David Tougeron

Effect of low-frequency KRAS mutations on the response to anti-EGFR therapy in metastatic colorectal cancer

BACKGROUND Only patients with wild-type (WT) KRAS tumors benefit from anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (Mabs) in metastatic colorectal cancer (mCRC). Pyrosequencing is now widely used for the determination of KRAS mutation burden and a conservative cut-off point of 10% has been defined. Up until now, the impact of low-frequency KRAS mutations (<10%) on the response to anti-EGFR Mabs has yet to be evaluated. PATIENTS AND METHODS Tumors from patients receiving anti-EGFR Mabs based on a WT genotype for KRAS, as determined using direct sequencing, have been retrospectively analyzed by pyrosequencing. Patients were categorized as WT (no KRAS mutation) or low-frequency mutation when KRAS mutation was <10% (KRAS low MT). RESULTS A total of 168 patients treated by anti-EGFR Mabs for mCRC were analyzed. According to pyrosequencing, 138 tumors remained KRAS WT, while 30 tumors were KRAS low MT. In the KRAS low MT and KRAS WT groups, the response rates were 6.7% and 37.0%, respectively, while stabilization amounted to 23.3% versus 32.6% and progression to 70% versus 29% (P < 0.01). Progression-free survival (PFS) was 2.7 ± 0.5 months for KRAS low MT and was 6.0 ± 0.3 months for KRAS WT (P < 0.01). CONCLUSIONS These results appear to validate consideration of low-frequency KRAS mutation tumors as positive, and justify a large-scale prospective study.

KRAS Codon 12 and 13 Mutations in Relation to Disease-Free Survival in BRAF–Wild-Type Stage III Colon Cancers from an Adjuvant Chemotherapy Trial (N0147 Alliance)

Purpose: We examined the prognostic impact of specific KRAS mutations in patients with stage III colon adenocarcinoma receiving adjuvant FOLFOX alone or combined with cetuximab in a phase III trial (N0147). Analysis was restricted to BRAF–wild-type tumors, because BRAF mutation was associated with poor prognosis, and BRAF and KRAS mutations are mutually exclusive. Experimental Design: The seven most common KRAS mutations in codon 12 and codon 13 were examined in 2,478 BRAF–wild-type tumors. Because KRAS mutations in codon 12 (n = 779) or 13 (n = 220) were not predictive of adjuvant cetuximab benefit, study arms were pooled for analysis. Disease-free survival (DFS) was evaluated by HRs using Cox models. Results: KRAS mutations in codon 12 (multivariate HR, 1.52; 95% confidence interval, CI, 1.28–1.80; P < 0.0001) or codon 13 (multivariate HR, 1.36; 95% CI, 1.04–1.77; P = 0.0248) were significantly associated with shorter DFS compared with patients with wild-type KRAS/BRAF tumors, independent of covariates. KRAS codon 12 mutations were independently associated with proficient mismatch repair (P < 0.0001), proximal tumor site (P < 0.0001), low grade, age, and sex, whereas codon 13 mutations were associated with proximal site (P < 0.0001). Conclusion: KRAS mutations in either codon 12 or 13 are associated with inferior survival in patients with resected stage III colon cancer. These data highlight the importance of accurate molecular characterization and the significant role of KRAS mutations in both codons in the progression of this malignancy in the adjuvant setting. Clin Cancer Res; 20(11); 3033–43. ©2014 AACR.

Usefulness of the Serum Carcinoembryonic Antigen Kinetic for Chemotherapy Monitoring in Patients With Unresectable Metastasis of Colorectal Cancer

PURPOSE The aim of the study was to evaluate the relationship between serum carcinoembryonic antigen (CEA) kinetic and response to chemotherapy in patients with unresectable metastasis of colorectal cancer. PATIENTS AND METHODS The kinetic was calculated using the slope of an exponential-regressive curve connecting the semi-logarithmic values of CEA. Receiver operating characteristic (ROC) curves were drawn to select the CEA slope thresholds to define patients with progressive or responsive disease with the highest sensitivity, specificity, and diagnosis accuracy odds ratio (DOR). The correlation between the CEA slopes and progression-free survival (PFS) was evaluated by the Cox model and Kaplan-Meier methods. RESULTS A total of 122 patients were included. Progression defined by CEA slope greater than +0.05 resulted in sensitivity of 85.7%, specificity of 85.1%, and DOR of 34. The area under the ROC (AUROC) curve was 0.885 (95% CI, 0.815 to 0.936; P = .0001). Response defined by CEA slope less than -0.2 resulted in sensitivity of 74.7%, specificity of 82.5%, and DOR of 16. The AUROC curve was 0.847 (95% CI, 0.770 to 0.906; P = .0001). The difference between AUROC curves calculated with six or four CEA values was not significant. PFS was correlated with CEA slopes (hazard ratio, 4.6; 95% CI, 2.48 to 8.57). The median PFS was 10 months for patients with CEA slope values less than -0.2 months versus 6 months for patients with CEA slope values greater than -0.2 (P < .0001). CONCLUSION These results suggest that the CEA kinetic is an accurate, simple, and noninvasive method to identify the disease progression in patients with unresectable metastasis of colorectal cancer.

Second-line chemotherapy with fluorouracil, leucovorin, and irinotecan (FOLFIRI regimen) in patients with advanced small bowel adenocarcinoma after failure of first-line platinum-based chemotherapy: a multicenter AGEO study.

Small bowel adenocarcinoma (SBA) is a rare tumor with poor prognosis. First‐line platinum‐based chemotherapy is active in patients with advanced SBA, but data regarding second‐line chemotherapy are lacking. The aim of this study was to evaluate the efficacy and tolerability of fluorouracil, leucovorin, and irinotecan (FOLFIRI regimen) as second‐line chemotherapy in patients with advanced SBA.

Efficacy of Adjuvant Chemotherapy in Colon Cancer With Microsatellite Instability: A Large Multicenter AGEO Study

BACKGROUND Deficient mismatch repair (dMMR) colon cancer (CC) is reportedly resistant to 5-fluorouracil (5FU) adjuvant chemotherapy while preliminary data suggest chemosensitivity to oxaliplatin. We assessed the efficacy of fluoropyrimidine with and without oxaliplatin in a large cohort of dMMR CC patients. METHODS This retrospective multicenter study included all consecutive patients who underwent curative surgical resection for stage II or III dMMR CC between 2000 and 2011. Prognostic factors were analyzed using Cox models, and hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated. All statistical tests were two-sided. RESULTS A total of 433 dMMR CC patients were included (56.8% stage II, 43.2% stage III). Mean follow-up was 47.0 months. The patients received surgery alone (n = 263) or surgery plus adjuvant chemotherapy consisting of fluoropyrimidine with (n = 119) or without (n = 51) oxaliplatin. Adjuvant chemotherapy was administered to 16.7% of stage II and 69.0% of stage III CC patients. As compared with surgery alone, adjuvant oxaliplatin-based chemotherapy improved disease-free survival (DFS) in multivariable analysis (HR = 0.35, 95% CI = 0.19 to 0.65, P < .001), contrary to adjuvant fluoropyrimidine alone (HR = 0.73, 95% CI = 0.36 to 1.49, P = .38). In the subgroup analysis, the DFS benefit of oxaliplatin-based chemotherapy was statistically significant in multivariable analysis only in stage III (HR = 0.41, 95% CI = 0.19 to 0.87, P = .02). CONCLUSION This study supports the use of adjuvant chemotherapy with fluoropyrimidine plus oxaliplatin in stage III dMMR CC.

Second‐line chemotherapy for advanced biliary tract cancer after failure of the gemcitabine‐platinum combination: A large multicenter study by the Association des Gastro‐Entérologues Oncologues

Few data are available on second‐line chemotherapy (CT2) for advanced biliary tract cancer (ABTC). The aim of this multicenter study was to describe the CT2 regimens used, the response rates, and the outcomes of patients treated with various CT2 regimens.

HLA-A*0201-restricted CEA-derived Peptide CAP1 Is Not a Suitable Target for T-cell-based Immunotherapy

Carcinoembryonic antigen (CEA) is a potential target for antigen-specific immunotherapy, as it is frequently overexpressed in human carcinomas. Moreover, an epitope derived from CEA, designated CAP1 (YLSGANLNL), has been proposed as naturally processed and presented by tumors in the human leukocyte antigen (HLA)-A*0201 context. Our aim was to fully characterize and assess the clinical relevance of the HLA-A*0201-restricted cytotoxic T lymphocyte (CTL) response against CEA. Stable and potent artificial antigen presenting cells (AAPCs) were used to evaluate T-cell response against CEA. These cells efficiently activate CTLs against tumor-derived epitopes after transduction with the antigenic peptides or full-length proteins. We found that AAPCs genetically modified to express CAP1, the agonist peptide CAP1-6D, or the whole CEA protein were not able to activate CAP1-specific CTLs from HLA-A*0201+ healthy donors or patients with colorectal carcinoma, even after multiple stimulations. In addition, we showed that a CAP1-specific T-cell clone, obtained after multiple stimulations of T cells of a HLA-A*0201+ healthy donor in vitro with autologous antigen presenting cells, recognized CEA− HLA-A*0201+ tumors transduced with a minigene encoding CAP1 but failed to react against HLA-A*0201+ tumor cells expressing CEA. Finally, AAPCs expressing the whole CEA protein did not induce any specific CTL response against CEA+ HLA-A*0201+ tumor cells highlighting the potential difficulty of mounting an efficacious T-cell response against this autoantigen. Altogether, our data indicate that CAP1 is not efficiently processed and presented by CEA+ tumor cells, and therefore, is not an appropriate target for T-cell-based immunotherapy.

Response to definitive chemoradiotherapy and survival in patients with an oesophageal adenocarcinoma versus squamous cell carcinoma: a matched-pair analysis.

Objectives: The impact of the histological tumour type in patients treated with definitive chemoradiotherapy (CRT) for an oesophageal cancer is not well established. The aim of this retrospective matched-pair analysis was to evaluate the clinical complete response (CCR) to definitive CRT and the outcome between 2 groups of patients. Methods: Fifty-seven patients with an oesophageal adenocarcinoma (ADC) were matched according to the tumour stage and the WHO performance as well as the CRT regimen status including 57 patients with an oesophageal squamous cell carcinoma (SCC). CRT was based on radiotherapy combined with a cisplatin-based chemotherapy. Results: A CCR was observed in 40 patients (70.2%) with an SCC as compared with 26 patients (45.6%) with an ADC (p = 0.013). SCC patients received significantly more of planned cisplatin and radiotherapy doses than ADC patients (82.0 vs. 67.7%, p = 0.042, and 92.5 vs. 84.5%, p = 0.023, respectively). In responders to CRT, local recurrence was significantly more frequent in SCC patients (52.5 vs. 26.9%, p = 0.046). Median survival in all patients as well as in responders to CRT was not different between the 2 groups. Conclusion: Our study showed that treatment completion and CCR to definitive CRT were more frequent in SCC with, however, more local recurrences in these patients. Further studies are required to confirm this difference in response rate to definitive CRT according to histological type of the tumour in oesophageal cancer.

Esophageal cancer in the elderly: an analysis of the factors associated with treatment decisions and outcomes

BackgroundOnly limited data has been reported so far regarding oesophageal cancer (EC) in elderly patients. The aim of the study is to identify the baseline parameters that influenced therapeutic decision.MethodsAll consecutive patients 70 years or older being treated for EC were retrospectively analyzed. Patients without visceral metastasis were divided into two groups: treatment with curative intent (chemoradiotherapy, surgery, radiotherapy, mucosectomy or photodynamic therapy) or best supportive care (BSC). Patients with metastasis were divided into two groups: palliative treatment (chemotherapy, chemoradiotherapy or radiotherapy) or BSC.ResultsTwo hundred and eighty-two patients were studied. Mean age was 76.5 ± 5.5 years and 22.4% of patients had visceral metastasis. In patients without visceral metastasis (n = 220) the majority had treatment with curative intent (n = 151) whereas in patients with metastasis (n = 62) the majority had BSC (n = 32). Severe adverse events (≥ grade 3) were observed in only 17% of the patients. Patients without specific carcinologic treatment were older, had more weight loss, worse WHO performance status and Charlson score in multivariate analysis.DiscussionOur results suggest that elderly patients with an EC could benefit from cancer treatment without major toxicities. Weight loss, WHO performance status and the Charlson score could be used to select the appropriate treatment in an elderly patient.

High plasma levels of the pro-inflammatory cytokine IL-22 and the anti-inflammatory cytokines IL-10 and IL-1ra in acute pancreatitis

BACKGROUND/OBJECTIVES Pancreatic acinar cells are major targets of IL-22. Our aim is to study early plasma levels of IL-22, of pro- and anti-inflammatory cytokines in acute pancreatitis, and their association with severity or necrosis infection. METHODS Consecutive patients admitted to the Department of Hepato-Gastroenterology at Poitiers University of Medicine Hospital (France) with a diagnosis of AP were prospectively enrolled. Plasma concentrations of IL-22, IL-6, IL-8, IL-1 α, IL-1β, TNF- α, IFN-γ, IL-17A, IL-10, IL-1ra and IL-4 were assessed by multiple immunoassay at the admission time. A thoracoabdominal contrast-enhanced CT scan was performed at day 2. RESULTS Sixty-two patients were included; 13 patients (21%) had a severe acute pancreatitis, 5 patients (8%) developed necrosis infection and 29 patients (47%) had pleural effusion. Plasma levels of IL-22 were high in AP (135 ± 31 vs 4.2 ± 1.8 pg/ml for controls, p < 0.05), but did not correlate with the severity of the disease, whereas IL-6, IL-10 and IL-1ra where enhanced in patients with severe acute pancreatitis and with pleural effusion. Patients who further developed necrosis infection had higher levels of IL-1ra at admission (p = 0.0004). CONCLUSION In acute pancreatitis, high plasma levels of IL-22 are observed, regardless the severity of the disease. In contrast, severe forms were associated with increased levels of IL-6, IL-10 and IL-1ra. The beneficial or deleterious role of IL-22 in AP remains to be further studied.