Treatment Outcomes of Adjunct and Stand-alone Photodynamic Therapy in Patients With Extramammary Paget Disease: A Literature Review.

BACKGROUND: Extramammary Paget disease (EMPD) is a rare malignant neoplasm arising from apocrine gland-bearing skin. The surgical management of EMPD is often coupled with noninvasive techniques including cryotherapy, ablative lasers, topical chemotherapies, and photodynamic therapy (PDT). The specificity and preservation of tissue that PDT with photosensitizers 5-aminolevulinic acid or 5-methyl aminolevulinate allows makes it a potential treatment of EMPD. METHODS: The authors present a review of 13 studies, from 2002 to 2019, examining the reported efficacy of PDT alone and adjunctive PDT in EMPD treatment. RESULTS: In the 52 patients with 56 lesions who received stand-alone PDT, 20 lesions (35.7%, n = 20/56) experienced complete resolution, 31 lesions (55.4%, n = 31/56) experienced partial resolution, 5 lesions (8.9%, n = 5/56) failed to demonstrate response to treatment, and 23 lesions (41.1%, n = 23/56) had recurrence. In the 56 patients with 66 lesions that received adjunctive PDT paired with surgery ( n = 55/66), imiquimod ( n = 4/66), holmium laser and surgery ( n = 1/66), Mohs surgery ( n = 2/66), and combined surgery, imiquimod, and 5-fluorouracil ( n = 1/66), 34 lesions (51.5%) experienced complete resolution, 27 lesions (40.9%) experienced partial resolution, 5 lesions (7.6%) failed to demonstrate any response to treatment, and 16 lesions (24.2%) had EMPD recurrence. CONCLUSION: Further studies with larger sample size are needed to consolidate these findings and inform clinical decisions.

Genotype and organ effect on the occupancy of phyllosphere prokaryotes in different rice landraces.

Bacteria community provides essential ecological services to rice plants. The bacterial diversity of rice varies across host plant genotype and organs. This study employed 16S rDNA amplicon sequencing to characterise the bacterial community associated with three rice landraces using leaf blade and stem samples. The prokaryotic community found in these rice landraces comprised of two kingdoms, 12 phyla, 25 classes, 40 orders, 80 families, and 118 genera. Proteobacteria (53.9%) was the most abundant phylum. The most abundant genus was an undefined genus under Cyanobacteria (33.0%). Homogeneity of prokaryotic community was observed across the three rice landraces, which may suggest a high similarity in biological and genetical properties of the rice landraces. The difference in prokaryotic composition between leaf blade and stem was depicted based on principal coordinate analysis. This study observed that the prokaryotic inhabitants in rice plants is predominantly determined by rice plant organs.

OPTICAL COHERENCE TOMOGRAPHY FEATURES IN IDIOPATHIC NONINFECTIOUS INTERMEDIATE, POSTERIOR, OR PANUVEITIS.

PURPOSE: To characterize optical coherence tomography features in patients with idiopathic intermediate, posterior, or panuveitis. METHODS: This is a retrospective case series of all consecutive cases of idiopathic intermediate, posterior, or panuveitis at four tertiary care centres between 2010 and 2021. RESULTS: A total of 94 eyes (55 patients) were followed for an average duration of 29.8 (SD 21) months. The median central macular thickness was 284 µ m at baseline and 267 µ m at last follow-up. At baseline and last follow-up, respectively, 24% and 20% of uveitic eyes had intraretinal fluid, 12% and 1% subretinal fluid, and 43% and 54% epiretinal membrane. In addition, ellipsoid zone abnormalities on en-face were noted in 34% and 19% of cases at baseline and last follow-up, respectively. The baseline median visual acuity was significantly lower among cases with ellipsoid zone en-face slab abnormalities compared with those without (0.2 logarithm of minimum angle of resolution [interquartile range: 0-0.6] vs. 0.1 logarithm of minimum angle of resolution [interquartile range: 0-0.3], P = 0.0051). CONCLUSION: With initiation of treatment, the central macular thickness, intraretinal fluid, subretinal fluid, and ellipsoid zone en-face abnormalities improved over time, whereas the number of cases with epiretinal membrane increased among eyes with idiopathic intermediate, posterior, and panuveitis. Presence of ellipsoid zone en-face abnormalities at presentation may be associated with worse visual acuity.

Laser Resurfacing Monotherapy for the Treatment of Actinic Keratosis.

Treating actinic keratosis (AK) and photodamaged skin is critical to reduce the risk of progression to skin cancer. Laser resurfacing for AK treatment is available as either lesion-directed or field therapy. Laser resurfacing removes the superficial epidermis and dermis containing actinic damage, promoting re-epithelialization of healthy skin. Although laser resurfacing has been explored as a modality for AK treatment in the literature, studies summarizing its efficacy in the treatment of AK are lacking. This review summarizes existing research on laser resurfacing as a monotherapy for AK treatment, highlighting the various laser resurfacing modalities available for AK treatment as well as their complications and efficacy in comparison to other therapies. Despite longer healing time, fully ablative laser resurfacing, including carbon dioxide and erbium-doped yttrium aluminum garnet were found to be more effective for AK treatment than fractional ablative techniques. Although some studies suggest laser resurfacing monotherapy as less efficacious than photodynamic therapy, and equally effective to 5-fluorouracil and 30% trichloroacetic acid, clinical trials of larger sample size are required to establish stronger evidence-based conclusions. Moreover, laser resurfacing used as lesion-directed therapy, as opposed to the usual field-therapy, requires further investigation.

Subthreshold Compared with Threshold Macular Photocoagulation for Diabetic Macular Edema: A Systematic Review and Meta-Analysis.

TOPIC: To compare the efficacy and safety of subthreshold macular laser to conventional focal laser photocoagulation for the treatment of vision loss secondary to diabetic macular edema (DME). CLINICAL RELEVANCE: Macular laser remains an important and cost effective treatment option for vision loss secondary to DME. Although anti-VEGF therapy is often first-line, macular laser is of utility in low-resource or remote settings, for patients at risk of loss to follow-up, and for DME not meeting country-specific reimbursement criteria for anti-VEGF therapy. Subthreshold laser is a modality that does not produce clinical or histologic evidence of thermal damage, thereby potentially limiting the common complications of conventional laser. METHODS: Ovid MEDLINE, EMBASE, and CENTRAL databases were searched for randomized controlled trials (RCTs) from inception to September 28, 2022. Meta-analyses were performed using random-effects modeling. Data were collected at 12 and 24 months for best-corrected visual acuity (BCVA), central retinal thickness, diabetic retinopathy severity scale, rate of adverse events, rate of enrolled patients not completing treatment, rate of patients receiving retreatment, and quality-of-life measures. The risk of bias and certainty of evidence were assessed using Cochrane's Risk-of-Bias version 2 and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) frameworks, respectively. Subgroup analysis was performed between subthreshold laser modalities and evaluated with Instrument to assess the Credibility of Effect Modification Analyses tool. RESULTS: Fourteen RCTs comprising 514 eyes receiving conventional laser and 574 eyes receiving subthreshold laser were included. Subthreshold laser likely results in no difference to BCVA (moderate GRADE certainty) compared with conventional laser. Conventional laser demonstrated a small, statistically significant improvement in central retinal thickness (low GRADE certainty); however, the magnitude of this improvement is unlikely to be clinically important. There may not be a difference in the rate of adverse events (low GRADE certainty) at 12 months when comparing subthreshold laser to conventional laser for DME. CONCLUSION: Randomized controlled trial literature to date suggests subthreshold laser to be as effective as conventional laser in the treatment of DME. Increased follow-up duration is needed to observe any long-term safety benefit from reduced retinal damage. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Characteristics of ocular hypertension and uveitic glaucoma among patients with noninfectious uveitis.

OBJECTIVE: Ocular hypertension and uveitic glaucoma are important downstream sequela of noninfectious uveitis (NIU). Herein, we describe the clinical outcomes of NIU cases with ocular hypertension and uveitic glaucoma. DESIGN: Retrospective cohort study. PARTICIPANTS: All adults (≥18 years) with NIU under the care of uveitis subspecialty tertiary care clinics between 2010 and 2021 were included. METHODS: The primary outcomes were baseline and final visual acuity. RESULTS: A total of 216 patients out of 914 (23.6%) cases with NIU had ocular hypertension or uveitic glaucoma over the study period. Of all patients with ocular hypertension or uveitic glaucoma, 46% were corticosteroid responders. Baseline and last median visual acuities were better for the ocular hypertension patients compared with patients with uveitic glaucoma (p < 0.001). A higher proportion of patients with uveitic glaucoma than patients with ocular hypertension required glaucoma surgery (p < 0.001). The regression analyses suggested that baseline visual acuity and anatomical classification are significant predictors of last visual acuity, whereas diagnosis of ocular hypertension versus uveitic glaucoma were significant predictors of requirement for glaucoma surgery (p < 0.001). CONCLUSION: A quarter of patients with NIU in this study developed ocular hypertension or uveitic glaucoma. Approximately half of the patients with ocular hypertension or uveitic glaucoma were deemed to be corticosteroid responders. Baseline and last visual acuity outcomes are better amongst ocular hypertension patients compared with those with uveitic glaucoma. Poor baseline visual acuity and panuveitis are predictors of worse vision at last follow-up. Additionally, diagnosis of uveitic glaucoma was a significant predictor of requirement for glaucoma surgery.

Long-term outcomes of noninfectious uveitis treated with systemic immunomodulatory therapy: a retrospective case series.

OBJECTIVE: To study the clinical characteristics and long-term outcomes of patients with noninfectious uveitis (NIU) who are treated with systemic immunomodulatory therapy (IMT). DESIGN: Retrospective case series. PARTICIPANTS: All consecutive cases of adults with NIU under the care of 5 uveitis subspecialty tertiary care clinics between 2010 to 2021 were included. METHODS: Patient outcomes were assessed at initial presentation and at the latest available follow-up. RESULTS: A total of 418 NIU patients receiving IMT therapy with a median age of 46.0 years and 59.3% female were identified. Each patient required an average of 1.4 agents until achieving an optimal response. Following initial treatment with prednisone, patients were most commonly initiated on methotrexate. The top 3 treatments with the highest proportion of optimal treatment response when taken alone or in combination with other agents were infliximab (79.3%), cyclosporine (75%), and adalimumab (70%). The strongest predictors for requiring a greater number of IMTs trialed were younger age, panuveitis, and a chronic or recurrent disease course. Multivariable linear regression analysis suggested that baseline visual acuity at diagnosis was the only significant predictor of final visual acuity (p < 0.001). CONCLUSIONS: NIU patients on IMT are often trialed on multiple therapeutic agents before achieving an optimal treatment response. Visual acuity at diagnosis is a predictor of final visual outcomes, whereas chronic or recurrent disease course, younger age, and panuveitis are predictors of requiring multiagent treatment regimens.

Clinical characteristics of non-infectious uveitis treated with and without systemic immunomodulatory therapy.

OBJECTIVE: To compare the patient characteristics and long-term outcomes for those treated with and without systemic immunomodulatory therapy (IMT) for non-infectious uveitis (NIU). DESIGN: Retrospective cohort study. PARTICIPANTS: All consecutive adults with NIU receiving care at 5 uveitis subspecialty tertiary care clinics between 2010 and 2021. METHODS: Clinical outcomes were evaluated on initial presentation and at the last available follow-up. The main outcome measures were baseline characteristics and final visual acuity. RESULTS: A total of 914 NIU patients (418 IMT, 496 non-IMT) with a median age of 51.0 years and 57.4% female were identified. Over half the patients had bilateral disease, with a significantly higher proportion of bilateral cases in the IMT group compared with the non-IMT group (p < 0.001). The IMT group was more likely to have chronic uveitis (p < 0.001), with a higher proportion of patients experiencing cataracts and cystoid macular edema (p < 0.001 for both). A significantly higher proportion of non-IMT patients had anterior uveitis and an idiopathic etiology (p < 0.001). Overall, visual acuity improved significantly from baseline to last follow-up in the entire cohort (p < 0.001), with a slightly better improvement in the IMT group. Multivariable linear regression analysis suggested that baseline visual acuity and panuveitis were significant predictors of final visual acuity (p < 0.001 for both). CONCLUSIONS: NIU patients on IMT are often younger, suffer from bilateral and chronic uveitis, and are more likely to have ocular complications. Those in the non-IMT group are more likely to have anterior idiopathic NIU. Baseline visual acuity and panuveitis are the main predictors of final vision outcomes among patients with NIU.

The effect of complement C3 or C5 inhibition on geographic atrophy secondary to age-related macular degeneration: A living systematic review and meta-analysis.

With the introduction of therapies to treat geographic atrophy (GA), GA management in clinical practice is now possible. A living systematic review can provide access to timely and robust evidence synthesis. This review found that complement factor 3 and 5 (C3 and C5) inhibition compared to sham likely reduces change in square root GA area at 12 months and untransformed GA area at 24 months. There is likely little to no difference in the rate of systemic treatment-emergent adverse events compared to sham. C3 and C5 inhibition, however, likely does not improve best-corrected visual acuity (BCVA) at 12 months, and the evidence is uncertain regarding change in BCVA at 24 months. Higher rates of ocular treatment emergent adverse effects with complement inhibition occur at 12 months and likely at 24 months. Complement inhibition likely results in new onset neovascular age-related macular degeneration at 12 months. This living meta-analysis will continuously incorporate new evidence.

Examining the Relationship Between Diabetic Macular Edema, and Obstructive Sleep Apnea.

Purpose: This prospective cohort study examined the relationship between diabetic macular edema (DME), diabetic retinopathy (DR) and obstructive sleep apnea (OSA) in patients after 1 year of treatment with anti-VEGF injection and/or continuous positive airway pressure (CPAP). Patients and Methods: The study included adults with type 1 or 2 diabetes mellitus with diabetic retinopathy. Polysomnography metrics were measured at baseline. Ophthalmologic metrics were measured at baseline, six-month (6m) and twelve-month (12m) follow-up. All DME+ patients received standard care, and all OSA+ patients were advised continuous positive airway pressure (CPAP). Logistic regression between DR severity and OSA severity was performed. Analysis of variance (ANOVA) was performed between subgroups. Results: Seventy-four eyes of 49 patients with DR were included. Prevalence of OSA was significantly higher in the DME+ group (70.7%) than DME- group (42.4%, p < 0.05). A significantly lower average minimum SaO2 was noted in OSA+DME+ (81.74%) than OSA+DME- eyes (88.23%, p < 0.05). Logistic regression analysis of ophthalmological and sleep metrics showed no correlation between DR and OSA severity. CPAP adherence was 20% (6/30) in the OSA+DME+ cohort and 36% (5/14) in the OSA+DME- cohort. At 12m, CPAP-adherent OSA+DME+ showed significantly lower DR severity score (1.00 ± 0.0) than CPAP non-adherent OSA+DME+ (1.36 ± 0.80, p = 0.042). No significant patterns were noted for visual acuity and mean central retinal thickness. Conclusion: DME is associated with the presence of OSA. Minimum SaO2 is a significant OSA clinical variable for DME. DR severity is not associated with OSA severity. CPAP coupled with intravitreal anti-VEGF therapy may be helpful for reducing DR severity in DME+ eyes. Presence of OSA may diminish intravitreal anti-VEGF efficacy on anatomical (mean CRT) and functional (VA) outcomes of DME.

Honey bee toxicological responses do not accurately predict environmental risk of imidacloprid to a solitary ground-nesting bee species.

Honey bees (Apis mellifera) are the current model species for pesticide risk assessments, but considering bee diversity, their life histories, and paucity of non-eusocial bee data, this approach could underestimate risk. We assessed whether honey bees were an adequate risk predictor to non-targets. We conducted oral and contact bioassays for Leioproctus paahaumaa, a solitary ground-nesting bee, and A. mellifera, using imidacloprid (neonicotinoid) and dimethoate (organophosphate). The bees responded inconsistently; L. paahaumaa were 36 and 194 times more susceptible to oral and topically applied imidacloprid than A. mellifera, but showed comparable sensitivity to dimethoate. Furthermore, the proposed safety factor of ten applied to honey bee endpoints did not cover the interspecific sensitivity difference. Our standard-setting study highlights the urgent need for more comparative inter-species toxicity studies and the development of standardized toxicity protocols to ensure regulatory pesticide risk assessment frameworks are protective of diverse pollinators.

Diagnostic accuracy of teleretinal screening for detection of diabetic retinopathy and age-related macular degeneration: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the diagnostic accuracy of teleretinal screening compared with face-to-face examination for detection of diabetic retinopathy (DR) and age-related macular degeneration (AMD). METHODS AND ANALYSIS: This study adhered to the Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA). A comprehensive search of OVID MEDLINE, EMBASE and Cochrane CENTRAL was performed from January 2010 to July 2021. QUADAS-2 tool was used to assess methodological quality and applicability of the studies. A bivariate random effects model was used to perform the meta-analysis. Referrable DR was defined as any disease severity equal to or worse than moderate non-proliferative DR or diabetic macular oedema (DMO). RESULTS: 28 articles were included. Teleretinal screening achieved a sensitivity of 0.91 (95% CI: 0.82 to 0.96) and specificity of 0.88 (0.74 to 0.95) for any DR (13 studies, n=7207, Grading of Recommendations, Assessment, Development and Evaluation (GRADE) low). Accuracy for referrable DR (10 studies, n=6373, GRADE moderate) was lower with a sensitivity of 0.88 (0.81 to 0.93) and specificity of 0.86 (0.79 to 0.90). After exclusion of ungradable images, the specificity for referrable DR increased to 0.95 (0.90 to 0.98), while the sensitivity remained nearly unchanged at 0.85 (0.76 to 0.91). Teleretinal screening achieved a sensitivity of 0.71 (0.49 to 0.86) and specificity of 0.88 (0.85 to 0.90) for detection of AMD (three studies, n=697, GRADE low). CONCLUSION: Teleretinal screening is highly accurate for detecting any DR and DR warranting referral. Data for AMD screening is promising but warrants further investigation. PROSPERO REGISTRATION NUMBER: CRD42020191994.

Malignant Melanoma within a Cellular Blue Nevi Presenting as a Vascular Malformation and the Connection to Sporadic KRAS Mutations.

We present a case of malignant melanoma (MM) developing within a vascular malformation showing features of cellular blue nevi. A 47-year-old male presented with acute symptoms of a temporal and zygomatic mass, which were both previously asymptomatic upon development 30 years ago. These masses were diagnosed as vascular malformations upon imaging and were treated with sclerotherapy. Embolization and surgical excision were performed 3 years later due to symptomatic growth. Final pathology reports showed MM with congenital blue nevi. We hypothesize a possible linkage to a sporadic KRAS mutation, linking both presentations of vascular malformation, MM, and cellular blue nevi. A literature search for similar cases is also reported.

Characteristics and Outcomes of Women Developing Heart Failure After Early Stage Breast Cancer Chemotherapy: A Population-Based Matched Cohort Study.

BACKGROUND: The prognosis of heart failure (HF) after early stage breast cancer (EBC) treatment with anthracyclines or trastuzumab is not well-characterized. METHODS: Using administrative databases, women diagnosed with HF after receiving anthracyclines or trastuzumab for EBC in Ontario during 2007 to 2017 (the EBC-HF cohort) were categorized by cardiotoxic exposure (anthracycline alone, trastuzumab alone, sequential therapy with both agents) and matched on age with ≤3 cancer-free HF controls to compare baseline characteristics. To study prognosis after HF onset, we conducted a second match on age plus important HF prognostic factors. The cumulative incidence function was used to describe risk of hospitalization or emergency department visits (hospital presentations) for HF and cardiovascular death. RESULTS: A total of 804 women with EBC developed HF after anthracyclines (n=312), trastuzumab (n=112), or sequential therapy (n=380); they had significantly fewer comorbidities than 2411 age-matched HF controls. After the second match, the anthracycline-HF cohort had a similar 5-year incidence of HF hospital presentations (16.5% [95% CI, 12.0%-21.7%]) as controls (17.1% [95% CI, 14.4%-20.1%]); the 5-year incidence was lower than matched controls for the trastuzumab-HF (9.7% [95% CI, 4.7%-16.9%]; controls 16.4% [95% CI, 12.1%-21.3%]; P=0.03) and sequential-HF cohorts (2.7% [95% CI, 1.4%-4.8%]; controls 10.8% [95% CI, 8.9%-13.0%]; P<0.001). At 5 years, the incidence of cardiovascular death was 2.9% (95% CI, 1.2%-5.9%) in the anthracycline-HF cohort vs. 9.5% (95% CI, 6.9%-12.6%) in controls, and 1.7% (0.6%-3.7%) for women developing HF after trastuzumab vs. 4.3% (95% CI, 3.1-5.8%) for controls. CONCLUSIONS: Women developing HF after cardiotoxic EBC chemotherapy have fewer comorbidities than cancer-free women with HF; trastuzumab-treated women who develop HF have better prognosis than matched HF controls.

Measuring fatigue: a meta-review.

There is a lack of validated tools to measure fatigue in patients with inflammatory skin, neuropsychiatric, and medical disorders. The use of nonvalidated tools may compromise the quality of data. The purpose of this meta-review was to evaluate existing fatigue scales commonly used to assess fatigue in other inflammatory conditions and to identify if there are scales that have been validated in dermatologic conditions. The PubMed/MEDLINE and SCOPUS databases were systematically searched from inception through March 10, 2020, in accordance with the PRISMA statement. Validated tools were identified and assessed according to their main measurement properties. The literature search identified 403 references, and eight studies were eligible and assessed in this review. The unidimensional fatigue scales included were the Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-F), Brief Fatigue Inventory, Fatigue Severity Scale, Numerical Rating Scale - Fatigue, and Visual Analog Scale - Fatigue. The multidimensional fatigue scales found were the Checklist Individual Strength, Chalder Fatigue Scale, Multidimensional Assessment of Fatigue, Multidimensional Fatigue Inventory Scale, and Piper Fatigue Scale. To measure fatigue, a brief scale with the ability to detect change is needed as there is a growing interest in evaluating this dimension of treatment response. In addition, a good content validity is also needed. From this systematic review, none of the selected scales have had content validation, even though the FACIT was validated in patients with psoriatic arthritis. Validation studies in specific disorders are urgently warranted.

Posterior lens capsule neovascularization treated with anti-VEGF complicated by phacogenic uveitis.

PURPOSE: To report a case of neovascularization of posterior capsule (NVPC) successfully treated with intravitreal ranibizumab (Lucentis) and neodymium:YAG (Nd:YAG) capsulotomy, followed by phacogenic uveitis. OBSERVATIONS: We report a systemically otherwise healthy 81-year-old male presenting with unilateral NVPC and iris (NVI) occurring five years after a central retinal vein occlusion. A single intravitreal injection of ranibizumab led to complete regression of NVPC and NVI within three weeks after which a Nd:YAG capsulotomy was performed. Two weeks later, the patient returned with a severe inflammatory reaction diagnosed as phacogenic uveitis and treated with surgical capsular bag/intraocular lens complex removal and peripheral pan-retinal photocoagulation. One-year follow-up demonstrated no recurrence of NVPC. Visual acuity remained at baseline of light perception. CONCLUSIONS: We acknowledge that intravitreal anti-vascular endothelial growth factor treatment with Nd:YAG capsulotomy for NVPC is a rational option, but raise awareness to the rare possibility of phacogenic uveitis.

A case of sporotrichosis infection mimicking pyoderma gangrenosum and the role of tissue culture in diagnosis: A case report.

Sporotrichosis infections may cause cutaneous lesions mimicking other infectious or non-infectious causes such as pyoderma gangrenosum. We present a case of cutaneous sporotrichosis misdiagnosed as pyoderma gangrenosum and treated with immunosuppressants for 17 months leading to exacerbation and atypical morphology mimicking Histoplasma organisms on biopsy. Exclusion of infection prior to diagnosing pyoderma gangrenosum is important to prevent iatrogenic immunosuppression, demonstrating the challenges with application of the updated pyoderma gangrenosum diagnostic criteria.

Reducing overutilisation of serum vitamin D testing at a tertiary care centre.

INTRODUCTION: Testing of 25-hydroxy (25-OH) vitamin D serum levels has increased drastically in recent years and much of it is considered inappropriate based on current guidelines. METHODS: In consultation with our physician groups (experts and frequent orderers), we modified existing guidelines and implemented a rational policy for 25-OH vitamin D testing and 1,25 dihydroxy (1,25 di-OH) vitamin D testing at a tertiary care centre. A computer decision support tool requiring selection of one of five acceptable testing indications was created for each test as part of a computerised physician order entry system. RESULTS: As a result of our intervention, we observed a 27% decrease in the average monthly test volume for 25-OH vitamin D from 504±62 (mean±SD) tests per month to 370±33 (p<0.001). 1,25 di-OH vitamin D testing decreased 58% from 71±18 to 30±10 (p<0.001). The departments ordering the tests were similar during the preintervention and postintervention periods, and further audits, patient chart reviews and individualised physician feedback were required to ensure appropriate ordering of 1,25 di-OH vitamin D. The most common ordering reasons selected were malabsorption/dietary concerns (46%) for 25-OH vitamin D and renal failure (42%) for 1,25 di-OH vitamin D. CONCLUSIONS: Limitations of our computer decision support tool include a dependence on an honour system in selecting the testing indication and an inability to limit ordering frequency. Periodic monitoring of test volumes will be required to ensure adherence to guidelines. Despite these limitations, we have improved appropriate utilisation of these tests and reduced costs by approximately $C60 375 per year.

Epigenetic Switch-Induced Viral Mimicry Evasion in Chemotherapy-Resistant Breast Cancer.

Tumor progression upon treatment arises from preexisting resistant cancer cells and/or adaptation of persister cancer cells committing to an expansion phase. Here, we show that evasion from viral mimicry response allows the growth of taxane-resistant triple-negative breast cancer (TNBC). This is enabled by an epigenetic state adapted to taxane-induced metabolic stress, where DNA hypomethylation over loci enriched in transposable elements (TE) is compensated by large chromatin domains of H3K27me3 to warrant TE repression. This epigenetic state creates a vulnerability to epigenetic therapy against EZH2, the H3K27me3 methyltransferase, which alleviates TE repression in taxane-resistant TNBC, leading to double-stranded RNA production and growth inhibition through viral mimicry response. Collectively, our results illustrate how epigenetic states over TEs promote cancer progression under treatment and can inform about vulnerabilities to epigenetic therapy. SIGNIFICANCE: Drug-resistant cancer cells represent a major barrier to remission for patients with cancer. Here we show that drug-induced metabolic perturbation and epigenetic states enable evasion from the viral mimicry response induced by chemotherapy in TNBC. These epigenetic states define a vulnerability to epigenetic therapy using EZH2 inhibitors in taxane-resistant TNBC.See related commentary by Janin and Esteller, p. 1258.This article is highlighted in the In This Issue feature, p. 1241.