Stereotactic Body Radiation Therapy for Oligoprogressive and Oligorecurrent Non-Small-Cell Lung Cancer.

BACKGROUND AND PURPOSE: The role of stereotactic body radiation therapy (SBRT) in oligoprogressive non-small-cell lung cancer (NSCLC) is controversial. We evaluated whether SBRT in a subset of patients with oligoprogressive or oligorecurrent NSCLC offers a durable response, obviating the need to change systemic therapy. METHODS: A retrospective analysis of 168 NSCLC patients who underwent SBRT for oligoprogressive or oligorecurrent disease was performed. Oligoprogression was defined as progression in ≤5 lesions during or after systemic therapy following an initial complete or partial response. Oligorecurrence was defined as progression while off systemic therapy. Progression-free survival (PFS), overall survival (OS) and time to next treatment or death (TNT-D) were estimated. RESULTS: Median age was 68 years. Sixty-seven percent of patients were on systemic therapy at the time of progression. Progression at the primary site was present in 31% of the patients. The number of sites of metastatic progression was 0 to 2 in 76% and 3 to 5 in 24% of the patients. Two-year OS and PFS were 56% (95%CI 46%-64%) and 14% (95%CI 8%-21%), respectively. Median TNT-D was 9 months (95%CI 6-11). No grade 4 or 5 toxicity was seen. In multivariable analysis, patients with 3 to 5 sites of metastatic progression had worse OS (HR 2.6, 95%CI 1.5-4.3, P < .001) and shorter TNT-D (HR 1.7, 95%CI 1.1-2.5, P = .01) than those with 0 to 2 sites. CONCLUSION: SBRT is a safe and viable treatment option for oligoprogressive and oligorecurrent NSCLC. Patients with 0 to 2 sites had better OS and longer TNT-D compared to those with 3 to 5 lesions.

Real-World Outcomes of Latinx Versus Non-Latinx Patients Treated With First-Line Immunotherapy for Metastatic Renal-Cell Carcinoma.

BACKGROUND: There are limited data regarding the impact of ethnicity among patients receiving immune checkpoint inhibitors. We evaluated real-world outcomes between Latinx and non-Latinx patients with metastatic renal-cell carcinoma (mRCC) treated with first-line nivolumab/ipilimumab within 2 different healthcare settings. METHODS: We performed a retrospective analysis of patients with mRCC who received nivolumab/ipilimumab within the Los Angeles County Department of Health Services (LAC-DHS), a safety-net healthcare system, and the City of Hope Comprehensive Cancer Center (COH), a tertiary oncology center, between January 1, 2015 and December 31, 2021. Progression-free survival (PFS) and overall survival (OS) were determined using the Kaplan-Meier method and covariates were adjusted using multivariate Cox proportional hazards regression. RESULTS: Of 94 patients, 40 patients (43%) were Latinx while the remainder were non-Latinx (44 pts [46%] White, 7 pts [7%] Asian, and 3 pts [3%] Other). Fifty (53%) and 44 (47%) patients received their care at COH and LAC-DHS, respectively. Most Latinx patients (95%) were treated at LAC-DHS, and most non-Latinx patients (89%) were treated at COH. Pooled analysis by ethnicity demonstrated significantly shorter PFS in Latinx versus non-Latinx patients (10.1 vs. 25.2 months, hazard ratios [HR] 3.61, 95% CI 1.96-6.66, P ≤ .01). Multivariate analysis revealed a HR of 3.41 (95% CI 1.31-8.84; P = .01). At a median follow-up of 11.0 months, the median OS was not reached in either arm at the time of data cutoff. CONCLUSION: Latinx patients with mRCC had a shorter PFS treated with frontline nivolumab/ipilimumab compared to their non-Latinx counterparts. No difference was observed in OS although these data were immature. Larger studies are needed to further interrogate the social and economic determinants of ethnicity on clinical outcomes in mRCC.

Recurrent/Metastatic Nasopharyngeal Carcinoma Treatment from Present to Future: Where Are We and Where Are We Heading?

OPINION STATEMENT: Nasopharyngeal carcinoma (NPC) is distinct in its anatomic location and biology from other epithelial head and neck cancer (HNC). There are 3 WHO subtypes, which considers the presence of Epstein-Barr virus (EBV) and other histopathology features. Despite the survival benefit obtained from modern treatment modalities and techniques specifically in the local and locally advanced setting, a number of patients with this disease will recur and subsequently die of distant metastasis, locoregional relapse, or both. In the recurrent setting, the ideal therapy approach continues to be a topic of discussion and current recommendations are platinum-based combination chemotherapy. Phase III clinical trials which led to the approval of pembrolizumab or nivolumab for head and neck squamous cell carcinoma (HNSCC) specifically excluded NPC. No immune checkpoint inhibitor therapy, to date, has been approved by the FDA to treat NPC although the National Comprehensive Cancer Network (NCCN) recommendations do include use of these agents. Hence, this remains the major challenge for treatment options. Nasopharyngeal carcinoma is challenging as it is really 3 different diseases, and much research is required to determine best options and sequencing of those options. This article is going to address the data to date and discuss ongoing research in EBV + and EBV - inoperable recurrent/metastatic NPC patients.

Analyzing TCGA Data to Identify Gene Mutations Linked to Hepatocellular Carcinoma in Asians.

Introduction: Liver cancer is the sixth most common and second most fatal type of cancer worldwide. Few treatment options are available as patients with liver cancer are often diagnosed in an advanced stage due to a lack of clinical symptoms. Effectively preventing and treating liver cancer relies heavily on early diagnosis; early diagnosis results from identifying and monitoring high-risk patients. Epigenetic risk factors, such as hepatitis B, hepatitis C, cirrhosis, nonalcoholic fatty liver disease, and alcohol/tobacco abuse, are highly prevalent in Asia and likely cause Asians to have a higher incidence and mortality rate of liver cancer. While these acquired risk factors are relatively well understood, the underlying genetic background of liver cancer in Asians has not been well established or correlated with clinical outcomes. Methods: In this study, we accessed The Cancer Genome Atlas (TCGA) hepatocellular carcinoma clinical and mutation data through TCGAbiolinksGUI. Results: We found that mutations in five genes (TP53, TTN, OBSCN, MUC5B, CSMD1) were statistically linked with increased mortality in Asians compared to non-Asians, four of which (TTN, OBSCN, MUC5B, CSMD1) were also more prevalent in the Asian population. Within the Asian cohort, two gene mutations (TTN, HMCN1) were statistically linked with worse outcomes. We also found that the TP53 mutation predicts worse outcomes within the non-Asian cohort but not within the Asian cohort. Discussion/Conclusion: Our findings can improve cancer care in the Asian population through better disease prognostication, evaluations for potential targeted therapy, and a deeper understanding of liver cancer pathogenesis.

Sarcoma of the Breast: Clinical Characteristics and Outcomes of 991 Patients from the National Cancer Database.

BACKGROUND: Sarcoma of the breast is a rare malignancy with heterogeneous histology. Angiosarcoma, including secondary angiosarcoma from previous radiation, is the most common type of sarcoma of the breast. Other types of sarcomas of the breast have limited clinical and survival information. METHODS: We obtained clinicopathological data and survival outcomes from the patients with sarcoma of the breast, excluding angiosarcoma, that were registered in the National Cancer Database (NCDB) from 2004 to 2016. The treatment patterns and prognostic factors were analyzed. RESULTS: A total of 991 patients had sarcoma of the breast other than angiosarcoma. The most common histology was spindle cell sarcoma (13.4%), followed by leiomyosarcoma (11.7%) and giant cell sarcoma (10.1%). Surgical resection was performed in 894 out of 991 patients (90.2%), including R0 resection achieved in 781 (87.4%). The patients who received surgery showed better survival than the patients without surgery regardless of radiation therapy. When radiation was added to the surgical management, the OS (overall survival) benefit was marginally significant (hazard ratio 1.30 (CI 1.01-1.67), p=0.044). Adding chemotherapy did not improve OS. CONCLUSIONS: Surgical resection seems to be the most important treatment modality in sarcoma of the breast from the analysis of a large database. Radiation therapy added a minor survival benefit to the patients who received surgical resection. Systemic chemotherapy did not play a clear role in sarcoma of the breast.

Conserved Interferon-γ Signaling Drives Clinical Response to Immune Checkpoint Blockade Therapy in Melanoma.

We analyze the transcriptome of baseline and on-therapy tumor biopsies from 101 patients with advanced melanoma treated with nivolumab (anti-PD-1) alone or combined with ipilimumab (anti-CTLA-4). We find that T cell infiltration and interferon-γ (IFN-γ) signaling signatures correspond most highly with clinical response to therapy, with a reciprocal decrease in cell-cycle and WNT signaling pathways in responding biopsies. We model the interaction in 58 human cell lines, where IFN-γ in vitro exposure leads to a conserved transcriptome response unless cells have IFN-γ receptor alterations. This conserved IFN-γ transcriptome response in melanoma cells serves to amplify the antitumor immune response. Therefore, the magnitude of the antitumor T cell response and the corresponding downstream IFN-γ signaling are the main drivers of clinical response or resistance to immune checkpoint blockade therapy.

Low Rates of Chemotherapy Use for Primary, High-Grade Soft Tissue Sarcoma: A National Cancer Database Analysis.

BACKGROUND: There is conflicting evidence regarding the role of chemotherapy for high-grade soft tissue sarcoma (STS) in adults. We sought to characterize patterns of chemotherapy use, including multiagent and neoadjuvant chemotherapy, in the United States. PATIENTS AND METHODS: Using the National Cancer Database, we identified 19,969 adult patients who underwent surgical resection for primary high-grade STS from 2004 to 2016. Using logistic regression, we examined factors associated with overall, multiagent, and neoadjuvant chemotherapy use. RESULTS: Chemotherapy was administered to 22% (n=4,377) of the study population. Among patients treated using chemotherapy, 85% received multiagent treatment and 47% received neoadjuvant treatment. On multivariate analysis, factors associated with chemotherapy use included tumor size, depth, histology, and primary site; receipt of radiation treatment; younger age; higher patient income; and academic treatment facility. Factors associated with multiagent chemotherapy use included tumor histology, tumor primary site, and younger age. Factors associated with neoadjuvant chemotherapy use included tumor size, depth, margin status, and primary site; receipt of radiation treatment; higher patient income; academic treatment facility type; and distance to treatment facility. Treatment at a high-volume facility was the only factor associated with overall, multiagent, and neoadjuvant chemotherapy use. No significant temporal trend was seen in overall, multiagent, or neoadjuvant chemotherapy use. CONCLUSIONS: Overall chemotherapy use was low (22%). The variability in chemotherapy use was driven by clinical, patient, demographic, and facility factors. Among patients treated with chemotherapy, the use of multiagent chemotherapy was high (85%), and nearly half received neoadjuvant therapy. There was a discrepancy in the use of chemotherapy-including neoadjuvant and multiagent chemotherapy-between high- and low-volume treatment centers.

Chemotherapy and Survival in Patients with Primary High-Grade Extremity and Trunk Soft Tissue Sarcoma.

The use of upfront chemotherapy for primary localized soft tissue sarcoma (STS) of the extremity and trunk is debated. It remains unclear if chemotherapy adds clinical benefit, which patients are likely to benefit, and whether the timing of therapy affects outcomes. We used the National Cancer Database (NCDB) to examine the association between overall survival (OS) and chemotherapy in 5436 patients with the five most common subtypes of STS with primary disease localized to the extremity or trunk, mirroring the patient population of a modern phase 3 clinical trial of neoadjuvant chemotherapy. We then examined associations between timing of multi-agent chemotherapy (neoadjuvant or adjuvant) and OS. We used a Cox proportional hazards model and propensity score matching (PSM) to account for covariates including demographic, patient, clinical, treatment, and facility factors. In the overall cohort, we observed no association between multi-agent chemotherapy or its timing and improved OS. Multi-agent chemotherapy was associated with improved OS in several subgroups, including patients with larger tumors (>5 cm), those treated at high-volume centers, or those who received radiation. We also identified an OS benefit to multi-agent chemotherapy among the elderly (>70 years) and African American patients. Multi-agent chemotherapy was associated with improved survival for patients with tumors >5 cm, who receive radiation, or who receive care at high-volume centers. Neither younger age nor chemotherapy timing was associated with better outcomes. These 'real-world' findings align with recent randomized trial data supporting the use of multi-agent chemotherapy in high-risk patients with localized STS.

Acute encephalopathy secondary to dabrafenib and trametinib in BRAF-positive metastatic adenocarcinoma of the lung.

Acute encephalopathy secondary to targeted therapy with BRAF inhibitors is uncommon. There are few case reports in patients with metastatic melanoma who received treatment with dabrafenib and trametinib, and developed acute confusion. The encephalopathy appears to resolve after the discontinuation of offending drug, with patient returning to their baseline mentation and functional ability. The mechanism of the encephalopathy has been unclear. Unlike posterior reversible encephalopathy syndrome, which has been reported with vemurafenib and cobimetinib combination in melanoma patients, there are generally no acute imaging abnormalities observed (e.g. on computed tomography and magnetic resonance imaging brain scans). We report a case of acute encephalopathy in a patient with BRAF mutated metastatic lung cancer due to dabrafenib and trametinib treatment. With the increasing use of targeted therapies in lung cancer treatments, it is important for clinicians to be aware of potentially toxic effects of novel treatments.

Characterization of hepatocellular carcinoma (HCC) in non-alcoholic fatty liver disease (NAFLD) patients without cirrhosis.

BACKGROUND: The incidence of hepatocellular carcinoma (HCC) has increased significantly in United States over the last few decades in parallel with the epidemic of nonalcoholic fatty liver disease (NAFLD). Limited data suggests that HCC could arise in steatotic liver without the presence of cirrhosis. The present study was conducted to characterize patients with NAFLD presenting with HCC in non-cirrhotic liver (NCL) compared to the NAFLD- HCC patients in association with cirrhotic liver (CL). METHODS: A retrospective analysis of all patients diagnosed with HCC and NAFLD diagnosis seen at our institution between 2003 and 2012 was done. The patients were characterized based on demographic and clinical variables as well as histological and tumor features. Comparisons between the NCL and CL groups were done using analysis of variance (ANOVA) or the non-parametric Kruskal-Wallis tests and Pearson's chi-square tests or Fisher's Exact tests as appropriate. P value of <0.05 was considered statistically significant. RESULTS: Thirty-six patients with NAFLD and HCC in NCL (HCC-NCL group) were identified and compared to 47 patients with NAFLD-HCC and Liver Cirrhosis (HCC-LC group). Liver fibrosis was not present in 55.9 % of patients in the HCC-NCL group (F0), stage 1 was present in 17.6 %, stage 2 in 8.8 % and stage 3 in 17.6 %. Lobular inflammation was present in 63.6 % of non-cirrhotic patients. Patients in the HCC-NCL were older (67.5 ± 12.3 vs. 62.7 ± 8.1 years), and less likely to be obese (52 % vs. 83 %) or have type 2 diabetes (38 % vs. 83 %), with p value <0.05 for all. More importantly, compared with the HCC-CL group, those in the HCC-NCL group were more likely to present with a single nodule (80.6 % vs. 52.2 %), larger nodule size (>5 cm) (77.8 % vs. 10.6 %), and receive hepatic resection as the modality of HCC treatment (66.7 % vs. 17 %); and were less likely to receive loco-regional therapy (22.3 % vs. 61.7 %) or orthotopic liver transplantation (OLT) (0 % vs. 72.3 %), with p value <0.001 for all. Furthermore, 86 % of patients without cirrhosis had HCC recurrence compared to only 14 % in patients with cirrhosis (p < 0.001). Unadjusted analysis indicates that non-cirrhotics had worse survival with mortality rate of 47 % vs. 28 % in CL group (p = 0.03); however this difference in survival between two groups was not significant after adjusting for age or OLT (p > 0.05). CONCLUSION: Patients with HCC in the absence of liver cirrhosis are more likely to present at an older age with larger tumor and have higher rates of tumor recurrence. Studies to assess the cost-effectiveness of HCC surveillance in this group should be conducted.

G-quadruplex formation between G-rich PNA and homologous sequences in oligonucleotides and supercoiled plasmid DNA.

Guanine (G)-rich DNA sequences can adopt four-stranded quadruplex conformations that may play a role in the regulation of genetic processes. To explore the possibility of targeted molecular recognition of DNA sequences with short G-rich peptide nucleic acids (PNA) and to assess the strand arrangement in such complexes, we used PNA and DNA with the Oxytricha nova telomeric sequence d(G4T4G4) as a model. PNA probes were complexed with DNA targets in the following forms: single-stranded oligonucleotides, a loop of DNA in a hairpin conformation, and as supercoiled plasmid with the (G4T4G4)/(C4A4C4) insert. Gel-shift mobility assays demonstrated formation of stable hybrid complexes between the homologous G4T4G4 PNA and DNA with multiple modes of binding. Chemical and enzymatic probing revealed sequence-specific and G-quadruplex dependent binding of G4T4G4 PNA to dsDNA. Spectroscopic and electrophoretic analysis of the complex formed between PNA and the synthetic DNA hairpin containing the G4T4G4 loop showed that the stoichiometry of a prevailing complex is three PNA strands per one DNA strand. We speculate how this new PNA-DNA complex architecture can help to design more selective, quadruplex-specific PNA probes.

PPG peptide nucleic acids that promote DNA guanine quadruplexes.

Recent studies have shown that guanine-rich (G-rich) sequences with the potential to form quadruplexes might play a role in normal transcription as well as overexpression of oncogenes. Chemical tools that allow examination of the specific roles of G-quadruplex formation in vivo, and their association with gene regulation will be essential to understanding the functions of these quadruplexes and might lead to beneficial therapies. Properly designed peptide nucleic acids (PNAs) can invade G-rich DNA duplexes and induce the formation of a G-quadruplex in the free DNA strand. Replacing guanines in the PNA sequence with pyrazolo[3,4-d]pyrimidine guanine (PPG) nucleobases eliminates G-quadruplex formation with PNA and promotes invasion of the target DNA.

Stimulation of cultured h9 human embryonic stem cells with thyroid stimulating hormone does not lead to formation of thyroid-like cells.

The sodium-iodine symporter (NIS) is expressed on the cell membrane of many thyroid cancer cells, and is responsible for the radioactive iodine accumulation. However, treatment of anaplastic thyroid cancer is ineffective due to the low expression of NIS on cell membranes of these tumor cells. Human embryonic stem cells (ESCs) provide a potential vehicle to study the mechanisms of NIS expression regulation during differentiation. Human ESCs were maintained on feeder-independent culture conditions. RT-qPCR and immunocytochemistry were used to study differentiation marker expression, (125)I uptake to study NIS function. We designed a two-step protocol for human ESC differentiation into thyroid-like cells, as was previously done for mouse embryonic stem cells. First, we obtained definitive endoderm from human ESCs. Second, we directed differentiation of definitive endoderm cells into thyroid-like cells using various factors, with thyroid stimulating hormone (TSH) as the main differentiating factor. Expression of pluripotency, endoderm and thyroid markers and (125)I uptake were monitored throughout the differentiation steps. These approaches did not result in efficient induction of thyroid-like cells. We conclude that differentiation of human ESCs into thyroid cells cannot be induced by TSH media supplementation alone and most likely involves complicated developmental patterns that are yet to be understood.

Targeting DNA G-quadruplex structures with peptide nucleic acids.

Regulation of genetic functions based on targeting DNA or RNA sequences with complementary oligonucleotides is especially attractive in the post-genome era. Oligonucleotides can be rationally designed to bind their targets based on simple nucleic acid base pairing rules. However, the use of natural DNA and RNA oligonucleotides as targeting probes can cause numerous off-target effects. In addition, natural nucleic acids are prone to degradation in vivo by various nucleases. To address these problems, nucleic acid mimics such as peptide nucleic acids (PNA) have been developed. They are more stable, show less off-target effects, and, in general, have better binding affinity to their targets. However, their high affinity to DNA can reduce their sequence-specificity. The formation of alternative DNA secondary structures, such as the G-quadruplex, provides an extra level of specificity as targets for PNA oligomers. PNA probes can target the loops of G-quadruplex, invade the core by forming PNA-DNA guanine-tetrads, or bind to the open bases on the complementary cytosine-rich strand. Not only could the development of such G-quadruplex-specific probes allow regulation of gene expression, but it will also provide a means to clarify the biological roles G-quadruplex structures may possess.

Quadruplex formation is necessary for stable PNA invasion into duplex DNA of BCL2 promoter region.

Guanine-rich sequences are highly abundant in the human genome, especially in regulatory regions. Because guanine-rich sequences have the unique ability to form G-quadruplexes, these structures may play a role in the regulation of gene transcription. In previous studies, we demonstrated that formation of G-quadruplexes could be induced with peptide nucleic acids (PNAs). PNAs designed to bind the C-rich strand upstream of the human BCL2 gene promoted quadruplex formation in the complementary G-rich strand. However, the question whether G-quadruplex formation was essential for PNA invasion remained unanswered. In this study, we compared PNA invasion in the native and mutant, i.e. not forming G-quadruplex, BCL2 sequences and showed that G-quadruplex is required for effective PNA invasion into duplex DNA. This finding provides strong evidence for not only sequence-specific, but also quadruplex specific, gene targeting with PNA probes. In addition, we examined DNA-duplex invasion potential of PNAs of various charges. Using the gel shift assay, chemical probing and dimethyl sulfate (DMS) protection studies, we determined that uncharged zwitterionic PNA has the highest binding specificity while preserving efficient duplex invasion.

Expression of pluripotency-associated genes in the surviving fraction of cultured human embryonic stem cells is not significantly affected by ionizing radiation.

Human embryonic stem cells (hESC) are capable to give rise to all cell types in the human body during the normal course of development. Therefore, these cells hold a great promise in regenerative cell replacement based therapeutical approaches. However, some controversy exists in literature concerning the ultimate fate of hESC after exposure to genotoxic agents, in particular, regarding the effect of DNA damaging insults on pluripotency of hESC. To comprehensively address this issue, we performed an analysis of the expression of marker genes, associated with pluripotent state of hESC, such as Oct-4, Nanog, Sox-2, SSEA-4, TERT, TRA-1-60 and TRA-1-81 up to 65h after exposure to ionizing radiation (IR) using flow cytometry, immunocytochemistry and quantitative real-time polymerase chain reaction techniques. We show that irradiation with relatively low doses of gamma-radiation (0.2Gy and 1Gy) does not lead to loss of expression of the pluripotency-associated markers in the surviving hESC. While changes in the levels of expression of some of the pluripotency markers were observed at different time points after IR exposure, these alterations were not persistent, and, in most cases, the expression of the pluripotency-associated markers remained significantly higher than that observed in fully differentiated human fibroblasts, and in hESCs differentiated into definitive endodermal lineage. Our data suggest that exposure of hESC to relatively low doses of IR as a model genotoxic agent does not significantly affect pluripotency of the surviving fraction of hESC.

Stabilization of G-quadruplex in the BCL2 promoter region in double-stranded DNA by invading short PNAs.

Numerous regulatory genes have G-rich regions that can potentially form quadruplex structures, possibly playing a role in transcription regulation. We studied a G-rich sequence in the BCL2 gene 176-bp upstream of the P1 promoter for G-quadruplex formation. Using circular dichroism (CD), thermal denaturation and dimethyl sulfate (DMS) footprinting, we found that a single-stranded oligonucleotide with the sequence of the BCL2 G-rich region forms a potassium-stabilized G-quadruplex. To study G-quadruplex formation in double-stranded DNA, the G-rich sequence of the BCL2 gene was inserted into plasmid DNA. We found that a G-quadruplex did not form in the insert at physiological conditions. To induce G-quadruplex formation, we used short peptide nucleic acids (PNAs) that bind to the complementary C-rich strand. We examined both short duplex-forming PNAs, complementary to the central part of the BCL2 gene, and triplex-forming bis-PNAs, complementary to sequences adjacent to the G-rich BCL2 region. Using a DMS protection assay, we demonstrated G-quadruplex formation within the G-rich sequence from the promoter region of the human BCL2 gene in plasmid DNA. Our results show that molecules binding the complementary C-strand facilitate G-quadruplex formation and introduce a new mode of PNA-mediated sequence-specific targeting.