Prognosis of microsatellite instability and/or mismatch repair deficiency stage III colon cancer patients after disease recurrence following adjuvant treatment: results of an ACCENT pooled analysis of seven studies.

BACKGROUND: Microsatellite instable/deficient mismatch repair (MSI/dMMR) metastatic colorectal cancers have been reported to have a poor prognosis. Frequent co-occurrence of MSI/dMMR and BRAFV600E complicates the association. PATIENTS AND METHODS: Patients with resected stage III colon cancer (CC) from seven adjuvant studies with available data for disease recurrence and MMR and BRAFV600E status were analyzed. The primary end point was survival after recurrence (SAR). Associations of markers with SAR were analyzed using Cox proportional hazards models adjusted for age, gender, performance status, T stage, N stage, primary tumor location, grade, KRAS status, and timing of recurrence. RESULTS: Among 2630 patients with cancer recurrence (1491 men [56.7%], mean age, 58.5 [19-85] years), multivariable analysis revealed that patients with MSI/dMMR tumors had significantly longer SAR than did patients with microsatellite stable/proficient MMR tumors (MSS/pMMR) (adjusted hazard ratio [aHR], 0.82; 95% CI [confidence interval], 0.69-0.98; P = 0.029). This finding remained when looking at patients treated with standard oxaliplatin-based adjuvant chemotherapy regimens only (aHR, 0.76; 95% CI, 0.58-1.00; P = 0.048). Same trends for SAR were observed when analyzing MSI/dMMR versus MSS/pMMR tumor subgroups lacking BRAFV600E (aHR, 0.84; P = 0.10) or those harboring BRAFV600E (aHR, 0.88; P = 0.43), without reaching statistical significance. Furthermore, SAR was significantly shorter in tumors with BRAFV600E versus those lacking this mutation (aHR, 2.06; 95% CI, 1.73-2.46; P < 0.0001), even in the subgroup of MSI/dMMR tumors (aHR, 2.65; 95% CI, 1.67-4.21; P < 0.0001). Other factors associated with a shorter SAR were as follows: older age, male gender, T4/N2, proximal primary tumor location, poorly differentiated adenocarcinoma, and early recurrence. CONCLUSIONS: In stage III CC patients recurring after adjuvant chemotherapy, and before the era of immunotherapy, the MSI/dMMR phenotype was associated with a better SAR compared with MSS/pMMR. BRAFV600E mutation was a poor prognostic factor for both MSI/dMMR and MSS/pMMR patients. TRIAL IDENTIFICATION NUMBERS: NCT00079274, NCT00265811, NCT00004931, NCT00004931, NCT00026273, NCT00096278, NCT00112918.

Subgroups and prognostication in stage III colon cancer: future perspectives for adjuvant therapy.

Since the MOSAIC study, oxaliplatin-based adjuvant chemotherapy has been the standard treatment of stage III colon cancer. Combination therapy with fluoropyrimidines and oxaliplatin has improved overall survival (OS) and reduced the risk of recurrence in patients with resected stage III colon cancer. However, only 20% of patients really benefit from adjuvant chemotherapy, exposing 80% of patients to unnecessary toxicity. Recent analyses of large multicenter adjuvant studies have focused on the prognostication of OS and disease-free survival in stage III colon cancer in order to reduce over-treatment and to find more accurate prognostic tools than those used for adjuvant treatment decision-making in stage II disease. Indeed, clinical and pathological prognostic factors, although important, are not sufficient to decide which stage III patients will benefit from adjuvant therapy, and biomarkers will help select patient that need adjuvant treatment. Molecular markers such as microsatellite status and BRAF and KRAS mutations have recently been explored, and molecular signatures have been identified as promising prognostic factor for OS. Furthermore, recent studies have highlighted the prognostic value of immune infiltration. This review focuses on pathologic, immunologic and molecular prognostic markers for stage III colon cancer that could help clinicians tailor adjuvant treatment in a comprehensive transversal approach.

Adjuvant FOLFOX +/- cetuximab in full RAS and BRAF wildtype stage III colon cancer patients.

Background: RAS mutations have been shown to confer resistance to anti- epidermal growth factor receptor (EGFR) treatment. We analysed the results of the PETACC8 trial (cetuximab + FOLFOX vs FOLFOX) in full RAS and BRAF wildtype (WT) patients (pts) with resected stage III colon cancer. Patients and methods: Exons 2, 3 and 4 of KRAS and NRAS, and BRAF exons 11 and 15, were sequenced using the Ampliseq colon-lung cancer panel version 2, in PETACC8 trial pts who consented to translational research. The impact of cetuximab on time to recurrence (TTR), disease-free survival (DFS) and overall survival (OS) was investigated in pts with tumours harbouring RAS and BRAF WT, and RAS mutations. The prognostic value of each individual mutation was also tested. Results: Among the 2559 pts analysed, 745 pts (29%) were known to have KRAS exon 2 mutations and 163 pts (6.4%) the BRAF V600E mutation. Of the remaining 1651 pts, 1054 were assessed by NGS, showing that a further 227 pts (21%) had KRAS exon 2, 3, 4 or NRAS exon 2, 3, 4 mutations, and that 46 pts (4.4%) had a newly diagnosed BRAF mutation. Cetuximab added to FOLFOX did not significantly improve TTR, DFS or OS in pts with RAS WT or RAS and BRAF WT tumours (HR 0.77-1.03, all P > 0.05). Cetuximab addition was not either significantly deleterious in RAS mutant pts or in pts with rare RAS or BRAF mutations. In the overall trial population, NRAS and KRAS codon 61 mutations were the only rare mutations with the same pejorative prognostic value as KRAS exon 2 or BRAF V600E mutations. Conclusion: Though not significant, the clinically relevant 0.76 adjusted HR observed for DFS in favour of adding cetuximab to FOLFOX, in full RAS and BRAF WT stage III colon cancer pts, may justify a new randomized controlled trial testing EGFR inhibitors in this setting. Clinical trial number: This is an ancillary study of the PETACC8 trial: EUDRACT 2005-003463-23.

ESMO consensus guidelines for the management of patients with metastatic colorectal cancer.

Colorectal cancer (CRC) is one of the most common malignancies in Western countries. Over the last 20 years, and the last decade in particular, the clinical outcome for patients with metastatic CRC (mCRC) has improved greatly due not only to an increase in the number of patients being referred for and undergoing surgical resection of their localised metastatic disease but also to a more strategic approach to the delivery of systemic therapy and an expansion in the use of ablative techniques. This reflects the increase in the number of patients that are being managed within a multidisciplinary team environment and specialist cancer centres, and the emergence over the same time period not only of improved imaging techniques but also prognostic and predictive molecular markers. Treatment decisions for patients with mCRC must be evidence-based. Thus, these ESMO consensus guidelines have been developed based on the current available evidence to provide a series of evidence-based recommendations to assist in the treatment and management of patients with mCRC in this rapidly evolving treatment setting.

Prognostic value of KRAS mutations in stage III colon cancer: post hoc analysis of the PETACC8 phase III trial dataset.

BACKGROUND: The prognostic value of KRAS mutations in colon adenocarcinoma is controversial. We examined this question as an ancillary study of the PETACC8 phase III trial. PATIENTS AND METHODS: We analyzed the prognostic impact of KRAS exon 2 mutations in stage III colon cancer patients (n = 1657) receiving adjuvant FOLFOX ± cetuximab therapy included in the PETACC8 trial. Patients with BRAF-mutated cancers were excluded and, as no difference was found for time to recurrence (TTR) and disease-free survival (DFS) between treatment arms, both were pooled for analysis. Associations with TTR and DFS were analyzed using a Cox proportional hazards model. RESULTS: KRAS mutations were found in 638 of 1657 tumors and linked to shorter TTR (P < 0.001). However, when specific mutations were compared with wild-type, codon 12 mutations [hazard ratio (HR) 1.67, 95% confidence interval (CI) 1.35-2.04; P < 0.001] but not codon 13 (HR 1.23, 95% CI 0.85-1.79; P = 0.26) were significantly associated with shorter TTR, independently of other covariates. The interaction test showed that, regarding tumor location (distal versus proximal), KRAS genotype affects differently on recurrence (P = 0.02) and DFS (P = 0.042). Subgroup analysis showed that KRAS only affected TTR and DFS in distal tumors (n = 1043; 692 wild type; 351 mutated), with an increased risk of relapse (HR 1.96, 95% CI 1.51-2.56; P < 0.0001) for KRAS codon 12 mutations and a borderline significance for codon 13 mutations (HR 1.59, 95% CI 1.00-2.56; P = 0.051). CONCLUSION: KRAS exon 2 mutations are independent predictors of shorter TTR in patients with resected stage III distal colon cancers receiving adjuvant therapy. Future clinical trials in the adjuvant setting should consider both the tumor location and KRAS mutations as important stratification factors. CLINICAL TRIAL NUMBER: This is an ancillary study of the PETACC8 trial: EUDRACT 2005-003463-23.

Small bowel adenocarcinoma phenotyping, a clinicobiological prognostic study.

BACKGROUND: Small bowel adenocarcinoma (SBA) is a rare tumour with a poor prognosis. Molecular biology data on SBA carcinogenesis are lacking. METHODS: Expression of HER2, ß-catenin, p53 and mismatch repair (MMR) protein was assessed by immunohistochemistry. KRAS, V600E BRAF mutations and microsatellite instability were investigated. RESULTS: We obtained samples from 63 SBA patients (tumour stages: I-II: 30%; III: 35%; IV: 32%; locally advanced: 3%). HER2 overexpression (3+) was observed in 2 out of 62 patients, overexpression of p53 in 26 out of 62, abnormal expression of ß-catenin in 12 out of 61, KRAS mutation in 21 out of 49, BRAF V600E mutation in 1 out of 40 patients, MMR deficiency (dMMR) in 14 out of 61 and was consistent with Lynch syndrome in 9 out of 14 patients. All of the dMMR tumours were in the duodenum or jejunum and only one was stage IV. Median overall survival (OS) was 36.6 months (95% CI, 26.9-72.2). For all patients, in univariate analysis, stages I-II (P<0.001), WHO PS 0-1 (P=0.01) and dMMR phenotype (P=0.02) were significantly associated with longer OS. In multivariate analysis, disease stage (P=0.01) and WHO PS 0-1 (P=0.001) independently predicted longer OS. For stage IV patients, median OS was 20.5 months (95% CI: 14.6; 36.6 months). In multivariate analysis, WHO PS 0-1 (P=0.0001) and mutated KRAS status (P=0.02) independently predicted longer OS. CONCLUSION: This large study suggests that molecular alterations in SBA are closer to those in colorectal cancer (CRC) than those in gastric cancer, with low levels of HER 2 overexpression and high frequencies of KRAS mutations. The seemingly higher frequency of dMMR than in CRC may be explained by the higher frequency of Lynch syndrome in SBA patients. A dMMR phenotype was significantly associated with a non-metastatic tumour (P=0.02). A trend for a good prognosis and a duodenum or jejunum primary site was associated with dMMR.

Trifluridine/tipiracil versus placebo for third or later lines of treatment in metastatic gastric cancer: an exploratory subgroup analysis from the TAGS study.

BACKGROUND: Metastatic gastric cancer and cancer of the esophagogastric junction (GC/EGJ) is an aggressive disease with poor prognosis. In the TAGS study, trifluridine/tipiracil (FTD/TPI) improved overall survival (OS) compared with placebo in heavily pre-treated patients. This unplanned, exploratory subgroup analysis of the TAGS study aimed to clarify outcomes when FTD/TPI was used as third-line (3L) treatment and fourth- or later-line (4L+) treatment. PATIENTS AND METHODS: Patients were divided into a 3L group (126 and 64 in FTD/TPI and placebo arms, respectively) and 4L+ group (211 and 106 in FTD/TPI and placebo arms, respectively). Endpoints included OS, progression-free survival (PFS), time to Eastern Cooperative Oncology Group performance status (ECOG PS) deterioration to ≥2, and safety. RESULTS: Baseline characteristics were generally well balanced between FTD/TPI and placebo for 3L and 4L+ treatment. Median OS (mOS) for FTD/TPI versus placebo was: 6.8 versus 3.2 months {hazard ratio (HR) [95% confidence interval (CI)] = 0.68 (0.47-0.97), P = 0.0318} in the 3L group; and 5.2 versus 3.7 months [0.73 (0.55-0.95), P = 0.0192] in the 4L+ group. Median PFS for FTD/TPI versus placebo was 3.1 versus 1.9 months [0.54 (0.38-0.77), P = 0.0004] in the 3L group; and 1.9 versus 1.8 months [0.57 (0.44-0.74), P < 0.0001] in the 4L+ group. Time to deterioration of ECOG PS to ≥2 for FTD/TPI versus placebo was 4.8 versus 2.0 months [HR (95% CI) = 0.60 (0.42-0.86), P = 0.0049] in the 3L group; and 4.0 versus 2.5 months [0.75 (0.57-0.98), P = 0.0329] in the 4L+ group. The safety of FTD/TPI was consistent in all subgroups. CONCLUSIONS: This analysis confirms the efficacy and safety of FTD/TPI in patients with GC/EGJ in third and later lines with a survival benefit that seems slightly superior in 3L treatment. When FTD/TPI is taken in 3L as recommended in the international guidelines, physicians can expect to provide patients with an mOS of 6.8 months.

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.

Chemotherapy of advanced small-bowel adenocarcinoma: a multicenter AGEO study.

BACKGROUND: Small-bowel adenocarcinoma (SBA) is a rare tumor of poor prognosis. Data on the efficacy of chemotherapy for advanced SBA are scarce. PATIENTS AND METHODS: All patients with advanced SBA who received frontline chemotherapy from 1996 to 2008 were eligible for this retrospective multicenter study. RESULTS: Ninety-three consecutive patients were included. In the entire population, the median progression-free survival (PFS) and overall survival (OS) times were 6.6 and 15.1 months, respectively. Median PFS times among patients treated with LV5FU2 (n = 10), FOLFOX (n = 48), FOLFIRI (n = 19) and LV5FU2-cisplatin (n = 16) were 7.7, 6.9, 6.0 and 4.8 months, respectively, while median OS times were 13.5, 17.8, 10.6 and 9.3 months, respectively. In multivariate analysis, World Health Organization performance status (PS) (P < 0.0001) and elevated serum levels of carcinoembryonic antigen (CEA) (P = 0.02) and carbohydrate antigen 19-9 (CA 19-9) (P = 0.03) were the only variables significantly associated with poor OS. In the subgroup of patients treated with platinum-based chemotherapy, multivariate analysis showed that LV5FU2-cisplatin was associated with poorer PFS (P < 0.0001) and OS (P = 0.02) compared with FOLFOX. CONCLUSIONS: This is the largest study of chemotherapy in advanced SBA. Baseline PS and CEA and CA 19-9 levels were the main prognostic factors. FOLFOX seems to be the most effective platinum-based chemotherapy regimen.

[Small bowel adenocarcinoma]. / Adénocarcinome de l'intestin grêle.

Small bowel adenocarcinoma is a rare tumor. These tumors are more often sporadic but there is some predisposing disease (Crohn disease, genetic syndrome and rarely celiac disease). Diagnosis is usually performed at an advanced stage because of non-specific nature of clinical manifestations. New methods of radiological and endoscopic exploration of small intestine should allow earlier diagnosis. Surgical resection remains the only potentially curative treatment for non-metastasic tumors. The main prognosis factor is lymph nodes involvement. The role of adjuvant chemotherapy is unclear. For metastatic tumors, 5-fluorouracil and platinum salt combination appears to be the most effective chemotherapy despite of the absence of randomized studies. A national prospective cohort study is currently evaluating the results of chemotherapy (recommended protocol: FOLFOX) as adjuvant and palliative treatment of small bowel adenocarcinoma.

Small bowel polyp resection using device-assisted enteroscopy in Peutz-Jeghers Syndrome: Results of a specialised tertiary care centre.

INTRODUCTION: Enteroscopy resection of small bowel polyps in Peutz-Jeghers syndrome has only been described in small case series. Herein, we aimed to assess the efficacy of enteroscopy resection of small bowel polyps within a specialised tertiary care centre and the impact on intraoperative enteroscopy. METHODS: This was an observational single-centre study. All adult Peutz-Jeghers syndrome patients followed in the Predisposition Digestive Ile-de-France network who underwent an endoscopic resection of at least one small bowel polyp ≥ 1 cm by enteroscopy between 2002-2015 were included. Small bowel polyps were detected under a dedicated screening programme by previous capsule endoscopy and/or magnetic resonance enterography, performed every 2-3 years. Complete treatment was defined as the absence of polyps ≥ 1 cm after conventional endoscopic resection. Intraoperative enteroscopy or surgical resection were indicated in incomplete treatments. The overall complete treatment rate including conventional enteroscopy and intraoperative enteroscopy was also considered. RESULTS: Endoscopic resection of 216 small bowel polyps (median: 8.6 per patient, size: 6-60 mm) was performed by 50 enteroscopies in 25 patients (mean age: 36 years, range: 18-71, 56% male) with small bowel polyp ≥ 1 cm. Twenty-three patients (92%) underwent 42 screening capsule endoscopies and 14 (57%) had 23 magnetic resonance enterographies during a median follow-up of 60 months. Complete treatment was achieved in 76%. Intraoperative enteroscopy and surgical resection were performed in four (16%) and two (8%) patients. Intraoperative enteroscopy improved by 16% the complete treatment rate and the overall rate was 92%. The complication rate was 6%. CONCLUSION: This long-term study confirmed the efficacy and safety of endoscopic resection of small bowel polyps in Peutz-Jeghers syndrome. Intraoperative enteroscopy can be a complementary approach in selected cases.

Immunotherapy in advanced gastric cancer, is it the future?

The prognosis of advanced gastric cancer remains extremely poor despite the use of standard therapies such as chemotherapy and biological agents. Blocking immune checkpoint especially programmed cell death-1 (PD-1) and its ligand (PD-L1 or B7-H1), has proven efficacy in several solid cancers, and seems to become a potential option in gastric cancer treatment. This review will focus on data describing the immune microenvironment of gastric tumors on which blocking PD-1/PD-L1 axis may have an anti-tumor efficacy. Then, the encouraging results of clinical trials evaluating anti-PD-1/PD-L1-based therapeutic strategy in first or later-line settings will be discuss. Finally, clinical outcomes according to PD-L1 expression, mismatch repair phenotype and other potential predictive biomarkers of anti-tumor response will be described. Altogether, immunotherapy seems promising in advanced gastric cancer in monotherapy or in combining strategies probably for a specific subgroup of patients who need to be better identified.

Predictors of disease-free survival in colorectal cancer with microsatellite instability: An AGEO multicentre study.

BACKGROUND: A microsatellite instability (MSI) phenotype is found in about 12% of colorectal cancers (CRCs) and is associated with a low recurrence rate after curative surgery. Several studies have identified clinical and pathological factors predictive of recurrence in resected CRC, but not in the MSI subgroup. PATIENTS AND METHODS: This multicentre retrospective study included patients with stage I, II or III MSI CRCs. Disease-free survival (DFS) was calculated with the Kaplan-Meier method. Factors associated with DFS were identified in univariate and multivariate Cox analyses. RESULTS: We studied 521 patients with MSI CRC. Respectively 11%, 51% and 38% of patients were at stage I, II and III. Mean age was 68.7years and 36% of the patients received adjuvant chemotherapy. Median follow-up was 32.8months. The disease recurrence rates were 6% and 21% in stage II and III patients, respectively. The 3-year DFS rate was 77%. In univariate analysis, age, bowel obstruction, lymph node invasion, stage T4, vascular emboli, lymphatic invasion and perinervous invasion were associated with poorer DFS (P<0.05). Three relevant independent predictors of poor DFS were identified in multivariate analysis, namely bowel obstruction (HR=2.46; 95%CI 1.31-4.62, P=0.005), vascular emboli (HR=2.79; 95%CI 1.74-4.47, P<0.001) and stage T4 (HR=2.16; 95%CI 1.31-3.56, P=0.002). CONCLUSIONS: Bowel obstruction, vascular emboli and stage T4 are independently associated with MSI CRC recurrence, suggesting that screening for vascular emboli in routine clinical practice may assist with adjuvant chemotherapy decision-making.

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.