Transmissible cancer and longitudinal telomere dynamics in Tasmanian devils (Sarcophilus harrisii).

A plethora of intrinsic and environmental factors have been shown to influence the length of telomeres, the protector of chromosome ends. Despite the growing interest in infection-telomere interactions, there is very limited knowledge on how transmissible cancers influence telomere maintenance. An emblematic example of transmissible cancer occurs in the Tasmanian devil (Sarcophilus harrisii), whose populations have been dramatically reduced by infectious cancer cells. To investigate associations between telomere dynamics and the transmissible cancer, we used longitudinal data from a Tasmanian devil population that has been exposed to the disease for over 15 years. We detected substantial temporal variation in individual telomere length (TL), and a positive significant association between TL and age, as well as a marginally significant trend for devils with devil facial tumour disease (DFTD) having longer telomeres. A proportional hazard analysis yielded no significant effect of TL on the development of DFTD. Like previous studies, we show the complexity that TL dynamics may exhibit across the lifetime of organisms. Our work highlights the importance of long-term longitudinal sampling for understanding the effects of wildlife diseases on TL.

Transmissible cancer influences immune gene expression in an endangered marsupial, the Tasmanian devil (Sarcophilus harrisii).

Understanding the effects of wildlife diseases on populations requires insight into local environmental conditions, host defence mechanisms, host life-history trade-offs, pathogen population dynamics, and their interactions. The survival of Tasmanian devils (Sarcophilus harrisii) is challenged by a novel, fitness limiting pathogen, Tasmanian devil facial tumour disease (DFTD), a clonally transmissible, contagious cancer. In order to understand the devils' capacity to respond to DFTD, it is crucial to gain information on factors influencing the devils' immune system. By using RT-qPCR, we investigated how DFTD infection in association with intrinsic (sex and age) and environmental (season) factors influences the expression of 10 immune genes in Tasmanian devil blood. Our study showed that the expression of immune genes (both innate and adaptive) differed across seasons, a pattern that was altered when infected with DFTD. The expression of immunogbulins IgE and IgM:IgG showed downregulation in colder months in DFTD infected animals. We also observed strong positive association between the expression of an innate immune gene, CD16, and DFTD infection. Our results demonstrate that sampling across seasons, age groups and environmental conditions are beneficial when deciphering the complex ecoevolutionary interactions of not only conventional host-parasite systems, but also of host and diseases with high mortality rates, such as transmissible cancers.

Quantifying 25 years of disease-caused declines in Tasmanian devil populations: host density drives spatial pathogen spread.

Infectious diseases are strong drivers of wildlife population dynamics, however, empirical analyses from the early stages of pathogen emergence are rare. Tasmanian devil facial tumour disease (DFTD), discovered in 1996, provides the opportunity to study an epizootic from its inception. We use a pattern-oriented diffusion simulation to model the spatial spread of DFTD across the species' range and quantify population effects by jointly modelling multiple streams of data spanning 35 years. We estimate the wild devil population peaked at 53 000 in 1996, less than half of previous estimates. DFTD spread rapidly through high-density areas, with spread velocity slowing in areas of low host densities. By 2020, DFTD occupied >90% of the species' range, causing 82% declines in local densities and reducing the total population to 16 900. Encouragingly, our model forecasts the population decline should level-off within the next decade, supporting conservation management focused on facilitating evolution of resistance and tolerance.

Evaluation of Clinical Properties and Treatment Responses of Infantile Hemangioma.

BACKGROUND: Infantile hemangiomas are the most common vascular tumors in childhood. Although spontaneous regression is common; several infantile hemangioma patients need treatment due to possible morbidities. The aim of this study was to investigate the medical methods used in the treatment of infantile hemangiomas and to evaluate the factors affecting treatment response. METHODS: Clinical and demographic characteristics, risk factors, treatment indications, modalities, duration, and responses of 100 patients between January 2007 and January 2017 were evaluated. RESULTS: The most common form of hemangiomas was superficial lesions. Sixty three per cent of the patients were female. Ulceration and hemorrhage were found in 26% of the cases and ocular problems were detected in 3% of the cases. Among the indications for treatment were cosmetic reasons with 56%, ulcer and bleeding with 25% and risk of vision problems with 13%. Propranolol with/without steroid was used as first line treatment and response rates were: 84 patients with more than 50% response, 9 patients with less than 50% response and 7 patients with treatment refractory. The most important factor affecting the treatment response was age at the beginning of the treatment. Duration of treatment, presence of ulceration, location, and size of hemangioma were also found to have significant effects on responses. CONCLUSIONS: This study demonstrated the importance of the kind and initiation time of infantile hemangioma treatment. A strong positive effect can be reached by starting treatment before the end of the proliferation phase. J Drugs Dermatol. 2020;19(12): doi:10.36849/JDD.2020.5009.

A transmissible cancer shifts from emergence to endemism in Tasmanian devils.

Emerging infectious diseases pose one of the greatest threats to human health and biodiversity. Phylodynamics is often used to infer epidemiological parameters essential for guiding intervention strategies for human viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2). Here, we applied phylodynamics to elucidate the epidemiological dynamics of Tasmanian devil facial tumor disease (DFTD), a fatal, transmissible cancer with a genome thousands of times larger than that of any virus. Despite prior predictions of devil extinction, transmission rates have declined precipitously from ~3.5 secondary infections per infected individual to ~1 at present. Thus, DFTD appears to be transitioning from emergence to endemism, lending hope for the continued survival of the endangered Tasmanian devil. More generally, our study demonstrates a new phylodynamic analytical framework that can be applied to virtually any pathogen.

Evolution and lineage dynamics of a transmissible cancer in Tasmanian devils.

Devil facial tumour 1 (DFT1) is a transmissible cancer clone endangering the Tasmanian devil. The expansion of DFT1 across Tasmania has been documented, but little is known of its evolutionary history. We analysed genomes of 648 DFT1 tumours collected throughout the disease range between 2003 and 2018. DFT1 diverged early into five clades, three spreading widely and two failing to persist. One clade has replaced others at several sites, and rates of DFT1 coinfection are high. DFT1 gradually accumulates copy number variants (CNVs), and its telomere lengths are short but constant. Recurrent CNVs reveal genes under positive selection, sites of genome instability, and repeated loss of a small derived chromosome. Cultured DFT1 cell lines have increased CNV frequency and undergo highly reproducible convergent evolution. Overall, DFT1 is a remarkably stable lineage whose genome illustrates how cancer cells adapt to diverse environments and persist in a parasitic niche.

Telomere Length is a Susceptibility Marker for Tasmanian Devil Facial Tumor Disease.

Telomeres protect chromosomes from degradation during cellular replication. In humans, it is well-documented that excessive telomere degradation is one mechanism by which cells can become cancerous. Increasing evidence from wildlife studies suggests that telomere length is positively correlated with survival and health and negatively correlated with disease infection intensity. The recently emerged devil facial tumor disease (DFTD) has led to dramatic and rapid population declines of the Tasmanian devil throughout its geographic range. Here, we tested the hypothesis that susceptibility to DFTD is negatively correlated with telomere length in devils across three populations with different infection histories. Our findings suggest telomere length is correlated with DFTD resistance in three ways. First, devils from a population with the slowest recorded increase in DFTD prevalence (West Pencil Pine) have significantly longer telomeres than those from two populations with rapid and exponential increases in prevalence (Freycinet and Narawantapu). Second, using extensive mark-recapture data obtained from a long-term demographic study, we found that individuals with relatively long telomeres tend to be infected at a significantly later age than those with shorter telomeres. Third, a hazard model showed devils with longer telomeres tended to become infected at a lower rate than those with shorter telomeres. This research provides a rare study of telomere length variation and its association with disease in a wildlife population. Our results suggest that telomere length may be a reliable marker of susceptibility to DFTD and assist with future management of this endangered species.

Locally advanced orofacial malignancy: Synopsis of inoperable lesions at an urban tertiary health facility in Nigeria.

BACKGROUND: Locally advanced inoperable orofacial malignancies do present clinically, and constitute a significant public health burden worldwide. OBJECTIVE: To determine the prevalence and clinical characteristics of Stage IV locally advanced inoperable orofacial malignancies for consecutive patients. MATERIALS AND METHODS: A 24-year retrospective study was undertaken, and data obtained from hospital register, case files, and histopathological reports of patients were recorded in a proforma. The variables studied were age, sex, type of lesion and site, duration of lesion, tobacco/alcohol use, and socioeconomic status of the patients and clinical features of the lesions. RESULTS: Twenty-six patients presented, giving a prevalence of 11.2%. The most common lesion was adenoid cystic carcinoma, 23.1%. Males accounted for 18 (69.2%) cases and females, 8 (30.8%) giving a male to female ratio of 2.3:1. The ages ranged from 21 to 65 years, mean (SD) 48.6 (7.3) years. The gender distribution was clinically and statistically significant in favor of the males (P = 0.001). The patients were in the low socioeconomic class and 20 (76.9%) indulged in chronic use of tobacco and alcohol. The duration of the lesions ranged from 1.8 to 3.1 years. The maxilla/facial skin was the commonest site (46.2%). Clinically and statistically, the relativity of site distribution of lesions was significant (P = 0. 002). The clinical features occurred in combination resulting in an average of 10 symptoms and signs in each patient. CONCLUSION: The synopsis of these lesions shows that all have undergone metastasis; salivary gland malignancies were most common with maxilla as the commonest site.

Oral and maxillofacial cancer in pediatric patients: 30 years experience from a Brazilian reference center.

OBJECTIVE: The aim of this study is to determine the relative frequency, demographic distribution and clinicopathological features of pediatric oral and maxillofacial cancer (POMC). METHODS: Medical records were retrospectively reviewed for all cancer cases diagnosed from 1986 to 2016 affecting patients aged 19 years and younger. Demographic variables, anatomical site, and histopathological diagnoses were collected and analyzed by descriptive statistics. RESULTS: Fifty-five (0.77%) POMCs were found among 7181 pediatric malignancies. Mean age at diagnosis was 8 years and patients aged 5-9 years presented the higher prevalence of malignant tumors (40%). White male patients were more frequently affected (78.18% and 65.45%, respectively). The most common cancer type was lymphomas (52.73%) followed by sarcomas (27.27%) and carcinomas (20%). Burkitt lymphoma (32.73%), rhabdomyosarcoma (14.55%), diffuse large B-cell lymphoma (9.09%), and mucoepidermoid carcinoma (9.09%) were the most common histopathological diagnoses. The main affected anatomical site was the oropharynx (38.18%), followed by salivary glands (30.91%), maxillofacial bone (20%), and oral cavity (10.91%). CONCLUSION: POMC has a low incidence; however, highly aggressive tumors, such as lymphomas and sarcomas, are common in this scenario. A better knowledge about the clinicopathological distribution of POMC may contribute to early diagnosis and improve survival rates.

Individual and temporal variation in pathogen load predicts long-term impacts of an emerging infectious disease.

Emerging infectious diseases increasingly threaten wildlife populations. Most studies focus on managing short-term epidemic properties, such as controlling early outbreaks. Predicting long-term endemic characteristics with limited retrospective data is more challenging. We used individual-based modeling informed by individual variation in pathogen load and transmissibility to predict long-term impacts of a lethal, transmissible cancer on Tasmanian devil (Sarcophilus harrisii) populations. For this, we employed approximate Bayesian computation to identify model scenarios that best matched known epidemiological and demographic system properties derived from 10 yr of data after disease emergence, enabling us to forecast future system dynamics. We show that the dramatic devil population declines observed thus far are likely attributable to transient dynamics (initial dynamics after disease emergence). Only 21% of matching scenarios led to devil extinction within 100 yr following devil facial tumor disease (DFTD) introduction, whereas DFTD faded out in 57% of simulations. In the remaining 22% of simulations, disease and host coexisted for at least 100 yr, usually with long-period oscillations. Our findings show that pathogen extirpation or host-pathogen coexistence are much more likely than the DFTD-induced devil extinction, with crucial management ramifications. Accounting for individual-level disease progression and the long-term outcome of devil-DFTD interactions at the population-level, our findings suggest that immediate management interventions are unlikely to be necessary to ensure the persistence of Tasmanian devil populations. This is because strong population declines of devils after disease emergence do not necessarily translate into long-term population declines at equilibria. Our modeling approach is widely applicable to other host-pathogen systems to predict disease impact beyond transient dynamics.

Sex bias in ability to cope with cancer: Tasmanian devils and facial tumour disease.

Knowledge of the ecological dynamics between hosts and pathogens during the initial stages of disease emergence is crucial to understanding the potential for evolution of new interspecific interactions. Tasmanian devil (Sarcophilus harrisii) populations have declined precipitously owing to infection by a transmissible cancer (devil facial tumour disease, DFTD) that emerged approximately 20 years ago. Since the emergence of DFTD, and as the disease spreads across Tasmania, the number of devils has dropped up to 90% across 80% of the species's distributional range. As a result, the disease is expected to act as a strong selective force on hosts to develop mechanisms of tolerance and/or resistance to the infection. We assessed the ability of infected devils to cope with infection, which translates into host tolerance to the cancer, by using the reaction norm of the individual body condition by tumour burden. We found that body condition of infected hosts is negatively affected by cancer progression. Males and females presented significant differences in their tolerance levels to infection, with males suffering declines of up to 25% of their body condition, in contrast to less than 5% in females. Sex-related differences in tolerance to cancer progression may select for changes in life-history strategies of the host and could also alter the selective environment for the tumours.

[A retrospective clinical study of 3 382 cases of malignant oral maxillofacial tumors].

To investigate the incidence of malignant tumors in oral and maxillofacial region and the pathological features of various tumors, a total of 3 382 cases of malignant tumors in oral and maxillofacial region admitted to Jilin University from Januarary 2000 to December 2017. The characteristics of age, sex, location and pathological types of all kinds of tumors were analyzed. The median onset age is 57 years old, 51 to 70 years old is a high-risk age group, the ratio of male to female was 1.9∶1. The primary tumor location is tongue, gingiva and floor of mouth. Epithelial, lymphatic hematopoietic system, bone and soft tissue were the three major sources of tumor tissue, and squamous cell carcinoma was the most common pathological type (65.1%), followed by mucoepidermoid carcinoma and adenoid cystic carcinoma. In summary, oral and maxillofacial malignancies have a high incidence in elderly men, and tongue is the most common site of disease. Epithelial-origin and squamous cell carcinomas are the first of their origins and pathological types, respectively.

Dermoscopic features of melanocytic skin lesions in Greek children and adolescents and their association with environmental factors and skin types.

BACKGROUND: Acquired naevi often present in childhood and increase in number and size during early and middle life. As naevi represent potential mimickers of melanoma, the knowledge of their epidemiologic and morphologic characteristics is essential. OBJECTIVE: In this study, we intend to determine the prevalence of dermoscopic patterns of naevi, as well their association with environmental and constitutional factors. METHODS: Cross-sectional data derived from a population-based cohort of children and adolescents aged 6-18 years, from 12 different schools in Thessaloniki, Greece. For each participant, a consent form and a questionnaire were completed, which included data on age, sex, phototype, sun sensitivity, sun exposure, sunscreen use and previous sunburn history. All naevi, their body distribution, and their dermoscopic patterns were recorded. RESULTS: Two thousand and five hundred and five (2505) subjects were enrolled into the study (47.8% males and 52.2% females). The mean number of MN counted in a single person was 29.11 (SD = ±23.863). TNC increased continuously with higher age. Males were found to have a significantly increased number on the trunk (11.7 ± 11.2 and 10.0 ± 8.7, respectively, P < 0.001) and face and neck (6.2 ± 5.3 and 5.1 ± 4.3, respectively, P < 0.001) while females on the upper (10.3 ± 10.1 and 9.3 ± 9.4, respectively, P = 0.008) and lower extremities (2.8 ± 3.4 and 2.5 ± 3.2, respectively, P = 0.008). Globular pattern was the most frequent dominant pattern in lower age groups, and its percentage fell as age increased. On the contrary, the reticular pattern was more often documented in individuals in adolescence. CONCLUSION: This first study of MN in our young population aims to be the basis of further investigation for the MM preventive policy of our state.

Acute lymphoblastic leukemia/lymphoma of the oral and maxillofacial region.

OBJECTIVE: Our objective was to describe the clinicopathologic and immunohistochemical features of acute lymphoblastic leukemia/lymphoma (ALL/LBL) of the oral and maxillofacial region (OMF). STUDY DESIGN: Cases diagnosed as ALL/LBL of the OMF region were retrieved from the files of 2 Brazilian and 1 Guatemalan oral pathology services from 2005 to 2017. Microscopic and immunohistochemical features of each case were reviewed and fully described, and clinical data were retrieved from the pathology reports. RESULTS: During the period considered, 6 cases were identified. Male patients were the most affected (4:2), with a mean age of 19 years old. The mandible was involved in 2 cases, the maxilla in 2, the cheek mucosa in 1, and the parotid gland in 1. Painful swelling was the most common presentation, and 3 patients also had systemic complaints. Microscopically, tumors revealed solid infiltrations of small to medium-sized immature cells. "Puzzle-like" and "starry-sky" patterns were observed, and "single lane" growth was also identified. Immunohistochemically, 2 cases were diagnosed as T-cell ALL/LBL with the leukocyte common antigen (LCA)+/cCD3+/CD79 a+focal/CD20-/PAX5-/CD99+/CD34-/CD10+/terminal deoxynucleotidyl transferase (TdT)+ phenotype and 4 as B-cell ALL/LBL with the LCA+/CD3-/CD20-/CD79 a+/CD10+/CD34 variable/TdT+ predominant phenotype. The Ki67 index ranged from 80% to 99%. CONCLUSION: OMF ALL/LBL is rare, but its microscopic features and immunohistochemical profiles CD3+or CD79 a+/CD10+/CD34+variable/CD99+/TdT+ contribute to the correct diagnosis.

Periapical Cemento-osseous Dysplasia Is Rarely Diagnosed on Orthopantomograms of Patients with Neurofibromatosis Type 1 and Is Not a Gender-specific Feature of the Disease.

Several skeletal aberrations of the skull have been described for the tumor predisposition syndrome neurofibromatosis type 1 (NF1). Recently, periapical cemental/cemento-osseous dysplasia (COD) has been described in females affected with NF1. This reactive lesion of the hard tissues in tooth-bearing areas of the jaw has been proposed to represent a gender-specific radiological feature of NF1. The aim of this study was to investigate the prevalence of COD in patients with NF1. PATIENTS AND METHODS: The orthopantomograms (OPGs) of 179 patients with a confirmed diagnosis of NF1 were analyzed for COD. The results were compared to radiographic findings obtained in OPGs of age- and sex-matched controls. The NF1 patient group was further differentiated according to the evidence of facial plexiform neurofibroma. RESULTS: COD was a very rare finding in both groups. The extension of the diagnostic criteria including radiologically-healthy teeth and a widened periodontal gap in the periapical area only marginally increased the number of considered cases. Although there was a somewhat more common occurrence of such changes in the patient group compared to the control group and the number of affected women was greater than the number of men, none of these differences reached statistical significance. Furthermore, COD or widening of the periradicular periodontal space was not found to be associated with facial tumor type in NF1. CONCLUSION: The investigation revealed that COD is not a diagnostic feature of NF1. There is no clear association of the rare finding of COD with gender. These studies should be compared with patient groups of other ethnic backgrounds.

Dermatofibrosarcoma protuberans: clinicopathologic presentation in Nigerians.

INTRODUCTION: Dermatofibrosarcoma protuberance (DFSP) is in general a rare low grade malignant sarcoma and possesses a tendency for local recurrence. It has a site predilection for the trunk. Occurrence in the facial area is extremely rare. Ample knowledge of its clinical, histological and biologic characteristics is vital for accurate and prompt recognition. METHODS: Over 13 years, clinicohistologic information of cases was retrieved. Histological and immunohistochemical re-evaluation were performed to re-confirm diagnosis. Data collected and analyzed with SPSS Statistics version 20 were presented as frequency tables, charts and proportions as appropriate. RESULTS: Of 191 soft tissue sarcomas, a total of 28 cases were diagnosed as DFSP (14.7%). Facial types occurred in 3 cases (1.6%). Tumour had age and site predilections for the 4th decade and trunk respectively. There was an equal gender distribution among cases. Most common clinical presentation was in form of painless protruding nodular mass. General histologic presentation revealed cellular lesions composed of spindle to oval neoplastic cells arranged in a storiform pattern. Mitotic figures were rare. All cases showed positive expressions to CD34. CONCLUSION: Facial DFSP is rare among Nigerians. Its clinical appearance may mimic other common benign lesions of the head and neck region often resulting in misdiagnoses. A comprehensive knowledge of its clinical and histologic presentations and biologic behavior, combined with its identification with the aid of advanced histologic and radiographic techniques results in prompt confirmatory diagnosis. Appropriate treatment should include adequate surgical excision techniques combined with adjuvant radiotherapy or chemotherapy.

A multicenter study of malignant oral and maxillofacial lesions in children and adolescents.

OBJECTIVES: To investigate the frequency of malignant oral and maxillofacial lesions among children and adolescents from representative geographic regions of Brazil. MATERIALS AND METHODS: A retrospective study was conducted on biopsies obtained from 1990 to 2016 at six Brazilian oral and maxillofacial pathology referral centers. A total of 85,105 biopsy specimens from children and adolescents were analyzed. Gender, age, anatomical location, symptomatology and histopathological diagnosis were evaluated. Data were analyzed using descriptive statistical methods. RESULTS: Fifty-eight (0.06%) malignant oral and maxillofacial lesions were diagnosed in children (19%) and adolescents (81%). The lesions were more frequent among females (60.3%) and adolescents. The most prevalent lesions were mucoepidermoid carcinomas (22.4%), osteosarcomas (13.8%), squamous cell carcinomas (12.1%), and Burkitt's lymphomas (12.1%). The most commonly affected sites were the palate (19%), mandible (13.8%), and maxilla (13.8%). Almost half the patients were asymptomatic. CONCLUSION: Pediatric oral and maxillofacial malignant lesions were infrequent and showed wide diversity, with a prevalence of mucoepidermoid carcinomas. Analysis of malignant lesions in children and adolescents helps pediatric dentists and oncologists to obtain a better understanding of such lesions and to reduce the time for diagnosis, with a consequent improvement of prognosis.