Posterior fossa (PF) diffuse gliomas in pediatric patients frequently harbor the H3 K27M mutation. Among adults, PF diffuse gliomas are rare, with limited data regarding molecular features and clinical outcomes. We identified 28 adult PF diffuse glioma patients (17 males; median: 50 y, range: 19 to 78 y), with surgery performed at our institution (13 brainstem; 15 cerebellum). Histologic subtypes included anaplastic astrocytoma (n=21), glioblastoma (n=6), and diffuse astrocytoma (n=1). Immunohistochemistry was performed for H3 K27M (n=26), IDH1-R132H (n=28), and ATRX (n=28). A 150-gene neuro-oncology-targeted next-generation sequencing panel was attempted in 24/28, with sufficient informative material in 15 (51.7%). Tumors comprised 4 distinct groups: driver mutations in H3F3A (brainstem=4; cerebellum=2), IDH1 (brainstem=4; cerebellum=4), TERT promotor mutation (brainstem=0; cerebellum=3), and none of these (n=5), with the latter harboring mutations of TP53 , PDGFRA , ATRX , NF1 , and RB1 . All TERT promoter–mutant cases were IDH-wild-type and arose within the cerebellum. To date, 20 patients have died of disease, with a median survival of 16.3 months, 1-year survival of 67.5%. Median survival within the subgroups included: H3F3A =16.4 months, IDH mutant=113.4 months, and TERT promoter mutant=12.9 months. These findings suggest that PF diffuse gliomas affecting adults show molecular heterogeneity, which may be associated with patient outcomes and possible response to therapy, and supports the utility of molecular testing in these tumors.
SATB2 Is Expressed in a Subset of Pulmonary and Thymic Neuroendocrine Tumors
Abstract Objectives To evaluate SATB2 expression and prognostic implications in a large cohort of thoracic neuroendocrine tumors. Methods Surgical pathology files (1995-2017) and an institutional thymic epithelial tumor database (2010-2020) were searched for resected neuroendocrine tumors. Cases were stained with SATB2 (clone EP281). Percent SATB2-positive tumor cells and expression intensity were scored. Results In the lung, SATB2 was expressed in 5% or more of tumor cells in 29 (74.4%) of 39 small cell carcinomas and 9 (22.5%) of 40 atypical and 26 (40.6%) of 64 typical carcinoid tumors. SATB2 percent tumor cell expression and intensity were higher in small cell carcinomas than in carcinoid tumors (both P < .001, respectively). After adjusting for tumor subtype, SATB2 expression did not correlate with outcome. In the thymus, four (100%) of four atypical carcinoid tumors and one large cell neuroendocrine carcinoma but no small cell carcinoma (n = 2) expressed SATB2 in 5% or more of tumor cells. Conclusions SATB2 (clone EP281) is expressed in a large subset of pulmonary and thymic neuroendocrine tumors and therefore does not appear to be a useful marker to identify the origin of neuroendocrine tumors. Validation studies are needed, specifically including thymic neuroendocrine tumors, as the expression pattern might be different in those tumors.
Abstract PO-245: Evaluating educational interventions to increase breast density awareness among Latinas: A randomized clinical trial in a Federally Qualified Health Center
Abstract Purpose: Among a Latina population in a low resource healthcare setting, to test the effectiveness of bilingual (Spanish/English) written and interpersonal educational interventions in increasing breast density (BD) awareness, knowledge, and conversations with healthcare providers, which are goals of BD notification mandates. Procedures: This randomized trial was conducted at a Federally Qualified Health Center (FQHC) in an urban community of the Southwest U.S. Women ages 40- 74 presenting for screening mammography were recruited and randomized 1:1:1 to usual care (mailed letter with mammogram and BD results), enhanced care (letter plus BD educational brochure), or interpersonal care (letter, brochure, and telephonic promotora education). The baseline survey was administered in person at enrollment prior to the mammogram. Follow-up surveys were by phone or mail after the mammography results letter was mailed and promotora delivery was complete (median days from baseline to follow-up survey = 97 days). Differences between groups at baseline or follow-up were assessed with chi-square tests. Logistic regression using generalized estimating equations to account for repeated data was used to assess differences by time (baseline to follow-up) within group, including a time-by-group interaction. Results: Between October 2016 and October 2019, 1377 women were enrolled. Of these, 1085 (79%) self-identified Latinas completed baseline and follow-up surveys. Median age was 47 years. Most (91%) reported speaking mostly Spanish, and 69.1% had less than a high school degree. At baseline, only 20.9% reported having heard of BD, and only 30.5% of those knew their personal BD category. At follow-up, women in the interpersonal group were more likely to report seeing their BD results in the notification letter compared to the usual care and enhanced groups (70.4% vs. 52.9% and 54.3%, p < 0.001) and to report having spoken with a provider about their BD (27.3% vs. 14.2% and 15.7%, p < 0.001). They also reported higher mean understanding of BD (7.7 on a 0-10 scale vs. 6.3 and 6.6, p < 0.001). There were no significant differences on these outcomes between the usual care and enhanced groups. All groups saw significant improvement in correct responses from baseline to follow-up for questions on the ability of BD to mask tumors on a mammogram and BD as a breast cancer risk factor (p < 0.001 all groups), but the degree of improvement in masking knowledge was significantly higher for the interpersonal vs usual care group [OR for a correct response in follow-up vs baseline: 6.4 (interpersonal) vs 3.7 (usual care), p=0.01]. Conclusion: Among a Latina population in a FQHC, telephonic promotora education was more effective than written notification alone or a mailed brochure on key goals of notification mandates. Adding a brochure does not appear to be more effective than sending a letter alone on key outcomes, but the interpersonal nature of promotora education may prompt attention to mailed information and provide an opportunity for questions. Citation Format: Jennifer L. Ridgeway, Sarah M. Jenkins, Deborah J. Rhodes, Bhavika K. Patel, Edna Ramos, Bijan Borah, Karthik Ghosh, Vera J. Suman, Aaron Norman, Davinder Singh, Celine M. Vachon. Evaluating educational interventions to increase breast density awareness among Latinas: A randomized clinical trial in a Federally Qualified Health Center [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-245.
Abstract PO-238: Breast density knowledge and awareness among Latinas in a low-resource setting: A comparison nationally-representative sample of Latinas
Abstract Objective: Breast density notification laws aim to increase women’s awareness and knowledge about breast density (BD). This study’s aim was to compare BD knowledge and awareness in two Hispanic populations: a safety-net clinic serving Latina population in Maricopa County, Arizona (AZ) and a national sample of Hispanic women participating in an online research panel. Materials/Methods: Women ages 40-74 were recruited at the AZ clinic from 2016-2019 at a screening mammography appointment as part of a larger clinical trial (AZ cohort). Surveys were completed in person (English or Spanish) at enrollment to assess awareness of BD, understanding of BD risk, and mammography history. The same questions were asked in a nationally representative online panel survey conducted in 2017. All data from the national survey were weighted to adjust for probability of selection into the panel and post-stratified to match known U.S. Hispanic population distributions (NS cohort). Univariate comparisons between the clinic and the national panel were performed using Rao-Scott chi-square tests. Associations with awareness and correct knowledge were examined with multivariable logistic regression. All summaries and analyses are weighted, and were performed with SAS version 9.4 SURVEY procedures (SAS Institute Inc., Cary, NC). Results: The analysis included 1332 Hispanic women from the AZ clinic and 152 Hispanic women who completed the national survey. The AZ cohort was younger (mean age: 48.5 vs 52.8), had less education (less than high school: 68.7% vs 34.8% less than high school), more likely to prefer Spanish (92.3% vs 53.1%) and less likely to have had a prior mammogram as compared NS cohort (82.8% vs 90.4%) (all p≤ 0.03). NS cohort was more likely to have awareness of BD (32.6% vs 20.7%); correct understanding of the masking effect of BD, (67.8% vs 37.0%,) and breast cancer risk (72.2% vs 32.6%,), compared to the AZ cohort (all p < 0.004). When adjusted for differences in education, age, language, and screening mammography history, BD awareness was similar between the two cohorts (adjusted odds ratio [ORadj] 0.95, p=0.83). Awareness was positively associated with more education, previous mammogram history, and English language. However, differences in BD knowledge remained (ORadj=2.8 [p=0.03] and 7.2 [P<0.001] for knowledge of masking and risk, respectively). Conclusions: There were significant differences in BD awareness and knowledge between a nationally-representative sample of Latinas and Latinas in a low-resource setting. The differences in BD awareness, but not knowledge, could be explained by education, screening history and preferred language. These findings suggest that a one-size-fits-all approach to raising BD awareness and knowledge will not work. To ensure equitable dissemination of health care to Latina women undergoing screening mammography, future work should be aimed at developing effective tools and resources for educating Spanish-speaking women about BD and risk-based screening. Citation Format: Jillian Leaver, Bhavika K. Patel, Jennifer L. Ridgeway, Sarah Jenkins, Vera Suman, Deborah J. Rhodes, Aaron Norman, Karthik Ghosh, Bijan Borah, Carrie Hruska, Edna Ramos, Davinder Singh, Matt Jewett, Carmen Radecki-Breitkof, Celine Vachon. Breast density knowledge and awareness among Latinas in a low-resource setting: A comparison nationally-representative sample of Latinas [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-238.
COVID-19–Associated Nonocclusive Fibrin Microthrombi in the Heart
Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its resultant clinical presentation, coronavirus disease 2019 (COVID-19), is an emergent cause of mortality worldwide. Cardiac complications secondary to this infection are common; however, the underlying mechanisms of such remain unclear. A detailed cardiac evaluation of a series of individuals with COVID-19 undergoing postmortem evaluation is provided, with 4 aims: (1) describe the pathological spectrum of the myocardium; (2) compare with an alternate viral illness; (3) investigate angiotensin-converting enzyme 2 expression; and (4) provide the first description of the cardiac findings in patients with cleared infection. Methods: Study cases were identified from institutional files and included COVID-19 (n=15: 12 active, 3 cleared), influenza A/B (n=6), and nonvirally mediated deaths (n=6). Salient information was abstracted from the medical record. Light microscopic findings were recorded. An angiotensin-converting enzyme 2 immunohistochemical H-score was compared across cases. Viral detection encompassed SARS-CoV-2 immunohistochemistry, ultrastructural examination, and droplet digital polymerase chain reaction. Results: Male sex was more common in the COVID-19 group ( P =0.05). Nonocclusive fibrin microthrombi (without ischemic injury) were identified in 16 cases (12 COVID-19, 2 influenza, and 2 controls) and were more common in the active COVID-19 cohort ( P =0.006). Four active COVID-19 cases showed focal myocarditis, whereas 1 case of cleared COVID-19 showed extensive disease. Arteriolar angiotensin-converting enzyme 2 endothelial expression was lower in COVID-19 cases than in controls ( P =0.004). Angiotensin-converting enzyme 2 myocardial expression did not differ by disease category, sex, age, or number of patient comorbidities ( P =0.69, P =1.00, P =0.46, P =0.65, respectively). SARS-CoV-2 immunohistochemistry showed nonspecific staining, whereas ultrastructural examination and droplet digital polymerase chain reaction were negative for viral presence. Four patients (26.7%) with COVID-19 had underlying cardiac amyloidosis. Cases with cleared infection had variable presentations. Conclusions: This detailed histopathologic, immunohistochemical, ultrastructural, and molecular cardiac series showed no definitive evidence of direct myocardial infection. COVID-19 cases frequently have cardiac fibrin microthrombi, without universal acute ischemic injury. Moreover, myocarditis is present in 33.3% of patients with active and cleared COVID-19 but is usually limited in extent. Histological features of resolved infection are variable. Cardiac amyloidosis may be an additional risk factor for severe disease.
Abstract C088: Assessing vitamin D and mammographic breast density in a population of Alaskan Native women
Abstract Background: Several studies have suggested that vitamin D may have antiproliferative and anticarcinogenic properties and a protective effect against breast cancer. Alaskan Natives have demonstrated high rates of vitamin D deficiency, particularly in young individuals. Hence, high breast density has been associated with increased breast cancer risk. Therefore, we examined the association between serum vitamin D levels and mammographic breast density in a population of Alaskan Native women. Methods: Patients seen in the Mayo Clinic-Alaska Native Medical Center telemedicine program from December 2014 to December 2017 were offered to enroll in the study. Consent was obtained by a study coordinator in Minnesota using a telemedicine platform. Participants were asked to complete the Breast Cancer Risk Questionnaire, which includes questions on hormonal, lifestyle factors and family history. Serum vitamin D levels (25-hydroxyvitamin D2 and D3) were obtained and later correlated with mammographic breast density (percent density). Data were summarized with frequencies and percentages or medians and interquartile ranges (IQR), as appropriate. Pearson correlation was used to estimate the association between breast density and vitamin D levels. Results: 33 women were included; median age was 53 years (IQR 45-58), 70% self-identified as American Indian/Alaskan Native, 12% as White, 6% as Native Hawaiian/Pacific islander and 12% as other. Median BMI was 31 kg/m² (IQR 26.4-34.3), menarche was at age 12 or older for 23 (70%) of the participants and 20 women were postmenopausal at the time enrollment. 10 participants had a hysterectomy, of whom 60% also had oophorectomy. 76% reported history of hormonal birth control use and 23% postmenopausal hormonal supplementation. Median number of pregnancies was 3 (IQR 2-5), and 20 women reported breastfeeding. Fifteen women were current or former smokers (>100 cigarettes) and 19 reported none or low alcohol consumption. Median serum vitamin D level was 39 ng/mL (IQR 30-52) and 9 (27%) women had low vitamin D levels. In regard to breast density, median percentage (average of images) was 15% (IQR 7.5-24.9) with a median dense area of 21.8 cm² (IQR 16.4-34.2). Median time from blood draw to mammogram was 110 days (IQR 41-172) and 19 (58%) participants were taking vitamin D supplementation at the time of study enrollment; doses ranged from 400 to 50,000 units. No correlation was identified between breast density and serum vitamin D levels (correlation=0.02). Conclusion: In this cohort, no association between serum vitamin D levels and breast density was observed. More than half of the participants were on vitamin D supplementation and this could have obscured our observations. Larger studies controlling for vitamin supplementation are needed, as this association could potentially impact breast cancer rates in populations at risk for vitamin D deficiency. Citation Format: Narjust Duma, Ivana Croghan, Sarah Jenkins, Loni Neal, Karthik Ghosh, Sandhya Pruthi. Assessing vitamin D and mammographic breast density in a population of Alaskan Native women [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C088.
Effect of Pause Procedures on Participant Reflection and Commitment-to-Change in Continuing Medical Education
Abstract Pleomorphic xanthoastrocytoma (PXA) is a rare astrocytoma predominantly affecting children and young adults. We performed comprehensive genomic characterization on a cohort of 67 patients with histologically defined PXA (n = 53, 79%) or anaplastic PXA (A‐PXA, n = 14, 21%), including copy number analysis (ThermoFisher Oncoscan, n = 67), methylation profiling (Illumina EPIC array, n = 43) and targeted next generation sequencing (n = 32). The most frequent alterations were CDKN2A/B deletion (n = 63; 94%) and BRAF p.V600E (n = 51, 76.1%). In 7 BRAF p.V600 wild‐type cases, alternative driver alterations were identified involving BRAF , RAF1 and NF1 . Downstream phosphorylation of ERK kinase was uniformly present. Additional pathogenic alterations were rare, with TERT , ATRX and TP53 mutations identified in a small number of tumors, predominantly A‐PXA. Methylation‐based classification of 46 cases utilizing a comprehensive reference tumor allowed assignment to the PXA methylation class in 40 cases. A minority grouped with the methylation classes of ganglioglioma or pilocytic astrocytoma (n = 2), anaplastic pilocytic astrocytoma (n = 2) or control tissues (n = 2). In 9 cases, tissue was available from matched primary and recurrent tumors, including 8 with anaplastic transformation. At recurrence, two tumors acquired TERT promoter mutations and the majority demonstrated additional non‐recurrent copy number alterations. Methylation class was preserved at recurrence. For 62 patients (92.5%), clinical follow‐up data were available (median follow‐up, 5.4 years). Overall survival was significantly different between PXA and A‐PXA (5‐year OS 80.8% vs. 47.6%; P = 0.0009) but not progression‐free survival (5‐year PFS 59.9% vs. 39.8%; P = 0.05). WHO grade remained a strong predictor of overall survival when limited to 38 cases defined as PXA by methylation‐based classification. Our data confirm the importance of WHO grading in histologically and epigenetically defined PXA. Methylation‐based classification may be helpful in cases with ambiguous morphology, but is largely confirmatory in PXA with well‐defined morphology.
Correlation of novel ALKATI with ALK immunohistochemistry and clinical outcomes in metastatic melanoma
AimsRecently, a novel isoform of anaplastic lymphoma kinase, with alternative transcription initiation (ALKATI), has been described in melanoma and is susceptible to targeted ALK‐inhibitor therapy. Clinical outcomes of patients with ALKATI mutated melanoma as well as correlation with immunohistochemical (IHC) methods have not yet been described.Methods and resultsClinicopathological characteristics were abstracted for 324 patients with metastatic melanoma (MM). IHC, fluorescence in‐situ hybridisation and RNA‐based digital molecular analysis assays were performed on archival tissue from 173 stage III and 192 stage IV tumours. ALKATI was identified in 12.7 and 4.8% stage III and IV tumours, respectively. Discrete presentations of the ALKATI are seen: isolated ALKATI (n = 20) and mixed ALKATI (combined ALKATI and ALKWT; n = 7). Isolated ALKWT expression (n = 4) was seen with no ALK fusions. Stage III patients showed improved survival with ALKATI expression compared to those with ALKWT or no expression [5‐year survival 80, 95% confidence interval (CI) = 57–100% versus 43%, 95% CI = 34–55%, P = 0.013]. Clinicopathological characteristics were not statistically significant. Strong diffuse cytoplasmic staining of ALK IHC (n = 12) has a sensitivity of 52.2%, specificity 100%, PPV of 100% and NPV of 92.5% of detecting isolated ALKATI.ConclusionPresence of ALKATI is a good prognostic indicator in MM. ALK IHC and digital molecular analysis can be incorporated into MM evaluation to identify patients with ALKATI for targeted therapy.
Salvage Therapy With Multikinase Inhibitors and Immunotherapy in Advanced Adrenal Cortical Carcinoma
Abstract Background Median overall survival is 12 to 15 months in patients with metastatic adrenal cortical carcinoma (ACC). Etoposide, doxorubicin, and cisplatin with or without the adrenolytic agent mitotane is considered the best first-line approach in this context, but has limited activity and no curative potential; additional salvage therapeutic options are needed. Methods Fifteen total patients with recurrent/metastatic ACC were treated with single-agent multikinase inhibitors (MKI) (n = 8), single-agent PD-1 inhibition (n = 8), or cytotoxic chemotherapy plus PD-1 inhibition (n = 4) at our institution as later-line systemic therapies in efforts to palliate disease and attempt to achieve a therapeutic response when not otherwise possible using standard approaches. Results Two of 8 patients (25%) treated with single-agent MKI achieved a partial response (PR), including 1 PR lasting 23.5 months. Another 3 patients (38%) had stable disease (SD); median progression-free survival (PFS) with single-agent MKI was 6.4 months (95% confidence interval [CI] 0.8—not reached). On the other hand, 2 of 12 patients (17%) treated with PD-1 inhibitors (either alone or in combination with cytotoxic chemotherapy) attained SD or better, with 1 patient (8%) achieving a PR; median PFS was 1.4 months (95% CI 0.6-2.7). Conclusions Our single-institution experience suggests that select ACC patients respond to late-line MKI or checkpoint inhibition despite resistance to cytotoxic agents. These treatments may be attractive to ACC patients with limited other therapeutic options. The use of MKI and immunotherapy in ACC warrants prospective investigation emphasizing parallel correlative studies to identify biomarkers that predict for response.