Fascin-1 expression is associated with neuroendocrine prostate cancer and directly suppressed by androgen receptor.

BACKGROUND: Neuroendocrine prostate cancer (NEPC) is an aggressive form of prostate cancer, arising from resistance to androgen-deprivation therapies. However, the molecular mechanisms associated with NEPC development and invasiveness are still poorly understood. Here we investigated the expression and functional significance of Fascin-1 (FSCN1), a pro-metastasis actin-bundling protein associated with poor prognosis of several cancers, in neuroendocrine differentiation of prostate cancer. METHODS: Differential expression analyses using Genome Expression Omnibus (GEO) database, clinical samples and cell lines were performed. Androgen or antagonist's cellular treatments and knockdown experiments were used to detect changes in cell morphology, molecular markers, migration properties and in vivo tumour growth. Chromatin immunoprecipitation-sequencing (ChIP-Seq) data and ChIP assays were analysed to decipher androgen receptor (AR) binding. RESULTS: We demonstrated that FSCN1 is upregulated during neuroendocrine differentiation of prostate cancer in vitro, leading to phenotypic changes and NEPC marker expression. In human prostate cancer samples, FSCN1 expression is restricted to NEPC tumours. We showed that the androgen-activated AR downregulates FSCN1 expression and works as a transcriptional repressor to directly suppress FSCN1 expression. AR antagonists alleviate this repression. In addition, FSCN1 silencing further impairs in vivo tumour growth. CONCLUSION: Collectively, our findings identify FSCN1 as an AR-repressed gene. Particularly, it is involved in NEPC aggressiveness. Our results provide the rationale for the future clinical development of FSCN1 inhibitors in NEPC patients.

FOLFIRINOX De-Escalation in Advanced Pancreatic Cancer: A Multicenter Real-Life Study.

BACKGROUND: Our study describes the feasibility and efficacy of a first-line FOLFIRINOX (5-fluorouracil [5FU], folinic acid, irinotecan, and oxaliplatin) induction chemotherapy (CT) followed by de-escalation as a maintenance strategy for advanced pancreatic cancer. MATERIALS AND METHODS: This multicenter retrospective study was conducted from January 2011 to December 2018. FOLFIRINOX de-escalation was defined as stopping oxaliplatin and/or irinotecan after at least four cycles of FOLFIRINOX, without evidence of disease progression. Maintenance schedules were fluoropyrimidine monotherapy (intravenous or oral [capecitabine]), FOLFOX (5FU, oxaliplatin), or FOLFIRI (5FU, irinotecan). Primary endpoint was overall survival (OS). Secondary endpoints were first progression-free survival (PFS1), second progression-free survival (PFS2), and toxicity. RESULTS: Among 321 patients treated with FOLFIRINOX, 147 (45.8%) were included. Median OS was 16.1 months (95% confidence interval [CI], 13.7-20.3) and median PFS1 was 9.4 months (95% CI, 8.5-10.4). The preferred maintenance regimen was FOLFIRI in 66 (45%) patients versus 5FU monotherapy in 52 (35%) and FOLFOX in 25 (17%) patients. Among 118 patients who received maintenance CT with FOLFIRI or 5FU, there was no difference in PFS1 (median, 9.0 vs. 10.1 months, respectively; p = .33) or OS (median, 16.6 vs. 18.7 months; p = .86) between the two maintenance regimens. Reintroduction of FOLFIRINOX was performed in 20.2% of patients, with a median PFS2 of 2.8 months (95% CI, 2.0-22.3). The rates of grade 3-4 toxicity were significantly higher with FOLFIRI maintenance CT than with 5FU (41% vs. 22%; p = .03), especially for neuropathy (73% vs. 9%). CONCLUSION: 5FU monotherapy maintenance appeared to be as effective as FOLFIRI, in a FOLFIRINOX de-escalation strategy, which is largely used in France. IMPLICATIONS FOR PRACTICE: FOLFIRINOX de-escalation and maintenance is a feasible strategy in advanced pancreatic cancer that decreases chemotherapy toxicity to improve both survival and quality of life. Survivals in patients with maintenance therapy are clinically meaningful. Fluoropyrimidine monotherapy maintenance seems to be as efficient as FOLFIRI and should be a reference arm in future pancreatic cancer maintenance trials.

FOLFOXIRI vs FOLFIRINOX as first-line chemotherapy in patients with advanced pancreatic cancer: A population-based cohort study.

BACKGROUND: FOLFIRINOX regimen is the first-line reference chemotherapy (L1) in advanced pancreatic ductal adenocarcinoma (aPDAC). FOLFOXIRI, a schedule with a lower dose of irinotecan and no bolus 5-fluorouracil, has demonstrated efficacy and feasibility in colorectal cancer. AIM: To investigate the potential clinical value of FOLFOXIRI in patients with aPDAC in routine clinical practice. METHODS: Analyses were derived from all consecutive aPDAC patients treated in L1 between January 2011 and December 2017 in two French institutions, with either FOLFOXIRI (n = 165) or FOLFIRINOX (n = 124) regimens. FOLFOXIRI consisted of irinotecan (165 mg/m2), oxaliplatin (85 mg/m2), leucovorin (200 mg/m2) and 5-fluorouracil (3200 mg/m2 as a 48-h continuous infusion) every 2 wk. Ninety-six pairs of patients were selected through propensity score matching, and clinical outcomes of the two treatment regimens were compared. RESULTS: Median overall survival was 11.1 mo in the FOLFOXIRI and 11.6 mo in the FOLFIRINOX cohorts, respectively. After propensity score matching, survival rates remained similar between the two regimens in terms of overall survival (hazard ratio = 1.22; P = 0.219) and progression-free survival (hazard ratio = 1.27; P = 0.120). The objective response rate was 37.1% in the FOLFOXIRI group vs 47.8% in the FOLFIRINOX group (P = 0.187). Grade 3/4 toxicities occurred in 28.7% of patients in the FOLFOXIRI cohort vs 19.5% in the FOLFIRINOX cohort (P = 0.079). FOLFOXIRI was associated with a higher incidence of grade 3/4 digestive adverse events. Hematopoietic growth factors were used after each chemotherapy cycle and the low hematological toxicity rates were below 5% with both regimens. CONCLUSION: FOLFOXIRI is feasible in L1 in patients with aPDAC but does not confer any therapeutic benefit as compared with FOLFIRINOX. The low hematological toxicity rates strengthened the relevance of primary prophylaxis with hematopoietic growth factors.