Pathology of explanted pediatric hearts: An 11-year study. Population characteristics and implications for outcomes.

BACKGROUND: As more pediatric patients become candidates for heart transplantation (HT), understanding pathological predictors of outcome and the accuracy of the pretransplantation evaluation are important to optimize utilization of scarce donor organs and improve outcomes. The authors aimed to investigate explanted heart specimens to identify pathologic predictors that may affect cardiac allograft survival after HT. METHODS: Explanted pediatric hearts obtained over an 11-year period were analyzed to understand the patient demographics, indications for transplant, and the clinical-pathological factors. RESULTS: In this study, 149 explanted hearts, 46% congenital heart defects (CHD), were studied. CHD patients were younger and mean pulmonary artery pressure and resistance were significantly lower than in cardiomyopathy patients. Twenty-one died or underwent retransplantation (14.1%). Survival was significantly higher in the cardiomyopathy group at all follow-up intervals. There were more deaths and the 1-, 5- and 7-year survival was lower in patients ≤10 years of age at HT. Early rejection was significantly higher in CHD patients exposed to homograft tissue, but not late rejection. Mortality/retransplantation rate was significantly higher and allograft survival lower in CHD hearts with excessive fibrosis of one or both ventricles. Anatomic diagnosis at pathologic examination differed from the clinical diagnosis in eight cases. CONCLUSIONS: Survival was better for the cardiomyopathy group and patients >10 years at HT. Prior homograft use was associated with a higher prevalence of early rejection. Ventricular fibrosis (of explant) was a strong predictor of outcome in the CHD group. We presented several pathologic findings in explanted pediatric hearts.

Herded and hunted goat genomes from the dawn of domestication in the Zagros Mountains.

The Aceramic Neolithic (∼9600 to 7000 cal BC) period in the Zagros Mountains, western Iran, provides some of the earliest archaeological evidence of goat (Capra hircus) management and husbandry by circa 8200 cal BC, with detectable morphological change appearing ∼1,000 y later. To examine the genomic imprint of initial management and its implications for the goat domestication process, we analyzed 14 novel nuclear genomes (mean coverage 1.13X) and 32 mitochondrial (mtDNA) genomes (mean coverage 143X) from two such sites, Ganj Dareh and Tepe Abdul Hosein. These genomes show two distinct clusters: those with domestic affinity and a minority group with stronger wild affinity, indicating that managed goats were genetically distinct from wild goats at this early horizon. This genetic duality, the presence of long runs of homozygosity, shared ancestry with later Neolithic populations, a sex bias in archaeozoological remains, and demographic profiles from across all layers of Ganj Dareh support management of genetically domestic goat by circa 8200 cal BC, and represent the oldest to-this-date reported livestock genomes. In these sites a combination of high autosomal and mtDNA diversity, contrasting limited Y chromosomal lineage diversity, an absence of reported selection signatures for pigmentation, and the wild morphology of bone remains illustrates domestication as an extended process lacking a strong initial bottleneck, beginning with spatial control, demographic manipulation via biased male culling, captive breeding, and subsequently phenotypic and genomic selection.

Modern Siberian dog ancestry was shaped by several thousand years of Eurasian-wide trade and human dispersal.

Dogs have been essential to life in the Siberian Arctic for over 9,500 y, and this tight link between people and dogs continues in Siberian communities. Although Arctic Siberian groups such as the Nenets received limited gene flow from neighboring groups, archaeological evidence suggests that metallurgy and new subsistence strategies emerged in Northwest Siberia around 2,000 y ago. It is unclear if the Siberian Arctic dog population was as continuous as the people of the region or if instead admixture occurred, possibly in relation to the influx of material culture from other parts of Eurasia. To address this question, we sequenced and analyzed the genomes of 20 ancient and historical Siberian and Eurasian Steppe dogs. Our analyses indicate that while Siberian dogs were genetically homogenous between 9,500 to 7,000 y ago, later introduction of dogs from the Eurasian Steppe and Europe led to substantial admixture. This is clearly the case in the Iamal-Nenets region (Northwestern Siberia) where dogs from the Iron Age period (∼2,000 y ago) possess substantially less ancestry related to European and Steppe dogs than dogs from the medieval period (∼1,000 y ago). Combined with findings of nonlocal materials recovered from these archaeological sites, including glass beads and metal items, these results indicate that Northwest Siberian communities were connected to a larger trade network through which they acquired genetically distinctive dogs from other regions. These exchanges were part of a series of major societal changes, including the rise of large-scale reindeer pastoralism ∼800 y ago.

Improving Mechanical Circulatory Support Outcomes in Failing Bidirectional Glenn Physiology.

There remains high morbidity and mortality with mechanical circulatory support (MCS) in failing bidirectional Glenn (BDG) physiology. We performed a retrospective analysis of children with BDG physiology supported with MCS before and after 2018. Fourteen patients met inclusion criteria (median age 1.5 years, weight 9 kg). Prior to 2018 (n = 7), with variable anticoagulation and strategies including pulsatile VAD, continuous flow VAD, and extracorporeal membrane oxygenation (ECMO), 3 (43%) of patients were transplanted with a total of 536 patient-days of support (median 59 days). Major hemocompatability-related adverse event (MHRAE) rate was 63 per 100 patient-months. After 2018 (n = 7), using a staged support strategy (ECMO to pulsatile VAD) and bivalirudin anticoagulation, 5 (71%) patients were transplanted with a total of 1260 patient-days of support (median 188 days) and MHRAE rate of 24 per 100 patient-months. Despite challenging physiology, we have observed improved survival and reduced MHRAE despite longer support duration.

The teammate trial: Study design and rationale tacrolimus and everolimus against tacrolimus and MMF in pediatric heart transplantation using the major adverse transplant event (MATE) score.

BACKGROUND: Currently there are no immunosuppression regimens FDA-approved to prevent rejection in pediatric heart transplantation (HT). In recent years, everolimus (EVL) has emerged as a potential alternative to standard tacrolimus (TAC) as the primary immunosuppressant to prevent rejection that may also reduce the risk of cardiac allograft vasculopathy (CAV), chronic kidney disease (CKD) and cytomegalovirus (CMV) infection. However, the 2 regimens have never been compared head-to-head in a randomized trial. The study design and rationale are reviewed in light of the challenges inherent in rare disease research. METHODS: The TEAMMATE trial (IND 127980) is the first multicenter randomized clinical trial (RCT) in pediatric HT. The primary purpose is to evaluate the safety and efficacy of EVL and low-dose TAC (LD-TAC) compared to standard-dose TAC and mycophenolate mofetil (MMF). Children aged <21 years at HT were randomized (1:1 ratio) at 6 months post-HT to either regimen, and followed for 30 months. Children with recurrent rejection, multi-organ transplant recipients, and those with an estimated glomerular filtration rate (eGFR) <30 mL/min/1.73m2 were excluded. The primary efficacy hypothesis is that, compared to TAC/MMF, EVL/LD-TAC is more effective in preventing 3 MATEs: acute cellular rejection (ACR), CKD and CAV. The primary safety hypothesis is that EVL/LD-TAC does not have a higher cumulative burden of 6 MATEs (antibody mediated rejection [AMR], infection, and post-transplant lymphoproliferative disorder [PTLD] in addition to the 3 above). The primary endpoint is the MATE score, a composite, ordinal surrogate endpoint reflecting the frequency and severity of MATEs that is validated against graft loss. The study had a target sample size of 210 patients across 25 sites and is powered to demonstrate superior efficacy of EVL/LD-TAC. Trial enrollment is complete and participant follow-up will be completed in 2023. CONCLUSION: The TEAMMATE trial is the first multicenter RCT in pediatric HT. It is anticipated that the study will provide important information about the safety and efficacy of everolimus vs tacrolimus-based regimens and will provide valuable lessons into the design and conduct of future trials in pediatric HT.

Equity factors in pediatric transplant listing: Initial findings from a single center review.

BACKGROUND: In order to improve transparency within the patient selection process, a transplant listing advisory committee was formed within the Boston Children's Hospital Pediatric Transplant Center. Its mission is to promote equity in access to organ transplantation by ensuring that the institutional transplant selection criteria are fair, unbiased, and nondiscriminatory. The committee conducts comprehensive case and data review of individual characteristics and reviews in aggregate to identify potential systems bias. METHODS: Charts for 256 patients evaluated for transplant from 3/2016 to 3/2019 were reviewed. Among these, 64 (25%) patients were declined for transplant. Univariate logistic regression analysis was used to identify demographic variables and vulnerable status factors associated with being declined. Odds ratios (OR) are reported. RESULTS: Among all patients, median age was 8.5 years and 58% were male. Asian patients were more likely to be declined than White patients (OR = 5.3, Wald p = .007). Socioeconomic factors that affected likelihood of listing decline included concerns for caregivers' ability to manage and understand care requirements (OR = 3.8, p = .011), caregiver employment status (OR = 1.9, p = .042), and use of public assistance programs (OR = 2.2, p = .05). Patients with severe neurodevelopmental delay were more likely to be declined for listing (OR = 3.7, p = .019). CONCLUSION: This analysis identified areas of potential bias related to race, socioeconomic status, and neurodevelopmental delay where initiatives can be targeted. Advisory committees are an important aspect of evaluating equity in transplant center selection policy and practice.

Pediatric heart transplant waiting times in the United States since the 2016 allocation policy change.

We describe waiting times for pediatric heart transplant (HT) candidates after the 2016 revision to the US allocation policy. The OPTN database was queried for pediatric HT candidates listed between 7/2016 and 4/2019. Of the 1789 included candidates, 65% underwent HT, 14% died/deteriorated, 8% were removed for improvement, and 13% were still waiting at the end of follow-up. Most candidates were status 1A at HT (81%). Median wait times differ substantially by listing status, blood type, and recipient weight. The likelihood of HT was lower in candidates <25 kg and in those with blood type O; The <25 kg, blood type O subgroup experiences longer wait times and higher wait list mortality. For status 1A candidates, median wait times were 108 days (≤25 kg, blood type O), 80 days (≤25 kg, non-O), 47 days (>25 kg, O), and 24 days (>25 kg, non-O). We found that centers with more selective organ acceptance practices, based on a lower median Pediatric Heart Donor Assessment Tool (PH-DAT) score for completed transplants, experience longer status 1A wait times for their listed patients. These data can be used to counsel families and to select appropriate advanced heart failure therapies to support patients to transplant.

Geographical contrasts of Y-chromosomal haplogroups from wild and domestic goats reveal ancient migrations and recent introgressions.

By their paternal transmission, Y-chromosomal haplotypes are sensitive markers of population history and male-mediated introgression. Previous studies identified biallelic single-nucleotide variants in the SRY, ZFY and DDX3Y genes, which in domestic goats identified four major Y-chromosomal haplotypes, Y1A, Y1B, Y2A and Y2B, with a marked geographical partitioning. Here, we extracted goat Y-chromosomal variants from whole-genome sequences of 386 domestic goats (75 breeds) and seven wild goat species, which were generated by the VarGoats goat genome project. Phylogenetic analyses indicated domestic haplogroups corresponding to Y1B, Y2A and Y2B, respectively, whereas Y1A is split into Y1AA and Y1AB. All five haplogroups were detected in 26 ancient DNA samples from southeast Europe or Asia. Haplotypes from present-day bezoars are not shared with domestic goats and are attached to deep nodes of the trees and networks. Haplogroup distributions for 186 domestic breeds indicate ancient paternal population bottlenecks and expansions during migrations into northern Europe, eastern and southern Asia, and Africa south of the Sahara. In addition, sharing of haplogroups indicates male-mediated introgressions, most notably an early gene flow from Asian goats into Madagascar and the crossbreeding that in the 19th century resulted in the popular Boer and Anglo-Nubian breeds. More recent introgressions are those from European goats into the native Korean goat population and from Boer goat into Uganda, Kenya, Tanzania, Malawi and Zimbabwe. This study illustrates the power of the Y-chromosomal variants for reconstructing the history of domestic species with a wide geographical range.

Waitlist Outcomes for Children With Congenital Heart Disease: Lessons Learned From Over 5000 Heart Transplant Listings in the United States.

BACKGROUND: We evaluated the impact of pediatric heart-allocation policy changes over time and the approval of the Berlin ventricular assist device (VAD) on waitlist (WL) outcomes for children with congenital heart disease (CHD). METHODS: The Scientific Registry of Transplant Recipients database was evaluated to include all children (age < 18) with CHD and cardiomyopathy (CMP) on the WL between 1999 and 2019, divided into 4 eras: Era 1 (1999-2008); Era 2 (2009-2011); Era 3 (2012-2016); and Era 4 (2016-2019). WL characteristics and survival outcomes were evaluated for patients with CHD over time and were compared to those with CMP listed currently (Era 4). RESULTS: We included 5185 children with CHD on the WL during the study period; 1999 (39%) were listed in Era 1; 693 (13%) in Era 2; 1196 (23%) in Era 3; and 1297 (25%) in Era 4. Compared to the CHD WL in eras 1 and 2, those in Era 4 were less likely to be infants (48% vs 49% vs 43%), on mechanical ventilation (30% vs 26% vs 19%), on extracorporeal membrane oxygenation (15% vs 9.7% vs 6.2%), and were more likely to be on a VAD (2.4% vs 2.2% vs 6.0%) (P < .05 for all). WL survival improved in children with CHD from Era 1 to Era 4 (P < .001). However, in Era 4, children with CHD had lower WL survival than those with CMP (P < .001). CONCLUSION: Children with CHD are increasingly being listed with less advanced heart failure, and they have had improved WL survival over time; however, WL outcomes remain inferior to those with CMP. Advances in pediatric medical and VAD therapy may improve future WL outcomes.

Giant Cell Myocarditis in Children: Elusive Giant Cells Might Not Be the Only Clue.

Giant cell myocarditis (GCM) is a form of fulminant myocarditis that is rapidly progressive and frequently lethal even in children. Over the course of 20 years, a definitive histopathologic diagnosis of GCM has been made at our institution in only two pediatric patients, and in neither instance was the diagnosis of GCM rendered on initial cardiac biopsy. We present the two patients and highlight the similarities in their clinical presentation and their challenging and inconclusive- albeit histologically similar- initial cardiac biopsy findings.

Ancient pigs reveal a near-complete genomic turnover following their introduction to Europe.

Archaeological evidence indicates that pig domestication had begun by ∼10,500 y before the present (BP) in the Near East, and mitochondrial DNA (mtDNA) suggests that pigs arrived in Europe alongside farmers ∼8,500 y BP. A few thousand years after the introduction of Near Eastern pigs into Europe, however, their characteristic mtDNA signature disappeared and was replaced by haplotypes associated with European wild boars. This turnover could be accounted for by substantial gene flow from local European wild boars, although it is also possible that European wild boars were domesticated independently without any genetic contribution from the Near East. To test these hypotheses, we obtained mtDNA sequences from 2,099 modern and ancient pig samples and 63 nuclear ancient genomes from Near Eastern and European pigs. Our analyses revealed that European domestic pigs dating from 7,100 to 6,000 y BP possessed both Near Eastern and European nuclear ancestry, while later pigs possessed no more than 4% Near Eastern ancestry, indicating that gene flow from European wild boars resulted in a near-complete disappearance of Near East ancestry. In addition, we demonstrate that a variant at a locus encoding black coat color likely originated in the Near East and persisted in European pigs. Altogether, our results indicate that while pigs were not independently domesticated in Europe, the vast majority of human-mediated selection over the past 5,000 y focused on the genomic fraction derived from the European wild boars, and not on the fraction that was selected by early Neolithic farmers over the first 2,500 y of the domestication process.

Exploring the phylogeography and population dynamics of the giant deer (Megaloceros giganteus) using Late Quaternary mitogenomes.

Late Quaternary climatic fluctuations in the Northern Hemisphere had drastic effects on large mammal species, leading to the extinction of a substantial number of them. The giant deer (Megaloceros giganteus) was one of the species that became extinct in the Holocene, around 7660 calendar years before present. In the Late Pleistocene, the species ranged from western Europe to central Asia. However, during the Holocene, its range contracted to eastern Europe and western Siberia, where the last populations of the species occurred. Here, we generated 35 Late Pleistocene and Holocene giant deer mitogenomes to explore the genetics of the demise of this iconic species. Bayesian phylogenetic analyses of the mitogenomes suggested five main clades for the species: three pre-Last Glacial Maximum clades that did not appear in the post-Last Glacial Maximum genetic pool, and two clades that showed continuity into the Holocene. Our study also identified a decrease in genetic diversity starting in Marine Isotope Stage 3 and accelerating during the Last Glacial Maximum. This reduction in genetic diversity during the Last Glacial Maximum, coupled with a major contraction of fossil occurrences, suggests that climate was a major driver in the dynamics of the giant deer.

Exceptional ancient DNA preservation and fibre remains of a Sasanian saltmine sheep mummy in Chehrabad, Iran.

Mummified remains have long attracted interest as a potential source of ancient DNA. However, mummification is a rare process that requires an anhydrous environment to rapidly dehydrate and preserve tissue before complete decomposition occurs. We present the whole-genome sequences (3.94 X) of an approximately 1600-year-old naturally mummified sheep recovered from Chehrabad, a salt mine in northwestern Iran. Comparative analyses of published ancient sequences revealed the remarkable DNA integrity of this mummy. Hallmarks of postmortem damage, fragmentation and hydrolytic deamination are substantially reduced, likely owing to the high salinity of this taphonomic environment. Metagenomic analyses reflect the profound influence of high-salt content on decomposition; its microbial profile is predominated by halophilic archaea and bacteria, possibly contributing to the remarkable preservation of the sample. Applying population genomic analyses, we find clustering of this sheep with Southwest Asian modern breeds, suggesting ancestry continuity. Genotyping of a locus influencing the woolly phenotype showed the presence of an ancestral 'hairy' allele, consistent with hair fibre imaging. This, along with derived alleles associated with the fat-tail phenotype, provides genetic evidence that Sasanian-period Iranians maintained specialized sheep flocks for different uses, with the 'hairy', 'fat-tailed'-genotyped sheep likely kept by the rural community of Chehrabad's miners.

Flight motor networks modulate primary olfactory processing in the moth Manduca sexta.

Nervous systems must distinguish sensory signals derived from an animal's own movements (reafference) from environmentally derived sources (exafference). To accomplish this, motor networks producing reafference transmit motor information, via a corollary discharge circuit (CDC), to affected sensory networks, modulating sensory function during behavior. While CDCs have been described in most sensory modalities, none have been observed projecting to an olfactory pathway. In moths, two mesothoracic to deutocerebral histaminergic neurons (MDHns) project from flight sensorimotor centers in the mesothoracic neuromere to the antennal lobe (AL), where they provide the sole source of histamine (HA), but whether they represent a CDC is unknown. We demonstrate that MDHn spiking activity is positively correlated with wing-motor output and increased before bouts of motor activity, suggesting that MDHns communicate global locomotor state, rather than providing a precisely timed motor copy. Within the AL, HA application sharpened entrainment of projection neuron responses to odor stimuli embedded within simulated wing-beat-induced flows, whereas MDHn axotomy or AL HA receptor (HA-r) blockade reduced entrainment. This finding is consistent with higher-order CDCs, as the MDHns enhanced rather than filtered entrainment of AL projection neurons. Finally, HA-r blockade increased odor detection and discrimination thresholds in behavior assays. These results establish MDHns as a CDC that modulates AL temporal resolution, enhancing odor-guided behavior. MDHns thus appear to represent a higher-order CDC to an insect olfactory pathway; this CDC's unique nature highlights the importance of motor-to-sensory signaling as a context-specific mechanism that fine-tunes sensory function.

Heteroarylamide smoothened inhibitors: Discovery of N-[2,4-dimethyl-5-(1-methylimidazol-4-yl)phenyl]-4-(2-pyridylmethoxy)benzamide (AZD8542) and N-[5-(1H-imidazol-2-yl)-2,4-dimethyl-phenyl]-4-(2- pyridylmethoxy)benzamide (AZD7254).

Aberrant hedgehog (Hh) pathway signaling is implicated in multiple cancer types and targeting the Smoothened (SMO) receptor, a key protein of the Hh pathway, has proven effective in treating metastasized basal cell carcinoma. Our lead optimization effort focused on a series of heteroarylamides. We observed that a methyl substitution ortho to the heteroaryl groups on an aniline core significantly improved the potency of this series of compounds. These findings predated the availability of SMO crystal structure in 2013. Here we retrospectively applied quantum mechanics calculations to demonstrate the o-Me substitution favors the bioactive conformation by inducing a dihedral twist between the heteroaryl rings and the core aniline. The o-Me also makes favorable hydrophobic interactions with key residue side chains in the binding pocket. From this effort, two compounds (AZD8542 and AZD7254) showed excellent pharmacokinetics across multiple preclinical species and demonstrated in vivo activity in abrogating the Hh paracrine pathway as well as anti- tumor effects.

Marijuana in pediatric and adult congenital heart disease heart transplant listing: A survey of provider practices and attitudes.

Despite increasing legalization and use of marijuana, there is no consensus among pediatric heart transplant institutions or providers regarding users' eligibility for cardiac transplant. We sent a survey to pediatric and ACHD transplant providers (physicians, surgeons, transplant coordinators, and pharmacists) assessing their current institution's policies and their personal opinions about marijuana use in patients being considered for heart transplantation. Of the respondents, 84% practice in the United States and Canada. Most providers (80%) care for both pediatric and ACHD patients. Respondents included cardiologists (77%) and surgeons (11%), with the remaining being coordinators and pharmacists. Most providers (73%) reported their institution had no policy regarding marijuana use in heart transplant candidates. Only 20% of respondents' institutions consider mode of consumption, with 87% and 53% approving of oral and transdermal routes, respectively, and only 7% approving of vaporized or smoked routes. While 73% of providers would consider illegal marijuana use an absolute/relative contraindication to heart transplant listing, the number decreases to 57% for legal recreational users and 21% for legal medical users. Most providers personally believe marijuana to be physically and mentally/emotionally harmful to pediatric patients (67% and 72%, respectively). Many institutions lack a policy regarding marijuana use in pediatric and ACHD heart transplant candidates, and there is considerable disagreement among providers on the best practice. With increasing legalization and use of marijuana, each institution will have to address this issue thoughtfully to continue to provide high-quality, consistent, and equitable care for pediatric and ACHD heart transplant candidates.

Use of the terminal complement inhibitor eculizumab in paediatric heart transplant recipients.

Antibody-mediated rejection is a major clinical challenge that limits graft survival. Various modalities of treatment have been reported in small studies in paediatric heart recipients. A novel approach is to use complement-inhibiting agents, such as eculizumab, which inhibits cleavage of C5 to C5a thereby limiting the formation of membrane attack complex and terminal complement-mediated injury of tissue-bound antibodies. This medical modality of treatment has theoretical advantages but the collective experience in its use in the solid organ transplant community remains small. We add to this experience by combining 14 cases from 6 paediatric heart centres in this descriptive study.

Myocardial Infarct After Marijuana Inhalation in a 16-year-old Adolescent Boy.

Many reports of marijuana-associated myocardial infarct (MI) are limited by incomplete evaluation of the toxicologic exposure, a lack of definitive anatomic findings, and the potential for comorbid coronary atherosclerosis inherent in an adult population. We report a 16-year-old adolescent boy who presented with chest pain after smoking marijuana and was found to have acute MI. Electrocardiogram showed diffuse ST-segment elevations. Exhaustive toxicologic testing confirmed the presence of Δ-9-tetrahydrocannabinol metabolite and ruled out other drugs of abuse. Echocardiography demonstrated moderate global left ventricular systolic dysfunction. Coronary angiography demonstrated no focal coronary lesions or obstruction. Right ventricular septal endomyocardial samples biopsied 36 hours after the onset of pain showed a subendocardial acute MI with a sparse neutrophilic infiltrate. One month after the event, magnetic resonance imaging showed a severely dilated left ventricle and moderately to severely depressed global systolic function. Late gadolinium enhancement consistent with myocardial fibrosis was seen in nearly all myocardial segments. Our unusually well-documented findings strengthen the potential association between marijuana and MI. Furthermore, we demonstrate a disease distribution supporting a process that affects the coronary circulation globally, likely at the distal, small-vessel level.

Simplified/Same Day(s)-GOLF as First-line Treatment of Metastatic Carcinoma of Unknown Primary (CUP), Suggestive of Pancreatobiliary Tumors.

BACKGROUND: Carcinoma of unknown primary represents a therapeutic challenge in oncological practice. Evidence lacks to support particular chemotherapy selection and empirical therapies are commonly extrapolated from data on patients where primary tumor site is known. Gemcitabine, Oxaliplatin, Leucovorin and 5-Fluorouracil was previously developed to treat pancreatic cancer. These agents have also demonstrated activities in other gastrointestinal malignancies. Considering promising anti-tumor effects of GOLF, we performed a retrospective study to investigate anti-tumor activity and safety of a simplified Gemcitabine, Oxaliplatin, Leucovorin and 5-Fluorouracil in patients with Carcinoma of unknown primary in whom immunohistostaining was suggestive of either upper gastrointestinal cancers or pancreatobiliary cancers. METHODS: This retrospective study included 18 patients recorded to have a diagnosis of Carcinoma of unknown primary between Aug 2010-Dec 2015, who received biweekly G 1000 mg/m2, O 85 mg/m2, L 200 mg/m2 and F 2400 mg/m2 over 46-h on day 1 with pegfilgrastim on day 3 every 14 days. IHC staining pattern favored upper GI origin, including stomach, bile duct or pancreas. Tumor assessments were repeated every 8 weeks. RESULTS: Median age was 67 years (range: 46-76), with ECOG PS<2, and 50% were women. Median number of cycles was 4 (range: 3-14). 7 partial responses were obtained (RR: 39%) and 7 achieved stable disease with overall disease control of 78%. Median time to tumor progression was 4 months (range: 2-9). 8 (44%) patients received liver-directed therapy and 1 underwent HIPEC (5%). Median survival time was 10.5 months (range: 6.7-14.5) and 1-year overall survival rate was 35%. Grade 3-4 toxicities included neutropenia, febrile neutropenia, thrombocytopenia, nausea, diarrhea, mucositis and oxaliplatin-induced neuropathy. CONCLUSION: Simplified Gemcitabine, Oxaliplatin, Leucovorin and 5-Fluorouracil regimen appears to be feasible with promising activity for Carcinoma of unknown primary and deserves to be evaluated in future trials.