Treatment of high-risk Hodgkin lymphoma with a modified Stanford V regimen in the AHOPCA: Substituting chemotherapy agents and hampered outcomes.

BACKGROUND/OBJECTIVES: High-risk Hodgkin lymphoma (HRHL) in children is curable with combined modality therapy. The Association of Pediatric Hematology-Oncology of Central America (AHOPCA) is a consortium of cancer centers from Central America. In 2004, AHOPCA implemented a guideline with a short course of chemotherapy (mStanfordV), strict diagnostics, and radiation guidelines, aimed at reducing abandonment and improving outcomes. METHODS: Newly diagnosed children less than 18 years of age with high-risk HL (Ann Arbor stages: IIB, IIIB, IV) from AHOPCA centers were staged with chest radiography and ultrasound or computed tomography. Therapy was a modified Stanford V (mStanfordV), substituting cyclophosphamide for mechlorethamine and involved field radiation. RESULTS: Of 219 patients with HRHL, 181 patients were eligible and evaluable; 146 (81%) were boys, 22% being less than 6 years; 43 were stage IIB, 84 IIIB, and 54 IV. Thirty-one (17%) abandoned therapy, 28 (15%) progressed, 30 (17%) relapsed, and eight (4%) died of toxicity. Radiation guidelines were not followed. Five-year abandonment-sensitive event-free survival and overall survival (AS-EFS, AS-OS ± SE) for the cohort were 46% ± 4% and 56% ± 4%; 5-year AS-OS for stages IIB, IIIB, and IV was 76% ± 7%, 59% ± 7%, and 35% ± 7% (p = .0006). CONCLUSION: Despite instituting a short treatment guideline, it did not improve the abandonment rate (17%) and did not achieve the reported outcomes of Stanford V. The cyclophosphamide dose used to replace merchlorethamine was inadequate. Despite strict guidelines, the radiation therapy application was inaccurate. Weekly chemotherapy may have adversely affected abandonment of therapy by increasing the burden of travel time. Based on these results, AHOPCA established a new abandonment strategy and a new guideline.

Implementation of the ß-hydroxyaspartate cycle increases growth performance of Pseudomonas putida on the PET monomer ethylene glycol.

Ethylene glycol (EG) is a promising next generation feedstock for bioprocesses. It is a key component of the ubiquitous plastic polyethylene terephthalate (PET) and other polyester fibers and plastics, used in antifreeze formulations, and can also be generated by electrochemical conversion of syngas, which makes EG a key compound in a circular bioeconomy. The majority of biotechnologically relevant bacteria assimilate EG via the glycerate pathway, a wasteful metabolic route that releases CO2 and requires reducing equivalents as well as ATP. In contrast, the recently characterized ß-hydroxyaspartate cycle (BHAC) provides a more efficient, carbon-conserving route for C2 assimilation. Here we aimed at overcoming the natural limitations of EG metabolism in the industrially relevant strain Pseudomonas putida KT2440 by replacing the native glycerate pathway with the BHAC. We first prototyped the core reaction sequence of the BHAC in Escherichia coli before establishing the complete four-enzyme BHAC in Pseudomonas putida. Directed evolution on EG resulted in an improved strain that exhibits 35% faster growth and 20% increased biomass yield compared to a recently reported P. putida strain that was evolved to grow on EG via the glycerate pathway. Genome sequencing and proteomics highlight plastic adaptations of the genetic and metabolic networks in response to the introduction of the BHAC into P. putida and identify key mutations for its further integration during evolution. Taken together, our study shows that the BHAC can be utilized as 'plug-and-play' module for the metabolic engineering of two important microbial platform organisms, paving the way for multiple applications for a more efficient and carbon-conserving upcycling of EG in the future.

Delayed Enucleation With Neoadjuvant Chemotherapy in Advanced Intraocular Unilateral Retinoblastoma: AHOPCA II, a Prospective, Multi-Institutional Protocol in Central America.

PURPOSE: Treatment abandonment because of enucleation refusal is a limitation of improving outcomes for children with retinoblastoma in countries with limited resources. Furthermore, many children present with buphthalmos and a high risk of globe rupture during enucleation. To address these unique circumstances, the AHOPCA II protocol introduced neoadjuvant chemotherapy with delayed enucleation. PATIENTS AND METHODS: Patients with advanced unilateral intraocular disease (International Retinoblastoma Staging System [IRSS] stage I) were considered for upfront enucleation. Those with diffuse invasion of the choroid, postlaminar optic nerve, and/or anterior chamber invasion received six cycles of adjuvant chemotherapy (vincristine, carboplatin, and etoposide). Patients with buphthalmos and those with a perceived risk for enucleation refusal and/or abandonment were given two to three cycles of chemotherapy before scheduled enucleation followed by adjuvant chemotherapy to complete six cycles, regardless of pathology. RESULTS: A total of 161 patients had unilateral IRSS stage I disease; 102 underwent upfront enucleation, and 59 had delayed enucleation. The estimated 5-year abandonment-sensitive event-free and overall survival rates for the group were 0.81 ± 0.03 and 0.86 ± 0.03, respectively. The 5-year estimated abandonment-sensitive event-free survival rates for patients undergoing upfront and delayed enucleation were 0.89 ± 0.03 and 0.68 ± 0.06, respectively (P = .001). Compared with AHOPCA I, abandonment for patients with IRSS stage I retinoblastoma decreased from 16% to 4%. CONCLUSION: AHOPCA describes the results of advanced intraocular retinoblastoma treated with neoadjuvant chemotherapy. In eyes with buphthalmos and patients with risk of abandonment, neoadjuvant chemotherapy can be effective when followed by enucleation and adjuvant chemotherapy. Our study suggests that this approach can save patients with buphthalmos from ocular rupture and might reduce refusal of enucleation and abandonment.

Effect of Thickness of Ceramic Veneers on Color Stability and Bond Strength of Resin Luting Cements Containing Alternative Photoinitiators.

PURPOSE: To evaluate the light transmittance of ceramic veneers of different thicknesses and verify their influence on the degree of conversion, color stability, and dentin bond strength of light-curing resin cements containing different photoinitiator systems. MATERIALS AND METHODS: Experimental resin cements were fabricated containing camphorquinone and amine (CQ-amine), TPO, Ivocerin (IVO), or TPO and Ivocerin (TPO-IVO). All photoinitiators were characterized by UV-Vis spectrophotometry. Disk-shaped lithium disilicate ceramic specimens that were 0.4, 0.7, and 1.5 mm in thickness were prepared using IPS e.max Press (Ivoclar Vivadent, shade LT/A2). Light transmittance through each specimen was measured using spectrophotometry. Specimens of each cement (n = 10) were made in a custom-designed mold and were light cured through each glass-ceramic disk using a multiwave LED (Bluephase G2, Ivoclar Vivadent). CS was evaluated using spectrophotometry before and after artificial aging with UV light. DC was evaluated using FTIR-spectroscopy. Dentin µSBS was evaluated using 0.75-mm-thick specimens that were light cured under the same protocol (n = 10). All data were submitted to two-way ANOVA and Tukey's test (α = 0.05; ß = 0.2). RESULTS: CQ-amine cements showed the highest color changes (p < 0.05) due to increased yellowing when compared to the amine-free cements (p < 0.05). However, all cements showed a significant color change after aging when cured through ceramics up to 1.5 mm thick (p < 0.05). The TPO-IVO cement showed the highest DC and the IVO cement showed a similar DC when compared to the CQ-amine cement. The TPO cement presented the lowest DC (p = 0.0377). No differences in mean dentin µSBS were found among the cements, except for the TPO cement, which presented a lower mean dentin µSBS (p = 0.0277). CONCLUSION: Amine-free cements containing Ivocerin and TPO seem to be a better alternative to CQ-amine cements, while not reducing either DC or dentin µSBS of amine-free cements. However, CQ-amine and amine-free cements still seem to change color over time.

Improvement in treatment abandonment in pediatric patients with cancer in Guatemala.

BACKGROUND: Treatment refusal and abandonment are major causes of treatment failure for children with cancer in low- and middle-income countries (LMICs), like Guatemala. This study identified risk factors for and described the intervention that decreased abandonment. METHODS: This was a retrospective study of Guatemalan children (0-18 years) with cancer treated at the Unidad Nacional de Oncología Pediátrica (UNOP), 2001-2008, using the Pediatric Oncology Network Database. Treatment refusal was a failure to begin treatment and treatment abandonment was a lapse of 4 weeks or longer in treatment. The impact of medicina integral, a multidisciplinary psychosocial intervention team at UNOP was evaluated. Cox proportional hazards analysis identified the effect of demographic and clinical factors on abandonment. Kaplan-Meier analysis estimated the survival. RESULTS: Of 1,789 patients, 21% refused or abandoned treatment. Abandonment decreased from 27% in 2001 to 7% in 2008 following the implementation of medicina integral. Factors associated with increased risk of refusal and abandonment: greater distance to the centre (P < 0.001), younger age (P = 0.017) and earlier year of diagnosis (P < 0.001). Indigenous race/ethnicity (P = 0.002) was associated with increased risk of abandonment alone. Abandonment correlated with decreased overall survival: 0.57 ± 0.02 (survival ± standard error) for those who completed therapy versus 0.06 ± 0.02 for those who abandoned treatment (P < 0.001) at 8.3 years. CONCLUSION: This study identified distance, age, year of diagnosis and indigenous race/ethnicity as risk factors for abandonment. A multidisciplinary intervention reduced abandonment and can be replicated in other LMICs.

The treatment of childhood acute lymphoblastic leukemia in Guatemala: Biologic features, treatment hurdles, and results.

BACKGROUND: The National Pediatric Oncology Unit (UNOP) is the only pediatric hemato-oncology center in Guatemala. METHODS: Patients ages 1 to 17 years with acute lymphoblastic leukemia (ALL) were treated according to modified ALL Intercontinental Berlin-Frankfurt-Münster (IC-BFM) 2002 protocol. Risk classification was based on age, white blood cell count, immunophenotype, genetics (when available), and early response to therapy. RESULTS: From July 2007 to June 2014, 787 patients were treated, including 160 who had standard-risk ALL, 450 who had intermediate-risk ALL, and 177 who had high-risk ALL. The induction death rate was 6.6%, and the remission rate was 92.9%. The rates of death and treatment abandonment during first complete remission were 4.8% and 2.5%, respectively. At a median observation time of 3.6 years, and with abandonment considered an event, the 5-year event-free survival and overall survival estimates ( ± standard error) were 56.2% ± 2.1% and 64.1% ± 2.1%, respectively, with a 5-year cumulative incidence of relapse of 28.9% ± 2.0%. Twenty-one of 281 patients (7.5%) investigated were positive for the ets variant 6/runt-related transcription factor 1 (ETV6/RUNX1) fusion. CONCLUSIONS: A well organized center in a low-middle-income country can overcome the disadvantages of malnutrition and reduce abandonment. Outcomes remain suboptimal because of late diagnosis, early death, and a high relapse rate, which may have a partly genetic basis. Earlier diagnosis, better management of complications, and better knowledge of ALL will improve outcomes. Cancer 2017;123:436-448. © 2016 American Cancer Society.

Pediatric Hodgkin Lymphoma.

Hodgkin lymphoma (HL) is one of the most curable pediatric and adult cancers, with long-term survival rates now exceeding 90% after treatment with chemotherapy alone or combined with radiotherapy (RT). Of note, global collaboration in clinical trials within cooperative pediatric HL study groups has resulted in continued progress; however, survivors of pediatric HL are at high risk of potentially life-limiting second cancers and treatment-associated cardiovascular disease. Over the last three decades, all major pediatric and several adult HL study groups have followed the paradigm of response-based treatment adaptation and toxicity sparing through the reduction or elimination of RT and tailoring of chemotherapy. High treatment efficacy is achieved using dose-dense chemotherapy. Refinement and reduction of RT have been implemented on the basis of results from collaborative group studies, such that radiation has been completely eliminated for certain subgroups of patients. Because pediatric staging and response criteria are not uniform, comparing the results of trial series among different pediatric and adult study groups remains difficult; thus, initiatives to harmonize criteria are desperately needed. A dynamic harmonization process is of utmost importance to standardize therapeutic risk stratification and response definitions as well as improve the care of children with HL in resource-restricted environments.

Increased incidence and disparity of diagnosis of retinoblastoma patients in Guatemala.

Analysis of 327 consecutive cases at a pediatric referral hospital of Guatemala reveals that retinoblastoma accounts for 9.4% of all cancers and the estimated incidence is 7.0 cases/million children, higher than the United States or Europe. The number of familial cases is low, and there is a striking disparity in indigenous children due to late diagnosis, advanced disease, rapid progression and elevated mortality. Nine germline mutations in 18 patients were found; two known and five new mutations. Hypermethylation of RB1 was identified in 13% of the tumors. An early diagnosis program could identify cases at an earlier age and improve outcome of retinoblastoma in this diverse population.

Retinoblastoma en Guatemala: diagnóstico temprano salva vidas / Retinoblastoma in Guatemala: early diagnosis saves lives

El retinoblastoma es el más común cáncer ocular de la niñez. El sitio primario es la retina y que se desarrolla en los primeros 6 años de vida. Su incidencia mundial es 1 en 18,000 niños menores de 5 años en EEUU (1) (2-4). Además, la literatura sugiere que hispanos tienen una incidencia más alta que otras razas (5-6). En EEUU se diagnostican alrededor de 300 casos al año. En Guatemala, la Unidad Nacional de Oncología Pediátrica diagnostica 27-30 casos anuales; y pone al retinoblastoma como tercer cáncer de la niñez, después de leucemias y linfomas (Datos UNOP, 2010)...

Development of retinoblastoma programs in Central America.

BACKGROUND: Retinoblastoma, a curable eye tumor, is associated with poor survival in Central America (CA). To develop a retinoblastoma program in El Salvador, Guatemala, and Honduras, twinning initiatives were undertaken between local pediatric oncology centers, nonprofit foundations, St. Jude Children's Research Hospital, and the University of Tennessee Hamilton Eye Institute. PROCEDURE: The retinoblastoma program focused on developing early diagnosis programs in Honduras with national vaccination campaigns, developing treatment protocols suited to local conditions, building local networks of oncologists and ophthalmologists, training local healthcare providers, using modern donated equipment for diagnosis and treatment, and the ORBIS Cybersight consultation program and Internet meetings to further education and share expertise. Pediatric ophthalmologists and oncologists worked with foundations to treat patients locally with donated equipment and Internet consultations, or at the center in Guatemala. RESULTS: Number of patients successfully treated increased after the program was introduced. For 2000-2003 and 2004-2007, patients abandoning/refusing treatment decreased in Guatemala from 20 of 95 (21%) to 14 of 123 (11%) and in Honduras from 13 of 37 (35%) to 7 of 37 (19%). Survival in El Salvador was good and abandonment/refusal low for both periods. Of 18 patients receiving focal therapy for advanced disease, 14 have single remaining eyes. CONCLUSION: Development of the program in CA has decreased abandonment/refusal and enabled ophthalmologists at local centers to use modern equipment to provide better treatment. This approach might serve as a guide for developing other multispecialty programs.

Treating Pediatric soft tissue sarcomas in a country with limited resources: the experience of the Unidad Nacional de Oncologia Pediatrica in Guatemala.

BACKGROUND: About 250-300 children with newly diagnosed cancer are treated each year at the Unidad Nacional de Oncologia Pediatrica in Guatemala City; less than 5% of them have soft tissue sarcomas (STS). The aim of the article was to evaluate whether the therapeutic standards achieved in STS in developed countries could be reproduced in a low-income country. PATIENTS AND METHODS: We reviewed the clinical data, treatment and outcome of 80 patients, 47 cases of rhabdomyosarcoma (RMS) and 33 of non-rhabdomyosarcoma soft tissue sarcoma (NRSTS), treated between January 2000 and October 2007. RESULTS: Most of the RMS patients had advanced disease at diagnosis (87% groups III-IV). Their 3-year event-free survival rate (EFS) was 26.4% if abandoning the treatment was considered as an event, or 32.4% if it was censored (14 patients abandoned the treatment), and the 3-year overall survival rate (OS) was 43.5%. Local progression/relapse was the main cause of treatment failure. Among the patients with NRSTS, the EFS at 3 years was 36.4% (when abandoning the treatment was considered as an event) or 43.3% (when it was censored), and the OS was 44.2%. Outcome was satisfactory for synovial sarcoma patients, those with tumors < or =5 cm, and those with localized disease. CONCLUSIONS: Overall results were unsatisfactory compared to results reported from developed countries. Late diagnosis and the consequently high proportion of cases of advanced disease at diagnosis, the large number of patients failing to complete the treatment, and the poor quality of local control (in RMS) adversely influence outcome.

World disparities in risk definition and management of retinoblastoma: a report from the International Retinoblastoma Staging Working Group.

Following from the publication of the International Retinoblastoma Staging System, an open internet discussion group was created at the www.cure4kids.org resource. The results of a survey distributed among participants are discussed. Although most patients with retinoblastoma were treated under prospective protocols, there was a wide variation in the definition of risk criteria and in the criteria for giving adjuvant chemotherapy following enucleation. Definition of high-risk histological features and the criteria for use of adjuvant therapy will be standardized in future studies. Internet meetings are a valuable mechanism for enabling participation from under-resourced countries in the development of cooperative studies.