Somatic Mutations in LRRK2 Identify a Subset of Invasive Mammary Carcinomas Associated with High Mutation Burden.

Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are the most common cause of familial Parkinson disease. Although LRRK2-related Parkinson disease patients have a heightened risk of certain nonskin cancers, including breast cancer, it is unknown whether LRRK2 somatic mutations occur and are associated with breast cancer. The objective of this study was to evaluate the occurrence of LRRK2 somatic mutations in breast cancer and the clinicopathologic features associated with LRRK2-mutated tumors. Using The Cancer Genome Atlas Breast Cancer Project, somatic LRRK2 DNA sequence information was obtained for 93 cases, of which 17 cases (18%) with 18 mutations were identified. LRRK2-mutated mammary carcinomas are enriched with stop-gain, truncating mutations predicted to result in loss of function; missense mutations frequently targeted the GTPase and kinase domains. Tumors displayed predominantly high-grade morphology with abundant granular eosinophilic cytoplasm, resembling mitochondria-rich apocrine-like carcinomas. Exploration of the genomic landscape of LRRK2-mutated carcinomas yielded frequent TP53 deactivation and a remarkably high tumor mutation burden. More important, breast cancers with LRRK2 mutations are associated with reduced patient survival compared with The Cancer Genome Atlas Breast Cancer Project cohort. These findings, for the first time, show that somatic LRRK2 mutations occur frequently in breast cancer, and the high mutation burden seen in this subset of tumors suggests that LRRK2 mutations may herald benefit from immune checkpoint inhibition.

Do Histopathology and Clinical Outcomes of Breast Atypia Vary by Race/Ethnicity?

BACKGROUND: The clinical behavior of breast cancer varies by racial and ethnic makeup (REM), but the impact of REM on the clinical outcomes of breast atypia remains understudied. We examined the impact of REM on risk of underlying or subsequent carcinoma following a diagnosis of breast atypia. METHODS: In this retrospective, single-institution chart review, adult women diagnosed with breast atypia (atypical ductal hyperplasia, atypical lobular hyperplasia, or lobular carcinoma in situ) were stratified by REM. Regression modeling was used to estimate risk of underlying or subsequent carcinoma. RESULTS: We identified 539 patients with breast atypia, including 15 Hispanic (2.8%), 127 non-Hispanic black (23.6%), and 397 non-Hispanic white women (73.7%). Diagnoses included 75.1% atypical ductal hyperplasia (n = 405), 4.6% atypical lobular hyperplasia (n = 25), and 20.2% lobular carcinoma in situ (n = 109). Rates for each type of atypia did not vary by REM (P = 0.33). Of those with atypia on needle biopsy, the rate of underlying carcinoma at excision was 17.3%. After adjustment, REM was not associated with greater risk for carcinoma at excision (P = 0.41). Of those with atypia alone on surgical excision, the rate of a subsequent carcinoma diagnosis was 15.4% (median follow-up 49 mo). REM was not associated with a long-term risk for carcinoma (P = 0.37) or differences in time to subsequent carcinoma (log-rank P = 0.52). Chemoprevention uptake rates were low (10.6%), especially among Hispanic (0%) and non-Hispanic black (3.8%) patients (P = 0.01). CONCLUSIONS: Among patients with atypia, REM does not appear to influence type of histologic atypia, risk for carcinoma, or clinical outcome, despite differences in chemoprevention rates.

The Influence of Age on the Histopathology and Prognosis of Atypical Breast Lesions.

BACKGROUND: Although several prognostic variables and risk factors for breast cancer are age-related, the association between age and risk of cancer with breast atypia is controversial. This study aimed to compare the type of breast atypia and risk of underlying or subsequent breast cancer by age. METHODS: Adult women with breast atypia (atypical ductal hyperplasia, atypical lobular hyperplasia, and lobular carcinoma in situ) at a single institution from 2008 to 2017 were stratified by age at initial diagnosis: <50 y, 50-70 y, and >70 y. Regression modeling was used to estimate the association of age with risk of underlying carcinoma or subsequent cancer diagnosis. RESULTS: A total of 530 patients with atypia were identified: 31.1% < 50 y (n = 165), 58.1% 50-70 y (n = 308), and 10.8% > 70 y (n = 57). The proportion of women with atypical ductal hyperplasia steadily increased with age, compared with atypical lobular proliferations (P = 0.04). Of those with atypia on needle biopsy, the overall rate of underlying carcinoma was 17.5%. After adjustment, older age was associated with a greater risk of underlying carcinoma (odds ratio: 1.028, 95% confidence interval: 1.003-1.053; P = 0.03). Of those confirmed to have atypia on surgical excision, the overall rate of a subsequent cancer diagnosis was 15.7%. Age was not associated with a long-term risk for breast cancer (P = 0.48) or the time to a subsequent diagnosis of carcinoma (log-rank P = 0.41). CONCLUSIONS: Although atypia diagnosed on needle biopsy may be sufficient to warrant surgical excision, older women may be at a greater risk for an underlying carcinoma, albeit the long-term risk for malignancy associated with atypia does not appear to be affected by age.

Far Upstream Element Binding Protein Plays a Crucial Role in Embryonic Development, Hematopoiesis, and Stabilizing Myc Expression Levels.

The transcription factor far upstream element binding protein (FBP) binds and activates the MYC promoter when far upstream element is via TFIIH helicase activity early in the transcription cycle. The fundamental biology and pathology of FBP are complex. In some tumors FBP seems pro-oncogenic, whereas in others it is a tumor suppressor. We generated an FBP knockout (Fubp1(-/-)) mouse to study FBP deficiency. FBP is embryo lethal from embryonic day 10.5 to birth. A spectrum of pathology is associated with FBP loss; besides cerebral hyperplasia and pulmonary hypoplasia, pale livers, hypoplastic spleen, thymus, and bone marrow, cardiac hypertrophy, placental distress, and small size were all indicative of anemia. Immunophenotyping of hematopoietic cells in wild-type versus knockout livers revealed irregular trilineage anemia, with deficits in colony formation. Despite normal numbers of hematopoietic stem cells, transplantation of Fubp1(-/-) hematopoietic stem cells into irradiated mice entirely failed to reconstitute hematopoiesis. In competitive transplantation assays against wild-type donor bone marrow, Fubp1(-/-) hematopoietic stem cells functioned only sporadically at a low level. Although cultures of wild-type mouse embryo fibroblasts set Myc levels precisely, Myc levels of mouse varied wildly between fibroblasts harvested from different Fubp1(-/-) embryos, suggesting that FBP contributes to Myc set point fixation. FBP helps to hold multiple physiologic processes to close tolerances, at least in part by constraining Myc expression.

ALK-negative anaplastic large cell lymphoma is a genetically heterogeneous disease with widely disparate clinical outcomes.

Anaplastic lymphoma kinase (ALK)-negative anaplastic large cell lymphoma (ALCL) is a CD30-positive T-cell non-Hodgkin lymphoma that morphologically resembles ALK-positive ALCL but lacks chromosomal rearrangements of the ALK gene. The genetic and clinical heterogeneity of ALK-negative ALCL has not been delineated. We performed immunohistochemistry and fluorescence in situ hybridization on 73 ALK-negative ALCLs and 32 ALK-positive ALCLs and evaluated the associations among pathology, genetics, and clinical outcome. Chromosomal rearrangements of DUSP22 and TP63 were identified in 30% and 8% of ALK-negative ALCLs, respectively. These rearrangements were mutually exclusive and were absent in ALK-positive ALCLs. Five-year overall survival rates were 85% for ALK-positive ALCLs, 90% for DUSP22-rearranged ALCLs, 17% for TP63-rearranged ALCLs, and 42% for cases lacking all 3 genetic markers (P < .0001). Hazard ratios for death in these 4 groups after adjusting for International Prognostic Index and age were 1.0 (reference group), 0.58, 8.63, and 4.16, respectively (P = 7.10 × 10(-5)). These results were similar when restricted to patients receiving anthracycline-based chemotherapy, as well as to patients not receiving stem cell transplantation. Thus, ALK-negative ALCL is a genetically heterogeneous disease with widely disparate outcomes following standard therapy. DUSP22 and TP63 rearrangements may serve as predictive biomarkers to help guide patient management.

BRAF V600E expression in Langerhans cell histiocytosis: clinical and immunohistochemical study on 25 pulmonary and 54 extrapulmonary cases.

Pulmonary Langerhans cell histiocytosis (PLCH) has been postulated to be a smoking-related non-neoplastic condition, distinct from extrapulmonary LCH, which is generally regarded as a clonal, neoplastic process. Recent genomic studies demonstrated BRAF V600E mutation in 38% to 57% of extrapulmonary LCH cases by polymerase chain reaction. We evaluated the BRAF V600E expression by immunohistochemistry (IHC) in PLCH and extrapulmonary LCH cases. We compared BRAF V600E expression in PLCH and extrapulmonary LCH with BRAF V600E mutation status. Our study included 25 PLCH (age 42.0±11.4, 10 men) and 54 extrapulmonary LCH (age 27.6±21.8, 37 men) cases. Seven of 25 (28%) PLCH cases were positive for BRAF V600E expression (age 45.3±8.1, 2 men); 6 of 7 cases with BRAF V600E expression were also positive by mutation analysis. Nineteen of 54 (35%) extrapulmonary LCH cases were positive for BRAF V600E expression (age 27.6±22.1, 13 men) as well as mutation. Two IHC-negative cases, however, were positive by mutation analysis. All PLCH cases were current or former smokers, whereas 28 of 54 extrapulmonary LCH patients were never-smokers. The cumulative tobacco exposure at the time of diagnosis was significantly higher in BRAF V600E-positive than in BRAF V600E-negative PLCH patients (mean pack-years 48.3 vs. 23.7, 2-tailed t test P=0.01). BRAF V600E expression by IHC correlated with BRAF V600E mutational status in most of the cases in our study except in 3 patients (4.4%). In conclusion, a subset of PLCH with BRAF V600E expression may be a clonal proliferative process, in which cigarette smoking might play a role.

Invasive aspergillosis due to Neosartorya udagawae.

BACKGROUND: Invasive aspergillosis (IA) is most commonly caused by the morphospecies Aspergillus fumigatus. However, genetic-based methods indicate that organisms phenotypically identified as A. fumigatus actually constitute a mold complex, designated Aspergillus section fumigati subgenus fumigati. METHODS: Multilocus sequencing and analysis was performed on fungi identified as A. fumigatus from the clinical culture collection maintained at the National Institutes of Health from 2000 through 2008, with a focus on the internal transcribed spacer 1 and 2 regions of ribosomal DNA (rDNA), beta-tubulin, and rodlet A genes. We reviewed the medical records, radiology, and histopathology of corresponding patients. To confirm identification of Neosartorya udagawae isolates, mating studies were performed with reference strains. Antifungal susceptibility testing was performed by broth microdilution and read at 48 hours. RESULTS: Thirty-six cases of infection attributed to A. fumigatus were identified; 4 were caused by N. udagawae (3 in patients with chronic granulomatous disease and 1 in a patient with myelodysplastic syndrome). Disease due to N. udagawae was chronic, with a median duration of 35 weeks, compared with a median duration of 5.5 weeks for patients with chronic granulomatous disease who had infection due to A. fumigatus sensu stricto (P < .05 , Mann-Whitney U test). Infection spread across anatomical planes in a contiguous manner and was refractory to standard therapy. Two of the 4 patients died. N. udagawae demonstrated relatively higher minimum inhibitory concentrations to various agents, compared with those demonstrated by contemporary A. fumigatus sensu stricto isolates. CONCLUSIONS: To our knowledge, this is the first report documenting infection due to N. udagawae. Clinical manifestations were distinct from those of typical IA. Fumigati-mimetics with inherent potential for antifungal resistance are agents of IA. Genetic identification of molds should be considered for unusual or refractory IA.

Evidence-based medicine as a tool for clinical decision-making in Puerto Rico.

Evidence-based medicine (EBM) is defined as "the process of systematically finding, appraising and using contemporaneous research findings as the basis for clinical decisions". Although EBM has been extensively described across the Americas and Europe, no study has looked at the practice of EBM in Puerto Rico. A cross-sectional analysis based on a 23-item questionnaire was employed. We showed that there is a high use (88%) and familiarity (93%) with EBM, and that physicians keep a positive attitude towards EBM (80%) in Puerto Rico. There is an over-representation of academicians (58.9% vs. 34.6%, p = 0.02) and an under-representation of solo office practitioners (10.5% vs. 26.9%, p = 0.03) among EBM users. Additionally, patient workload (48%), time constraints (36%), and limited access to the Internet (28%) were the most frequently cited obstacles to the practice of EBM in Puerto Rico. Taken together, these results help create a cross-sectional profile of EBM practice among Puerto Rican physicians.

Dial 9-1-1 for DNA damage: the Rad9-Hus1-Rad1 (9-1-1) clamp complex.

Genotoxic stress activates checkpoint signaling pathways that block cell cycle progression, trigger apoptosis, and regulate DNA repair. Studies in yeast and humans have shown that Rad9, Hus1, Rad1, and Rad17 play key roles in checkpoint activation. Three of these proteins-Rad9, Hus1, and Rad1-interact in a heterotrimeric complex (dubbed the 9-1-1 complex), which resembles a PCNA-like sliding clamp, whereas Rad17 is part of a clamp-loading complex that is related to the PCNA clamp loader, replication factor-C (RFC). In response to genotoxic damage, the 9-1-1 complex is loaded around DNA by the Rad17-containing clamp loader. The DNA-bound 9-1-1 complex then facilitates ATR-mediated phosphorylation and activation of Chk1, a protein kinase that regulates S-phase progression, G2/M arrest, and replication fork stabilization. In addition to its role in checkpoint activation, accumulating evidence suggests that the 9-1-1 complex also participates in DNA repair. Taken together, these findings suggest that the 9-1-1 clamp is a multifunctional complex that is loaded onto DNA at sites of damage, where it coordinates checkpoint activation and DNA repair.

Cut5 is required for the binding of Atr and DNA polymerase alpha to genotoxin-damaged chromatin.

DNA damage triggers the assembly of checkpoint signaling proteins on chromatin that activate the Chk1 signaling pathway and block S-phase progression. Here we show that genotoxin-induced Chk1 activation requires Cut5 (Mus101/TopBP1) in a process that is independent of the role of Cut5 in DNA replication. Analysis of the role of Cut5 in checkpoint activation revealed that it associated with chromatin following DNA damage in a process that required RPA. Additionally, Cut5 was required for the recruitment of Atr, DNA polymerase alpha, and Rad1 but not RPA to chromatin following DNA damage. Taken together, these results demonstrate that Cut5 plays an integral role in the recruitment and assembly of the Chk1 signaling cascade components following DNA damage.