Minimally Invasive vs Open Pancreatectomy for Pancreatic Neuroendocrine Tumors: Multi-Institutional 10-Year Experience of 1,023 Patients.

BACKGROUND: Resection of pancreatic neuroendocrine tumors (PNETs) may be associated with adverse perioperative outcomes compared with pancreatic adenocarcinoma given the high-risk nature of soft glands with small pancreatic ducts. The effect of minimally invasive surgery (MIS) pancreatectomy on outcomes of PNETs remains to be examined, which is the aim of this study. STUDY DESIGN: Between 2009 and 2019, 1,023 patients underwent pancreatectomy for PNETs at 4 institutions. Clinicopathologic data and perioperative outcomes of patients who underwent MIS (n = 447) and open resections (n = 576) were compared. RESULTS: Of the 1,023 patients, 51% were male, the mean age was 58, the median tumor size was 2.1 cm, and 73% were grade 1 PNETs. There were 318 (31%) pancreatoduodenectomies (PDs), 541 (53%) distal pancreatectomies (DPs), 80 (7.8%) enucleation (ENs), 72 (7%) central pancreatectomies (CPs), and 12 (1.2%) total pancreatectomies. Almost half of the patients (N = 447, 44%) had MIS operations, of which 230 (51%) were robotic and 217 (49%) were laparoscopic. Compared with open operations, MIS PDs had significantly lower operative blood loss (150 vs 400 mL, p < 0.001) and rate of clinically relevant postoperative pancreatic fistulas (CR-POPFs; 13% vs 27%, p = 0.030), and MIS DPs had a shorter length of stay (5 vs 6 days, p < 0.001). Although MIS DPs and ENs had CR-POPFs comparable with open operations, MIS CPs had a higher CR-POPF rate (45% vs 15%, p = 0.013). After adjusting for pathological differences, MIS pancreatectomy was associated with recurrence-free survival and overall survival comparable with open pancreatectomy. CONCLUSIONS: MIS pancreatectomy for PNETs is associated with improved outcomes or outcomes comparable with open resection.

Everolimus with or without bevacizumab in advanced pNET: CALGB 80701 (Alliance).

Treatment with the MTOR inhibitor everolimus improves progression-free survival (PFS) in pancreatic neuroendocrine tumors (pNETs), but it is not known if the addition of a VEGF pathway inhibitor to an MTOR inhibitor enhances antitumor activity. We performed a randomized phase II study evaluating everolimus with or without bevacizumab in patients with advanced pNETs. One hundred and fifty patients were randomized to receive everolimus 10 mg daily with or without bevacizumab 10 mg/kg i.v. every 2 weeks. Patients also received standard dose of octreotide in both arms. The primary endpoint was PFS, based on local investigator review. Treatment with the combination of everolimus and bevacizumab resulted in improved progression-free survival compared to everolimus (16.7 months compared to 14.0 months; one-sided stratified log-rank P = 0.1028; hazard ratio (HR) 0.80 (95% CI 0.56-1.13)), meeting the predefined primary endpoint. Confirmed tumor responses were observed in 31% (95% CI 20%, 41%) of patients receiving combination therapy, as compared to only 12% (95% CI 5%, 19%) of patients receiving treatment with everolimus (P = 0.0053). Median overall survival duration was similar in the everolimus and combination arm (42.5 and 42.1 months, respectively). Treatment-related toxicities were more common in the combination arm. In summary, treatment with everolimus and bevacizumab led to superior PFS and higher response rates compared to everolimus in patients with advanced pNETs. Although the higher rate of treatment-related adverse events may limit the use of this combination, our results support the continued evaluation of VEGF pathway inhibitors in pNETs.

Orbital medulloepithelioma in an adult patient: Radiation-induced second neoplasia?

Second cancers in survivors of hereditary retinoblastoma occur much more commonly than in the general population. This can be attributed both to the germline mutation of the RB gene and chemoradiation used for treatment of this paediatric cancer. Medulloepithelioma is an uncommon tumor of neuroectodermal origin, seen largely in the paediatric population and rarely reported in adults. Though the incidence of second malignancies is common in retinoblastoma, medulloepithelioma as a second malignancy in retinoblastoma survivors is rare, with only one case reported so far. Herein, we present a case of a 29-year-old patient presenting with medulloepithelioma of the right orbit, arising in the radiation field of previously treated retinoblastoma. This case was also peculiar in that though the origin of tumor was in the eyeball it had a very aggressive clinical course.

Radiation-Induced Supratentorial Primitive Neuroectodermal Tumor after Treatment for Non-Hodgkin's Lymphoma.

Secondary, radiation-induced, supratentorial primitive neuroectodermal tumors (PNETs) are extremely rare entities which may present in survivors of childhood cancers after central nervous system radiation. These lesions have been described after a number of pediatric cancers and demonstrate unique treatment problems and an accelerated clinical course compared to primary PNETs. We present a case of a sixteen year old male with a history of non-Hodgkin's lymphoma who presented with a radiation-induced PNET, and describe our treatment for this lesion. These secondary, radiation-induced tumors increase in significance as the survival of childhood malignancy increases in West Virginia.

Primitive neuroectodermal tumor after radiation therapy for craniopharyngioma.

The authors report a case of primitive neuroectodermal tumor induced by radiation therapy of craniopharyngioma. This African-American male patient originally presented with craniopharyngioma, for which he underwent resection and whole-brain radiation therapy. Eight years later, at the age of 20 years, he returned with a left facial droop and left hemiparesis. A right basal ganglia mass was identified and resected. Histopathological examination identified the lesion as primitive neuroectodermal tumor. Although radiation therapy has shown to be beneficial in decreasing the recurrence rate in subtotally resected craniopharyngioma, the risks of radiation treatment should be clearly communicated to the patients, their families, and neurosurgeons before starting such treatment. This report expands the spectrum of reported radiation-induced neoplasms in the CNS.

Radiotherapy-induced supratentorial primitive neuroectodermal tumour in a 17-year-old female: a case report and review of the literature.

We report a case of a 17-year-old female who presented with a CNS primitive neuroectodermal tumour 12 years after cranial radiotherapy for relapsed childhood acute lymphoblastic leukaemia. In this article, we discuss the association of these rare tumours with previous craniospinal irradiation and review the pertinent literature.

De novo appearance of primitive neuroectodermal tumor in a patient with systemic lupus erythematosus and moyamoya disease.

Primitive neuroectodermal tumor is a rare brain tumor composed of undifferentiated or poorly differentiated neuroepithelial cells with a high malignant potential that usually occurs in children, and which is only occasionally encountered in adults. A 19-year-old female with systemic lupus erythematosus presented with right hemiparesis and a headache of 10 days duration. Brain magnetic resonance imaging showed a large solid mass with necrotic portions in the left frontoparietal lobe. Primitive neuroectodermal tumor was confirmed by a neuronavigator-guided brain biopsy. This is the first case report of primitive neuroectodermal tumor associated with systemic lupus erythematosus and moyamoya disease. This case demonstrates that brain tumors, such as primitive neuroectodermal tumor, should be included in the differential diagnosis of neurological manifestations in children and adolescent patients with systemic lupus erythematosus.

Head injury, diagnostic X-rays, and risk of medulloblastoma and primitive neuroectodermal tumor: a Children's Oncology Group study.

OBJECTIVE: A comprehensive case-control study was conducted to determine potential risk factors for medulloblastoma/primitive neuroectodermal tumor (PNET), a common brain tumor in children. This analysis evaluated possible associations between previous head injury and ionizing radiation exposure through diagnostic X-rays and medulloblastoma/PNET. METHODS: Mothers of 318 cases <6 years of age at diagnosis between 1991 and 1997 and registered with the Children's Oncology Group were interviewed. Mothers of 318 matching controls were selected through random digit dialing and interviewed. RESULTS: An association was not detected between previous head injury (OR: 0.78, 95% CI: 0.40-1.5) or head X-ray for any reason including head injury with medulloblastoma/PNET. A statistically non-significant excess of cases reported having an X-ray for reason other than head injury (OR 2.3, 95% CI 0.91-5.7). When cases that received an X-ray for a common symptom of medulloblastoma/PNET were considered unexposed this association weakened (OR: 1.3, 95% CI: 0.49-3.7). No dose-response relationship was observed. CONCLUSIONS: Head injury and exposure to diagnostic head X-rays were not associated with medulloblastoma/PNET in this study. Future studies should investigate all imaging procedures with ionizing radiation exposure including computed tomography scans and utilize radiation dose estimations.

Combinations of genetic mutations in the adult neural stem cell compartment determine brain tumour phenotypes.

It has been suggested that intrinsic brain tumours originate from a neural stem/progenitor cell population in the subventricular zone of the post-natal brain. However, the influence of the initial genetic mutation on the phenotype as well as the contribution of mature astrocytes to the formation of brain tumours is still not understood. We deleted Rb/p53, Rb/p53/PTEN or PTEN/p53 in adult subventricular stem cells; in ectopically neurografted stem cells; in mature parenchymal astrocytes and in transplanted astrocytes. We found that only stem cells, but not astrocytes, gave rise to brain tumours, independent of their location. This suggests a cell autonomous mechanism that enables stem cells to generate brain tumours, whereas mature astrocytes do not form brain tumours in adults. Recombination of PTEN/p53 gave rise to gliomas whereas deletion of Rb/p53 or Rb/p53/PTEN generated primitive neuroectodermal tumours (PNET), indicating an important role of an initial Rb loss in driving the PNET phenotype. Our study underlines an important role of stem cells and the relevance of initial genetic mutations in the pathogenesis and phenotype of brain tumours.

Molecular genetic analysis of a primitive neuroectodermal tumor arising after intracranial radiation and chemotherapy for leukemia.

Primitive neuroectodermal tumors are aggressive tumors of the central nervous system (CNS), yet their etiology remains unclear. We report a case of a primitive neuroectodermal tumor (PNET) arising in the cerebellum and pons 7 yr after intracranial radiation and chemotherapy for leukemia involving the CNS. This case suggests a possible link between radiation, chemotherapy, and the formation of these tumors, with a potential new pathogenetic role for somatic inactivation of the protooncogene RET.

Secondary supratentorial primitive neuroectodermal tumor following treatment of childhood osteosarcoma.

A 16-year-old Caucasian male was diagnosed with a primitive neuroectodermal tumor (PNET) 5 years following the diagnosis of nonmetastatic osteosarcoma of the left proximal humerus. The patient was initially treated with standard chemotherapy and limb salvage resection for osteosarcoma. Nine months after the completion of therapy, he developed lung metastases for which he underwent surgical resection and received additional chemotherapy. Almost 5 years after the osteosarcoma diagnosis, the patient was diagnosed with a supratentorial PNET, which represents the first known case reported in a patient with osteosarcoma.

Primitive neuroectodermal tumour arising within low grade astrocytoma: transformation, de novo or radiation induced? Report of three cases and review of literature.

The transformation from low grade to aggressive astrocytoma is well known. However, the development of a completely different tumour such as a primitive neuroectodermal tumour (PNET) within a low grade astrocytoma (LGA) is rare. Only two cases have been reported to date. We present three cases and review the literature. One case was identified at presentation. A subsequent review of our histopathology database revealed two further cases. All three patients had histologically proven low-grade astrocytoma and received radiotherapy following biopsy. The tumour location was infratentorial in one and supratentorial in two. The mean age at presentation with initial tumour was 20 years. Two patients underwent partial resection for recurrence, one at five and the other ten years later with histological confirmation of low-grade astrocytoma. At subsequent recurrence eight and thirty years following original presentation and eleven years later for the third patient, further tumour debulking was performed. Histology now revealed high grade PNET. Cytogenetics showed a complex karyotype with multiple chromosomal abnormalities in all three patients. All patients died within 1 year of final surgery. Among the six reported cases of PNET arising following prophylactic radiation therapy to low grade astrocytomas, only two occurred within the original tumour. Whether these cases represent transformation of low-grade astrocytoma, de novo formation of new tumour or radiation induced neoplasm is uncertain.

c-Myc and beta-catenin cooperate with loss of p53 to generate multiple members of the primitive neuroectodermal tumor family in mice.

Primitive neuroectodermal tumors (PNETs) are a family of primary malignant brain tumors that include medulloblastomas. Although genetic models of a subset of medulloblastomas are documented over the past decade, the molecular basis of other subclasses of PNET remains unclear. As elevated c-Myc expression, activation of Wnt/beta-catenin signaling and dysfunction of p53 are seen in human PNETs, we investigated what role these abnormalities have in the formation of PNETs. Incorporating these abnormalities, we generated supratentorial PNET (sPNET) in mice using somatic cell gene transfer. We show that sPNETs arise from GFAP-expressing cells by forced c-Myc expression combined with p53 inactivation. beta-catenin activation promotes tumor progression and induces divergent differentiation. These c-Myc+beta-catenin-induced PNETs are histologically similar to large cell/anaplastic medulloblastomas and can occur in both cerebrum and cerebellum. Furthermore, we have obtained one PNET with marked epithelial differentiation having histological resemblance to choroid plexus carcinoma in this series. Our results in mice suggest that sPNET with varied differentiation and large cell/anaplastic medulloblastomas may be two tumor groups with similar genetic foundations. These data provide insights into the biology and classification of human PNETs and suggest that multiple tumor types or variants can be generated from a fixed set of genetic abnormalities.

Parental heat exposure and risk of childhood brain tumor: a Children's Oncology Group study.

Medulloblastoma (MB) and primitive neuroectodermal tumor (PNET) are histologically similar brain tumors that occur mostly in children. As part of a comprehensive case-control study of MB/PNET, this study explored parental exposure to heat and electromagnetic fields as potential risk factors. Parents of 318 cases (<6 years of age at diagnosis in 1991-1997 and registered with the Children's Cancer Group) and 318 controls selected by random digit dialing were interviewed. In univariate analyses, moderately strong associations were observed for mother's sauna use close to conception (odds ratio = 3.8, 95% confidence interval (CI): 1.0, 13.7) or in the first trimester (odds ratio = 3.6, 95% CI: 0.7, 17.3) and for father's exposure in the 3 months before the pregnancy to sauna (odds ratio = 2.4, 95% CI: 1.3, 4.5), electric blanket (odds ratio = 2.0, 95% CI: 0.9, 4.3), or any heat source (for higher exposure: odds ratio = 2.5, 95% CI: 1.4, 4.6). In multivariate models, father's sauna use and father's exposure to any heat source were associated with MB/PNET in a dose-response fashion (for high exposure: odds ratio = 3.4, 95% CI: 1.2, 9.7, and odds ratio = 2.1, 95% CI: 1.1, 4.3, respectively). This new observation regarding paternal exposure to heat just prior to the index pregnancy deserves consideration in future animal and human studies of MB/PNET.

[Primitive neuroectodermal tumor arising 8 years after chemotherapy and radiotherapy for acute lymphoblastic leukemia: case report].

We report a case of primitive neuroectodermal tumor (PNET) arising 8 years after chemotherapy and radiotherapy for acute lymphoblastic leukemia. A 15-year-old boy with a history of acute lymphoblastic leukemia, at the age of 7, underwent chemotherapy and 14Gy of radiotherapy to the whole brain. He was admitted to our department due to the development of aphasia, right hemiparesis and generalized convulsive seizure. MRI showed an irregularly enhanced mass in the left frontal lobe. A gross total removal of the tumor was performed and histological examination showed it to be PNET. Postoperatively, the patient underwent 20Gy of radiotherapy to the whole brain and 42Gy of local radiotherapy. Follow-up MRI showed no evidence of recurrent tumor 4 months after the radiotherapy. This tumor was thought to be a secondary brain tumor arising in this survivor of childhood acute lymphoblastic leukemia and it is a rare complication of successful leukemia treatment.

Primitive neuroectodermal tumor (PNET) of the uterus in a renal allograft patient: a case report.

The incidence of malignancy after renal transplant has been reported to range from 4% to 18%. Tumors of the skin and lip tend to be the most common with non-Hodgkin lymphoma comprising 20% of all neoplasms. Primitive neuroectodermal tumors (PNET) are collectively described as being a part of the Ewing sarcoma family of tumors. PNET occur more commonly in the second decade of life, predominantly affecting Whites and Hispanics, and rarely occur in individuals of African or Asian descent. The most common primary site of involvement is along the central axis, particularly the chest (Askin tumor), but it can arise in any soft tissue. PNET also occur in the head and neck. PNET involving the cervix, urinary bladder, uterus, and vagina have been reported. We describe a case of a 15-year-old female who, 9 years after receiving a living related renal transplant, developed a post-transplant PNET of the uterus.

Farm-related exposures and childhood brain tumours in seven countries: results from the SEARCH International Brain Tumour Study.

A total of 1218 cases of childhood brain tumours (CBT) and 2223 control subjects from the general population were included in a population-based case-control study conducted in nine centres in seven countries. Mothers were asked about farm- or agriculture-related exposures. Significantly elevated odds ratios (OR) for CBT were associated with children's personal and maternal prenatal exposure while living on a farm with pigs (child OR = 1.7, mother OR = 2.3), horses (child OR = 1.6, mother OR = 1.8), dogs (child OR = 1.5, mother OR = 1.5) and cats (child OR = 1.5, mother OR = 1.7). Children who were exposed to pigs, horses and cats combined, while living on a farm, had a threefold elevated OR for CBT. Increased ORs for primitive neuroectodermal tumours (PNET) were associated with children's farm exposure to dogs (OR = 1.9) and cats (OR = 2.2), and maternal farm exposure to pigs (OR = 4.2). The OR for CBT was elevated (OR = 2.3) for children of mothers who had preconception/prenatal farm- or agriculture-related employment involving potential contact with animals, relative to no farm- or agriculture-related employment. In particular, increased ORs for CBT were observed for children of mothers who were employed as general farmers (OR = 4.1) or general farm workers (OR = 3.8). During the 5 years preceding the index child's birth, maternal exposures were related to CBT, relative to no maternal exposure to agricultural chemicals or animal products: fertilisers (OR = 1.8), pesticides (OR = 2.0), animal manure (OR = 2.0) and unprocessed wool (OR = 3.0). Our findings suggest that various farm-related exposures are positively associated with CBT and warrant further investigation into the public health importance of these associations.

Birth characteristics and brain cancers in young children.

BACKGROUND: High birthweight is a potential risk factor for childhood brain tumours, particularly astrocytomas. We investigated several birth characteristics in relationship to brain cancers in young children. METHODS: We obtained 849 invasive central nervous system (CNS) cancer cases, ages 0-4 years, from California's population-based cancer registry for 1988-1997. We matched 746 (88%) of these cases to a California live birth certificate. We randomly selected two control birth certificates for each case, matched on date of birth and gender. We used conditional logistic regression to obtain odds ratios (OR) and 95% CI. The birth characteristics examined included birthweight, gestational age, race, parental age, and parental education. RESULTS: Analysing all CNS tumours combined, we found that children of other racial/ ethnic groups had OR below one compared with non-Hispanic white children. When adjusted for gestational age, race/ethnicity, and mother's place of birth, the OR for high birthweight (>/=4000 g) was 1.05 (95% CI: 0.79-1.38) compared with children with birthweights of 2500-3999 g. For astrocytomas (313 cases), the adjusted OR for high birthweight was 1.40 (95% CI: 0.90-2.18). When parental education was included in the model (available for only a subset of the birth years), the adjusted OR was 1.71 (95% CI: 1.01-2.90). High birthweight did not appear to be a risk factor for primitive neuroectodermal tumours (PNET). CONCLUSIONS: We found high birthweight associated with increased risk of astrocytomas, but not PNET, in young children.