Inducible directed evolution of complex phenotypes in bacteria.

Directed evolution is a powerful method for engineering biology in the absence of detailed sequence-function relationships. To enable directed evolution of complex phenotypes encoded by multigene pathways, we require large library sizes for DNA sequences >5-10 kb in length, elimination of genomic hitchhiker mutations, and decoupling of diversification and screening steps. To meet these challenges, we developed Inducible Directed Evolution (IDE), which uses a temperate bacteriophage to package large plasmids and transfer them to naive cells after intracellular mutagenesis. To demonstrate IDE, we evolved a 5-gene pathway from Bacillus licheniformis that accelerates tagatose catabolism in Escherichia coli, resulting in clones with 65% shorter lag times during growth on tagatose after only two rounds of evolution. Next, we evolved a 15.4 kb, 10-gene pathway from Bifidobacterium breve UC2003 that aids E. coli's utilization of melezitose. After three rounds of IDE, we isolated evolved pathways that both reduced lag time by more than 2-fold and enabled 150% higher final optical density. Taken together, this work enhances the capacity and utility of a whole pathway directed evolution approach in E. coli.

Pharmacogenetic study in gastric cancer patients treated with adjuvant fluorouracil/leucovorin or epirubicin/cisplatin/fluorouracil before and after chemoradiation on CALGB 80101 (Alliance).

There is a lack of pharmacogenetic predictors of outcome in gastric cancer patients. The aim of this study was to assess previously identified candidate genes associated with 5-fluorouracil (5-FU), cisplatin, or epirubicin toxicity or response in a cohort of resected gastric cancer patients treated on CALGB (Alliance) 80101. Gastric or gastroesophageal cancer patients randomized to adjuvant 5-FU/leucovorin or epirubicin/cisplatin/5-FU before and after 5-FU chemoradiation were genotyped for single nucleotide polymorphisms (SNPs) in GSTP1 (rs1695), ERCC1 (rs11615 and rs3212986), XRCC1 (rs25487), UGT2B7 (rs7439366) and the 28 base-pair tandem repeats in TYMS (rs34743033). Logistic regression and log rank tests were used to assess the association between each SNP and incidence of grade 3/4 neutropenia and leukopenia, overall (OS) and progression-free survival (PFS), respectively. Toxicity endpoint analyses were adjusted for the treatment arm, while OS and PFS were also adjusted for performance status, sex, age, lymph node involvement, and primary tumor site and size. Of 281 subjects with successful genotyping results and available clinical (toxicity and efficacy) data, 166 self-reported non-Hispanic White patients were included in the final analysis. There was a lack of evidence of an association among any SNPs tested with grade 3/4 neutropenia and leukopenia or OS and PFS. Age, lymph node involvement, and primary tumor size were significantly associated with OS and PFS. This study failed to confirm results of previous gastric cancer pharmacogenetic studies.

Intergroup Randomized Phase III Study of Postoperative Oxaliplatin, 5-Fluorouracil, and Leucovorin Versus Oxaliplatin, 5-Fluorouracil, Leucovorin, and Bevacizumab for Patients with Stage II or III Rectal Cancer Receiving Preoperative Chemoradiation: A Trial of the ECOG-ACRIN Research Group (E5204).

BACKGROUND: The addition of bevacizumab to chemotherapy improved outcomes for patients with metastatic colon cancer. E5204 was designed to test whether the addition of bevacizumab to mFOLFOX6, following neoadjuvant chemoradiation and definitive surgery, could improve overall survival (OS) in patients with stage II/III adenocarcinoma of the rectum. SUBJECTS, MATERIALS, AND METHODS: Patients with stage II/III rectal cancer who had completed neoadjuvant 5-fluorouracil-based chemoradiation and had undergone complete resection were enrolled. Patients were randomized to mFOLFOX6 (Arm A) or mFOLFOX6 with bevacizumab (Arm B) administered every 2 weeks for 12 cycles. RESULTS: E5204 registered only 355 patients (17% of planned accrual goal) as it was terminated prematurely owing to poor accrual. At a median follow-up of 72 months, there was no difference in 5-year overall survival (88.3% vs. 83.7%) or 5-year disease-free survival (71.2% vs. 76.5%) between the two arms. The rate of treatment-related grade ≥ 3 adverse events (AEs) was 68.8% on Arm A and 70.7% on Arm B. Arm B had a higher proportion of patients who discontinued therapy early as a result of AEs and patient withdrawal than did Arm A (32.4% vs. 21.5%, p = .029).The most common grade 3-4 treatment-related AEs were neutropenia, leukopenia, neuropathy, diarrhea (without prior colostomy), and fatigue. CONCLUSION: At 17% of its planned accrual, E5204 did not meet its primary endpoint. The addition of bevacizumab to FOLFOX6 in the adjuvant setting did not significantly improve OS in patients with stage II/III rectal cancer. IMPLICATIONS FOR PRACTICE: At 17% of its planned accrual, E5204 was terminated early owing to poor accrual. At a median follow-up of 72 months, there was no significant difference in 5-year overall survival (88.3% vs. 83.7%) or in 5-year disease-free survival (71.2% vs. 76.5%) between the two arms. Despite significant advances in the treatment of rectal cancer, especially in improving local control rates, the risk of distant metastases and the need to further improve quality of life remain a challenge. Strategies combining novel agents with chemoradiation to improve both distant and local control are needed.

Effect of adjuvant capecitabine or fluorouracil, with or without oxaliplatin, on survival outcomes in stage III colon cancer and the effect of oxaliplatin on post-relapse survival: a pooled analysis of individual patient data from four randomised controlled trials.

BACKGROUND: Oxaliplatin-based adjuvant therapy is the standard of care for stage III colon cancer. Adjuvant capecitabine with or without oxaliplatin versus leucovorin and fluorouracil with or without oxaliplatin has not been directly compared; therefore, we aimed to analyse the efficacy and safety of these treatments using individual patient data pooled from four randomised controlled trials. We also assessed post-relapse survival, which has been postulated to be worse in patients receiving adjuvant oxaliplatin. METHODS: Patients with resected stage III colon cancer who were 18 years of age or older, with an Eastern Cooperative Oncology Group performance status of 0 or 1, from four randomised controlled trials (NSABP C-08, XELOXA, X-ACT, and AVANT; 8734 patients in total) were pooled and analysed. The treatment regimens included in our analyses were: XELOX (oxaliplatin and capecitabine); leucovorin and fluorouracil; capecitabine; FOLFOX-4 (leucovorin, fluorouracil, and oxaliplatin); and modified FOLFOX-6 (mFOLFOX-6). Disease-free survival was the primary endpoint for all trials that supplied patients for this analysis. Here, we compared disease-free, relapse-free, and overall survival between the patient groups who received capecitabine with or without oxaliplatin and those who received leucovorin and fluorouracil with or without oxaliplatin. Post-relapse survival was compared between the combined XELOX and FOLFOX groups, and the leucovorin and fluorouracil groups. Post-relapse survival was also compared between the capecitabine with or without oxaliplatin and leucovorin and fluorouracil with or without oxaliplatin groups. FINDINGS: Disease-free survival did not differ significantly between patients who received leucovorin and fluorouracil versus those who received capecitabine in adjusted analyses (hazard ratio [HR] 1·02 [0·93-1·11; p=0·72]) or in unadjusted analyses (HR 1·01 [95% CI 0·92-1·10; p=0·86]). Relapse-free survival was similar (adjusted HR 1·02 [0·93-1·12; p=0·72] and unadjusted HR 1·01 [95% CI 0·92-1·11; p=0·86]), as was overall survival (adjusted HR 1·04 [95% CI 0·93-1·15; p=0·50] and unadjusted HR 1·02 [0·92-1·14]; p=0·65). For overall survival, a significant interaction between oxaliplatin and fluoropyrimidine was recorded in the multiple Cox regression analysis (p=0·014). Post-relapse survival was similar in adjusted (p=0·23) and unadjusted analyses (p=0·33) for the comparison of XELOX or FOLFOX versus leucovorin and fluorouracil, and was also similar for capecitabine-based regimens versus leucovorin and fluorouracil-based regimens (unadjusted p=0·26). INTERPRETATION: Combination therapy with oxaliplatin provided consistently improved outcomes without adversely affecting post-relapse survival in the adjuvant treatment of stage III colon cancer, irrespective of whether the fluoropyrimidine backbone was capecitabine or leucovorin and fluorouracil. These data add to the existing evidence that oxaliplatin plus capecitabine or leucovorin and fluorouracil is the standard of care for the adjuvant treatment of stage III colon cancer, and offers physicians flexibility to treat patients according to the patients' overall physical performance and preference. FUNDING: Genentech Inc.

Particulate matter composition drives differential molecular and morphological responses in lung epithelial cells.

Particulate matter (PM) is a ubiquitous component of air pollution that is epidemiologically linked to human pulmonary diseases. PM chemical composition varies widely, and the development of high-throughput experimental techniques enables direct profiling of cellular effects using compositionally unique PM mixtures. Here, we show that in a human bronchial epithelial cell model, exposure to three chemically distinct PM mixtures drive unique cell viability patterns, transcriptional remodeling, and the emergence of distinct morphological subtypes. Specifically, PM mixtures modulate cell viability, DNA damage responses, and induce the remodeling of gene expression associated with cell morphology, extracellular matrix organization, and cellular motility. Profiling cellular responses showed that cell morphologies change in a PM composition-dependent manner. Finally, we observed that PM mixtures with higher cadmium content induced increased DNA damage and drove redistribution among morphological subtypes. Our results demonstrate that quantitative measurement of individual cellular morphologies provides a robust, high-throughput approach to gauge the effects of environmental stressors on biological systems and score cellular susceptibilities to pollution.

Programming Probiotics: Diet-Responsive Gene Expression and Colonization Control in Engineered S. boulardii.

Saccharomyces boulardii (Sb) is an emerging probiotic chassis for delivering biomolecules to the mammalian gut, offering unique advantages as the only eukaryotic probiotic. However, precise control over gene expression and gut residence time in Sb have remained challenging. To address this, we developed five ligand-responsive gene expression systems and repaired galactose metabolism in Sb, enabling inducible gene expression in this strain. Engineering these systems allowed us to construct AND logic gates, control the surface display of proteins, and turn on protein production in the mouse gut in response to dietary sugar. Additionally, repairing galactose metabolism expanded Sb's habitat within the intestines and resulted in galactose-responsive control over gut residence time. This work opens new avenues for precise dosing of therapeutics by Sb via control over its in vivo gene expression levels and localization within the gastrointestinal tract.

Particulate matter composition drives differential molecular and morphological responses in lung epithelial cells.

Particulate matter (PM) is a ubiquitous component of indoor and outdoor air pollution that is epidemiologically linked to many human pulmonary diseases. PM has many emission sources, making it challenging to understand the biological effects of exposure due to the high variance in chemical composition. However, the effects of compositionally unique particulate matter mixtures on cells have not been analyzed using both biophysical and biomolecular approaches. Here, we show that in a human bronchial epithelial cell model (BEAS-2B), exposure to three chemically distinct PM mixtures drives unique cell viability patterns, transcriptional remodeling, and the emergence of distinct morphological subtypes. Specifically, PM mixtures modulate cell viability and DNA damage responses and induce the remodeling of gene expression associated with cell morphology, extracellular matrix organization and structure, and cellular motility. Profiling cellular responses showed that cell morphologies change in a PM composition-dependent manner. Lastly, we observed that particulate matter mixtures with high contents of heavy metals, such as cadmium and lead, induced larger drops in viability, increased DNA damage, and drove a redistribution among morphological subtypes. Our results demonstrate that quantitative measurement of cellular morphology provides a robust approach to gauge the effects of environmental stressors on biological systems and determine cellular susceptibilities to pollution.

Prognostic Impact of Early Treatment and Oxaliplatin Discontinuation in Patients With Stage III Colon Cancer: An ACCENT/IDEA Pooled Analysis of 11 Adjuvant Trials.

PURPOSE: Oxaliplatin-based adjuvant chemotherapy in patients with stage III colon cancer (CC) for 6 months remains a standard in high-risk stage III patients. Data are lacking as to whether early discontinuation of all treatment (ETD) or early discontinuation of oxaliplatin (EOD) could worsen the prognosis. MATERIALS AND METHODS: We studied the prognostic impact of ETD and EOD in patients with stage III CC from the ACCENT/IDEA databases, where patients were planned to receive 6 months of infusional fluorouracil, leucovorin, and oxaliplatin or capecitabine plus oxaliplatin. ETD was defined as discontinuation of treatment and EOD as discontinuation of oxaliplatin only before patients had received a maximum of 75% of planned cycles. Association between ETD/EOD and overall survival and disease-free survival (DFS) were assessed by Cox models adjusted for established prognostic factors. RESULTS: Analysis of ETD and EOD included 10,447 (20.9% with ETD) and 7,243 (18.8% with EOD) patients, respectively. Compared with patients without ETD or EOD, patients with ETD or EOD were statistically more likely to be women, with Eastern Cooperative Oncology Group performance status ≥ 1, and for ETD, older with a lower body mass index. In multivariable analyses, ETD was associated with a decrease in disease-free survival and overall survival (hazard ratio [HR], 1.61, P < .001 and HR, 1.73, P < .001), which was not the case for EOD (HR, 1.07, P = .3 and HR, 1.13, P = .1). However, patients who received < 50% of the planned cycles of oxaliplatin had poorer outcomes. CONCLUSION: In patients treated with 6 months of oxaliplatin-based chemotherapy for stage III CC, ETD was associated with poorer oncologic outcomes. However, this was not the case for EOD. These data favor discontinuing oxaliplatin while continuing fluoropyrimidine in individuals with significant neurotoxicity having received > 50% of the planned 6-month chemotherapy.

A Novel Method of Inducible Directed Evolution to Evolve Complex Phenotypes.

Directed evolution is a powerful technique for identifying beneficial mutations in defined DNA sequences with the goal of improving desired phenotypes. Recent methodological advances have made the evolution of short DNA sequences quick and easy. However, the evolution of DNA sequences >5kb in length, notably gene clusters, is still a challenge for most existing methods. Since many important microbial phenotypes are encoded by multigene pathways, they are usually improved via adaptive laboratory evolution (ALE), which while straightforward to implement can suffer from off-target and hitchhiker mutations that can adversely affect the fitness of the evolved strain. We have therefore developed a new directed evolution method (Inducible Directed Evolution, IDE) that combines the specificity and throughput of recent continuous directed evolution methods with the ease of ALE. Here, we present detailed methods for operating Inducible Directed Evolution (IDE), which enables long (up to 85kb) DNA sequences to be mutated in a high throughput manner via a simple series of incubation steps. In IDE, an intracellular mutagenesis plasmid (MP) tunably mutagenizes the pathway of interest, located on the phagemid (PM). MP contains a mutagenic operon ( danQ926, dam, seqA, emrR, ugi , and cda1 ) that can be expressed via the addition of a chemical inducer. Expression of the mutagenic operon during a cell cycle represses DNA repair mechanisms such as proofreading, translesion synthesis, mismatch repair, and base excision and selection, which leads to a higher mutation rate. Induction of the P1 lytic cycle results in packaging of the mutagenized phagemid, and the pathway-bearing phage particles infect naïve cells, generating a mutant library that can be screened or selected for improved variants. Successive rounds of IDE enable optimization of complex phenotypes encoded by large pathways (as of this writing up to 36 kb), without requiring inefficient transformation steps. Additionally, IDE avoids off-target genomic mutations and enables decoupling of mutagenesis and screening steps, establishing it as a powerful tool for optimizing complex phenotypes in E. coli .

Phase 2 trial of bevacizumab, capecitabine, and oxaliplatin in treatment of advanced hepatocellular carcinoma.

BACKGROUND: Anti-angiogenesis agents have shown effectiveness in treatment of hepatocellular carcinoma (HCC). It is important to investigate more effective and safe systemic treatment options for patients with advanced HCC. This phase 2 study was designed to determine the efficacy and toxicity of the combination of bevacizumab, capecitabine, and oxaliplatin in patients with advanced unresectable and untransplantable HCC. METHODS: Chemotherapy-naive patients with advanced unresectable and untransplantable HCC were treated with bevacizumab 5 mg/kg and oxaliplatin 130 mg/m(2) on day 1 of each cycle, and capecitabine 825 mg/m² orally twice a day from days 1 to 14 of a 21-day cycle. RESULTS: Forty patients were enrolled to the study, in which 40% had Child-Pugh B disease. Forty percent had an Eastern Cooperative Oncology Group performance status (PS) of 0, 55% had PS of 1, and 5% had PS of 2. Forty percent of patients had hepatitis B virus infection. The median progression-free survival was 6.8 months (95% CI, 3.4-9.1 months), and the median overall survival was 9.8 months (95% CI, 5.2-12.1 months). Eight patients (20%) achieved partial response; 23 patients had stable disease with overall 77.5% disease control rate. The combination was tolerable with limited grade 3/4 toxicity, mainly peripheral neurotoxicity and fatigue. CONCLUSIONS: The combination appeared effective and safe, and the results were encouraging. Further investigation should be considered.

Resection status, age and nodal involvement determine survival among patients receiving adjuvant chemoradiotherapy in pancreatic adenocarcinoma.

CONTEXT: Pancreas cancer can potentially be cured by resection, but the role of adjuvant chemotherapy and/or chemoradiation has been controversial. OBJECTIVES: To better define clinicopathological factors that may serve as predictive and/or prognostic variables. PATIENTS: Between 1984 and 2006, we retrospectively analyzed 91 patients with pancreas cancer treated with pancreaticoduodenectomy or total pancreatectomy followed by adjuvant 5-fluorouracil-based chemoradiation at the University of Pennsylvania. Final pathological coding including margin status was confirmed by a pathologist. INTERVENTIONS: Patients were treated with 48.6 to 63.0 Gy, and 96.7% completed their prescribed radiation dose. MAIN OUTCOME MEASURES: The prognostic significance of demographic factors, stage, year of surgery, tumor location, grade, resection status, and number of positive lymph nodes on overall survival were examined. RESULTS: With a median follow-up of 6.5 years, the overall median survival was 2.3 years (95% CI 1.5-3.2 years), and the 5-year overall survival was 28.9%. In multivariate analysis, completeness of resection (P<0.001), fewer number of positive lymph nodes (0 vs. 1-2 vs. 3 or more) (P=0.004), and age less than, or equal to, 60 years (P=0.006) were all independently associated with improved overall survival. The overall survival reported in this study compares favorably with the results of other single-institution studies and with the RTOG 97-04 trial. CONCLUSIONS: Adjuvant 5-FU-based chemoradiation following radical pancreatectomy can be delivered safely and results in comparatively good overall survival. The results of this analysis underscore the importance of resection status, number of involved lymph nodes and patient age as prognostic characteristics. These factors may be considered stratification variables for future post-pancreatectomy adjuvant therapy trials.

Benefit of Oxaliplatin in Stage III Colon Cancer According to IDEA Risk Groups: Findings from the ACCENT Database of 4934 Patients.

BACKGROUND: The International Duration Evaluation of Adjuvant Chemotherapy (IDEA) pooled analysis compared 3 to 6 months of adjuvant chemotherapy for stage III colon cancer. Patients were classified into low risk and high risk, suggesting low-risk patients may be offered only 3 months of treatment. In this study, we aimed to assess the benefit of oxaliplatin in the adjuvant setting per IDEA risk groups, using data from 3 large adjuvant phase III studies, namely Multicenter International Study of Oxaliplatin/Fluorouracil/ Leucovorin in the Adjuvant Treatment of Colon Cancer (MOSAIC), C-07, and XELOXA. METHODS: Using the MOSAIC, C-07, and XELOXA previously published studies, we identified 2810 low-risk and 2124 high-risk patients with stage III colon cancer. We used Cox regression model to evaluate the magnitude of survival differences between IDEA risk groups, according to oxaliplatin use. Based on design similarity and equivalent follow-up data, MOSAIC and C-07 were pooled, whereas XELOXA was analyzed separately. Subgroup analyses were also performed for T4 and/or N2 patients. RESULTS: Individuals with IDEA low and high risk derived overall survival benefit from the addition of oxaliplatin to adjuvant chemotherapy, with adjusted hazard ratios of 0.79 (0.66-0.95) and 0.84 (0.71-0.99), respectively. Among individuals with IDEA high risk, those with T4 disease did not gain overall survival benefit from addition of oxaliplatin with hazard ratio of 0.95 (0.71-1.27). Similar results were demonstrated using data from the XELOXA study. CONCLUSION: IDEA risk classification per se does not predict benefit from addition of oxaliplatin to adjuvant chemotherapy in stage III colon cancer. T4 disease may predict lack of benefit from oxaliplatin addition.

Microsatellite Instability in Patients With Stage III Colon Cancer Receiving Fluoropyrimidine With or Without Oxaliplatin: An ACCENT Pooled Analysis of 12 Adjuvant Trials.

PURPOSE: In patients with stage III colon cancer (CC) whose tumors demonstrate microsatellite instability (MSI), the efficacy of adjuvant fluoropyrimidine (FP) with or without oxaliplatin has not been clearly demonstrated and the prognostic value of MSI remains uncertain. MATERIALS AND METHODS: Individual patient data from the ACCENT database were used to evaluate the effect of FP with or without oxaliplatin on disease-free survival (DFS) and overall survival (OS) among patients with MSI stage III CC and the prognostic value of MSI in patients treated with FP plus oxaliplatin, by stratified Cox models adjusted for demographic and clinicopathological factors. RESULTS: MSI status was available for 5,457 patients (609 MSI, 11.2%; 4848 microsatellite stable [MSS], 88.8%) from 12 randomized clinical trials (RCTs). Oxaliplatin significantly improved OS of MSI patients from the two RCTs testing FP with or without oxaliplatin (n = 185; adjusted hazard ratio [aHR] = 0.52, 95% CI, 0.28 to 0.93). Among the 4,250 patients treated with FP plus oxaliplatin (461 MSI and 3789 MSS), MSI was associated with better OS in the N1 group compared with MSS (aHR = 0.66; 95% CI, 0.46 to 0.95) but similar survival in the N2 population (aHR = 1.13; 95% CI, 0.86 to 1.48; P interaction = .029). The main independent prognosticators of MSI patients treated with FP plus oxaliplatin were T stage (aHR = 2.09; 95% CI, 1.29 to 3.38) and N stage (aHR = 3.57; 95% CI, 2.32 to 5.48). Similar results were observed for DFS in all analyses. CONCLUSION: Adding oxaliplatin to FP improves OS and DFS in patients with MSI stage III CC. Compared with MSS, MSI patients experienced better outcomes in the N1 group but similar survival in the N2 group.

Sex and Adverse Events of Adjuvant Chemotherapy in Colon Cancer: An Analysis of 34 640 Patients in the ACCENT Database.

BACKGROUND: Adjuvant chemotherapy is a standard treatment option for patients with stage III and high-risk stage II colon cancer. Sex is one of several factors responsible for the wide inter-patient variability in drug responses. Amalgamated data on the effect of sex on the toxicity of current standard adjuvant treatment for colorectal cancer are missing. METHODS: The objective of our study was to compare incidence and severity of major toxicities of fluoropyrimidine- (5FU or capecitabine) based adjuvant chemotherapy, with or without oxaliplatin, between male and female patients after curative surgery for colon cancer. Adult patients enrolled in 27 relevant randomized trials included in the ACCENT (Adjuvant Colon Cancer End Points) database, a large, multi-group, international data repository containing individual patient data, were included. Comparisons were conducted using logistic regression models (stratified by study and treatment arm) within each type of adjuvant chemotherapy (5FU, FOLFOX, capecitabine, CAPOX, and FOLFIRI). The following major toxicities were compared (grade III or IV and grade I-IV, according to National Cancer Institute Common Terminology Criteria [NCI-CTC] criteria, regardless of attribution): nausea, vomiting, nausea or vomiting, stomatitis, diarrhea, leukopenia, neutropenia, thrombocytopenia, anemia, and neuropathy (in patients treated with oxaliplatin). RESULTS: Data from 34 640 patients were analyzed. Statistically significant and clinically relevant differences in the occurrence of grade III or IV nonhematological {especially nausea (5FU: odds ratio [OR] = 2.33, 95% confidence interval [CI] = 1.90 to 2.87, P < .001; FOLFOX: OR = 2.34, 95% CI = 1.76 to 3.11, P < .001), vomiting (5FU: OR = 2.38, 95% CI = 1.86 to 3.04, P < .001; FOLFOX: OR = 2.00, 95% CI = 1.50 to 2.66, P < .001; CAPOX: OR = 2.32, 95% CI = 1.55 to 3.46, P < .001), and diarrhea (5FU: OR = 1.35, 95% CI = 1.21 to 1.51, P < .001; FOLFOX: OR = 1.60, 95% CI = 1.35 to 1.90, P < .001; FOLFIRI: OR = 1.57, 95% CI = 1.25 to 1.97, P < .001)} as well as hematological toxicities (neutropenia [5FU: OR = 1.55, 95% CI = 1.37 to 1.76, P < .001; FOLFOX: OR = 1.96, 95% CI = 1.71 to 2.25, P < .001; FOLFIRI: OR = 2.01, 95% CI = 1.66 to 2.43, P < .001; capecitabine: OR = 4.07, 95% CI = 1.84 to 8.99, P < .001] and leukopenia [5FU: OR = 1.74, 95% CI = 1.40 to 2.17, P < .001; FOLFIRI: OR = 1.75, 95% CI = 1.28 to 2.40, P < .001]) were observed, with women being consistently at increased risk. CONCLUSIONS: Our analysis confirms that women with colon cancer receiving adjuvant fluoropyrimidine-based chemotherapy are at increased risk of toxicity. Given the known sex differences in fluoropyrimidine pharmacokinetics, sex-specific dosing of fluoropyrimidines warrants further investigation.

Clinicopathological and Molecular Characteristics of Early-Onset Stage III Colon Adenocarcinoma: An Analysis of the ACCENT Database.

BACKGROUND: Colon cancer (CC) incidence in young adults (age 20-49 years), termed early-onset CC (EO-CC), is increasing. METHODS: Individual patient data on 35 713 subjects with stage III colon cancer from 25 randomized studies in the Adjuvant Colon Cancer ENdpoint database were pooled. The distributions of demographics, clinicopathological features, biomarker status, and outcome data were summarized by age group. Overall survival, disease-free survival, time to recurrence, and survival after recurrence were assessed by Kaplan-Meier curves and Cox models stratified by treatment arms within studies, adjusting for sex, race, body mass index, performance status, disease stage, grade, risk group, number of lymph nodes examined, disease sidedness, and molecular markers. All statistical tests were 2-sided. RESULTS: Using a 5% difference between age groups as the clinically meaningful cutoff, patients with stage III EO-CC had similar sex, race, performance status, risk group, tumor sidedness, and T stage compared with patients with late-onset CC (age 50 years and older). EO-CC patients were less likely to be overweight (30.2% vs 36.2%) and more commonly had 12 or more lymph nodes resected (69.5% vs 58.7%). EO-CC tumors were more frequently mismatch repair deficient (16.4% vs 11.5%) and less likely to have BRAFV600E (5.6% vs 14.0%), suggesting a higher rate of Lynch syndrome in EO-CC. Patients with EO-CC had statistically significantly better overall survival (hazard ratio [HR] = 0.81, 95% confidence interval [CI] = 0.74 to 0.89; P < .001), disease-free survival (HR = 0.91, 95% CI = 0.84 to 0.98; P = .01), and survival after recurrence (HR = 0.88, 95% CI = 0.80 to 0.97; P = .008) in the analysis without molecular markers; however, age at onset of CC lost its prognostic value when outcome was adjusted for molecular markers. CONCLUSION: Tumor biology was found to be a more important prognostic factor than age of onset among stage III colon cancer patients in the Adjuvant Colon Cancer ENdpoint database.

Schizonts of Theileria annulata interact with the microtubuli network of their host cell via the membrane protein TaSP.

Intracellular leukoproliferative Theileria are unique as eukaryotic organisms that transform the immune cells of their ruminant host. Theileria utilize the uncontrolled proliferation for rapid multiplication and distribution into host daughter cells. The parasite distribution into the daughter cells is accompanied by a tight association with the host cell mitotic apparatus. Since the molecular basis for this interaction is largely unknown, we investigated the possible involvement of the immunodominant Theileria annulata surface protein, TaSP, in the attachment of the parasite to host cell microtubule network. Confocal microscopic analyses showed co-localization of the TaSP protein with alpha-tubulin and reciprocal immuno-co-precipitation experiments demonstrated an association of TaSP with alpha-tubulin in vivo. In addition, the partially expressed predicted extracellular domain of TaSP co-localized with the mitotic spindle of dividing cells and was co-immunoprecipitated with alpha-tubulin in transiently transfected Cos-7 cells devoid of other T. annulata expressed proteins. Pull-down studies showed that there is a direct interaction between TaSP and polymerized microtubules. Analysis of the interaction of TaSP and host microtubulin during host cell mitosis indicated that TaSP co-localizes and interacts with the spindle poles, the mitotic spindle apparatus and the mid-body. Moreover, TaSP was demonstrated to be localized to the microtubule organizing center and to physically interact with gamma-tubulin. These data support the notion that the TaSP-microtubule interaction may be playing a potential role in parasite distribution into daughter host cells and give rise to the speculation that TaSP may be involved in regulation of microtubule assembly in the host cell.

Update on optimal treatment for metastatic colorectal cancer from the AGITG expert meeting: ESMO congress 2019.

Introduction: Outcomes in metastatic colorectal cancer are improving, due to the tailoring of therapy enabled by better understanding of clinical behavior according to molecular subtype.Areas covered: A review of the literature and recent conference presentations was undertaken on the topic of systemic treatment of metastatic colorectal cancer. This review summarizes expert discussion of the current evidence for therapies in metastatic colorectal cancer (mCRC) based on molecular subgrouping.Expert opinion: EGFR-targeted and VEGF-targeted antibodies are now routinely incorporated into treatment strategies for mCRC. EGFR-targeted antibodies are restricted to patients with extended RAS wild-type profiles, with evidence that they should be further restricted to patients with left-sided tumors. Clinically distinct treatment pathways based on tumor RAS, BRAF, HER2 and MMR status, are now clinically applicable. Evidence suggests therapy for additional subgroups will soon be defined; the most advanced being for patients with KRAS G12 C mutation and gene TRK fusion defects.

Resection of the primary colorectal cancer is not necessary in nonobstructed patients with metastatic disease.

Asymptomatic patients with metastatic colorectal cancer do not routinely need to undergo resection of the primary tumor. Although several retrospective analyses suggest that patients who undergo resection of the primary tumor live longer, most of these reviewed data prior to the advent of modern polychemotherapy and are subject to considerable bias, as patients who were considered able to undergo surgery likely had better overall prognoses than those who were not. In addition to significant prolongation of overall survival, current combinations of systemic chemotherapeutic agents and targeted agents have allowed improved local and distant tumor control, decreasing the likelihood of local tumor-related complications requiring colon resection.

Improved patient and regimen selection in locally advanced rectal cancer: who, how, and what next?

Before the advent of neoadjuvant chemoradiation therapy (NCRT) for locally advanced rectal cancer, local failure represented half of treatment failures. The German Rectal Cancer Study Group trial demonstrated that NCRT along with total mesorectal excision can improve local control and the rate of sphincter-preserving surgery. Thus, the National Comprehensive Cancer Network now recommends NCRT as the standard of care for stage III and IV rectal cancer. Recent trials and analysis have questioned accepted wisdom regarding patient selection for NCRT and methods of administration. EORTC 22921 demonstrated that the addition of chemotherapy to radiation therapy, regardless of timing, improved local control but not overall survival, and subgroup analysis from this study generated the hypothesis that the subgroup of patients with good pathologic response to NCRT would benefit the most from additional chemotherapy following surgery. The prognosis of rectal cancer is stage dependent, and 2 major analyses question whether T1/2 N1 and T3 N0 patients benefit from NCRT. Application of the results from these studies is hindered by imperfections in staging. Future improvement in patient selection might result from biologic analysis of tumor sensitivity. NCRT might be improved with the use of oral fluoropyrimidines and perhaps the addition of a second agent such as oxaliplatin, irinotecan, or cetuximab. Improvements in radiation, such as the use of more conformal techniques, might decrease the toxicity of therapy. Given the success of NCRT in improving local control, distant metastasis now predominates as the cause of treatment failure, and larger gains will likely be made from improvements in adjuvant chemotherapy.

A randomized trial of generic versus tailored interventions to increase colorectal cancer screening among intermediate risk siblings.

BACKGROUND: Individuals with a sibling who has had colorectal cancer diagnosed before age 61 are at increased risk for colorectal cancer and may derive particular benefit from screening. Tailored interventions may increase participation in appropriate colorectal cancer screening. PURPOSE: This study evaluated the efficacy of two tailored interventions and a generic print intervention. METHODS: Participant siblings (N = 412) who were not up-to-date with colorectal cancer screening were randomly assigned to receive either a generic print pamphlet, a tailored print pamphlet, or a tailored print pamphlet and tailored counseling call. Colorectal cancer screening 6 months after the baseline interview was the outcome measure. RESULTS: Results indicated that colorectal cancer screening adherence increased among intermediate risk siblings enrolled in all three intervention groups. Participants in both tailored intervention groups reported having colorectal cancer screening at significantly higher rates than participants in the generic print group. The increase in colorectal cancer screening in the tailored print and counseling call group was not significantly higher than that achieved by the tailored print alone. Decisional balance partially mediated treatment effects. Tailored behavioral interventions are effective methods for increasing screening adherence but telephone counseling did not add significantly to treatment effects.