Bulk Nanostructure of Mixtures of Choline Arginate, Choline Lysinate, and Water.

Neutron diffraction with empirical potential structure refinement was used to investigate the bulk liquid nanostructure of mixtures of choline arginate (Ch[Arg]), choline lysinate (Ch[Lys]), and water at mole ratios of 1Ch[Arg]:1Ch[Lys]:6H2O (balanced), 1Ch[Arg]:1Ch[Lys]:20H2O (balanced dilute), 3Ch[Arg]:1Ch[Lys]:12H2O (Arg- rich), and 1Ch[Arg]:3Ch[Lys]:12H2O (Lys- rich). The Arg- and Lys- anions tend not to associate due to electrostatic repulsion between charge groups and weak anion-anion attractions. This means that the local ion structures around the anions in these mixtures resemble the parent single-component systems. The bulk liquid nanostructure varies with the Arg-:Lys- ratio. In the Lys--rich mixture (1Ch[Arg]:3Ch[Lys]:12H2O), Lys- side chains cluster into a continuous apolar domain separated from a charged domain of polar groups. In the balanced mixture (1Ch[Arg]:1Ch[Lys]:6H2O), Lys- side chains form discrete apolar aggregates within a continuous polar domain of Arg-, Ch+, and water, and in the Arg--rich mixture (3Ch[Arg]:1Ch[Lys]:12H2O), the distribution of Lys- and Arg- is nearly homogeneous. Finally, in the balance dilute system (1Ch[Arg]:1Ch[Lys]:20H2O), a percolating water domain forms.

Pembrolizumab Plus mFOLFOX7 or FOLFIRI for Microsatellite Stable/Mismatch Repair-Proficient Metastatic Colorectal Cancer: KEYNOTE-651 Cohorts B and D.

BACKGROUND: The phase 1b KEYNOTE-651 study evaluated pembrolizumab plus chemotherapy in microsatellite stable or mismatch repair-proficient metastatic colorectal cancer. PATIENTS AND METHODS: Patients with microsatellite stable or mismatch repair-proficient metastatic colorectal cancer received pembrolizumab 200 mg every 3 weeks plus 5-fluorouracil, leucovorin, oxaliplatin (previously untreated; cohort B) or 5-fluorouracil, leucovorin, irinotecan (previously treated with fluoropyrimidine plus oxaliplatin; cohort D) every 2 weeks. Primary end point was safety; investigator-assessed objective response rate per RECIST v1.1 was secondary and biomarker analysis was exploratory. RESULTS: Thirty-one patients were enrolled in cohort B and 32 in cohort D; median follow-up was 30.2 and 33.5 months, respectively. One dose-limiting toxicity (grade 3 small intestine obstruction) occurred in cohort D. In cohort B, grade 3 or 4 treatment-related adverse events (AEs) occurred in 18 patients (58%), most commonly neutropenia and decreased neutrophil count (n = 5 each). In cohort D, grade 3 or 4 treatment-related AEs occurred in 17 patients (53%), most commonly neutropenia (n = 7). No grade 5 treatment-related AEs occurred. Objective response rate was 61% in cohort B (KRAS wildtype: 71%; KRAS mutant: 53%) and 25% in cohort D (KRAS wildtype: 47%; KRAS mutant: 6%). In both cohorts, PD-L1 combined positive score and T-cell-inflamed gene expression profiles were higher and HER2 expression was lower in responders than nonresponders. No association between tumor mutational burden and response was observed. CONCLUSION: Pembrolizumab plus 5-fluorouracil, leucovorin, oxaliplatin/5-fluorouracil, leucovorin, irinotecan demonstrated an acceptable AE profile. Efficacy data appeared comparable with current standard of care (including by KRAS mutation status). Biomarker analyses were hypothesis-generating, warranting further exploration. GOV IDENTIFIER: ClinicalTrials.gov; NCT03374254.

Pembrolizumab Plus Binimetinib With or Without Chemotherapy for MSS/pMMR Metastatic Colorectal Cancer: Outcomes From KEYNOTE-651 Cohorts A, C, and E.

BACKGROUND: Cohorts A, C, and E of the phase Ib KEYNOTE-651 study evaluated pembrolizumab + binimetinib ± chemotherapy in microsatellite stable/mismatch repair-proficient metastatic colorectal cancer. PATIENTS AND METHODS: Patients received pembrolizumab 200 mg every 3 weeks plus binimetinib 30 mg twice daily alone (cohort A; previously treated with any chemotherapy) or with 5-fluorouracil, leucovorin, oxaliplatin (cohort C; previously untreated) or 5-fluorouracil, leucovorin, irinotecan (cohort E; previously treated with 1 line of therapy including fluoropyrimidine + oxaliplatin-based regimen) every 2 weeks. Binimetinib dose-escalation to 45 mg twice daily was planned in all cohorts using a modified toxicity probability interval design (target dose-limiting toxicity [DLT], 30%). The primary endpoint was safety; investigator-assessed objective response rate was secondary. RESULTS: In cohort A, 1/6 patients (17%) had DLTs with binimetinib 30 mg; none occurred in 14 patients with 45 mg. In cohort C, 3/9 patients (33%) had DLTs with binimetinib 30 mg; dose was not escalated to 45 mg. In cohort E, 1/5 patients (20%) had DLTs with binimetinib 30 mg; 5/10 patients (50%) had DLTs with 45 mg. Enrollment was stopped in cohort E binimetinib 45 mg and deescalated to 30 mg; 2/4 additional patients (50%) had DLTs with binimetinib 30 mg (total 3/9 [33%] had DLTs with binimetinib 30 mg). Objective response rate was 0% in cohort A, 9% in cohort C, and 15% in cohort E. CONCLUSION: Per DLT criteria, binimetinib + pembrolizumab (cohort A) was tolerable, binimetinib + pembrolizumab + 5-fluorouracil, leucovorin, oxaliplatin (cohort C) did not qualify for binimetinib dose escalation to 45 mg, and binimetinib + pembrolizumab + 5-fluorouracil, leucovorin, irinotecan (cohort E) required binimetinib dose reduction from 45 to 30 mg. No new safety findings were observed across cohorts. There was no apparent additive efficacy when binimetinib + pembrolizumab was added to chemotherapy. Data did not support continued enrollment in cohorts C and E.

The use of cannabinoids in palliating cancer-related symptoms: a narrative review.

Despite uncertain efficacy, cannabinoids and derived products are becoming increasingly used in the field of palliative care for oncologic patients. Cannabinoids chiefly include psychoactive tetrahydrocannabinol (THC) and nonpsychoactive cannabidiol (CBD). Use of and research interest in THC, CBD, and combination THC/CBD products have increased in recent years, particularly after the Agriculture Improvement Act of 2018 made cannabis plants with <0.3% THC no longer controlled substances, and many states recently legalized THC use altogether. To provide an updated review of this topic, we reviewed randomized controlled trials with >50 patients studying cannabinoid use in cancer patients. We found that THC products, including THC and THC/CBD combination products, are helpful for treating chemotherapy-induced nausea/vomiting. CBD products were not helpful for this indication. For most other studied indications (anorexia/cachexia, mood, general global symptoms), there was no convincing evidence to support widespread cannabinoid use in cancer symptom management. The evidence for treating cancer-related pain with THC/CBD products is somewhat conflicting. We conclude that, apart from using THC products to treat chemotherapy-induced nausea/vomiting, cannabinoid products should not be routinely recommended for cancer supportive care. Further research in the form of large randomized controlled trials is warranted in this area.

Bulk nanostructure of a deep eutectic solvent with an amphiphilic hydrogen bond donor.

Neutron diffraction with empirical potential structure refinement (EPSR) show the deep eutectic solvent (DES) 1 : 4 choline chloride : butyric acid is amphiphilically nanostructured. Nanostructure results from solvophobic interactions between the alkyl chains of the butyric acid hydrogen bond donor (HBD) and is retained with addition of 10 wt% water. EPSR fits to the diffraction data is used to produce a three-dimensional model of the liquid which is interrogated to reveal the interactions leading to the solvophobic effect, and therefore nanostructure, in this DES at atomic resolution. The model shows electrostatic and hydrogen bond interactions cause the cation, anion and HBD acid group to cluster into a polar domain, from which the acid alkyl chains are solvophobically excluded into theapolar domain. The polar and apolar domains percolate through the liquid in a bicontinuous sponge-like structure. The effect of adding 10 wt% water is probed, revealing that water molecules are sequestered around the cation and anion within the polar domain, while the neat bulk structure is retained. Alkyl chain packing in the apolar domain becomes slightly better-defined indicating water marginally strengthens solvophobic segregation. These findings reveal bulk self-assembled nanostructure can be produced in DESs via an amphiphilic HBD.

Improved Pathologic response to chemoradiation in MGMT methylated locally advanced rectal cancer.

Background and Purpose: With the growing interest in total neoadjuvant treatment for locally advanced rectal adenocarcinoma (LARC) there is an urgent unmet need to identify predictive markers of response to long-course neoadjuvant concurrent chemoradiotherapy (LCRT). O6-Methylguanine (O6-MG)-DNA-methyltransferase (MGMT) gene methylation has been associated in some malignancies with response to concurrent chemoradiotherapy. We attempted to find if pathologic response to LCRT was associated with MGMT promoter hypermethylation (MGMTh). Materials and Methods: Patients were identified with LARC, available pre-treatment biopsy specimens, and at least 1 year of follow-up who received LCRT followed by surgical resection within 6 months. Biopsies were tested for MGMTh using a Qiagen pyrosequencing kit (Catalog number 970061). The primary outcome of LCRT responsiveness was based on tumor regression grade (TRG), with grades of 0-1 considered to have excellent response and grades of 2-3 considered to be non-responders. Secondary outcomes included overall survival (OS) and recurrence free survival (RFS). Results: Of 96 patients who met inclusion criteria, 76 had samples which produced reliable assay results. MGMTh corresponded with higher grade and age of the biopsy specimen. The percentage of responders to LCRT was higher amongst the MGMTh patients than the MGMTn patients (60.0% vs 27.5%, p value = 0.0061). MGMTh was not significantly associated with improved OS (2-year OS of 96.0% vs 98.0%, p = 0.8102) but there was a trend for improved RFS (2-year RFS of 87.6% vs 74.2%, p = 0.0903). Conclusion: Significantly greater tumor regression following LCRT was seen in MGMTh LARC. Methylation status may help identify good candidates for close observation without surgery following LCRT.

The Texas Immuno-Oncology Biorepository, a statewide biospecimen collection and clinical informatics system to enable longitudinal tumor and immune profiling.

A detailed understanding of the molecular and immunological changes that occur longitudinally across tumors exposed to immune checkpoint inhibitors is a significant knowledge gap in oncology. To address this unmet need, we created a statewide biospecimen collection and clinical informatics system to enable longitudinal tumor and immune profiling and to enhance translational research. The Texas Immuno-Oncology Biorepository (TIOB) consents patients to collect, process, store, and analyze serial biospecimens of tissue, blood, urine, and stool from a diverse population of over 100,000 cancer patients treated each year across the Baylor Scott & White Health system. Here we sought to demonstrate that these samples were fit for purpose with regard to downstream multi-omic assays. Plasma, urine, peripheral blood mononuclear cells, and stool samples from 11 enrolled patients were collected from various cancer types. RNA isolated from extracellular vesicles derived from plasma and urine was sufficient for transcriptomics. Peripheral blood mononuclear cells demonstrated excellent yield and viability. Ten of 11 stool samples produced RNA quality to enable microbiome characterization. Sample acquisition and processing methods are known to impact sample quality and performance. We demonstrate that consistent acquisition methodology, sample preparation, and sample storage employed by the TIOB can produce high-quality specimens, suited for employment in a wide array of multi-omic platforms, enabling comprehensive immune and molecular profiling.

Intracellular Communication between Synthetic Macromolecules.

Non-viral delivery is an important strategy for selective and efficient gene therapy, immunization, and RNA interference, which overcomes problems of genotoxicity and inherent immunogenicity associated with viral vectors. Liposomes and polymers are compelling candidates as carriers for intracellular, non-viral delivery, but maximal efficiencies of around 1% have been reported for the most advanced non-viral carriers. Here, we develop a library of dendronized bottlebrush polymers with controlled defects, displaying a level of precision surpassed only by biological molecules like DNA, RNA, and proteins. We test concurrent and competitive delivery of DNA and show for the first time that, while intracellular communication is thought to be an exclusively biomolecular phenomenon, such communication between synthetic macromolecular complexes can also take place. Our findings challenge the assumption that delivery agents behave as bystanders that enable transfection by passive intracellular release of genetic cargo and improve upon coarse strategies in intracellular carrier design lacking control over polymer sequence, architecture, and composition, leading to a hit-or-miss outcome. Understanding the communication that takes place between macromolecules will help improve the design of non-viral delivery agents and facilitate translation of genome engineering, vaccines, and nucleic acid-based therapies.

Polycation radius of gyration in a polymeric ionic liquid (PIL): the PIL melt is not a theta solvent.

The conformation of the polycation in the prototypical polymeric ionic liquid (PIL) poly(3-methyl-1-aminopropylimidazolylacrylamide) bis(trifluoromethylsulfonyl)imide (poly(3MAPIm)TFSI) was probed using small-angle neutron scattering (SANS) and ultra-small-angle neutron scattering (USANS) at 25 °C and 80 °C. Poly(3MAPIm)TFSI contains microvoids which lead to intense low q scattering that can be mitigated using mixtures of hydrogen- and deuterium-rich materials, allowing determination of the polycation conformation and radius of gyration (Rg). In the pure PIL, the polycation adopts a random coil conformation with Rg = 52 ± 0.5 Å. In contrast to conventional polymer melts, the pure PIL is not a theta solvent for the polycation. The TFSI- anions, which comprise 48% v/v of the PIL, are strongly attracted to the polycation and act like small solvent molecules which leads to chain swelling analogous to an entangled, semi-dilute, or concentrated polymer solution in a good solvent.

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone provokes progression from chronic pancreatitis to pancreatic intraepithelial neoplasia.

The risk of pancreatic cancer is higher among people who are cigarette smokers than among non-smokers; however, the action mechanisms of cigarette metabolites are not yet fully understood. In this study, we investigated the effect of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in cigarette smoking on chronic pancreatitis and pancreatic cancer as well as the biological mechanism of NNK causing malignant transformation. We show that smoking may promote Kras mutation and P16 promoter methylation from clinical samples and NNK markedly facilitates the growth and migration of pancreatic cancer cells via the activation of Sonic Hedgehog signaling. We demonstrate that NNK promotes acinar-to-ductal metastasis and pancreatic intraepithelial neoplasia in rats with chronic pancreatitis, accompanied by desmoplastic reaction and Gli1 overexpression. Together, we here present evidence that NNK provokes the progression of chronic pancreatitis toward pancreatic cancer and highlight potential strategies and targets for early prevention of pancreatic cancer and its therapeutics.

Reviewing the Outcomes of Different Treatment Approaches in Elderly Pancreatic Cancer Patients.

OBJECTIVES: The incidence of pancreatic cancer is age dependent. Ninety percent of new diagnoses occur in patients older than 55 years. Despite the association with age and cancer, elderly patients are historically underrepresented in clinical trials. Thus, optimal management of elderly patients has a lack of data. The purpose of this retrospective study was to investigate the outcomes of palliative chemotherapy in elderly patients with pancreatic cancer compared with supportive care alone. METHODS: Unicentric data were reviewed on all elderly patients (defined as age >65 years) with a diagnosis of pancreatic cancer from 2008 through 2019 to compare outcomes in those who received chemotherapy versus supportive care alone. RESULTS: The study reviewed 665 patients with a median age of 75 years (mean, 75.7 years) and average Charlson Comorbidity Score of 5.74. Of them, 291 received chemotherapy and 363 received supportive care only. Chemotherapy was associated with a median overall survival of 250 versus 93 days with supportive care (P < 0.0001). Analysis showed improved survival for all age ranges, cancer stages, and Charlson Comorbidity Scores. CONCLUSIONS: Elderly pancreatic cancer patients can benefit from palliative chemotherapy, and it should be considered, especially in patients with fewer medical comorbidities and better functional status.

NAF-1 Inhibition by Resveratrol Suppresses Cancer Stem Cell-Like Properties and the Invasion of Pancreatic Cancer.

Resveratrol is a natural polyphenolic compound with multiple biological effects, e.g., proliferation inhibition, anti-oxidation, and neuroprotection. Besides that, studies have shown that resveratrol inhibits tumor growth and migration, as well as epithelial-mesenchymal transition (EMT). However, its molecular mechanisms in tumor progression are not fully understood. Nutrient-deprivation autophagy factor-1 (NAF-1) is mainly found in the endoplasmic reticulum and mitochondrial outer membrane. It is an important genetic locus for regulating oxidative stress and autophagy. The molecular mechanism of NAF-1 in pancreatic cancer is currently unclear. The current study found that NAF-1 is expressed in pancreatic cancer tissue and correlated with the progression of pancreatic cancer. Furthermore, we found that NAF-1 inhibition significantly inhibits the stem cell characteristics and the invasion and migration abilities of pancreatic cancer cells. In a subcutaneous xenograft model of pancreatic cancer in nude mice, resveratrol inhibited the expression of NAF-1, thereby inhibiting tumor growth. Taken together, resveratrol could be an effective anti-tumor drug, and NAF-1 may be a rational therapeutic target.

A randomized trial of nurse-administered behavioral interventions to manage anticipatory nausea and vomiting in chemotherapy.

PURPOSE: Chemotherapy side effects diminish quality of life and can lead to treatment delay. Nausea and vomiting can occur prior to chemotherapy because of classical conditioning. We studied the effects of 20-minute behavioral interventions, administered by oncology nurses, of higher intensity (mindfulness relaxation-MR) or lower intensity (relaxing music-RM), on anticipatory nausea and vomiting (ANV). PATIENTS AND METHODS: Patients undergoing chemotherapy for solid tumors were randomized to MR (N = 160), RM (N = 159), or standard care SC (N = 155). Subjects were mostly female (91.8%) and white (86.1%) with breast cancer (85%). Most patients had early stage disease (Stage I: 26%; II: 52.9%; III: 19%; IV: 0.1%). Anticipatory nausea and vomiting were assessed at the midpoint and end of the chemotherapy course using the Morrow Assessment of Nausea and Emesis (MANE). RESULTS: Compared to SC, there was reduced anticipatory nausea at the midpoint of chemotherapy in those receiving MR (OR 0.44, 95% CI 0.20-0.93) and RM (OR 0.40, 95% CI 0.20-0.93), controlling for age, sex, cancer stage, and emetogenic level of chemotherapy. There was no difference between treatment groups in anticipatory nausea at the end of chemotherapy or in anticipatory vomiting and postchemotherapy nausea and vomiting at either time point. CONCLUSION: A brief nurse-delivered behavioral intervention can reduce midpoint ANV associated with chemotherapy.

Prognostic factors and hazard ratios in colorectal cancer patients over 80 years of age: a retrospective, 20-year, single institution review.

BACKGROUND: An aging population and a high incidence of colorectal cancer (CRC) in patients over the age of 80 make it important to understand survival times, hazard ratios and prognostic factors in this group. A better understanding of these factors will help clinicians determine appropriate therapeutic strategies for such patients, including when more aggressive treatment strategies may be preferred to palliative treatment. METHODS: A retrospective analysis of 619 CRC patients of ≥80 years of age from 1991-2010 at Baylor Scott & White Hospital in Temple, Texas. Twelve variables were analyzed through statistical analysis as potential prognostic factors for survival. Univariate and multivariate Cox proportional hazard models were used to determine hazard ratios. The elderly population was further stratified by age subgroup (80-84, 85-89, ≥90). RESULTS: Median survival time was 53.6, 30.0, and 11.3 months for age groups of 80-84, 85-89, and ≥90, respectively. Median survival time for stage 0/I, II, III, and IV patients was 72.4, 53.5, 28.0, and 5.9 months, respectively. Patients not receiving surgery had significantly higher mortality (hazard ratio 2.605; 95% CI, 1.826-3.694). For stage III CRC patients, those not receiving chemotherapy had significantly higher mortality (hazard ratio 1.808; 95% CI, 1.018-1.827). CONCLUSIONS: Our study provides evidence to support the benefits of surgery and chemotherapy (for stage III) patients over 80, potentially contributing to improved clinical decisions in treating elderly CRC patients. Such patients are sometimes undertreated due to their underrepresentation in clinical trials. Additional prospective studies with a higher proportion of patients over 80 are needed.

A Phase 2 Randomized, Double-Blind, Multicenter Trial of Imexon Plus Gemcitabine Versus Gemcitabine Plus Placebo in Patients With Metastatic Chemotherapy-naïve Pancreatic Adenocarcinoma.

BACKGROUND: Imexon is a cyanoaziridine-derived iminopyrrolidone which has synergistic cytotoxicity with gemcitabine. A phase 1 study of the combination demonstrated good tolerance with encouraging clinical activity and thus we conducted this randomized phase II study. MATERIALS AND METHODS: Patients with measurable, metastatic, treatment-naive pancreatic adenocarcinoma were randomized 1:1 to receive gemcitabine at 1000 mg/m days 1, 8, and 15 with either imexon, 875 mg/m or placebo days 1, 8, and 15 every 28 days. The primary endpoint was overall survival. Secondary endpoints included progression-free survival and response rate. RESULTS: A total of 142 patients were randomized, 72 to the imexon containing arm and 70 to the placebo arm. Patients in the imexon arm received an average of 3.6 cycles (range, 1 to 23) compared with 4.4 (range, 1 to 21) in the placebo arm. There was no increased rate of ≥grade 3 toxicity in the imexon arm. Seven patients had objective responses in the imexon arm (13.7%), whereas 9 did in the placebo arm (17%). In the imexon arm, 23 patients had ≥50% reduction in CA 19-9 from baseline (33%), whereas 22 did in the placebo arm (31.4%). The median progression-free survival was 2.8 months in the imexon arm (95% confidence interval [CI], 2.0-4.1 m) and 3.8 months in the placebo arm (95% CI, 2.2-4.7 m), P=0.504. The median overall survival time in the imexon arm was 5.2 months (95% CI, 4.2-6.7 m) as compared with 6.8 m (95% CI, 4.9-8.5 m) in the placebo arm, P=0.6822. CONCLUSIONS: The combination of imexon and gemcitabine does not result in improved outcome as initial therapy of metastatic pancreatic adenocarcinoma.

Phase II study of olaratumab with paclitaxel/carboplatin (P/C) or P/C alone in previously untreated advanced NSCLC.

BACKGROUND: In non-small cell lung cancer (NSCLC), platelet-derived growth factor receptor (PDGFR) mediates angiogenesis, tissue invasion, and tumor interstitial pressure. Olaratumab (IMC-3G3) is a fully human anti-PDGFRα monoclonal antibody. This Phase II study assessed safety and efficacy of olaratumab+paclitaxel/carboplatin (P/C) versus P/C alone for previously untreated advanced NSCLC. MATERIALS AND METHODS: Patients received up to six 21-day cycles of P 200mg/m2 and C AUC 6 (day 1)±olaratumab 15mg/kg (days 1 and 8). Primary endpoint was PFS. Olaratumab was continued in the olaratumab+P/C arm until disease progression. RESULTS: 131 patients were: 67 with olaratumab+P/C and 64 with P/C; 74% had nonsquamous NSCLC. Median PFS was similar between olaratumab+P/C and P/C (4.4 months each) (HR 1.29; 95% CI [0.86-1.93]; p=0.21). Median OS was similar between olaratumab+P/C (11.8 months) and P/C (11.5 months) (HR 1.04; 95% CI [0.68-1.57]; p=0.87). Both arms had similar toxicity profiles. All evaluable cases were PDGFR-negative by immunohistochemistry. Tumor stroma PDGFR expression was evaluable in 23/131 patients, of which 78% were positive. CONCLUSIONS: The addition of olaratumab to P/C did not result in significant prolongation of PFS or OS in advanced NSCLC. Olaratumab studies in other patient populations, including soft tissue sarcoma (NCT02783599), pancreatic cancer (NCT03086369), and pediatric malignancies (NCT02677116) are underway.

Bile duct lymphoma disguised as cholangiocarcinoma.

We present a case of intrabiliary primary B-cell lymphoma masked as a cholangiocarcinoma in an HIV-positive patient. The two entities have similar symptoms, laboratory findings, and imaging findings but require very different treatments. The case highlights the need to confirm the diagnosis by biopsy.

High- versus low-dose leucovorin in the modified FOLFOX6 regimen for first-line treatment of metastatic colorectal cancer.

Background In response to the national leucovorin shortage in 2008, our institution adjusted the modified FOLFOX6 (leucovorin, fluorouracil, and oxaliplatin) protocol to utilize a lower dose of leucovorin (20 mg/m2). This adjustment was based on prospective studies suggesting that lower doses of leucovorin may be equally effective in other fluorouracil containing regimens. This retrospective study evaluates outcomes in metastatic colorectal cancer (mCRC) patients treated with low- (20 mg/m2) vs. high-dose (400 mg/m2) leucovorin in the FOLFOX6 regimen for mCRC. Methods This retrospective analysis included consecutive mCRC patients from 2004 to 2011 if they received at least one cycle of modified FOLFOX6 as first line therapy. Patients who received an initial leucovorin dose other than 20 mg/m2 or 400 mg/m2 on their first cycle were excluded. Patient characteristics included demographics, metastatic site at initial diagnosis, and treatment history including chemotherapy and surgery. Primary outcome was date of death or last contact. Cox proportional hazards regression analysis and Kaplan-Meier survival curves were utilized to evaluate the effect of leucovorin dose on overall survival. Log-rank tests were used to compare median survival times by dose group. Results Of the 93 mCRC patients who received first line modified FOLFOX6, leucovorin 400 mg/m2 was administered to 47 (51%) patients and 20 mg/m2 to 46 (49%) patients. There were no differences of baseline characteristics between the groups with exception of primary site of cancer ( p = 0.038). The overall survival time was 22.5 months (95% CI 16.6-29.6). The median survival time in the leucovorin 400 mg/m2 group was 23.1 months (95% CI 16.2-35.7) compared to leucovorin 20 mg/m2 which was 20.5 months (95% CI 14.2-34.2); p = 0.573. The median survival times in patients with one versus two or more sites with metastasis were statistically different (26.9 vs. 16.2 months, p = 0.009). Metastatic site removal or ablation showed differences in the median survival, 34.2 months (95% CI 20.8-50.9) vs. 16.6 months (95% CI 14.1-23.6) without metastatic disease removal ( p = 0.004). The odds of dying for patients with two metastatic sites was higher compared with the odds of those patients with one site, HR 1.8 (95% CI 1.08-3.0). Patients without metastatic site removal or ablation had higher odds of dying compared to those patients without this procedure, HR 0.47 (95% CI 0.27-0.81). Conclusion In this single center retrospective study, there was no difference in overall survival for mCRC patients treated with first line FOLFOX6 with low- vs. high-dose leucovorin.

Inhibition of Mast Cell-Derived Histamine Decreases Human Cholangiocarcinoma Growth and Differentiation via c-Kit/Stem Cell Factor-Dependent Signaling.

The tumor microenvironment of cholangiocarcinoma (CCA) is composed of numerous cells, including mast cells (MCs). MCs release histamine, which increases CCA progression and angiogenesis. Cholangiocytes secrete stem cell factor, which functions via the MC growth factor receptor c-Kit. Here, we show that cholangiocytes express histidine decarboxylase and its inhibition reduces CCA growth. MC recruitment in the tumor microenvironment increased CCA growth. MC infiltration and MC markers were detected by toluidine blue staining and real-time PCR in human biopsies and in tumors from athymic mice treated with saline, histamine, histidine decarboxylase inhibitor, or cromolyn sodium. Tumor growth, angiogenesis, and epithelial-mesenchymal transition (EMT)/extracellular matrix (ECM) markers were measured in mice treated with cromolyn sodium. In vitro, human CCA cells were treated with MC supernatant fluids before evaluating angiogenesis and EMT/ECM expression. Migration assays were performed with CCA cells treated with the stem cell factor inhibitor. MC supernatant fluids increased CCA histidine decarboxylase, vascular endothelial growth factor, and MC/EMT/ECM expression that decreased with pretreatment of cromolyn sodium. MCs were found in human biopsies. In mice treated with cromolyn sodium, MC infiltration and tumor growth decreased. Inhibition of CCA stem cell factor blocked MC migration and MC/EMT/ECM in CCA. MCs migrate into CCA tumor microenvironment via c-Kit/stem cell factor and increase tumor progression, angiogenesis, EMT switch, and ECM degradation.

Randomized trial of medroxyprogesterone acetate for the prevention of endometrial pathology from adjuvant tamoxifen for breast cancer: SWOG S9630.

The proliferative effect of adjuvant tamoxifen on the endometrium can potentially result in endometrial abnormalities, including cancer in postmenopausal women. We conducted a randomized, controlled trial to assess endometrial pathological diagnoses in postmenopausal women with early stage, ER-positive breast cancer without endometrial pathology at baseline. They were assigned to tamoxifen alone versus tamoxifen plus cyclical medroxyprogesterone acetate (MPA 10 mg for 14 days every 3 months) for 5 years. Endovaginal sonograms (EVS) +/- endometrial biopsies (EMB) were required at baseline, 2 and 5 years. Of 313 patients registered, 296 were eligible and 169 (57%; 89, tamoxifen; 80, tamoxifen+MPA) were evaluable (completed year-2 EVS, with an EMB if stripe width was ⩾5 mm). Sixty (67%) of these in the tamoxifen arm had an endometrial stripe width ⩾5 mm (and underwent subsequent EMB) compared with 48 (60%) in the tamoxifen+MPA arm (P=0.40). There were four cases of proliferative endometrium and one simple hyperplasia on the tamoxifen arm (6% (95% confidence interval (CI): 2-13%) among evaluable patients and one proliferative endometrium on the tamoxifen+MPA arm (P=0.11). The overall fraction with benign endometrial abnormalities at year 2 was 3.6% (6/169; 95% CI: 1.3-7.6%), with only 1 (of 102) new benign proliferative event at year 5. The event rate in both arms was much lower than projected, making treatment arm comparisons less informative. A normal endometrium prior to tamoxifen may provide reassurance regarding future endometrial events. However, validation in a larger trial is needed before changing practice in asymptomatic, postmenopausal women.