Provincial Review of Adherence to Age-specific Guidelines for Umbilical Hernia Repair and Trends in Management.

BACKGROUND: Umbilical hernia (UH) is a common pediatric condition, for which delaying surgical repair for asymptomatic UH until after age 3 is recommended due to a high incidence of spontaneous closure. We aimed to determine the adherence to guidelines, rate of urgent surgical repair, outcomes, cost, and interinstitutional referral patterns of UH repair in the province of Quebec (Canada). METHODS: This was a population-based retrospective cohort study of children 28 days to 17 years old who underwent UH repair between 2010 and 2020 using health administrative databases. Children who had multiple procedures, or prolonged peri-operative stays were excluded. Early repair was defined as elective surgery at or under age 3. RESULTS: Of the 3215 children, 1744 (54.2%) were female, and 1872 (58.2%) were treated in a tertiary children's hospital. Guidelines were respected for 2853 out of 3215 children (89.7%). Patients living over 75 km from their treating hospitals (OR 2.36, 95% CI 1.33-4.16, P < 0.01), with pre-existing comorbidities (OR, 2.82; 95% CI, 1.96-4.05; P < 0.001), or being treated in a tertiary center (OR 2.10, 95% CI 1.45-3.03, P < 0.001) had a higher risk of early repair. Repair at or under age 3 and urgent surgery were associated with significant cost increases of 411$ (P < 0.001) and 558$ (P < 0.001), respectively. CONCLUSION: Quebec has a high rate of adherence to age-specific guidelines for UH repair. Future research should explore factors that explain transfers into tertiary centers, and the extent to which these reflect efficient use of resources. LEVEL OF EVIDENCE: level III. TYPE OF STUDY: Retrospective comparative study.

Use of a risk communication survey to prioritize family-valued outcomes and communication preferences for children undergoing outpatient surgical procedures.

BACKGROUND: Effective shared decision-making in pediatric surgery requires clarity regarding which surgical outcomes are most important to patients and their families, and how they prefer to receive the information. Despite how essential this is for effective risk communication, little is known about the communication needs and preferences of patients and their families in elective pediatric surgery. METHODS: We administered a mailed and online cross-sectional survey in English and French to 548 families before or after surgery for hernia/hydrocele repair or tonsillectomy/adenoidectomy between July 2019 and February 2021. The survey consisted of 22 questions eliciting most valued patient-reported outcomes (PROs) across 4 domains: health-related quality of life (5), functional status (5), symptoms and symptom burden (5), health behaviours and patient experience (7), as well as overall impressions (3), surgical risks (5), communication preferences (4), and demographic questions (16). RESULTS: The survey was completed by 368 patient families (60 preoperative, 308 postoperative, response rate 67.2%). Most respondents (72%) indicated a significant desire to be informed on all listed PROs alongside surgical complications, and highly valued all functional and quality of life outcomes (92.9% & 89.8%, respectively). Preoperatively, patient families preferred to receive information in the form of pamphlets and websites, whereas postoperatively they preferred direct communication. CONCLUSION: Families value functional and quality of life PROs as much as clinical outcomes, and increasingly seek more contemporary (electronic) means of risk communication than we currently offer. This data will inform the development of mobile tools for personalized communication in pediatric surgery.

Mobile Audio Recording Technology to Promote Informed Decision Making in Advanced Prostate Cancer.

PURPOSE: Men with metastatic castration-resistant prostate cancer increasingly encounter complex treatment decisions. Consultation audio recordings and summaries promote patient informed decision making but are underutilized. Mobile recording software applications may increase access. Little is known regarding the feasibility of implementation in clinical encounters. METHODS: We conducted a mixed-methods pilot study in men with progressive metastatic castration-resistant prostate cancer. We instructed patients to use a mobile software application to record an oncology visit. Patients could share the recording with our patient scribing program to receive a written summary. We assessed feasibility and acceptability with postvisit surveys. We measured patient-reported helpfulness of the intervention in decision making and change in Decisional Conflict Scale-informed subscale. We conducted semistructured interviews to explore implementation and analyzed transcripts using thematic analysis. RESULTS: Across 20 patients, 18 (90%) recorded their visits. Thirteen of 18 (72%) listened to the recording, and 14 of 18 (78%) received a summary. Eighteen of 20 (90%) visits were telehealth. Fourteen patients (70% of all 20; 78% of 18 question respondents) found the application easy to use. Nine patients (50% of 18 recording patients; 90% of 10 question respondents) reported that the recording helped treatment decision making. Decisional conflict decreased from baseline to 1-week postvisit (47.4-28.5, P < .001). Interviews revealed benefits, facilitators, contextual factors, and technology and patient-related barriers to recordings and summaries. CONCLUSION: In this single-institution academic setting, a mobile application for patients to record consultations was a feasible, acceptable, and potentially valued intervention that improved decision making in the telehealth setting. Studies in larger, diverse populations are needed.

Cell-Free DNA Detection of Tumor Mutations in Heterogeneous, Localized Prostate Cancer Via Targeted, Multiregion Sequencing.

Cell-free DNA (cfDNA) may allow for minimally invasive identification of biologically relevant genomic alterations and genetically distinct tumor subclones. Although existing biomarkers may detect localized prostate cancer, additional strategies interrogating genomic heterogeneity are necessary for identifying and monitoring aggressive disease. In this study, we aimed to evaluate whether circulating tumor DNA can detect genomic alterations present in multiple regions of localized prostate tumor tissue. METHODS: Low-pass whole-genome and targeted sequencing with a machine-learning guided 2.5-Mb targeted panel were used to identify single nucleotide variants, small insertions and deletions (indels), and copy-number alterations in cfDNA. The majority of this study focuses on the subset of 21 patients with localized disease, although 45 total individuals were evaluated, including 15 healthy controls and nine men with metastatic castration-resistant prostate cancer. Plasma cfDNA was barcoded with duplex unique molecular identifiers. For localized cases, matched tumor tissue was collected from multiple regions (one to nine samples per patient) for comparison. RESULTS: Somatic tumor variants present in heterogeneous tumor foci from patients with localized disease were detected in cfDNA, and cfDNA mutational burden was found to track with disease severity. Somatic tissue alterations were identified in cfDNA, including nonsynonymous variants in FOXA1, PTEN, MED12, and ATM. Detection of these overlapping variants was associated with seminal vesicle invasion (P = .019) and with the number of variants initially found in the matched tumor tissue samples (P = .0005). CONCLUSION: Our findings demonstrate the potential of targeted cfDNA sequencing to detect somatic tissue alterations in heterogeneous, localized prostate cancer, especially in a setting where matched tumor tissue may be unavailable (ie, active surveillance or treatment monitoring).

2020 edition of the Rourke Baby Record: What is new in preventive care of children up to 5 years of age?

OBJECTIVE: To update primary care providers practising well-child and well-baby clinical care on the evidence that contributed to the recommendations of the 2020 edition of the Rourke Baby Record (RBR). QUALITY OF EVIDENCE: Pediatric preventive care literature was searched from June 2016 to May 2019, primary research studies were reviewed and critically appraised using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, and recommendations were updated where there was support from the literature. MAIN MESSAGE: Notable changes in the 2020 edition of the RBR include the recommendations to limit or avoid consumption of highly processed foods high in dietary sodium, to ensure safe sleep (healthy infants should sleep on their backs and on a firm surface for every sleep, and should sleep in a crib, cradle, or bassinette in the parents' room for the first 6 months of life), to not swaddle infants after they attempt to roll, to inquire about food insecurity, to encourage parents to read and sing to infants and children, to limit screen time for children younger than 2 years of age (although it is accepted for videocalling), to educate parents on risks and harms associated with e-cigarettes and cannabis, to avoid pesticide use, to wash all fruits and vegetables that cannot be peeled, to be aware of the new Canadian Caries Risk Assessment Tool, to note new red flags for cerebral palsy and neurodevelopmental problems, and to pay attention to updated high-risk groups for lead and anemia screening. CONCLUSION: The RBR endeavours to guide clinicians in providing evidence-informed primary care to Canadian children. The revisions are rigorously considered and are based on appraisal of a growing, albeit still limited, evidence base for pediatric preventive care.

Cell-free DNA concentration and fragment size as a biomarker for prostate cancer.

Prostate cancer is the most commonly diagnosed neoplasm in American men. Although existing biomarkers may detect localized prostate cancer, additional strategies are necessary for improving detection and identifying aggressive disease that may require further intervention. One promising, minimally invasive biomarker is cell-free DNA (cfDNA), which consist of short DNA fragments released into circulation by dying or lysed cells that may reflect underlying cancer. Here we investigated whether differences in cfDNA concentration and cfDNA fragment size could improve the sensitivity for detecting more advanced and aggressive prostate cancer. This study included 268 individuals: 34 healthy controls, 112 men with localized prostate cancer who underwent radical prostatectomy (RP), and 122 men with metastatic castration-resistant prostate cancer (mCRPC). Plasma cfDNA concentration and fragment size were quantified with the Qubit 3.0 and the 2100 Bioanalyzer. The potential relationship between cfDNA concentration or fragment size and localized or mCRPC prostate cancer was evaluated with descriptive statistics, logistic regression, and area under the curve analysis with cross-validation. Plasma cfDNA concentrations were elevated in mCRPC patients in comparison to localized disease (OR5ng/mL = 1.34, P = 0.027) or to being a control (OR5ng/mL = 1.69, P = 0.034). Decreased average fragment size was associated with an increased risk of localized disease compared to controls (OR5bp = 0.77, P = 0.0008). This study suggests that while cfDNA concentration can identify mCRPC patients, it is unable to distinguish between healthy individuals and patients with localized prostate cancer. In addition to PSA, average cfDNA fragment size may be an alternative that can differentiate between healthy individuals and those with localized disease, but the low sensitivity and specificity results in an imperfect diagnostic marker. While quantification of cfDNA may provide a quick, cost-effective approach to help guide treatment decisions in advanced disease, its use is limited in the setting of localized prostate cancer.

The burden of waiting: wait times for pediatric surgical procedures in Quebec and compliance with national benchmarks.

Background: Wait time information and compliance with national guidelines are limited to a few adult conditions in the province of Quebec. We aimed to assess compliance with Paediatric Canadian Access Targets for Surgery (P-CATS) guidelines and determine the burden incurred due to waiting for 3 common elective surgical conditions (inguinal hernia, cryptorchidism and hypospadias) in a pediatric population. Methods: We carried out a population-based retrospective cohort study of randomly selected children residing in Quebec without complex chronic medical conditions, using administrative databases belonging to the Régie de l'assurance maladie du Québec for the period 2010-2013. Disability-adjusted life years (DALYs) were calculated to measure the burden due to waiting. Multivariate forward regression identified risk factors for compliance with national guidelines. Results: Surgical wait time information was assessed for 1515 patients, and specialist referral wait time was assessed for 1389 patients. Compliance with P-CATS benchmarks was 76.6% for seeing a specialist and 60.7% for receiving surgery. Regression analysis identified older age (p < 0.0001) and referring physician specialty (p = 0.001) as risk factors affecting specialist referral wait time target compliance, whereas older age (p = 0.040), referring physician specialty (p = 0.043) and surgeon specialty (p = 0.002) were significant determinants in surgical wait time compliance. The total burden accrued due to waiting beyond benchmarks was 35 DALYs. Conclusion: Our results show that provincial compliance rates with wait time benchmarks are still inadequate and need improvement. Patient age and physician specialty were both found to have significant effects on wait time target compliance.

Contexte: L'information sur les temps d'attente et le respect des lignes directrices nationales au Québec est limitée à quelques affections chez les adultes. Nous avons voulu évaluer le respect des objectifs canadiens en matière d'accès aux chirurgies pédiatriques (P-CATS) et déterminer le fardeau associé à l'attente pour 3 affections courantes nécessitant une intervention chirurgicale non urgente (hernie inguinale, cryptorchidie et hypospadias) chez une population pédiatrique. Méthodes: Pour ce faire, nous avons mené une étude de cohorte populationnelle rétrospective portant sur des enfants vivant au Québec et n'ayant pas de problèmes de santé chroniques complexes. Leur sélection aléatoire a été faite à partir de bases de données administratives appartenant à la Régie de l'assurance maladie du Québec pour la période de 2010 à 2013. Nous avons calculé les années de vie ajustées en fonction de l'incapacité (AVAI) pour mesurer le fardeau associé à l'attente. Une régression ascendante multivariée a permis de relever les facteurs de risque relatifs au respect des lignes directrices nationales. Résultats: Nous avons évalué les données sur le temps d'attente pour une intervention chirurgicale chez 1515 patients, et sur le temps d'attente pour la consultation d'un spécialiste chez 1389 patients. Les valeurs de référence pour le respect des P-CATS étaient de 76,6 % pour la consultation d'un spécialiste et de 60,7 % pour la réalisation d'une intervention. L'analyse de régression a montré que l'âge plus avancé (p < 0,0001) et la spécialité du médecin traitant (p = 0,001) étaient des facteurs de risque pour la consultation d'un spécialiste, tandis que l'âge plus avancé (p = 0,040), la spécialité du médecin traitant (p = 0,043) et la spécialité du chirurgien (p = 0,002) étaient des déterminants significatifs du respect des objectifs d'attente pour une intervention. Le fardeau total causé par l'attente au-delà des valeurs de référence était de 35 AVAI. Conclusion: Nos résultats montrent que le taux provincial de respect des lignes directrices d'attente demeure inadéquat et doit être amélioré. L'âge des patients et la spécialité des médecins ont tous deux un effet significatif sur le respect des objectifs d'attente.

A machine learning approach to optimizing cell-free DNA sequencing panels: with an application to prostate cancer.

BACKGROUND: Cell-free DNA's (cfDNA) use as a biomarker in cancer is challenging due to genetic heterogeneity of malignancies and rarity of tumor-derived molecules. Here we describe and demonstrate a novel machine-learning guided panel design strategy for improving the detection of tumor variants in cfDNA. Using this approach, we first generated a model to classify and score candidate variants for inclusion on a prostate cancer targeted sequencing panel. We then used this panel to screen tumor variants from prostate cancer patients with localized disease in both in silico and hybrid capture settings. METHODS: Whole Genome Sequence (WGS) data from 550 prostate tumors was analyzed to build a targeted sequencing panel of single point and small (< 200 bp) indel mutations, which was subsequently screened in silico against prostate tumor sequences from 5 patients to assess performance against commonly used alternative panel designs. The panel's ability to detect tumor-derived cfDNA variants was then assessed using prospectively collected cfDNA and tumor foci from a test set 18 prostate cancer patients with localized disease undergoing radical proctectomy. RESULTS: The panel generated from this approach identified as top candidates mutations in known driver genes (e.g. HRAS) and prostate cancer related transcription factor binding sites (e.g. MYC, AR). It outperformed two commonly used designs in detecting somatic mutations found in the cfDNA of 5 prostate cancer patients when analyzed in an in silico setting. Additionally, hybrid capture and 2500X sequencing of cfDNA molecules using the panel resulted in detection of tumor variants in all 18 patients of a test set, where 15 of the 18 patients had detected variants found in multiple foci. CONCLUSION: Machine learning-prioritized targeted sequencing panels may prove useful for broad and sensitive variant detection in the cfDNA of heterogeneous diseases. This strategy has implications for disease detection and monitoring when applied to the cfDNA isolated from prostate cancer patients.

Down-regulation of ADRB2 expression is associated with small cell neuroendocrine prostate cancer and adverse clinical outcomes in castration-resistant prostate cancer.

OBJECTIVES: The net oncogenic effect of ß2-adrenergic receptor ADRB2, whose downstream elements induce neuroendocrine differentiation and whose expression is regulated by EZH2, is unclear. ADRB2 expression and associated clinical outcomes in metastatic castration-resistant prostate cancer (mCRPC) are unknown. METHODS AND MATERIALS: This was a retrospective analysis of a multi-center, prospectively enrolled cohort of mCRPC patients. Metastatic biopsies were obtained at progression, and specimens underwent laser capture microdissection and RNA-seq. ADRB2 expression was stratified by histology and clustering based on unsupervised hierarchical transcriptome analysis and correlated with EZH2 expression; an external dataset was used for validation. The association between ADRB2 expression and overall survival (OS) was assessed by log-rank test and a multivariable Cox proportional hazard model. RESULTS: One hundred and twenty-seven patients with progressive mCRPC had sufficient metastatic tumor for RNA-seq. ADRB2 expression was lowest in the small cell-enriched transcriptional cluster (P < 0.01) and correlated inversely with EZH2 expression (r = -0.28, P < 0.01). These findings were validated in an external cohort enriched for neuroendocrine differentiation. Patients with tumors harboring low ADRB2 expression (lowest quartile) had a shorter median OS than those with higher (9.5 vs. 20.5 months, P = 0.02). In multivariable analysis, low ADRB2 expression was associated with a trend toward shorter OS (HR for death = 1.54, 95%CI 0.98-2.44). Conversely, higher expression of upstream transcriptional regulator EZH2 was associated with shortened OS (HR for death = 3.01, 95%CI 1.12-8.09). CONCLUSIONS: Low ADRB2 expression is associated with neuroendocrine differentiation and is associated with shortened survival. EZH2 is a potential therapeutic target for preventing neuroendocrine transdifferentiation and improving outcomes in mCRPC. Further studies of agents targeting ß-adrenergic signaling are warranted.

Identification and Characterization of Circulating Tumor Cells in Men Who have Undergone Prostatectomy for Clinically Localized, High Risk Prostate Cancer.

PURPOSE: Approximately 15% of men with newly diagnosed prostate cancer have high risk features which increase the risk of recurrence and metastasis. Better predictive biomarkers could allow for earlier detection of biochemical recurrence and change surveillance and adjuvant treatment paradigms. Circulating tumor cells are thought to represent the earliest form of metastases. However, their role as biomarkers in men with high risk, localized prostate cancer is not well defined. MATERIALS AND METHODS: Two to 5 months after prostatectomy we obtained blood samples from 37 patients with high risk, localized prostate cancer, defined as stage T3a or higher, Gleason score 8 or greater, or prostate specific antigen 20 ng/ml or greater. Circulating tumor cells were enumerated using a commercial platform. Matched tumor and single circulating tumor cell sequencing was performed. RESULTS: Circulating tumor cells were detected in 30 of 37 samples (81.1%) with a median of 2.4 circulating tumor cells per ml (range 0 to 22.9). Patients with detectable circulating tumor cells showed a trend toward shorter recurrence time (p=0.12). All patients with biochemical recurrence had detectable circulating tumor cells. Androgen receptor over expression was detected in 7 of 37 patients (18.9%). Patients with biochemical recurrence had more circulating tumor cell copy number aberrations (p=0.027). Matched tumor tissue and single circulating tumor cell sequencing revealed heterogeneity. CONCLUSIONS: We noted a high incidence of circulating tumor cell detection after radical prostatectomy and shorter time to biochemical recurrence in men with a higher circulating tumor cell burden and more circulating tumor cell copy number aberrations. Genomic alterations consistent with established copy number aberrations in prostate cancer were detectable in circulating tumor cells but often discordant with cells analyzed in bulk from primary lesions. With further testing in appropriately powered cohorts early circulating tumor cell detection could be an informative biomarker to assist with adjuvant treatment decisions.

Rourke Baby Record 2014: Evidence-based tool for the health of infants and children from birth to age 5.

OBJECTIVE: To update the 2011 edition of the Rourke Baby Record (RBR) by reviewing current best evidence on health supervision of infants and children from birth to 5 years of age. QUALITY OF EVIDENCE: The quality of evidence was rated with the former (until 2006) Canadian Task Force on Preventive Health Care classification system and GRADE (grading of recommendations, assessment, development, and evaluation) approach. MAIN MESSAGE: New evidence has been incorporated into the 2014 RBR recommendations related to growth monitoring, nutrition, education and advice, development, physical examination, and immunization. Growth is monitored with the World Health Organization growth charts that were revised in 2014. Infants' introduction to solid foods should be based on infant readiness and include iron-containing food products. Delaying introduction to common food allergens is not currently recommended to prevent food allergies. At 12 months of age, use of an open cup instead of a sippy cup should be promoted. The education and advice section counsels on injuries from unstable furniture and on the use of rear-facing car seats until age 2, and also includes information on healthy sleep habits, prevention of child maltreatment, family healthy active living and sedentary behaviour, and oral health. The education and advice section has also added a new environmental health category to account for the effects of environmental hazards on child health. The RBR uses broad developmental surveillance to recognize children who might be at risk of developmental delays. Verifying tongue mobility and patency of the anus is included in the physical examination during the first well-baby visit. The 2014 RBR also provides updates regarding the measles-mumps-rubella, live attenuated influenza, and human papillomavirus vaccines. CONCLUSION: The 2014 RBR is the most recent update of a longstanding evidence-based, practical knowledge translation tool with related Web-based resources to be used by both health care professionals and parents for preventive health care during early childhood. The 2014 RBR is endorsed by the Canadian Paediatric Society, the College of Family Physicians of Canada, and the Dietitians of Canada. National and Ontario versions of the RBR are available in English and French.

Percutaneous pigtail catheter versus tube thoracostomy for pediatric empyema: A comparison of outcomes.

PURPOSE: Randomized trials have shown no benefit to thoracoscopic decortication over pleural drainage with fibrinolytic installation for pediatric empyema. However, the optimal method of pleural drainage has not been defined. The present study compares outcomes of 8.5-Fr soft pigtail catheters (PC) placed via Seldinger technique with larger caliber, stiff chest tubes (12- to 24-Fr) placed via tube thoracostomy (TT). METHODS: A retrospective review of all pediatric patients treated for empyema during a 5-year period (2006-2011) was conducted. Clinical, therapeutic, and outcomes data from patients treated by PC were compared with those treated by TT. Treatment failure, the primary outcome, was defined as need for an additional invasive thoracic procedure (second tube or catheter or thoracoscopic decortication). RESULTS: We treated 43 patients, 21 by PC and 22 by TT. Fibrinolytics were used in 71% of the PC and 64% of the TT groups. Baseline clinical parameters were not different between the 2 groups. Treatment failure was significantly higher in the PC group (43% vs 14%; P = .045). When the analysis was limited to patients who received fibrinolytics, the failure rate was greater in the PC group (40% vs 14%; P = .129), and duration of illness was shorter (18.3 ± 1.0 vs 25.6 ± 3.5 days; P = .048). CONCLUSION: Soft PCs are associated with higher failure rates but shorter total duration of illness in the treatment of pediatric empyema. The ideal method for draining pediatric empyema may be a small-caliber, stiff chest tube placed percutaneously.

Misuse of baseline comparison tests and subgroup analyses in surgical trials.

It is unclear whether the misuse of statistical tests that compare patients' baseline characteristics and subgroup analyses in randomized controlled trials can be extrapolated to the surgical literature. We did an observational study evaluating the current use of baseline comparability tests and subgroup analyses in surgical randomized controlled trials. Published surgical randomized controlled trials in four medical journals were identified. We also identified randomized controlled trials in the Journal of Bone and Joint Surgery (American and British volumes). We identified 72 randomized controlled trials, with a mean of 10 +/- 8 baseline variables. Of 166 significance tests, 17 (10%) were significant. Twenty-seven (38%) trials included 54 subgroup analyses with a minimum of one and maximum of 23 subgroup analyses per study. Inappropriate emphasis on subgroup analyses occurred frequently. Forty-nine (91%) analyses were performed post hoc without prior hypotheses. Investigators reported differences between subgroups in 31 (57%) of the analyses, all of which were featured in the summary or conclusion. These inferences may be misleading, making their application to clinical practice unwarranted.

Pulmonary Langerhans cell histiocytosis: a variable disease in childhood.

BACKGROUND: Pulmonary Langerhans cell histiocytosis (PLCH) is rare in childhood but occurs most commonly in children with multisystem (MS) LCH. In adults, by contrast, the lung is the most common and usually the sole organ affected. This retrospective study describes the clinical manifestation, course, and outcome of PLCH in children consecutively diagnosed at two Canadian institutions. PROCEDURE: The medical records of children (<18 years of age) consecutively diagnosed with LCH at the two institutions, were examined to ascertain the demographic details, pathological diagnosis, and organs involved. Further clinical details including, the clinical manifestation, details of therapy, course of lung disease, and clinical outcome were extracted for patients with PLCH. Initial and follow-up lung radiographs and CT scans were re-reviewed. RESULTS: Of the 178 patients with LCH, 40 (22.5%) presented with MS disease. Thirteen (7.3%) had PLCH, seven at initial diagnosis, and six at the time of disease progression. The median age was 10.1 months and mean was 11.9 months at diagnosis of PLCH. Lung involvement was always in the context of MS LCH, and half of the patients had no respiratory symptoms. Disease-free survival was around 70%, with a mean follow-up duration of 7 years. Of the four patients who died, three had other risk-organ involvement. Five of the nine surviving patients have had complete radiological resolution of PLCH. CONCLUSION: PLCH is seen in less than 10% of childhood LCH, but more than 30% of MS LCH. About half of children with PLCH may be asymptomatic, and the prognosis appears to depend on the presence or absence of other risk-organ involvement. The MS PLCH found in children appears to be a different disease from the single system (SS) PLCH seen in adults.

Cyr61 promotes breast tumorigenesis and cancer progression.

Cyr61, a member of the CCN family of genes, is an angiogenic factor. We have shown that it is overexpressed in invasive and metastatic human breast cancer cells and tissues. Here, we investigated whether Cyr61 is necessary and/or sufficient to bypass the 'normal' estrogen (E2) requirements for breast cancer cell growth. Our results demonstrate that Cyr61 is sufficient to induce MCF-7 cells to grow in the absence of E2. Cyr61-transfected MCF-7 cells (MCF-7/Cyr61) became E2-independent but still E2-responsive. On the other hand, MCF-7 cells transfected with the vector DNA (MCF-7/V) remain E2-dependent. MCF-7/Cyr61 cells acquire an antiestrogen-resistant phenotype, one of the most common clinical occurrences during breast cancer progression. MCF-7/Cyr61 cells are anchorage-independent and capable of forming Matrigel outgrowth patterns in the absence of E2. ER alpha expression in MCF-7/Cyr61 cells is decreased although still functional. Moreover, MCF-7/Cyr61 cells are tumorigenic in ovariectomized athymic nude mice. The tumors resemble human invasive carcinomas with increased vascularization and overexpression of vascular endothelial growth factor (VEGF). Our results demonstrate that Cyr61 is a tumor-promoting factor and a key regulator of breast cancer progression. This study provides evidence that Cyr61 is sufficient to induce E2-independence and antiestrogen-resistance, and to promote invasiveness in vitro, and to induce tumorigenesis in vivo, all of which are characteristics of an aggressive breast cancer phenotype.

Expression and regulation of Cyr61 in human breast cancer cell lines.

We have shown that Cyr61, an angiogenic regulator, is overexpressed in invasive and metastatic human breast cancer cells and tumor biopsies. We have further demonstrated that Cyr61 promotes acquisition of estrogen-independence and anti-estrogen resistance in vivo in breast cancer cells. Moreover, we have demonstrated that Cyr61 induces tumor formation and tumor vascularization in vivo, events mediated through the activation of the MAPK and the Akt signaling pathways. Here we investigate how Cyr61 expression is regulated in both estrogen receptor (ER)-positive and ER-negative breast cancer cells. We demonstrate that Cyr61 mRNA and protein expression is inducible by estrogen and anti-estrogens in ER-positive breast cancer cells. We show that a labile protein as well as a negative regulator might be involved in Cyr61 expression in estrogen-dependent breast cancer cells. Other important regulators of Cyr61 expression in breast cancer cells that we found are the phorbol ester TPA, vitamin D, and retinoic acid. TPA causes positive regulation of Cyr61 expression in ER-positive MCF-7 cells. Vitamin D induces a transient stimulatory effect on Cyr61 gene expression. Lastly, retinoic acid has a negative effect on Cyr61 expression and downregulates its expression in MCF-7 cells. Interestingly, most of these effects are not seen in aggressive breast cancer cells that do not express ER and express high levels of Cyr61, such as the MDA-MB-231 cells. Our results are in agreement with our knowledge that Cyr61 promotes tumor growth, and that tumor-promoting agents have a positive impact on cells that express low levels of Cyr61, such as the ER-positive breast cancer cells; however, these agents have no significant effect on cells that express high levels of Cyr61. Our findings suggest an association between increased Cyr61 expression and an aggressive phenotype of breast cancer cells.