Citations

INTRODUCTION The human cerebral cortex has undergone an extraordinary increase in size and complexity during mammalian evolution. Cortical cell lineages are specified in the embryo, and genetic and epidemiological evidence implicates early cortical development in the etiology of neuropsychiatric disorders such as autism spectrum disorder (ASD), intellectual disabilities, and schizophrenia. Most of the disease-implicated genomic variants are located outside of genes, and the interpretation of noncoding mutations is lagging behind owing to limited annotation of functional elements in the noncoding genome. RATIONALE We set out to discover gene-regulatory elements and chart their dynamic activity during prenatal human cortical development, focusing on enhancers, which carry most of the weight upon regulation of gene expression. We longitudinally modeled human brain development using human induced pluripotent stem cell (hiPSC)–derived cortical organoids and compared organoids to isogenic fetal brain tissue. RESULTS Fetal fibroblast–derived hiPSC lines were used to generate cortically patterned organoids and to compare oganoids’ epigenome and transcriptome to that of isogenic fetal brains and external datasets. Organoids model cortical development between 5 and 16 postconception weeks, thus enabling us to study transitions from cortical stem cells to progenitors to early neurons. The greatest changes occur at the transition from stem cells to progenitors. The regulatory landscape encompasses a total set of 96,375 enhancers linked to target genes, with 49,640 enhancers being active in organoids but not in mid-fetal brain, suggesting major roles in cortical neuron specification. Enhancers that gained activity in the human lineage are active in the earliest stages of organoid development, when they target genes that regulate the growth of radial glial cells. Parallel weighted gene coexpression network analysis (WGCNA) of transcriptome and enhancer activities defined a number of modules of coexpressed genes and coactive enhancers, following just six and four global temporal patterns that we refer to as supermodules, likely reflecting fundamental programs in embryonic and fetal brain. Correlations between gene expression and enhancer activity allowed stratifying enhancers into two categories: activating regulators (A-regs) and repressive regulators (R-regs). Several enhancer modules converged with gene modules, suggesting that coexpressed genes are regulated by enhancers with correlated patterns of activity. Furthermore, enhancers active in organoids and fetal brains were enriched for ASD de novo variants that disrupt binding sites of homeodomain, Hes1, NR4A2, Sox3, and NFIX transcription factors. CONCLUSION We validated hiPSC-derived cortical organoids as a suitable model system for studying gene regulation in human embryonic brain development, evolution, and disease. Our results suggest that organoids may reveal how noncoding mutations contribute to ASD etiology. Summary of the study, analyses, and main results. Data were generated for iPSC-derived human telencephalic organoids and isogenic fetal cortex. Organoids modeled embryonic and early fetal cortex and show a larger repertoire of enhancers. Enhancers could be divided into activators and repressors of gene expression. We derived networks of modules and supermodules with correlated gene and enhancer activities, some of which were implicated in autism spectrum disorders (ASD).

147 Background: Prostate cancer patients treated with external beam radiation therapy are instructed to present daily with a full bladder to decrease small bowel and bladder toxicity and to increase reproducibility of treatment. However, older patients may have difficulty presenting with full bladders and variation of bladder volume with treatment is unknown. The objective of this study was to assess bladder filling at the time of radiation treatment (RT) using a bladder ultrasound in patients undergoing treatment for prostate cancer. Methods: Patients with prostate cancer were prospectively enrolled prior to CT simulation from January to August 2017. Bladder volume was recorded during CT simulation and daily immediately prior to RT. Patients were instructed to drink 8-12 ounces of water 30-60 minutes prior to RT. Three bladder volume measurements were recorded daily and averaged at the time of each treatment. Average bladder volume during treatment and the number of treatments with low bladder volumes ( < 50cc, < 60cc, and < 100cc) were reported using descriptive statistics. Results: A total of 13 patients completed a median of 42 days of RT during the study period, resulting in 550 daily bladder volumes. Ten patients were treated definitively and 3 with salvage radiation after prostatectomy. The median age of patients in the study was 72 years. Older patients were statistically more likely to present with low bladder volumes, with percentage of treatments with a bladder volume less than 50cc, 60cc, and 100cc being 29%, 42%, and 66% compared to only 4%, 7%, and 18% in patients aged < 70 (P < 0.01). The average bladder volume at the time of CT simulation was 176cc ± 57cc and the average volume during treatment was 140cc± 93cc, which was not statistically different (P = 0.28). The bladder volume did not significantly change over the course of treatment. Conclusions: Older patients (age 70+) with prostate cancer were more likely to present for RT with low bladder volumes in this prospective study. Our findings suggest that older patients should receive extra counseling about bladder filling and/or may require less bladder filling at the time of CT simulation to provide more accurate bowel dosimetry measurements.

Key Clinical Message Myxoinflammatory fibroblastic sarcoma is a rare sarcoma which typically presents in the extremities and is treated by definitive surgery. In recurrent disease, the reported utilization of radiotherapy is increasing, and more modern techniques such as intensity‐modulated radiotherapy may be improving long‐term outcomes.

192 Background: Patient privacy is of the utmost importance for the emotional needs of a cancer patient and their family. As an effort to improve privacy, quality, and coordination of care within our Radiation Oncology department, in 2016 a patient pager system was devised to inform patients to prepare for daily treatment rather than verbally call the patient's name in waiting rooms. Methods: During June 2016, patients undergoing daily radiation therapy participated in a six-question survey addressing various aspects of the paging service, privacy prior to pager use, and demographics. Six radiation therapists also participated in a 7-question survey addressing privacy and workflow. Participants rated their experience on a scale of 1 to 5 (1 being poor, 5 being excellent). Surveys were collected and retrospectively reviewed. Results: 42 patients completed the survey. Patients rated "Very Good" to "Excellent" for the following categories: “Paging system more convenient than being called”(4.6), “Protection of privacy”(4.6), “Easiness”(4.7) and whether “Pager should be utilized for all appointments” (4.3). Patients rated “Patient privacy when name is called” as "Good" to "Very Good" (3.7). Seven patients also underwent therapy prior to pager implementation and rated the new system in comparison as "Very Good" to "Excellent" for “Privacy protection”(4.6), “Efficiency” (4.6), and “Satisfaction” (4.6). Only 24 filled out demographic information. Of the 24 patients, 54% of patients were female, 87% were above the age of 50, and all patients were receiving at least 10 treatments. Staff rated "Fair" to "Very Good" for “More preparation time” (2.8), “Patient use difficulty”(3.2), “Patient positive feedback”(2.3), “Receiving patients” (2.2) and “Workflow” (2). However, “Patient privacy” was rated as "Very Good" to "Excellent" (4.2). Conclusions: Overall, patients and staff highly rated the paging system for protecting privacy in the waiting room. Patients who experienced waiting room procedure prior to pager implementation display greater satisfaction with a paging system. However, it did not change overall workflow. Our study shows clinics should prioritize patient privacy in the waiting room to improve the emotional needs of the patient.

Prostate cancer is the most common malignancy of men in the United States. Small-cell carcinoma (SCC), which typically presents as an aggressive lung malignancy, is a rare diagnosis within the setting of prostate cancer pathology. Due to its limited prevalence, little information regarding the treatment and prognosis of this disease in large populations is available. To date our current knowledge base is largely limited to case reports and retrospective case reviews. The mainstay of treatment for this particular histology most often involves a multimodality approach utilizing chemotherapy in conjunction with radiation therapy, androgen deprivation therapy, or prostatectomy. Here we present the case of an elderly 89-year-old Caucasian male who was diagnosed with SCC of the prostate. Despite proceeding with a course of definitive radiotherapy, the patient experienced rapid progression of disease and ultimately elected to discontinue radiation therapy and receive hospice care.

Recurrent invasive high-grade mucoepidermoid carcinoma of the larynx and hypopharynx is a rare occurrence. These tumors have been commonly associated with salivary gland tumors, most commonly the parotid gland. The patient usually presents with the following symptoms: hoarseness (if larynx is involved), or changes in voice character, sore throat, cough, odynophagia, dysphagia, otalgia, difficulty breathing, weight loss, lymphadenopathy. Here we present a case of a recurrent invasive high-grade mucoepidermoid carcinoma of larynx and hypopharynx. The patient was a 67-year-old male that originally presented in 2006. At that time he underwent a wide field laryngectomy, right thyroid lobectomy, and biopsy of the right digastric node. He was a clinical stage III, pT3N0M0. No adjuvant radiation therapy was given at that time. The patient remained asymptomatic until February 2014, when he presented with dysphagia and neck swelling. Positron emission tomography/computed tomography showed evidence of recurrence. The patient was treated with definitive intensity modulated radiation therapy (IMRT) with concurrent chemotherapy. Treatment for this disease is gathered by scattered case reports. If surgery is a possibility it is considered as first line therapy. Post-surgical radiation is then offered. However, in this case the recurrent tumor was located near the carotid artery, and thus surgery was not a possibility. Therefore, concurrent chemotherapy and radiation with IMRT and weekly cis-platinum was given. While the optimum combination of treatment has not yet been established because of the rarity of this cancer's location site, the current patient appeared to have an excellent response from the definitive IMRT and chemotherapy treatment.

Langerhan's cell sarcoma (LCS) is a rare neoplasm with a poor prognosis. To our knowledge, only sixty-six cases have been published. We discuss two patients who presented very differently with LCS, as well as a recently published review of all sixty-six cases. Our first case had a complicated history of metastatic, high-grade myxofibrosarcomas and presented with a single skin lesion of LCS which was treated with resection to a positive margin and adjuvant radiotherapy. The LCS recurred locoregionally and was again resected. The patient is alive two years after initial diagnosis. The second case presented with bone marrow and splenic involvement, leukocytosis, and thrombocytopenia. This patient had an excellent response to etoposide, prednisone, oncovorin, cyclophosphamide, and adriamycin, with normalization of the complete blood count, negative bone marrow biopsy at follow up, and splenectomy without viable neoplasm. This patient is alive without signs of disease at 16 months after initial diagnosis.

Hidradenocarcinoma is a rare aggressive form of cutaneous adnexal skin carcinoma originating from the sweat gland. Due to its low incidence, prognostic and treatment strategies are still being explored both for primary and advanced disease. This tumor most often presents as either solid or cystic appearing subcutaneous nodules, which may be associated with pruritus or ulceration. To date the mainstay of treatment for local disease has been surgical excision; however, the paucity of historical data available has shown that these tumors often behave aggressively with high rates of local recurrence, metastasis, and poor overall outcomes. There are few case reports describing the utility of radiation therapy in the treatment of hidradenocarcinoma. Herein, we present a case of metastatic apocrine hidradenocarcinoma in a 32-year-old Caucasian male. The patient initially underwent excisional biopsy which confirmed the diagnosis of poorly differentiated, highly infiltrative, apocrine hidradenocarcinoma. He received systemic chemotherapy for metastatic disease, followed by radiation therapy to areas of grossly palpable adenopathy. Prior to radiation therapy the patient had an enlarged hypermetabolic conglomerate of lymph nodes in the right axilla, and borderline enlarged low activity nodes within the left axilla. He received 3 cycles of chemotherapy followed by tamoxifen and radiation therapy (50.4 Gy in 28 fractions) to areas of progressive disease in the bilateral axilla, lower neck, and axillary skin. Following treatment, the patient had complete resolution of skin nodules and improvement of his pruritus. While the role of radiation therapy in the treatment of hidradenocarcinoma has not been well established, this case report demonstrated the potential benefit of external beam radiotherapy in the management of this rare disease.