Mohamed Hebbar

BACKGROUND: Among patients with metastatic pancreatic cancer, combination chemotherapy with fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX) leads to longer overall survival than gemcitabine therapy. We compared the efficacy and safety of a modified FOLFIRINOX regimen with gemcitabine as adjuvant therapy in patients with resected pancreatic cancer. METHODS: We randomly assigned 493 patients with resected pancreatic ductal adenocarcinoma to receive a modified FOLFIRINOX regimen (oxaliplatin [85 mg per square meter of body-surface area], irinotecan [180 mg per square meter, reduced to 150 mg per square meter after a protocol-specified safety analysis], leucovorin [400 mg per square meter], and fluorouracil [2400 mg per square meter] every 2 weeks) or gemcitabine (1000 mg per square meter on days 1, 8, and 15 every 4 weeks) for 24 weeks. The primary end point was disease-free survival. Secondary end points included overall survival and safety. RESULTS: At a median follow-up of 33.6 months, the median disease-free survival was 21.6 months in the modified-FOLFIRINOX group and 12.8 months in the gemcitabine group (stratified hazard ratio for cancer-related event, second cancer, or death, 0.58; 95% confidence interval [CI], 0.46 to 0.73; P<0.001). The disease-free survival rate at 3 years was 39.7% in the modified-FOLFIRINOX group and 21.4% in the gemcitabine group. The median overall survival was 54.4 months in the modified-FOLFIRINOX group and 35.0 months in the gemcitabine group (stratified hazard ratio for death, 0.64; 95% CI, 0.48 to 0.86; P=0.003). The overall survival rate at 3 years was 63.4% in the modified-FOLFIRINOX group and 48.6% in the gemcitabine group. Adverse events of grade 3 or 4 occurred in 75.9% of the patients in the modified-FOLFIRINOX group and in 52.9% of those in the gemcitabine group. One patient in the gemcitabine group died from toxic effects (interstitial pneumonitis). CONCLUSIONS: Adjuvant therapy with a modified FOLFIRINOX regimen led to significantly longer survival than gemcitabine among patients with resected pancreatic cancer, at the expense of a higher incidence of toxic effects. (Funded by R&D Unicancer and others; ClinicalTrials.gov number, NCT01526135 ; EudraCT number, 2011-002026-52 .).

Tumor-associated macrophages (TAMs), the most abundant immunosuppressive cells in the tumor microenvironment, originate from blood monocytes and exhibit an IL-10(high)IL-12(low) M2 profile. The factors involved in TAM generation remain unidentified. We identify here leukemia inhibitory factor (LIF) and IL-6 as tumor microenvironmental factors that can promote TAM generation. Ovarian cancer ascites switched monocyte differentiation into TAM-like cells that exhibit most ovarian TAM functional and phenotypic characteristics. Ovarian cancer ascites contained high concentrations of LIF and IL-6. Recombinant LIF and IL-6 skew monocyte differentiation into TAM-like cells by enabling monocytes to consume monocyte-colony-stimulating factor (M-CSF). Depletion of LIF, IL-6, and M-CSF in ovarian cancer ascites suppressed TAM-like cell induction. We extended these observations to different tumor-cell line supernatants. In addition to revealing a new tumor-escape mechanism associated with TAM generation via LIF and IL-6, these findings offer novel therapeutic perspectives to subvert TAM-induced immunosuppression and hence improve T-cell-based antitumor immunotherapy efficacy.

Abstract Purpose: Metastasis and drug resistance are the major limitations in the survival and management of patients with cancer. This study aimed to identify the mechanisms underlying HT29 colon cancer cell chemoresistance acquired after sequential exposure to 5-fluorouracil (5FU), a classical anticancer drug for treatment of epithelial solid tumors. We examined its clinical relevance in a cohort of patients with colon cancer with liver metastases after 5FU-based neoadjuvant chemotherapy and surgery. Results: We show that a clonal 5F31 cell population, resistant to 1 μmol/L 5FU, express a typical cancer stem cell–like phenotype and enter into a reversible quiescent G0 state upon reexposure to higher 5FU concentrations. These quiescent cells overexpressed the tyrosine kinase c-Yes that became activated and membrane-associated upon 5FU exposure. This enhanced signaling pathway induced the dissociation of the Yes/YAP (Yes-associated protein) molecular complex and depleted nuclear YAP levels. Consistently, YES1 silencing decreased nuclear YAP accumulation and induced cellular quiescence in 5F31 cells cultured in 5FU-free medium. Importantly, YES1 and YAP transcript levels were higher in liver metastases of patients with colon cancer after 5FU-based neoadjuvant chemotherapy. Moreover, the YES1 and YAP transcript levels positively correlated with colon cancer relapse and shorter patient survival (P &amp;lt; 0.05 and P &amp;lt; 0.025, respectively). Conclusions: We identified c-Yes and YAP as potential molecular targets to eradicate quiescent cancer cells and dormant micrometastases during 5FU chemotherapy and resistance and as predictive survival markers for colon cancer. Clin Cancer Res; 20(4); 837–46. ©2013 AACR.

Tumor-associated macrophages (TAM) are M2d-polarized cells (IL-10(high), IL-12(low), ILT3(high), CD86(low)) that accumulate in tumor microenvironment. TAM inhibit antitumor T lymphocyte generation and function, contribute to tumor tolerance and are trophic for tumors. In this study, we investigated whether some immunological factors may reverse TAM immunosuppressive properties. Among 32 cytokines, we have identified IFNgamma on its ability to switch immunosuppressive TAM into immunostimulatory cells. Upon IFNgamma exposure, TAM purified from ovarian cancer ascites recover a M1 phenotype (IL-10(low), IL-12(high)), express high levels of CD86 and low levels of ILT3, enhance the proliferation of CD4(+) T lymphocytes and potentiate the cytotoxic properties of a MelanA-specific CD8(+) T cell clone. IFNgamma-treated TAM also secreted reduced levels of mediators promoting suppressive T cell accumulation (CCL18) and trophic for tumors (VEGF and MMP9). As TAM derive from the local differentiation of peripheral blood monocytes, we investigated whether IFNgamma may also affect TAM generation. In the presence of ovarian ascites, IFNgamma skewed monocyte differentiation from TAM-like cells to M1-polarized immunostimulatory macrophages. Together, these data show that IFNgamma overcomes TAM-induced immunosuppression by preventing TAM generation and functions. These data highlight that IFNgamma used locally at the tumor site could potentiate the efficacy of antitumor immunotherapies based on the generation of effector T cells.

Importance: Early results at 3 years from the PRODIGE 24/Canadian Cancer Trials Group PA6 randomized clinical trial showed survival benefits with adjuvant treatment with modified FOLFIRINOX vs gemcitabine in patients with resected pancreatic ductal adenocarcinoma; mature data are now available. Objective: To report 5-year outcomes and explore prognostic factors for overall survival. Design, Setting, and Participants: This open-label, phase 3 randomized clinical trial was conducted at 77 hospitals in France and Canada and included patients aged 18 to 79 years with histologically confirmed pancreatic ductal adenocarcinoma who had undergone complete macroscopic (R0/R1) resection within 3 to 12 weeks before randomization. Patients were included from April 16, 2012, through October 3, 2016. The cutoff date for this analysis was June 28, 2021. Interventions: A total of 493 patients were randomized (1:1) to receive treatment with modified FOLFIRINOX (oxaliplatin, 85 mg/m2 of body surface area; irinotecan, 150-180 mg/m2; leucovorin, 400 mg/m2; and fluorouracil, 2400 mg/m2, every 2 weeks) or gemcitabine (1000 mg/m2, days 1, 8, and 15, every 4 weeks) as adjuvant therapy for 24 weeks. Main Outcomes and Measures: Primary end point was disease-free survival. Secondary end points included overall survival, metastasis-free survival, and cancer-specific survival. Prognostic factors for overall survival were determined. Results: Of the 493 patients, 216 (43.8%) were women, and the mean (SD) age was 62.0 (8.9) years. At a median of 69.7 months' follow-up, 367 disease-free survival events were observed. In patients receiving chemotherapy with modified FOLFIRINOX vs gemcitabine, median disease-free survival was 21.4 months (95% CI, 17.5-26.7) vs 12.8 months (95% CI, 11.6-15.2) (hazard ratio [HR], 0.66; 95% CI, 0.54-0.82; P < .001) and 5-year disease-free survival was 26.1% vs 19.0%; median overall survival was 53.5 months (95% CI, 43.5-58.4) vs 35.5 months (95% CI, 30.1-40.3) (HR, 0.68; 95% CI, 0.54-0.85; P = .001), and 5-year overall survival was 43.2% vs 31.4%; median metastasis-free survival was 29.4 months (95% CI, 21.4-40.1) vs 17.7 months (95% CI, 14.0-21.2) (HR, 0.64; 95% CI, 0.52-0.80; P < .001); and median cancer-specific survival was 54.7 months (95% CI, 45.8-68.4) vs 36.3 months (95% CI, 30.5-43.9) (HR, 0.65; 95% CI, 0.51-0.82; P < .001). Multivariable analysis identified modified FOLFIRINOX, age, tumor grade, tumor staging, and larger-volume center as significant favorable prognostic factors for overall survival. Shorter relapse delay was an adverse prognostic factor. Conclusions and Relevance: The final 5-year results from the PRODIGE 24/Canadian Cancer Trials Group PA6 randomized clinical trial indicate that adjuvant treatment with modified FOLFIRINOX yields significantly longer survival than gemcitabine in patients with resected pancreatic ductal adenocarcinoma. Trial Registration: EudraCT: 2011-002026-52; ClinicalTrials.gov Identifier: NCT01526135.