P16 and HPV status in head and neck sarcomas and sarcomatoid carcinomas.

Human papillomavirus (HPV)-positive oropharyngeal carcinoma is a distinct type of head and neck carcinoma with improved prognosis. p16 immunostaining is often used as a surrogate marker for HPV infection in this particular setting. The aim of this study is to estimate the prevalence of p16 staining and HPV infection in head and neck sarcomatoid carcinomas as well as head and neck sarcomas. 21 sarcomatoid carcinomas and 28 head and neck sarcomas were tested for p16 positivity using immunohistochemical staining, and for high-risk HPV infection using In situ hybridization (ISH). 24 % of sarcomatoid carcinomas and 21 % of sarcomas were positive for p16 staining. All 49 cases were negative for HPV ISH. The results confirm that p16 staining is not specific and may not be associated with HPV infection in non-oropharyngeal head and neck sites. They also indicate that non-oropharyngeal head and neck sarcomatoid carcinomas are not likely to be HPV related.

Local control outcomes for combination of stereotactic radiosurgery and immunotherapy for non-small cell lung cancer brain metastases.

BACKGROUND: Previous series have demonstrated CNS activity for immune checkpoint inhibitors, yet no prior data exists regarding whether this activity can improve outcomes of stereotactic radiosurgery. METHODS: In this single institution retrospective series, the clinical outcomes of 80 consecutive lung cancer patients treated with concurrent immune checkpoint inhibitors and stereotactic radiosurgery were compared to 235 in the historical control cohort in which patients were treated prior to immune checkpoint inhibition being standard upfront therapy. Overall survival was estimated using the Kaplan Meier method. Cumulative incidence of local progression was estimated using a competing risk model. RESULTS: Median overall survival time was improved in patients receiving upfront immunotherapy compared to the historical control group (40 months vs 8 months, p < 0.001). Factors affected overall survival include concurrent immunotherapy (HR 0.23, p < 0.0001) and KPS (HR 0.97, p = 0.0001). Cumulative incidence of local failure in the historical control group was 10% at 1 year, compared to 1.1% at 1 year in the concurrent immunotherapy group (p = 0.025). Factors affected local control included use of concurrent immunotherapy (HR 0.09, p = 0.012), and lowest margin dose delivered to a metastasis (HR 0.8, p = 0.0018). CONCLUSION: Local control and overall survival were both improved in patients receiving concurrent immune checkpoint inhibitors with radiosurgery compared to historical controls. While these data remain to be validated, they suggest that brain metastasis patients may benefit from concurrent use of immunotherapy with SRS.

Sudden Unexpected Death in a Child From Acute Myeloid Leukemia.

ABSTRACT: Acute myeloid leukemia can rarely cause sudden, unexpected death in children. Presentation may be non-specific and death may occur in children with no prior medical history. Herein we present the case of a previously healthy 2-year and 2 month-old White girl, who on autopsy, was found to have acute myeloid leukemia with KMT2A rearrangement extensively involving all major thoracic and abdominal organs. This case is presented to the forensic community to discuss the presentation and findings in sudden death caused by acute leukemia. The case highlights when acute leukemia should enter the differential as a potential cause of death, as well as potential resources available in the postmortem workup of acute leukemias.

Prognostic Molecular Classification of Appendiceal Mucinous Neoplasms Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy.

BACKGROUND: Appendiceal mucinous neoplasm (AMN) with peritoneal metastasis is a rare but deadly disease with few prognostic or therapy-predictive biomarkers to guide treatment decisions. Here, we investigated the prognostic and biological attributes of gene expression-based AMN molecular subtypes. METHODS: AMN specimens (n = 138) derived from a population-based subseries of patients treated at our institution with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) between 05/2000 and 05/2013 were analyzed for gene expression using a custom-designed NanoString 148-gene panel. Signed non-negative matrix factorization (sNMF) was used to define a gene signature capable of delineating robustly-classified AMN molecular subtypes. The sNMF class assignments were evaluated by topology learning, reverse-graph embedding and cross-cohort performance analysis. RESULTS: Three molecular subtypes of AMN were discerned by the expression patterns of 17 genes with roles in cancer progression or anti-tumor immunity. Tumor subtype assignments were confirmed by topology learning. AMN subtypes were termed immune-enriched (IE), oncogene-enriched (OE) and mixed (M) as evidenced by their gene expression patterns, and exhibited significantly different post-treatment survival outcomes. Genes with specialized immune functions, including markers of T-cells, natural killer cells, B-cells, and cytolytic activity showed increased expression in the low-risk IE subtype, while genes implicated in the promotion of cancer growth and progression were more highly expressed in the high-risk OE subtype. In multivariate analysis, the subtypes demonstrated independent prediction power for post-treatment survival. CONCLUSIONS: Our findings suggest a greater role for the immune system in AMN than previously recognized. AMN subtypes may have clinical utility for predicting CRS/HIPEC treatment outcomes.

Clinical Implications of Genetic Signatures in Appendiceal Cancer Patients with Incomplete Cytoreduction/HIPEC.

INTRODUCTION: Clinical decision-making is challenging in patients who undergo cytoreductive surgery/hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) when complete cytoreduction is not feasible. Nevertheless, some patients still benefit with long-term survival after incomplete CRS/HIPEC. There is currently no robust predictive tool that can assist clinical decision-making in this setting. METHODS: We quantified gene expression of 79 appendiceal mucinous neoplasms (AMN) from patients with incomplete CRS/HIPEC (R2 resection) using a custom NanoString gene panel. Using our previously defined, prognostic subtype classification algorithm based on signed nonnegative matrix factorization, we classified AMN cases into three molecular subtypes termed: immune enriched (IE), mixed (M), and oncogene enriched (OE). Kaplan-Meier and Cox proportional hazards analyses were used to associate subtypes and individual genes with overall survival (OS). RESULTS: Median overall survival (OS) was 7.7 years for IE, 3.6 years for M, and 1.4 years for OE. Compared with IE, OE was associated with significantly lower survival [hazard ratio (HR) 3.64, 95% confidence interval (CI) 1.63-8.13; p = 0.0017]. The differences were observed in both low-grade and high-grade tumors. While only two genes were identified to be associated with OS in low-grade tumors, multiple genes were identified to be associated with OS in high-grade tumors, particularly genes with functions in cell cycle/proliferation, mucin production, immune pathways, and cell adhesion/migration. CONCLUSION: Genetic signatures have prognostic value in patients with incomplete cytoreduction and provide valuable information to assist clinical and operative decision-making. Unraveling genetic alterations and involved pathways can direct efforts to design novel therapeutic modalities.

Rapid BRAF Mutation Testing in Pigmented Melanomas.

BRAF mutations are present in ∼40%-60% of melanomas, and targeted therapy in advanced-stage melanoma is associated with improvement in overall and progression-free survival. Accordingly, BRAF mutation determination is standard-of-care in metastatic melanoma, and a rapid, accurate assay is desirable. Melanin can present unique challenges due to inhibition of the polymerase chain reaction. The novel cartridge-based Idylla platform offers rapid molecular oncology testing; however, a formal evaluation of the impact of melanin on testing heretofore has not been explored. In this study, we evaluated the performance of Idylla BRAF mutation detection in 23 melanomas including resections, small biopsies, and cytology cell blocks. Pathologists assigned each case a pigment score from 0 to 2 based on extent of melanin content. Samples with a pigment score of 2 were successfully resulted, thus demonstrating that high melanin content did not inhibit the assay. Sensitivity and specificity of BRAF mutation detection were 100% compared with reference laboratory testing. Tissue input requirements were low, with the Idylla successfully detecting a BRAF mutation in cell block material containing only ∼400 tumor cells. The assay was simple and quick to perform, with total hands-on time of 5-10 minutes and instrument time ∼90 minutes. In summary, the Idylla BRAF mutation assay provides rapid, robust testing for melanomas with high melanin content, including samples with limited material. The assay requires minimal technical expertise, making mutation status determination accessible in a range of clinical laboratory settings. The total assay time of <2 hours facilitates prompt results to guide patient care decisions.

Revisiting Bone Marrow Core Biopsy Adequacy Criteria in the Era of Extensive Ancillary Testing.

BACKGROUND: Bone marrow core biopsy is a routine component of comprehensive marrow evaluation, and adequacy criteria have been recommended. However, the effectiveness of these adequacy criteria for diagnostic bone marrow evaluation needs to be reassessed in the current era of extensive ancillary testing. We aimed to determine the impact of core biopsy length and intertrabecular area of evaluable bone marrow on overall adequacy for diagnostic marrow evaluation at our tertiary care institution. METHODS: Five hundred sequential cases of iliac crest bone marrow sampling were identified by retrospective re-view at our tertiary care institution. In this cohort, 470 core biopsies were obtained for histologic evaluation. Data including gross core biopsy length, number of intertrabecular 40x high power fields of evaluable marrow, and other pathologic/clinical parameters were compiled. RESULTS: The mean core biopsy length was 1.2 cm, and only 23% measured the recommended ≥ 1.5 cm. However, 96% of the core biopsies were interpretable and contributed to the comprehensive bone marrow evaluation. Notably, 100% of biopsies with ≥ 5.5 intertrabecular areas were contributory. Ancillary testing including immunophenotypic, cytogenetic, and/or molecular studies were performed in > 99% of cases. CONCLUSIONS: When histology was integrated with ancillary testing, the overall diagnosis was substantially limited in only 0.4% of cases and material deemed entirely insufficient in 0.4%. The number of intertrabecular 40x areas of evaluable marrow is a better predictor of adequacy than core biopsy length, and adequacy criteria should be revised in this era of extensive ancillary testing.

Favorable outcome of patients with lung adenocarcinoma harboring POLE mutations and expressing high PD-L1.

Mutations in polymerase ε (POLE) confer favorable prognosis and outcomes in various cancer types, but their role in non-small cell lung cancer (NSCLC) is unknown. Utilizing the data of 513 patients with adenocarcinoma (LUAD) and 497 patients with squamous cell carcinoma (LUSC) from The Cancer Genome Atlas (TCGA) cohort, we tested the prognostic value of POLE mutations and programmed cell death ligand 1 (PD-L1) expression in the two main subtypes of NSCLC. POLE mutation is a favorable biomarker for the improved overall survival (OS) of the LUSC patients (P = 0.033, 28 mutant vs. 469 wildtype patients), but not that of the LUAD patients (P = 0.12, 31 mutant vs. 482 wildtype patients). POLE-mutant LUAD patients with high expression of PD-L1 (Mut-High, n = 6) exhibited improved OS (P = 0.024) when compared to POLE-mutant patients with low PD-L1 expression (Mut-Low, n = 24) and other patients without POLE mutation (n = 476). This benefit was not due to the high content of the tumor infiltrating lymphocytes. Instead, the antitumor immune response was activated in Mut-High patients so that these patients were likely responding more effectively to immuno-oncology (IO) treatments; whereas genes involved with metabolic pathways were enriched in Mut-Low group, which may cause the decreased OS of these patients. Our study sheds light on the molecular basis of NSCLC and adds to our understanding of responses to chemotherapy and IO therapy.

Initial brain metastasis velocity: does the rate at which cancers first seed the brain affect outcomes?

PURPOSE/OBJECTIVE(S): Brain metastasis velocity (BMV) is a metric that describes the rate of development of new brain metastases (BM) after initial stereotactic radiosurgery (SRS). A limitation in the application of BMV is it cannot be applied until time of first BM failure after SRS. We developed initial BM velocity (iBMV), a new metric that accounts for the number of BM at first SRS and the time since initial cancer diagnosis. MATERIALS/METHODS: We reviewed patients with BM treated at our institution with upfront SRS without WBRT. iBMV was calculated as the number of BM at initial SRS divided by time (years) from initial cancer diagnosis to first SRS. We performed a linear regression to correlate BMV as a continuous variable and with low, intermediate, and high BMV risk groups. Kaplan-Meier estimation of OS was calculated from time of first SRS to death. iBMV was not calculated for patients who presented with BM at initial cancer diagnosis. RESULTS: 994 patients were treated with upfront SRS without WBRT between 2000 and 2017. Median OS was 8.5 mos. 595 (60%) patients developed BM after cancer diagnosis and median time to first SRS from time of initial diagnosis was 2.2 years. Median iBMV was 0.79 BM/year. iBMV correlated with BMV (ß = 1.57 p = 0.021) and independently predicted for mortality [Cox proportional hazard ratio (HR) 1.11, p = 0.036] after accounting for histology, number of initial brain metastases (HR 1.03, p = 0.32), time from cancer diagnosis to SRS (HR 0.98, p = 0.157) in a multivariate model. CONCLUSION: iBMV correlates with BMV and OS. With further validation, iBMV could serve as a metric to risk stratify patients for WBRT or SRS at time of first BM presentation.

Side scatter ratio of the CD105-positive and CD105-negative red blood cell fractions is useful for the detection of low-grade myelodysplastic neoplasms by flow cytometry.

OBJECTIVES: We assessed the utility of red blood cell (RBC) CD105 and side scatter (SSC) parameters by flow cytometry for the detection of low-grade myelodysplastic neoplasms (MDS) in bone marrow specimens. METHODS: Ten RBC parameters incorporating CD105 or SSC combined with the Meyerson-Alayed scoring system (MASS) metrics were retrospectively evaluated by flow cytometry for utility in detecting low-grade MDS (n = 56) compared with cytopenic controls (n = 86). RESULTS: Myelodysplastic neoplasms were associated with 7 of the RBC parameters in univariate analysis. Multivariate analysis using cutoff values based on optimal and 95% specificity levels of the RBC metrics and the MASS parameters revealed the SSC ratio of CD105-positive and CD105-negative RBC fractions (CD105+/- SSC); the percentage and coefficient of variation of the CD105-positive fraction of RBCs (CD105%, CD105+CV) emerged as significant RBC variables. Two simple scoring schemes using these RBC values along with MASS parameters were identified: 1 using CD105+/- SSC, CD105%, and CD105+CV combined with the percentage of CD177-positive granulocytes (CD177%), myeloblast percentage (CD34%), and granulocyte SSC (GranSSC), and the other incorporating CD105+/- SSC, CD105+CV, CD177%, CD34%, GranSSC, and B-cell progenitor percentage. Both demonstrated a sensitivity of approximately 80%, with a specificity of roughly 90% for the detection of MDS compared with cytopenic controls. CONCLUSIONS: The red blood cell parameter, CD105+/- SSC, appears to be beneficial in the evaluation of low-grade MDS by flow cytometry.

Comparison of the Biofire FilmArray RP, Genmark eSensor RVP, Luminex xTAG RVPv1, and Luminex xTAG RVP fast multiplex assays for detection of respiratory viruses.

There are several U.S. FDA-cleared molecular respiratory virus panels available today, each with advantages and disadvantages. This study compares four multiplex panels, the BioFire Diagnostics FilmArray RP (respiratory panel), the GenMark Dx eSensor RVP (respiratory viral panel), the Luminex xTAG RVPv1, and the Luminex xTAG RVP fast. Three hundred specimens (200 retrospective and 100 consecutive) were tested using all four platforms to determine performance characteristics. The overall sensitivity and specificity, respectively, and 95% confidence interval (CI; in parentheses) for each panel were as follows: FilmArray RP, 84.5% (79.2, 88.6) and 100% (96.2, 100); eSensor RVP, 98.3% (95.5, 99.5) and 99.2% (95.4, 100); xTAG RVPv1, 92.7% (88.5, 95.4) and 99.8% (96.0, 100); and xTAG RVP fast, 84.4% (78.5, 88.9) and 99.9% (96.1, 100). The sensitivity of each assay fluctuated by viral target, with the greatest discrepancies noted for adenovirus and influenza virus B detection. Hands-on time and time to result were recorded and ease of use was assessed to generate a complete profile of each assay.

Patients with diffuse large B-cell lymphoma of germinal center origin with BCL2 translocations have poor outcome, irrespective of MYC status: a report from an International DLBCL rituximab-CHOP Consortium Program Study.

Diffuse large B-cell lymphoma can be classified by gene expression profiling into germinal center and activated B-cell subtypes with different prognoses after rituximab-CHOP. The importance of previously recognized prognostic markers, such as Bcl-2 protein expression and BCL2 gene abnormalities, has been questioned in the new therapeutic era. We analyzed Bcl-2 protein expression, and BCL2 and MYC gene abnormalities by interphase fluorescence in situ hybridization in 327 patients with de novo disease treated with rituximab-CHOP. Isolated BCL2 and MYC rearrangements were not predictive of outcome in our patients as a whole, but only in those with the germinal center subtype of lymphoma. The prognostic relevance of isolated MYC rearrangements was weaker than that of BCL2 isolated translocations, but was probably limited by the rarity of the rearrangements. Seven of eight patients with double hit lymphoma had the germinal center subtype with poor outcome. The germinal center subtype patients with isolated BCL2 translocations had significantly worse outcome than the patients without BCL2 rearrangements (P=0.0002), and their outcome was similar to that of patients with the activated B-cell subtype (P=0.30), but not as bad as the outcome of patients with double hit lymphoma (P<0.0001). Bcl-2 protein overexpression was associated with inferior outcome in patients with germinal center subtype lymphoma, but multivariate analysis showed that this was dependent on BCL2 translocations. The gene expression profiling of patients with BCL2 rearrangements was unique, showing activation of pathways that were silent in the negative counterpart. BCL2 translocated germinal center subtype patients have worse prognosis after rituximab-CHOP, irrespective of MYC status, but the presence of combined gene breaks significantly overcomes the prognostic relevance of isolated lesions.

Single-cell sequencing reveals the landscape of the human brain metastatic microenvironment.

Brain metastases is the most common intracranial tumor and account for approximately 20% of all systematic cancer cases. It is a leading cause of death in advanced-stage cancer, resulting in a five-year overall survival rate below 10%. Therefore, there is a critical need to identify effective biomarkers that can support frequent surveillance and promote efficient drug guidance in brain metastasis. Recently, the remarkable breakthroughs in single-cell RNA-sequencing (scRNA-seq) technology have advanced our insights into the tumor microenvironment (TME) at single-cell resolution, which offers the potential to unravel the metastasis-related cellular crosstalk and provides the potential for improving therapeutic effects mediated by multifaceted cellular interactions within TME. In this study, we have applied scRNA-seq and profiled 10,896 cells collected from five brain tumor tissue samples originating from breast and lung cancers. Our analysis reveals the presence of various intratumoral components, including tumor cells, fibroblasts, myeloid cells, stromal cells expressing neural stem cell markers, as well as minor populations of oligodendrocytes and T cells. Interestingly, distinct cellular compositions are observed across different samples, indicating the influence of diverse cellular interactions on the infiltration patterns within the TME. Importantly, we identify tumor-associated fibroblasts in both our in-house dataset and external scRNA-seq datasets. These fibroblasts exhibit high expression of type I collagen genes, dominate cell-cell interactions within the TME via the type I collagen signaling axis, and facilitate the remodeling of the TME to a collagen-I-rich extracellular matrix similar to the original TME at primary sites. Additionally, we observe M1 activation in native microglial cells and infiltrated macrophages, which may contribute to a proinflammatory TME and the upregulation of collagen type I expression in fibroblasts. Furthermore, tumor cell-specific receptors exhibit a significant association with patient survival in both brain metastasis and native glioblastoma cases. Taken together, our comprehensive analyses identify type I collagen-secreting tumor-associated fibroblasts as key mediators in metastatic brain tumors and uncover tumor receptors that are potentially associated with patient survival. These discoveries provide potential biomarkers for effective therapeutic targets and intervention strategies.

Collagen deposition within brain metastases is associated with leptomeningeal failure after cavity-directed radiosurgery.

Background: Leptomeningeal failure (LMF) represents a devastating progression of disease following resection of brain metastases (BrM). We sought to identify a biomarker at time of BrM resection that predicts for LMF using mass spectrometry-based proteomic analysis of resected BrM and to translate this finding with histochemical assays. Methods: We retrospectively reviewed 39 patients with proteomic data available from resected BrM. We performed an unsupervised analysis with false discovery rate adjustment (FDR) to compare proteomic signature of BrM from patients that developed LMF versus those that did not. Based on proteomic analysis, we applied trichrome stain to a total of 55 patients who specifically underwent resection and adjuvant radiosurgery. We used competing risks regression to assess predictors of LMF. Results: Of 39 patients with proteomic data, FDR revealed type I collagen-alpha-1 (COL1A1, P = .045) was associated with LMF. The degree of trichrome stain in each block correlated with COL1A1 expression (ß = 1.849, P = .001). In a cohort of 55 patients, a higher degree of trichrome staining was associated with an increased hazard of LMF in resected BrM (Hazard Ratio 1.58, 95% CI 1.11-2.26, P = .01). Conclusion: The degree of trichrome staining correlated with COL1A1 and portended a higher risk of LMF in patients with resected brain metastases treated with adjuvant radiosurgery. Collagen deposition and degree of fibrosis may be able to serve as a biomarker for LMF.

Cardiac Involvement by Human Herpesvirus 8-Positive Diffuse Large B-Cell Lymphoma: An Unusual Presentation in a Patient with Human Immunodeficiency Virus.

Human immunodeficiency virus (HIV) infection predisposes patients to the development of lymphomas, both due to immune suppression and coinfection with viruses with oncogenic potential. Coinfection with human herpesvirus 8 (HHV8) in particular has been associated with the development of aggressive lymphomas, including primary effusion lymphoma and diffuse large B-cell lymphoma (DLBCL). Herein, we report an unusual case of HHV8-positive DLBCL with extensive cardiac involvement which was diagnosed at autopsy in a patient with long-standing untreated HIV infection.

Upfront immunotherapy leads to lower brain metastasis velocity in patients undergoing stereotactic radiosurgery for brain metastases.

Background: While immunotherapy has been shown to improve survival and decrease neurologic death in patients with brain metastases, it remains unclear whether this improvement is due to prevention of new metastasis to the brain. Method: We performed a retrospective review of patients presenting with brain metastases simultaneously with the first diagnosis of metastatic disease and were treated with upfront immunotherapy as part of their treatment regimen and stereotactic radiosurgery (SRS) to the brain metastases. We compared this cohort with a historical control population (prior to the immunotherapy era) who were treated with pre-immunotherapy standard of care systemic therapy and with SRS to the brain metastases. Results: Median overall survival time was improved in the patients receiving upfront immunotherapy compared to the historical cohort (48 months vs 8.4 months, p=0.001). Median time to distant brain failure was statistically equivalent (p=0.3) between the upfront immunotherapy cohort and historical control cohort (10.3 vs 12.6 months). Brain metastasis velocity was lower in the upfront immunotherapy cohort (median 3.72 metastases per year) than in the historical controls (median 9.48 metastases per year, p=0.001). Cumulative incidence of neurologic death at one year was 12% in the upfront immunotherapy cohort and 28% in the historical control cohort (p=0.1). Conclusions: Upfront immunotherapy appears to improve overall survival and decrease BMV compared to historical controls. While these data remain to be validated, they suggest that brain metastasis patients may benefit from concurrent immunotherapy with SRS.

BCR-ABL1 p210 screening for chronic myeloid leukemia in patients with peripheral blood cytoses.

INTRODUCTION: Chronic myeloid leukemia (CML) usually presents with leukocytosis with neutrophilia, left shift, and basophilia. Documentation of the BCR-ABL1 fusion is required for diagnosis, and this is often achieved via p210 BCR-ABL1 real-time polymerase chain reaction (RT-PCR). METHODS: Patients undergoing first-time testing for p210 BCR-ABL1 at our institution were retrospectively identified. The medical record was reviewed, and the patient age, sex, clinical indication for testing, and concurrent CBC with differential were identified for 518 patients. BCR-ABL1 p210 testing had been performed using a laboratory-developed quantitative RT-PCR assay. Statistical analysis of the results was performed using an unpaired t test, and P values of <.05 were considered statistically significant. RESULTS: Twenty-four patients received a new diagnosis of CML (4.6%). As compared to patients with a negative PCR, these patients were more likely to have a markedly elevated white blood cell count (WBC), neutrophilia, and a mild anemia. Ninety-two percent (22/24) of new CML patients had a WBC ≥20 × 109 /L, and the two new CML patients with WBC <20 × 109 /L had basophilia in the peripheral blood. By contrast, 92% (449/490) of non-CML patients had a WBC <20 × 109 /L. CONCLUSION: The peripheral blood parameters of total WBC ≥20 × 109 /L and absolute basophil count can help guide the need for BCR-ABL1 PCR testing, which can lead to more judicious test utilization, decreased healthcare costs, and decreased false positives, while keeping a high sensitivity for CML. This study also underscores the importance of obtaining a complete differential in patients for whom CML is suspected.

Comparing Outcomes for Patients with Human Papillomavirus (HPV) Type 16 versus Other High-Risk HPV Types in Oropharyngeal Squamous Cell Carcinoma.

Human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) is related to improved treatment outcomes. What remains unclear is whether all HPV DNA genotypes carry similar prognostic relevance. We aimed to evaluate disease control and survival outcomes by HPV DNA genotype. Patients with primary OPSCC without distant metastases treated with curative intent were retrospectively identified from an IRB-approved institutional database. Patients that underwent HPV DNA polymerase chain reaction (PCR) testing with available genotype were included and dichotomized by the presence of HPV type 16 (HPV-16) or other high-risk HPV genotype (HPV-non16). Overall survival (OS), disease-free survival (DFS), locoregional control (LRC) and distant control (DC) were determined using the Kaplan-Meier method and compared using the log-rank test. In our cohort of 193 patients treated from 2012 to 2018 with HPV DNA PCR, 10% were detected as HPV-non16 high-risk types. Patients with HPV-16 were significantly younger than those with HPV-non16, but no other baseline factors were associated with HPV-non16. With a median follow-up of 42.9 months, there were no significant differences in outcomes between the HPV-16 and HPV-non16 groups for 3-year OS (87.7% v. 73.6%), DFS (82.9% v. 68.7%), LRC (92.8% v. 88.5%) or DC (91% v. 89.2%). There is no statistically significant difference in outcomes between OPSCC with HPV-16 and HPV-non16 high-risk genotypes in our cohort, though trends of overall worse survival and disease-free survival in HPV-non 16 OPSCC were seen. Further studies with larger cohorts of patients with HPV-non 16-associated OPSCC are required to make definitive conclusions regarding the prognostic and clinical significance of HPV type.

Recruitment of KMT2C/MLL3 to DNA Damage Sites Mediates DNA Damage Responses and Regulates PARP Inhibitor Sensitivity in Cancer.

When recruited to promoters, histone 3 lysine 4 (H3K4) methyltransferases KMT2 (KMT2A-D) activate transcription by opening chromatin through H3K4 methylation. Here, we report that KMT2 mutations occur frequently in non-small cell lung cancer (NSCLC) and are associated with high mutation loads and poor survival. KMT2C regulated DNA damage responses (DDR) through direct recruitment to DNA damage sites by Ago2 and small noncoding DNA damage response RNA, where it mediates H3K4 methylation, chromatin relaxation, secondary recruitment of DDR factors, and amplification of DDR signals along chromatin. Furthermore, by disrupting homologous recombination (HR)-mediated DNA repair, KMT2C/D mutations sensitized NSCLC to Poly(ADP-ribose) polymerase inhibitors (PARPi), whose efficacy is unclear in NSCLC due to low BRCA1/2 mutation rates. These results demonstrate a novel, transcription-independent role of KMT2C in DDR and identify high-frequency KMT2C/D mutations as much-needed biomarkers for PARPi therapies in NSCLC and other cancers with infrequent BRCA1/2 mutations. SIGNIFICANCE: This study uncovers a critical role for KMT2C in DDR via direct recruitment to DNA damage sites, identifying high-frequency KMT2C/D mutations as biomarkers for response to PARP inhibition in cancer.