical excision were compared between patients with OST before 13.00h and after. RESULTS: A total of 137 patients were included in the study (71 Romarobot-assisted and 66 conventional laparoscopic). Ninety-nine (72%) patients were operated before 13.00h and 38 after 13.00h. The majority of cases were low/middle rectal tumors (69%). Patient's baseline characteristics were quite similar in both groups. The rate of severe complication (p=0.460) or reoperation (p=0.614) was the same. Pathologic criteria (T or N stage, number of harvested lymph nodes, and presence of any positive margin) were the same between groups except for the quality of mesorectal excision (ME) that was significantly poorer for cases beginning after 13.00h (complete 91% vs 74%; p=0.016). The OST was found to be the only parameter associated with a poor quality of ME [OR 2.55 (1.08 - 6.36)]. CONCLUSION: Perioperative outcome after MIRS does not appear to be influenced by OST. Poorer quality of ME was observed and may thus raise important questions about the timing and sequence of case scheduling.

Prognostic value and characteristics of N1c colorectal cancer.

AIM: The presence of tumour deposits (TDs) in colorectal cancer (CRC) is associated with poor prognosis. The seventh edition of TNM subclassified a new nodal stage, N1c, characterized by the presence of TDs without any concurrent positive lymph node (LN). It is not clear if the N1c category is or is not equal to LN metastasis. We aimed to examine the prevalence, characteristics and prognostic significance of this new subcategory. METHOD: Consecutive patients who underwent surgery for CRC in two centres (2011-2014) were analysed. N1 cM0 patients were matched against non-N1 cM0 (N0, N1a and N1b) patients for 3-year overall survival (OS) and disease-free survival (DFS). RESULTS: We identified 1122 patients with 648 (57.8%) colonic cancers. In 57 patients (5.1%), N1c status was associated with rectal cancers [rectum = 33/57 (57.9%) vs colon = 24/57 (42.1%); P = 0.029], a higher pathological tumour stage [pT3-T4 N1c = 55/843 (6.5% vspT3-T4 non-N1c = 2/279 (0.7%); P < 0.0001] and vascular emboli [n = 35 (61.4%) vs n = 552 (51.8%); P = 0.0305]. Synchronous metastasis was observed in 23 cases (40%). After a mean follow-up of 31 months, 3-year OS for M0 patients, was 89.4%, 89.1%, 86.6% and 81.8% for N0, N1a, N1b and N1c tumours, respectively. DFS was significantly worse for N1c than for N0 (P = 0.0169), with N1c status having a significant effect on DFS in colonic cancers (P = 0.014). The presence of more than one TD was associated with a significantly worse DFS (P = 0.021). CONCLUSION: Our results indicate that N1c CRC patients should be included among high-risk patients for whom it is widely accepted that adjuvant chemotherapy should be considered.

Recommendations for reporting tumor budding in colorectal cancer based on the International Tumor Budding Consensus Conference (ITBCC) 2016

Tumor budding is a well-established independent prognostic factor in colorectal cancer but a standardized method for its assessment has been lacking. The primary aim of the International Tumor Budding Consensus Conference (ITBCC) was to reach agreement on an international, evidence-based standardized scoring system for tumor budding in colorectal cancer. The ITBCC included nine sessions with presentations, a pre-meeting survey and an e-book covering the key publications on tumor budding in colorectal cancer. The 'Grading of Recommendation Assessment, Development and Evaluation' method was used to determine the strength of recommendations and quality of evidence. The following 10 statements achieved consensus: tumor budding is defined as a single tumor cell or a cell cluster consisting of four tumor cells or less (22/22, 100%). Tumor budding is an independent predictor of lymph node metastases in pT1 colorectal cancer (23/23, 100%). Tumor budding is an independent predictor of survival in stage II colorectal cancer (23/23, 100%). Tumor budding should be taken into account along with other clinicopathological features in a multidisciplinary setting (23/23, 100%). Tumor budding is counted on H&E (19/22, 86%). Intratumoral budding exists in colorectal cancer and has been shown to be related to lymph node metastasis (22/22, 100%). Tumor budding is assessed in one hotspot (in a field measuring 0.785 mm2) at the invasive front (22/22, 100%). A three-tier system should be used along with the budding count in order to facilitate risk stratification in colorectal cancer (23/23, 100%). Tumor budding and tumor grade are not the same (23/23, 100%). Tumor budding should be included in guidelines/protocols for colorectal cancer reporting (23/23, 100%). Members of the ITBCC were able to reach strong consensus on a single international, evidence-based method for tumor budding assessment and reporting. It is proposed that this method be incorporated into colorectal cancer guidelines/protocols and staging systems.

Clinicopathological and virological characteristics of superficially invasive squamous-cell carcinoma of the anus.

AIM: The clinicopathological and virological characteristics of anal superficially invasive squamous-cell carcinoma (SISCCA) were determined. METHOD: Seventeen patients with a completely excised stage T1N0M0 anal squamous-cell carcinoma (SCC) were included in the study. The tumours were divided into superficially invasive and invasive. Patients with anal high-grade squamous intraepithelial dysplasia, which corresponded to anal intraepithelial neoplasia (AIN) Grades 2 or 3, were used as a control group. Clinicopathological and virological characteristics were investigated. Overall survival and cancer recurrence-free survival were also assessed. RESULTS: Of the 17 patients, 12 (70.5%) were men. Ten (58.8%) were human immunodeficiency virus positive. Seven (41%) patients met the same diagnostic criteria as those recently proposed for anal SISCCA. According to the results obtained using the polymerase chain reaction, human papillomavirus (HPV) 16 was the most commonly detected (94%) type of HPV. Twelve (70.6%) patients with an inadequate surgical margin around the tumour received adjuvant radiotherapy, including the two (11.7%) tumours that locally recurred, one of which was an anal SISCCA. Superficially invasive anal cancers differed from the other T1N0M0 anal carcinomas according to the clinical presentation and the absence of lymph-vascular invasion (LVI). There were no differences in cancer recurrence-free and overall survival rates between the superficially invasive and invasive groups. CONCLUSION: Anal SISCCAs have a low index of clinical suspicion, are associated with an absence of LVI and are linked to high-risk HPV. Prospective studies are needed to define the clinical behaviour of these anal tumours and to determine their best therapeutic strategy.

Involvement of small ArfGAP1 (SMAP1), a novel Arf6-specific GTPase-activating protein, in microsatellite instability oncogenesis.

Small ArfGAP1 (stromal membrane-associated protein 1, SMAP1), a GTPase-activating protein specific for ADP-ribosylation factor 6 (Arf6), which is a small GTPase acting on membrane trafficking and actin remodeling, is frequently mutated in various tumors displaying microsatellite instability (MSI), notably in MSI colorectal cancers (CRC). Genotyping of 93 MSI CRCs (40 stage II, 32 stage III and 21 stage IV) allowed us to underscore that SMAP1 mutation frequency was inversely correlated with disease stage (P=0.01). Analysis of 46 cancer cell lines showed that SMAP1 mutations occurred only in MSI tumors, and consisted exclusively in short insertion or deletion in the coding 10-adenine repeat, generating a premature termination codon located downstream the ArfGAP domain. SMAP1 transcript levels were significant decreased (P=0.006), and truncated SMAP1 protein could not be detected in cells displaying biallelic SMAP1 mutations, owing to its sensitivity to proteasome degradation. To investigate the role of SMAP1 mutations, we used the SMAP1-null HCT116 cell line and we established three isogenic SMAP1-complemented clones. Cell proliferation was first assessed in vivo using subcutaneous xenografts into immunodeficient mice. Tumors developed in all animals regardless of the cell line injected, but tumor volumes were significantly smaller for both SMAP1-complemented clones compared with HCT116 (P<0.0001, at the time of killing). In vitro, SMAP1 mutations also increased cell clonogenicity (P=0.02-0.04), cell proliferation (P=0.008) by shortening the G2/M phase and decreased cell invasiveness (P=0.03-0.003). In keeping, SMAP1-complemented HCT116 gained several mesenchymal markers (Snail, Slug and vimentin) considered as a hallmark of epithelial-to-mesenchymal transition. These observations are reminiscent of some clinical characteristics of MSI CRCs, notably their larger size and lower rate of metastasis. Our observations suggest that SMAP1 loss-of-function mutations in MSI CRC may contribute to the emerging oncogenic pathway involving abnormal Arf6 regulation.

A distinctive epitheliomesenchymal biphasic tumor in the duodenum: the first case of duodenoblastoma?

Epitheliomesenchymal biphasic neoplasms are extremely rare in the duodenum, and most of these are carcinosarcomas. Miettinen et al. (Am J Surg Pathol 33:1370-7, 2009) recently reported three cases of a novel distinctive epitheliomesenchymal biphasic tumor of the stomach in young adults. In view of the resemblance to other childhood blastomas, they proposed to refer to this entity as a gastroblastoma. Since none of the components were sufficiently atypical, the gastroblastoma seemed more comparable to this kind of tumor than carcinosarcomas or other aggressive and malignant biphasic tumors. This report describes a duodenal location of a similar epitheliomesenchymal biphasic tumor in a 22-year-old woman. To our knowledge, this is the first reported case occurring primarily in the duodenum and might be the first case of "duodenoblastoma."

Morphological analysis of circulating tumour cells in patients undergoing surgery for non-small cell lung carcinoma using the isolation by size of epithelial tumour cell (ISET) method.

BACKGROUND AND OBJECTIVE: Recurrence rates after surgery for non-small cell lung cancer (NSCLC) range from 25 to 50% and 5-year survival is only 60-70%. Because no biomarkers are predictive of recurrence or the onset of metastasis, pathological TNM (pTNM) staging is currently the best prognostic factor. Consequently, the preoperative detection of circulating tumour cells (CTCs) might be useful in tailoring therapy. The aim of this study was to characterize morphologically any circulating non-haematological cells (CNHCs) in patients undergoing surgery for NSCLC using the isolation by size of epithelial tumour cell (ISET) method. METHODS: Of 299 blood samples tested, 250 were from patients with resectable NSCLC and 59 from healthy controls. The presence of CNHCs was assessed blindly and independently by 10 cytopathologists on May-Grünwald-Giemsa stained filters and the cells classified into three groups: (i) malignant cells, (ii) uncertain malignant cells, and (iii) benign cells. We assessed interobserver agreement using Kappa (κ) analysis as the measure of agreement. RESULTS: A total of 123 out of 250 (49%) patients showed CNHCs corresponding to malignant, uncertain malignant and benign cells, in 102/250 (41%), 15/250 (6%) and 6/250 (2%) cases, respectively. No CNHCs were detected in the blood of healthy subjects. Interobserver diagnostic variability was absent for CNHCs, low for malignant cells and limited for uncertain malignant and benign cells. CONCLUSION: Identification of CTCs in resectable NSCLC patients, using ISET technology and according to cytopathological criteria of malignancy, appears to be a new and promising field of cytopathology with potential relevance to lung oncology.

Unexplained polyposis: a challenge for geneticists, pathologists and gastroenterologists.

Two main colorectal polyposis syndromes have been described, familial adenomatous polyposis and MUTYH-associated polyposis syndromes. Some polyposis remains unexplained: 20% of adenomatous polyposis and serrated polyposis. The aim of this study was to evaluate in a cohort of patients with unexplained polyposis whether a genetic defect could be detected. Individuals presenting polyposis with more than 40 adenomas or more than 20 serrated polyps (hyperplastic, sessile serrated and mixed), without causative mutation identified, were included. Complementary explorations on APC or MUTYH were performed: search for APC mosaicism, splicing-affecting mutations, large genomic rearrangement of MUTYH. Four genes of Wnt pathway (AXIN2, PPP2R1B, WIF1, SFRP1) and two genes of transforming growth factor-ß (TGF-ß) pathway (SMAD4, BMPR1A) were screened for germline mutation. Twenty-five patients had an unexplained adenomatous polyposis (familial or sporadic). Five pathogenic mutations were found: four in APC gene (with one case of mosaicism) and one in BMPR1A gene. The exploration of APC mosaicism was better performed from adenoma DNA with high-resolution melting. The screening of the candidate genes did not find any causative mutation. Thirteen individuals had an unexplained serrated polyposis and a frameshift on SMAD4 gene was identified. All mutations were identified in familial cases of polyposis. After new pathological examination, both BMPR1A and SMAD4 cases were found to be associated with a juvenile polyposis while the polyposis was initially described as adenomatous or undetermined. In 17% (6/38) of the patients the causative mutation of the polyposis was identified. Genetic causes were heterogeneous. Sporadic polyposis patients must be considered as potential APC mosaicism. The histological classification of polyposis is strongly important in direct genetic exploration.

The effect of ursodesoxycholic acid on duodenal adenomas in familial adenomatous polyposis: a prospective randomized placebo-control trial.

AIM: Duodenal adenomas occur in about 90% of patients with familial adenomatous polyposis (FAP) and are the second cause of death of patients who have had a prophylactic proctocolectomy. Studies suggest that biliary acids have a role in the development of duodenal adenomas. The aim of this study was to evaluate the impact of ursodesoxycholic acid (UDCA) on duodenal adenoma formation in patients with FAP. METHOD: A randomized, double-blinded, placebo-controlled study was carried out of 71 patients (20-65 years) who already had a restorative proctocolectomy. Subjects received either 10 mg/kg of UDCA orally per day or a placebo tablet for 24 months. The Spigelman severity score was determined after duodenal axial and lateral view endoscopy at 12 and 24 months. RESULTS: At 2 years 55 patients had completed the entire period of treatment. At the end of the follow-up period, nine (25%) patients in the UDCA group and seven (20%) in the placebo group had a decrease in the Spigelman score (P = 0.6142). Patients receiving UDCA had no side-effects (0%) compared with four (14%) in the placebo group (P = 0.0392). CONCLUSION: UDCA had no effect on the development of duodenal adenomas in FAP patients (NCT: 00134758).

Tumours with loss of MSH6 expression are MSI-H when screened with a pentaplex of five mononucleotide repeats.

BACKGROUND: microsatellite instability (MSI) is commonly screened using a panel of two mononucleotide and three dinucleotide repeats as recommended by a consensus meeting on MSI tumours held at the National Cancer Institute (Bethesda, MD, USA). According to these recommendations, tumours are classified as MSI-H when at least two of the five microsatellite markers show instability, MSI-L when only one marker shows instability and MSS when none of the markers show instability. Almost all MSI-H tumours are characterised by alterations in one of the four major proteins of the mismatch repair (MMR) system (MLH1, MSH2, MSH6 or PMS2) that renders them MMR deficient, whereas MSI-L and MSS tumours are generally MMR proficient. However, tumours from patients with a pathogenic germline mutation in MSH6 can sometimes present an MSI-L phenotype with the NCI panel. The MSH6 protein is not involved in the repair of mismatches of two nucleotides in length and consequently the three dinucleotide repeats of the NCI panel often show stability in MSH6-deficient tumours. METHODS: a pentaplex panel comprising five mononucleotide repeats has been recommended as an alternative to the NCI panel to determine tumour MSI status. Several studies have confirmed the sensitivity, specificity and ease of use of the pentaplex panel; however, its sensitivity for the detection of MSH6-deficient tumours is so far unknown. Here, we used the pentaplex panel to evaluate MSI status in 29 tumours known to harbour an MSH6 defect. RESULTS: MSI-H status was confirmed in 15 out of 15 (100%) cases where matching normal DNA was available and in 28 out of 29 (97%) cases where matching DNA was not available or was not analysed. CONCLUSION: these results show that the pentaplex assay efficiently discriminates the MSI status of tumours with an MSH6 defect.

Impact of p53 expression and microsatellite instability on stage III colon cancer disease-free survival in patients treated by 5-fluorouracil and leucovorin with or without oxaliplatin.

BACKGROUND: The aim was to determine the values of p53 tumour expression and microsatellite instability (MSI) phenotype to predict benefit from adjuvant chemotherapy of colon cancer by 5-fluorouracil and leucovorin (FL) alone or with oxaliplatin (FOLFOX). PATIENTS AND METHODS: This retrospective study included 233 unselected patients with stage III colon cancer treated by FL (n = 124) or FOLFOX (n = 109). The impact of p53 expression and MSI on disease-free survival (DFS) was defined using univariate and multivariate analyses. A Cox proportional hazards model was specifically designed to evaluate the interaction between chemotherapy and these genetic alterations. RESULTS: In univariate analyses, addition of oxaliplatin significantly improved DFS provided that tumour overexpressed p53 [hazard ratio (HR) 0.39; 95% confidence interval (CI) 0.19-0.82; P = 0.01] or displayed MSI phenotype (HR 0.17; 95% CI 0.04-0.68; P = 0.01). In multivariate analyses, p53 was confirmed as an independent factor predictive of benefit from FOLFOX (P = 0.03), while the interaction of MSI with chemotherapy could not be determined in the absence of relapse in the MSI group treated with FOLFOX. CONCLUSION: Our observations indicate that MSI status and p53 expression may influence the impact of oxaliplatin on adjuvant treatment of stage III colon cancer patients.

[Pathology: on the way to molecular analysis]. / Anatomie pathologique: en marche vers l'analyse moléculaire.

For a long time, pathology has been playing an important role in digestive diseases, especially in digestive cancers. This contribution was based and is still based on classical morphological techniques: staining of cells and tissues and recognition of diagnostic morphological patterns characteristic for a disease. Pathology is changing, and accompanies major improvements in endoscopy and imaging of gastrointestinal diseases, and new high throughput biological techniques. Recent examples show that molecular pathology (including immunohistochemistry), often included in wider "biopathology" processes, participates to pathophysiological research (for example recognition of the serrated pathway in colorectal carcinogenesis and its relation with microsatellite instability and methylation of promoters), and to diagnostic and therapeutic procedures (for example targeted therapies of gastrointestinal stromal tumours). However, the current example of the recognition of predictive factors of response to anti-EGFR treatments in colorectal cancer shows that morphological and non morphological techniques have to find their respective role in this kind of process.