Racial and ethnic disparities in Acute Myeloid Leukemia: 15-year experience at a safety net hospital system.

Despite recent therapeutic advances, ethnic minorities in the U.S. continue to have disproportionately poor outcomes in many hematologic malignancies including AML. We identified 162 adult AML patients treated at a non-transplant safety net hospital from 2007 to 2022 and evaluated differences in disease characteristics, treatment and clinical outcomes based on race and ethnicity. Our cohort consisted of 82 (50.6%) Hispanic, 36 (22.2%) non-Hispanic black and 44 (27.2%) non-Hispanic white and Asian patients. Median age at diagnosis was 42.5, 49.0 and 52.5 years respectively (p=0.025). Hispanics had higher rates of intermediate and high-risk disease (p=0.699) and received high intensity induction and consolidation chemotherapy at lower rates (p=0.962), although differences did not reach statistical significance. Despite this, similar remission rates were achieved. Hispanics with high-risk disease had longer overall survival (OS) than the combined non-Hispanic cohort (mOS 14 m vs 7 m, p=0.030). Multivariate regression analysis showed that OS was negatively associated with age (HR 1.023, p=0.006), intermediate (HR 3.431, p=0.0003) and high-risk disease (HR 4.689, p<0.0001) and positively associated with Hispanic ethnicity (HR 0.614, p=0.026). This report suggests that contrary to other studies, Hispanics, particularly those with high-risk AML, may have improved OS compared to other ethnic groups. These results are unique to our safety net hospital setting where common barriers to medical care and healthcare disparities are largely mitigated.

The phosphatidylserine targeting antibody bavituximab plus pembrolizumab in unresectable hepatocellular carcinoma: a phase 2 trial.

Immune checkpoint inhibitors targeting PD-1/L1 have modest efficacy in hepatocellular carcinoma as single agents. Targeting membranous phosphatidylserine may induce pro-inflammatory and -immune stimulating effects that enhance immunotherapy activity. This hypothesis was tested in a single-arm phase 2 trial evaluating frontline bavituximab, a phosphatidylserine targeting antibody, plus pembrolizumab (anti-PD-1) in patients with unresectable hepatocellular carcinoma (NCT03519997). The primary endpoint was investigator-assessed objective response rate among evaluable patients, and secondary end points included progression-free survival, incidence of adverse events, overall survival, and duration of response. Among 28 evaluable patients, the confirmed response rate was 32.1%, which met the pre-specified endpoint, and the median progression-free survival was 6.3 months (95% CI, 1.3-11.3 months). Treatment related-adverse events of any grade occurred in 45.7% of patients, with grade 3 or greater adverse events in 14.3% of patients. Adverse events of any cause were observed in 33 patients (94.3%), with grade 3 or greater adverse events in 11 patients (31.4%). Prespecified exploratory analyses of baseline tumor specimens showed that a depletion of B cells, and the presence of fibrotic tissue and expression of immune checkpoints in stroma was associated with tumor response. These results suggest that targeting phosphatidylserine may lead to synergistic effects with PD-1 blockade without increasing toxicity rates, and future studies on this therapeutic strategy may be guided by biomarkers characterizing the pre-treatment tumor microenvironment.

Outcomes in Kaposi's sarcoma-associated herpesvirus -associated primary effusion lymphoma and multicentric Castleman's disease in patients with human immunodeficiency virus (HIV) in a safety-net hospital system.

OBJECTIVE: To describe cases of Kaposi's sarcoma-associated herpesvirus (KSHV)-associated multicentric Castleman's disease (MCD) and primary effusion lymphoma (PEL) in patients with HIV from a large, safety-net hospital system in Dallas, Texas, USA. METHODS: We conducted a retrospective review of patients with HIV-associated PEL and/or MCD. RESULTS: Twelve patients with PEL and 10 patients with MCD were identified. All patients were male and 17 of 20 were men who have sex with men; 66.7% of PEL patients and 50% of MCD patients had concurrent KS at the time of diagnosis; 42% of patients with PEL and 20% of patients with MCD died during the follow-up period. We noted improved survival in our cohort compared to previous studies, particularly in our PEL patients with a median survival of 11.4 months compared to 3-6-month median survival historically. Median follow-up time for MCD patients was 17.5 months. This improved survival is despite suboptimal antiretroviral therapy (ART) adherence at diagnosis, with only 50% of patients on ART at the time of MCD/PEL diagnosis. CONCLUSION: These data highlight the importance of early recognition of PEL and MCD, and the larger-scale efforts needed to better understand the pathogenetic drivers of clinical outcomes in patients affected by KSHV-related diseases.

Characteristics and clinical outcomes in young-onset cholangiocarcinoma.

BACKGROUND: While the incidence of cholangiocarcinoma is rising, little is known about young-onset disease. We compared clinical characteristics and outcomes between patients with young-onset cholangiocarcinoma, diagnosed between the ages of 18 and <50 years, and patients with typical-onset cholangiocarcinoma, diagnosed at age 50 years or greater. METHODS: We used the National Cancer Database to identify patients with young-onset cholangiocarcinoma (n = 2520) and typical-onset cholangiocarcinoma (n = 23,826). We compared the frequency of demographic and clinical characteristics between the two groups. We compared overall survival between the two groups using multivariable Cox regression analysis after adjusting for age, gender, race/ethnicity, comorbidity, facility type, tumor location, tumor stage, surgical status, and receipt of radiotherapy, chemotherapy and surgery. RESULTS: When compared to patients with typical-onset disease (median age 68 years), patients with young-onset cholangiocarcinoma (median age 44 years) were more likely to be non-White (35.0% vs. 27.4%, p < 0.01), and had lower overall comorbidity burden. Patients with young-onset disease had a greater proportion of intrahepatic cholangiocarcinoma (56.0% vs. 45.5%, p < 0.001) and stage IV disease (50.5% vs. 43.5%, p < 0.001). Younger patients were more likely than typical-onset patients to receive definitive surgery (30.9% vs. 25.0%, p < 0.001), radiation (27.7% vs. 19.6%, p < 0.001) and chemotherapy (73.1% vs. 50.1%, p < 0.001). In adjusted analyses, patients with young-onset disease had a 15% decreased risk of death, compared with patients with typical-onset disease (HR 0.85 [95% CI 0.80-0.89], p < 0.001). CONCLUSIONS: Patients with young-onset cholangiocarcinoma may represent a demographically and clinically distinct group from those with more typical-onset disease.

High Seroprevalence of Kaposi Sarcoma-Associated Herpesvirus in Men Who Have Sex With Men With HIV in the Southern United States.

Background: Disparities in mortality in human immunodeficiency virus (HIV)-associated Kaposi sarcoma have been described, particularly in Black men in the southern United States. It is unclear if there are racial/ethnic differences in the seroprevalence of Kaposi sarcoma-associated herpesvirus (KSHV) that may be contributing. Methods: This is a cross-sectional study of men who have sex with men (MSM) and transgender women with HIV. Participants were recruited from an outpatient HIV clinic in Dallas, Texas, for a 1-time study visit and were excluded from analysis if they had any history of KSHV disease. Plasma was tested for antibodies to KSHV K8.1 or ORF73 antigens, and KSHV DNA was measured in oral fluids and blood by polymerase chain reaction. KSHV seroprevalence and viral shedding in blood and oral fluids were calculated. Additionally, independent risk factors for KSHV seropositivity were assessed by multivariable logistic regression analysis. Results: Two hundred five participants were included in our analysis. Overall, KSHV seroprevalence was high (68%) with no significant difference between racial/ethnic groups. Among seropositive participants, KSHV DNA was detected in 28.6% of oral fluids and 10.9% of peripheral blood specimens, respectively. The factors most strongly associated with KSHV seropositivity were oral-anal sex (odds ratio [OR], 3.02), oral-penile sex (OR, 4.63), and methamphetamine use (OR, 4.67). Conclusions: High local seroprevalence of KSHV is likely a key driver of the high burden of KSHV-associated diseases regionally, though it does not explain the observed disparities in KSHV-associated disease prevalence among racial/ethnic groups. Our findings support that KSHV is primarily transmitted via exchange of oral fluids.

Trends in Adjuvant Chemotherapy Use Among Stage III Colon Cancer in Non-Elderly and Low Comorbidity Patients.

BACKGROUND: Adjuvant chemotherapy for stage III colon cancer is underutilized in the United States. The aim of this study was to assess the use of adjuvant chemotherapy in younger and medically fit patients and analyze the socioeconomic factors associated with its utilization. METHODS: Using the National Cancer Database from 2004 to 2015, we selected stage III colon cancer patients between age 18 to 65, Charlson-Deyo Comorbidity Index (CDCI) of 0 or 1, and those that survived at least 12 months after surgery. We then compared patients that underwent surgery only with those that received adjuvant chemotherapy. Multivariable logistic regression analysis was performed to identify variables associated with adjuvant chemotherapy use in the population. Overall survival was estimated by Kaplan-Meier curves. RESULTS: Of the 48,336 patients that met inclusion criteria, 43,315 (90%) received adjuvant chemotherapy. The utilization of adjuvant chemotherapy increased from 87% in 2004 to 91% in 2015. On multivariable regression analysis, the use of adjuvant chemotherapy was lower among males, Non-Hispanic Blacks and Hispanics, low-grade cancer, left-sided tumors, CDCI 1, those who travel ≥ 50 miles, yearly income < $40,227, and uninsured patients. The most common reason for the omission of adjuvant chemotherapy was the patient or caregiver's choice (40% between 2013 and 2015). The 5-year and 10-year overall survival rates were 76.7% and 63.8% respectively, in those who received adjuvant chemotherapy as compared to 65.1% and 49.3% in those who underwent surgery only (P < .001). CONCLUSION: In young and medically fit stage III colon cancer patients, most patients received guideline-compliant care in the United States. However, socioeconomic disparities adversely impacted the use of adjuvant chemotherapy. The patient or caregiver's decision was the most common reason for non-adherence to adjuvant chemotherapy and lead to poor survival outcomes. Emphasis should be placed on developing patient-centered strategies to improve adherence to chemotherapy in all patients.

Primary central nervous system lymphoma: a real-world comparison of therapy access and outcomes by hospital setting.

Background: This study analyzes sociodemographic barriers for primary CNS lymphoma (PCNSL) treatment and outcomes at a public safety-net hospital versus a private tertiary academic institution. We hypothesized that these barriers would lead to access disparities and poorer outcomes in the safety-net population. Methods: We reviewed records of PCNSL patients from 2007-2020 (n = 95) at a public safety-net hospital (n = 33) and a private academic center (n = 62) staffed by the same university. Demographics, treatment patterns, and outcomes were analyzed. Results: Patients at the safety-net hospital were significantly younger, more commonly Black or Hispanic, and had a higher prevalence of HIV/AIDS. They were significantly less likely to receive induction chemotherapy (67% vs 86%, P = .003) or consolidation autologous stem cell transplantation (0% vs. 47%, P = .001), but received more whole-brain radiation therapy (35% vs 16%, P = .001). Younger age and receiving any consolidation therapy were associated with improved progression-free (PFS, P = .001) and overall survival (OS, P = .001). Hospital location had no statistical impact on PFS (P = .725) or OS (P = .226) on an age-adjusted analysis. Conclusions: Our study shows significant differences in treatment patterns for PCNSL between a public safety-net hospital and an academic cancer center. A significant survival difference was not demonstrated, which is likely multifactorial, but likely was positively impacted by the shared multidisciplinary care delivery between the institutions. As personalized therapies for PCNSL are being developed, equitable access including clinical trials should be advocated for resource-limited settings.

Racial and Ethnic Differences in Genomic Profiling of Early Onset Colorectal Cancer.

The incidence and mortality of early onset colorectal cancer (EOCRC) is rising; outcomes appear to differ by race and ethnicity. We aimed to assess differences in mutational landscape and gene expression of EOCRC by racial and ethnic groups (non-Hispanic Asian, non-Hispanic Black, non-Hispanic White, White Hispanic) using data from the American Association for Cancer Research Project GENIE (10.2) and University of Texas Southwestern, the latter enriched in Hispanic patients. All statistical tests were 2-sided. Of 1752 EOCRC patients, non-Hispanic Black patients had higher rates of KRAS mutations (60.9%; P = .001, q = 0.015), and non-Hispanic White and non-Hispanic Black patients had higher rates of APC mutations (77.1% and 76.6% among non-Hispanic White and non-Hispanic Black patients, respectively; P = .001, q = 0.015) via the Fisher exact test with Benjamini-Hochberg correction. Using R packages DESeq2 and clusterProfiler, we found that White Hispanic patients had increased expression of genes involved in oxidative phosphorylation (P < .001, q = 0.025). Genomic profiling has the potential to identify novel diagnostics and influence individualized treatment options to address the currently limited prognosis of EOCRC.

Importance of addressing malnutrition in cancer and implementation of a quality improvement project in a gastrointestinal cancer clinic.

Malnutrition is exceedingly common in cancer patients, with some of the highest rates seen in gastrointestinal (GI) malignancies. Malnutrition and cachexia in cancer patients is associated with worse quality of life, poor treatment tolerance, and increased morbidity and mortality. The importance of early recognition of malnutrition in cancer patients is key, and numerous screening tools have been validated to aid practitioners in this diagnosis. In this paper, we summarize the importance of identifying and managing malnutrition in GI cancer patients as well as its impact on clinical outcomes. We then focus on presenting our own novel quality improvement project that aims to expand access to dietitian services in a GI cancer clinic at a large safety-net hospital system. Utilizing evidence-based quality improvement methodologies including the Model for Improvement and Plan-Do-Study-Act cycles, we increased the proportion of GI oncology patients seen by a dietitian from 5% to 20% from October 2018 to July 2019. In particular, we outline the challenges faced in the implementation process of a malnutrition screening tool built into the electronic medical record in an outpatient oncology clinic. We focus on the tool's ability to capture a greater number of patients with malnutrition and its clinical impact.

Mortality disparities among patients with HIV-associated Kaposi's sarcoma in the southern United States.

OBJECTIVE: To describe risk factors for mortality in HIV-associated Kaposi's sarcoma in an urban population in Dallas, Texas. DESIGN: Retrospective electronic medical record review of patients with HIV-associated Kaposi's sarcoma. METHODS: Electronic medical records were reviewed from 1 January 2009 to 31 December 2018 for patients with a diagnosis of HIV and Kaposi's sarcoma by ICD-9 or ICD-10 codes. Demographics, HIV history, Kaposi's sarcoma history, treatment, and mortality data were collected. Mortality data was supplemented by an inquiry from the National Death Index (NDI). Survival analyses were performed using Cox proportional hazards analysis to determine independent predictors of mortality. RESULTS: Black patients had higher mortality than white or Hispanic patients (hazard ratio 2.07, 95% confidence interval 1.12-3.82), even after adjusting for covariates. This mortality difference correlates with higher rates of advanced Kaposi's sarcoma disease and KS-IRIS in black patients compared with other groups and is not explained by differences in CD4+ cell count, HIV viral load, engagement in care, or ART adherence at the time of cancer diagnosis. CONCLUSION: Despite nationwide trends showing decreased incidence and decreased mortality in Kaposi's sarcoma in the ART era, a high number of Kaposi's sarcoma cases and disparities in Kaposi's sarcoma outcomes persist in certain populations in the United States.

Use of Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer: Initial Results From the Pembrolizumab Arm of a Phase 2 Randomized Clinical Trial.

IMPORTANCE: Total neoadjuvant therapy (TNT) is often used to downstage locally advanced rectal cancer (LARC) and decrease locoregional relapse; however, more than one-third of patients develop recurrent metastatic disease. As such, novel combinations are needed. OBJECTIVE: To assess whether the addition of pembrolizumab during and after neoadjuvant chemoradiotherapy can lead to an improvement in the neoadjuvant rectal (NAR) score compared with treatment with FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin) and chemoradiotherapy alone. DESIGN, SETTING, AND PARTICIPANTS: In this open-label, phase 2, randomized clinical trial (NRG-GI002), patients in academic and private practice settings were enrolled. Patients with stage II/III LARC with distal location (cT3-4 ≤ 5 cm from anal verge, any N), with bulky disease (any cT4 or tumor within 3 mm of mesorectal fascia), at high risk for metastatic disease (cN2), and/or who were not candidates for sphincter-sparing surgery (SSS) were stratified based on clinical tumor and nodal stages. Trial accrual opened on August 1, 2018, and ended on May 31, 2019. This intent-to-treat analysis is based on data as of August 2020. INTERVENTIONS: Patients were randomized (1:1) to neoadjuvant FOLFOX for 4 months and then underwent chemoradiotherapy (capecitabine with 50.4 Gy) with or without intravenous pembrolizumab administered at a dosage of 200 mg every 3 weeks for up to 6 doses before surgery. MAIN OUTCOMES AND MEASURES: The primary end point was the NAR score. Secondary end points included pathologic complete response (pCR) rate, SSS, disease-free survival, and overall survival. This report focuses on end points available after definitive surgery (NAR score, pCR, SSS, clinical complete response rate, margin involvement, and safety). RESULTS: A total of 185 patients (126 [68.1%] male; mean [SD] age, 55.7 [11.1] years) were randomized to the control arm (CA) (n = 95) or the pembrolizumab arm (PA) (n = 90). Of these patients, 137 were evaluable for NAR score (68 CA patients and 69 PA patients). The mean (SD) NAR score was 11.53 (12.43) for the PA patients (95% CI, 8.54-14.51) vs 14.08 (13.82) for the CA patients (95% CI, 10.74-17.43) (P = .26). The pCR rate was 31.9% in the PA vs 29.4% in the CA (P = .75). The clinical complete response rate was 13.9% in the PA vs 13.6% in the CA (P = .95). The percentage of patients who underwent SSS was 59.4% in the PA vs 71.0% in the CA (P = .15). Grade 3 to 4 adverse events were slightly increased in the PA (48.2%) vs the CA (37.3%) during chemoradiotherapy. Two deaths occurred during FOLFOX: sepsis (CA) and pneumonia (PA). No differences in radiotherapy fractions, FOLFOX, or capecitabine doses were found. CONCLUSIONS AND RELEVANCE: Pembrolizumab added to chemoradiotherapy as part of total neoadjuvant therapy was suggested to be safe; however, the NAR score difference does not support further study. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02921256.

Implementation of a Quality Improvement Project to Increase Access to Dietitian Services for Patients With Gastrointestinal Cancer in a Safety-Net Hospital System.

PURPOSE: Rates of malnutrition are high in patients with GI cancer, leading to poor outcomes. The aim of our project was to increase the rate of documented dietitian assessment in patients with GI cancer at Parkland Health and Hospital System from 5% to 25%. METHODS: Three PDSA cycles were conducted after identifying barriers to dietitian services. A registered dietitian was assigned to the GI oncology clinic during the first cycle, an adapted Malnutrition Screening Tool was implemented through the electronic medical record during the second cycle, and clinical staff training was performed during the third cycle. New patients with GI cancer seen by the registered dietitian had weight, Eastern Cooperative Oncology Group performance status, and serum albumin recorded at initial visit and 3-month follow-up. Paired t tests were performed. Emergency department visits and hospital admissions were also recorded during this time. RESULTS: Through these interventions, the percentage of patients with GI cancer with documented assessment by the registered dietitian increased from 5.1% in October 2018 prior to our interventions to 21.8% in July 2019 and has sustained in the 15%-20% range thereafter. From May to July 2019, there were 63 new patients with GI cancer seen by a registered dietitian. No significant difference was observed in average difference in weight and serum albumin level at initial visit and 3-month follow-up. CONCLUSION: A nutrition-focused quality improvement project led to a more than three-fold increase in the rate of documented dietitian assessment in patients with GI cancer.

Disparities in Characteristics, Access to Care, and Oncologic Outcomes in Young-Onset Colorectal Cancer at a Safety-Net Hospital.

PURPOSE: Young-onset colorectal cancer is an emerging cause of significant morbidity and mortality globally. Despite this, limited data exist regarding clinical characteristics and outcomes, particularly in safety-net populations where access to care is limited. We aimed to study disparities in clinical characteristics and outcomes in patients with young-onset colorectal cancer in the safety-net setting. METHODS: We performed a retrospective review of patients < 50 years old diagnosed and/or treated for colorectal cancer between 2001 and 2017 at a safety-net hospital. Kaplan-Meier and Cox regression models were constructed to compare overall survival (OS), progression-free survival (PFS), and relapse-free survival (RFS) by race and ethnicity, stratifying for relevant clinical and pathologic factors. RESULTS: A total of 395 young-onset patients diagnosed at a safety-net hospital were identified and 270 were included in the analysis (49.6% Hispanic, 25.9% non-Hispanic Black, 20.0% non-Hispanic White, and 4.4% other). Non-Hispanic White race was independently associated with worse OS (hazzard ratio [HR], 0.53; 95% CI, 0.29 to 0.97), as were lack of insurance, higher clinical stage, and mismatch repair proficiency. There was no significant difference seen in PFS or RFS between racial and ethnic groups. CONCLUSION: Non-Hispanic White race or ethnicity was found to be independently associated with worse OS in a safety-net population of patients with young-onset colorectal cancer. Other independent predictors of worse OS include higher stage, lack of insurance, and mismatch repair proficiency.

Racial/Ethnic Disparities and Survival Characteristics in Non-Pancreatic Gastrointestinal Tract Neuroendocrine Tumors.

Background: We studied the effect of race and ethnicity on disease characteristics and survival in gastrointestinal neuroendocrine tumors. Methods: The Surveillance, Epidemiology, and End Results database was used to select patients with non-pancreatic gastrointestinal neuroendocrine tumors diagnosed between 2004 and 2015. Trends in survival were evaluated among three groups: Hispanic, non-Hispanic White, and non-Hispanic Black. Kaplan-Meier and Cox regression methods were performed to calculate overall survival and cause-specific survival after adjusting for patient and tumor characteristics. Results: A total of 26,399 patients were included in the study: 65.1% were non-Hispanic White, 19.9% were non-Hispanic Black, and 15% were Hispanic. Non-Hispanic White patients were more likely to be male (50.0%, p < 0.001), older than 60 years (48.0%, p < 0.001), and present with metastatic disease (17.7%, p < 0.001). Non-Hispanic White patients had small intestine neuroendocrine tumors, while Hispanic and non-Hispanic Black patients had rectum neuroendocrine tumors as the most common primary site. Hispanic patients had better overall survival, while non-Hispanic Black patients had better cause-specific survival versus non-Hispanic White patients. This finding was confirmed on multivariable analysis where Hispanic patients had improved overall survival compared to non-Hispanic White patients (Hazard ratio (HR): 0.89 (0.81-0.97)), whereas non-Hispanic Black patients had better cause-specific survival compared to non-Hispanic White patients (HR: 0.89 (0.80-0.98)). Conclusions: Race/ethnicity is an independent prognostic factor in patients with gastrointestinal neuroendocrine tumors.

Adjuvant chemotherapy for ypT0N0M0 rectal cancer following chemoradiotherapy and total mesorectal excision.

The management of adenocarcinoma of the rectum is a dynamic field in oncology. The multidisciplinary approach to the management of this disease continues to evolve in each segment of its trimodality treatment. New scheduling regimens and radiosensitizing agents continue to emerge. Although total mesorectal excision continues to be the operation of choice for rectal cancers, what is done before and after surgery continues to evolve to maximize an ideal oncologic outcome with minimal morbidity. The achievement of a pathological complete response [pCR (i.e. ypT0N0)] in a fraction of patients undergoing neoadjuvant chemoradiation poses an interesting management dilemma. The cohort of patients who can achieve a pCR have superior oncologic outcomes compared to nonresponders. The present review addresses the need for adjuvant therapy in patients with a pCR. We discuss the evolution of the role of adjuvant therapy in patients with rectal cancer and the studies addressing the elimination of this strategy in all patients with rectal cancer with a goal of determining the current evidence that might result in the omission of adjuvant therapy for patients with ypT0N0 rectal cancer after chemoradiation and total mesorectal excision.

Dabrafenib.

Dabrafenib was developed as a highly specific reversible inhibitor of V600-mutant BRAF kinase, an oncogenic mutation driving proliferation in many different types of aggressive tumors. Metastatic melanoma has a high prevalence of V600-mutant BRAF, and clinical trials showed that dabrafenib improved response rates and median progression-free survival in patients with V600E BRAF mutations, including those with brain metastasis. Preliminary results suggest that dabrafenib may also have some role in non-melanoma V600-mutant solid tumors; however, more studies are needed. With a well-tolerated toxicity profile and few drug interactions, dabrafenib is effective as a monotherapy; however, resistance eventually develops in most patients after persistent exposure to the drug. Current research focuses on combination strategies with dabrafenib to not only improve response rates but also overcome resistance.

Dabrafenib for treatment of BRAF-mutant melanoma.

Melanoma has the highest mortality of all the skin cancer subtypes. Historically, chemotherapy and immunologic therapies have yielded only modest results in the treatment of metastatic melanoma. The discovery of prevalent V600 BRAF mutations driving proliferation makes this oncogenic protein an ideal target for therapy. Dabrafenib, a reversible inhibitor of mutant BRAF kinase, improved response rates and median progression-free survival in patients with V600E BRAF-mutant metastatic melanoma, including those with brain metastases. With a well-tolerated toxicity profile, dabrafenib is effective as a monotherapy; however, resistance eventually develops in almost all patients. As a result, current research is exploring the role of combination therapies with dabrafenib to overcome resistance.

Regulation of telomerase alternative splicing: a target for chemotherapy.

Telomerase is present in human cancer cells but absent in most somatic tissues. The messenger RNA of human telomerase (hTERT) is alternatively spliced into mostly nonfunctional products. We sought to understand splicing so that we could decrease functional splice isoforms to reduce telomerase activity in order to complement direct enzyme inhibition. Unexpectedly, minigenes containing hTERT exons 5-10 flanked by 150-300 bp intronic sequences did not produce alternative splicing. A 1.1 kb region of 38 bp repeats ~2 kb from the exon 6/intron junction restored the exclusion of exons 7 and 8. An element within intron 8, also >1 kb from intron/exon junctions, modulated this effect. Transducing an oligonucleotide complementary to this second element increased nonfunctional hTERT messenger RNA from endogenous telomerase. These results demonstrate the potential of manipulating hTERT splicing for both chemotherapy and regenerative medicine and provide specific sequences deep within introns that regulate alternative splicing in mammalian cells by mechanisms other than the introduction of cryptic splice sites.