encodes the p110α catalytic subunit of PI3K and is frequently mutated in human cancers, including ∼30% of colorectal cancer. Oncogenic mutations in
render colorectal cancers more dependent on ...glutamine. Here we report that the glutaminase inhibitor CB-839 preferentially inhibits xenograft growth of
-mutant, but not wild-type (WT), colorectal cancers. Moreover, the combination of CB-839 and 5-fluorouracil (5-FU) induces
-mutant tumor regression in xenograft models. CB-839 treatment increased reactive oxygen species and caused nuclear translocation of Nrf2, which in turn upregulated mRNA expression of uridine phosphorylase 1 (UPP1). UPP1 facilitated the conversion of 5-FU to its active compound, thereby enhancing the inhibition of thymidylate synthase. Consistently, knockout of UPP1 abrogated the tumor inhibitory effect of combined CB-839 and 5-FU administration. A phase I clinical trial showed that the combination of CB-839 and capecitabine, a prodrug of 5-FU, was well tolerated at biologically-active doses. Although not designed to test efficacy, an exploratory analysis of the phase I data showed a trend that
-mutant patients with colorectal cancer might derive greater benefit from this treatment strategy as compared with
WT patients with colorectal cancer. These results effectively demonstrate that targeting glutamine metabolism may be an effective approach for treating patients with
-mutant colorectal cancers and warrants further clinical evaluation. SIGNIFICANCE: Preclinical and clinical trial data suggest that the combination of CB-839 with capecitabine could serve as an effective treatment for
-mutant colorectal cancers.
PURPOSE
The aim of this work was to provide an update to the ASCO guideline on metastatic pancreatic cancer pertaining to recommendations for therapy options after first-line treatment.
METHODS
ASCO ...convened an Expert Panel and conducted a systematic review to update guideline recommendations for second-line therapy for metastatic pancreatic cancer.
RESULTS
One randomized controlled trial of olaparib versus placebo, one report on phase I and II studies of larotrectinib, and one report on phase I and II studies of entrectinib met the inclusion criteria and inform the guideline update.
RECOMMENDATIONS
New or updated recommendations for germline and somatic testing for microsatellite instability high/mismatch repair deficiency, BRCA mutations, and TRK alterations are provided for all treatment-eligible patients to select patients for recommended therapies, including pembrolizumab, olaparib, larotrectinib, or entrectinib, or potential clinical trials. The Expert Panel continues to endorse the remaining recommendations for second-line chemotherapy, as well as other recommendations related to treatment, follow-up, and palliative care from the 2018 version of this guideline. Additional information is available at www.asco.org/gastrointestinal-cancer-guidelines .
Purpose In 2016, ASCO published a guideline to assist in clinical decision making in metastatic pancreatic cancer for initial assessment after diagnosis, first- and second-line treatment options, ...palliative and supportive care, and follow-up. The purpose of this update is to incorporate new evidence related to second-line therapy for patients who have experienced disease progression or intolerable toxicity during first-line therapy. Methods ASCO convened an Expert Panel to conduct a systematic review of the literature on second-line therapy published between June 2015 and January 2018. Recommendations on other topics covered in the 2016 Metastatic Pancreatic Cancer Guideline were endorsed by the Expert Panel. Results Two new studies were found that met the inclusion criteria. Recommendations For second-line therapy, gemcitabine plus nanoparticle albumin-bound paclitaxel should be offered to patients with first-line treatment with FOLFIRINOX (leucovorin, fluorouracil, irinotecan, and oxaliplatin), an Eastern Cooperative Oncology Group performance status (ECOG PS) of 0 to 1, and a favorable comorbidity profile; fluorouracil plus nanoliposomal irinotecan can be offered to patients with first-line treatment with gemcitabine plus NAB-paclitaxel, an ECOG PS of 0 to 1, and a favorable comorbidity profile; fluorouracil plus irinotecan or fluorouracil plus oxaliplatin may be offered when there is a lack of availability of fluorouracil plus nanoliposomal irinotecan; gemcitabine or fluorouracil should be offered to patients with either an ECOG PS of 2 or a comorbidity profile that precludes other regimens. Testing select patients for mismatch repair deficiency or microsatellite instability is recommended, and pembrolizumab is recommended for patients with mismatch repair deficiency or high microsatellite instability tumors. Endorsed recommendations from the 2016 version of this guideline for computed tomography, baseline performance status and comorbidity profile, defining goals of care, first-line therapy, and palliative care are also contained within the full guideline text. Additional information is available at www.asco.org/gastrointestinal-cancer-guidelines .
Delayed chemotherapy is associated with inferior survival in stage III colon and stage II/III rectal cancer patients, but similar studies have not been performed in stage II colon cancer patients. We ...investigate the association between delayed and incomplete chemotherapy, and the association of delayed chemotherapy with survival in stage II colon cancer patients.
Patients (age ≥ 66) diagnosed as stage II colon cancer and received chemotherapy from 1992 to 2005 were identified from the linked SEER-Medicare database. The association between delayed and incomplete chemotherapy was assessed using unconditional and conditional logistic regressions. Survival outcomes were assessed using stratified Cox regression based on propensity score matched samples.
4,209 stage II colon cancer patients were included, of whom 73.0% had chemotherapy initiated timely (≤ 2 months after surgery), 14.7% had chemotherapy initiated with moderate delay (2-3 months), and 12.3% had delayed chemotherapy (≥ 3 months). Delayed chemotherapy was associated with not completing chemotherapy (adjusted odds ratio (OR): 1.33 (95% confidence interval: 1.11, 1.59) for moderately delayed group, adjusted OR: 2.60 (2.09, 3.24) for delayed group). Delayed chemotherapy was associated with worse survival outcomes (hazard ratio (HR): 1.75 (1.29, 2.37) for overall survival; HR: 4.23 (2.19, 8.20) for cancer-specific survival).
Although the benefit of chemotherapy is unclear in stage II colon cancer patients, delay in initiation of chemotherapy is associated with an incomplete chemotherapy course and poorer survival, especially cancer-specific survival. Causal inference in the association between delayed initiation of chemotherapy and inferior survival requires further investigation.
The antiepidermal growth factor receptor (EGFR) antibody cetuximab shows activity in multiple epithelial tumor types; however, responses are seen in only a subset of patients. This study was ...conducted to identify markers that are associated with disease control in patients treated with cetuximab.
One hundred ten patients with metastatic colorectal cancer were enrolled onto a cetuximab monotherapy trial. Transcriptional profiling was conducted on RNA from mandatory pretreatment metastatic biopsies to identify genes whose expression correlates with best clinical responses. EGFR and K-ras mutation analyses and EGFR gene copy number analyses were performed on DNA from pretreatment biopsies.
Gene expression profiles showed that patients with tumors that express high levels of the EGFR ligands epiregulin and amphiregulin are more likely to have disease control with cetuximab (EREG, P = .000015; AREG, P = .000025). Additionally, patients whose tumors do not have K-ras mutations have a significantly higher disease control rate than patients with K-ras mutations (P = .0003). Furthermore, patients with tumors that have high expression of EREG or AREG also have significantly longer progression-free survival (PFS) than patients with low expression (EREG: P = .0002, hazard ratio HR = 0.47, and median PFS, 103.5 v 57 days, respectively; AREG: P < .0001, HR = 0.44, and median PFS, 115.5 v 57 days, respectively).
Patients with tumors that have high gene expression levels of epiregulin and amphiregulin and patients with wild-type K-ras are more likely to have disease control on cetuximab treatment. The identified markers could be developed further to select patients for cetuximab therapy.
Hepatocellular carcinoma (HCC) is a major cause of cancer-related death. It is a highly vascular tumour with multiple angiogenic factors, most importantly vascular endothelial growth factor (VEGF), ...involved in HCC progression. Tivozanib is an oral inhibitor of VEGFR-1/2/3 with promising activity against HCC in vivo.
We conducted a phase 1b/2 study of tivozanib in patients with advanced HCC. The safety, dosing, pharmacokinetics, pharmacodynamics, and preliminary antineoplastic efficacy of tivozanib were evaluated.
Twenty-seven patients received at least one dose of tivozanib. Using a 3+3 design, the recommended phase 2 dose (RP2D) of tivozanib was determined to be 1 mg per os once daily, 21 days on-7 days off. The median progression-free and overall survival were 24 weeks and 9 months, respectively, for patients treated at RP2D. The overall response rate was 21%. Treatment was well tolerated. A significant decrease in soluble plasma VEGFR-2 was noted, assuring adequate target engagement.
Although this study did not proceed to stage 2, there was an early efficacy signal with a very favourable toxicity profile. A phase 1/2 trial of tivozanib in combination with durvalumab is currently underway.
ClinicalTrials.gov NCT01835223, registered on 15 April 2013.
Deleterious effects of environmental exposures may contribute to the rising incidence of early-onset colorectal cancer (eoCRC). We assessed the metabolomic differences between patients with eoCRC, ...average-onset CRC (aoCRC), and non-CRC controls, to understand pathogenic mechanisms. Patients with stage I-IV CRC and non-CRC controls were categorized based on age ≤ 50 years (eoCRC or young non-CRC controls) or ≥ 60 years (aoCRC or older non-CRC controls). Differential metabolite abundance and metabolic pathway analyses were performed on plasma samples. Multivariate Cox proportional hazards modeling was used for survival analyses. All P values were adjusted for multiple testing (false discovery rate, FDR P < 0.15 considered significant). The study population comprised 170 patients with CRC (66 eoCRC and 104 aoCRC) and 49 non-CRC controls (34 young and 15 older). Citrate was differentially abundant in aoCRC vs. eoCRC in adjusted analysis (Odds Ratio = 21.8, FDR P = 0.04). Metabolic pathways altered in patients with aoCRC versus eoCRC included arginine biosynthesis, FDR P = 0.02; glyoxylate and dicarboxylate metabolism, FDR P = 0.005; citrate cycle, FDR P = 0.04; alanine, aspartate, and glutamate metabolism, FDR P = 0.01; glycine, serine, and threonine metabolism, FDR P = 0.14; and amino-acid t-RNA biosynthesis, FDR P = 0.01. 4-hydroxyhippuric acid was significantly associated with overall survival in all patients with CRC (Hazards ratio, HR = 0.4, 95% CI 0.3-0.7, FDR P = 0.05). We identified several unique metabolic alterations, particularly the significant differential abundance of citrate in aoCRC versus eoCRC. Arginine biosynthesis was the most enriched by the differentially altered metabolites. The findings hold promise in developing strategies for early detection and novel therapies.
Background
Despite continued investigation, limited progress has been made in the adjuvant treatment of resected pancreatic cancer. Novel or targeted therapies are needed.
Methods
...Multi-institutional, open-label, dose-finding, phase 2 trial evaluating the use of algenpantucel-L (NewLink Genetics Corporation, Ames, IA) immunotherapy in addition to chemotherapy and chemoradiotherapy in the adjuvant setting for resected pancreatic cancer (ClinicalTrials.gov identifier, NCT00569387). The primary outcome was 12-month disease-free survival. Secondary outcomes included overall survival and toxicity.
Results
Seventy patients were treated with gemcitabine and 5-fluorouracil-based chemoradiotherapy as well as algenpantucel-L (mean 12 doses, range 1–14). After a median follow-up of 21 months, the 12-month disease-free survival was 62 %, and the 12-month overall survival was 86 %. The most common adverse events were injection site pain and induration.
Conclusions
The addition of algenpantucel-L to standard adjuvant therapy for resected pancreatic cancer may improve survival. A multi-institutional, phase 3 study is ongoing (ClinicalTrials.gov identifier, NCT01072981).
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