A Novel Role of Uricosuric Agent Benzbromarone in BK Channel Activation and Reduction of Airway Smooth Muscle Contraction.

The uricosuric drug benzbromarone, widely used for treatment of gout, hyperpolarizes the membrane potential of airway smooth muscle cells, but how it works remains unknown. Here we show a novel role of benzbromarone in activation of large conductance calcium-activated K+ channels. Benzbromarone results in dose-dependent activation of macroscopic big potassium (BK) currents about 1.7- to 14.5-fold with an EC50 of 111 µM and shifts the voltage-dependent channel activation to a more hyperpolarizing direction about 10 to 54 mV in whole-cell patch clamp recordings. In single-channel recordings, benzbromarone decreases single BKα channel closed dwell time and increases the channel open probability. Coexpressing ß1 subunit also enhances BK activation by benzbromarone with an EC50 of 67 µM and a leftward shift of conductance-voltage (G-V) curve about 44 to 138 mV. Site-directed mutagenesis reveals that a motif of three amino acids 329RKK331 in the cytoplasmic linker between S6 and C-terminal regulator of potassium conductance (RCK) gating ring mediates the pharmacological activation of BK channels by benzbromarone. Further ex vivo assay shows that benzbromarone causes reduction of tracheal strip contraction. Taken together, our findings demonstrate that uricosuric benzbromarone activates BK channels through molecular mechanism of action involving the channel RKK motif of S6-RCK linker. Pharmacological activation of BK channel by benzbromarone causes reduction of tracheal strip contraction, holding a repurposing potential for asthma and pulmonary arterial hypertension or BK channelopathies. SIGNIFICANCE STATEMENT: We describe a novel role of uricosuric agent benzbromarone in big potassium (BK) channel activation and relaxation of airway smooth muscle contraction. In this study, we find that benzbromarone is an activator of the large-conductance Ca2+- and voltage-activated K+ channel (BK channel), which serves numerous cellular functions, including control of smooth muscle contraction. Pharmacological activation of BK channel by the FDA-approved drug benzbromarone may hold repurposing potential for treatment of asthma and pulmonary arterial hypertension or BK channelopathies.

IMB5036, a novel pyridazinone compound, inhibits hepatocellular carcinoma growth and metastasis.

Background Hepatocellular carcinoma (HCC) is one of the most common cancers with a high mortality rate due to metastasis and relapse. Purpose Here, we reported a small-molecule pyridazinone compound, designated as IMB5036. Its antitumor activity against HCC and underlying mechanism were studied. Methods In vitro cytotoxicity, apoptosis, DNA breaks, and cell motility assays were performed. Protein expression was analyzed by Western blot and microarray analysis. A xenograft tumor model in athymic mice was used to evaluate the antitumor activity. Results IMB5036 displayed potent cytotoxicity against various HCC cell lines. It caused double DNA breakages and induced cell death via apoptosis. It also significantly inhibited the motility of HCC cells. Western blot showed that IMB5036 induced the up-regulation of E-cadherin, while down-regulation of N-cadherin. The gene expression profile analysis and Western blot assay revealed that IMB5036 down-regulated the expression of Tau protein. Analysis of the TCGA dataset revealed that high expression of Tau decreased the survival rate of HCC patients. In vivo experiments proved that IMB5036 significantly inhibited the growth of HCC xenografts in athymic mice. Conclusions These results collectively demonstrate IMB5036 can be a promising therapeutic candidate for patients with HCC.

Impact of rheumatoid arthritis on radiation-related toxicity and cosmesis in breast cancer patients: a contemporary matched-pair analysis.

PURPOSE: To evaluate the impact of rheumatoid arthritis (RA) on toxicity and cosmesis in women undergoing radiotherapy for breast cancer. METHODS: We queried an institutional database for women with RA treated with external beam radiotherapy for breast cancer between 1981 and 2016. Matching each patient to three controls without RA was attempted. Radiation toxicity was graded using CTCAE 4.0. Cosmesis was graded using the Global Harris Scoring System of Excellent, Good, Fair, or Poor. Grade 2+ (G2+) acute and late toxicities were compared between women with RA and their matched pairs using a generalized estimating equation (GEE). Wilcoxon test and mixed effects model were used to compare the cosmesis between two groups. RESULTS: Forty women with RA at time of radiation were matched to 117 controls. The median radiation dose was 60 Gy (50-66 Gy) and the median follow-up was 94 months (1-354 months). When comparing the women with RA to their matched pairs, there was no significant difference in the rates of G2+ acute toxicity (25.0 vs. 13.7%, O 2.1, CI 0.91-4.9) or G2+ late toxicity (7.5 vs. 4.3%, OR 1.8, CI 0.48-6.8). Mean cosmesis was between Good and Excellent for both groups of patients, although women with RA were less likely to get Excellent cosmesis compared to their matched pairs (OR 0.35, CI 0.15-0.84). CONCLUSIONS: Among women with RA, radiation for breast cancer was well tolerated without significantly increased toxicity. Their cosmesis was generally Good to Excellent, although they might be less likely to get Excellent cosmesis compared to their matched pairs.

A simple and efficient method for successful gene silencing of HspA1 in Trametes hirsuta AH28-2.

Trametes sp. are among the most extensively studied basidiomycetes due to their importance in biotechnology. However, they are difficult to genetically modify. For instance, the low incidence of homologous integration hampers gene inactivation. To overcome this, we here constructed two post-transcriptional gene-silencing vectors that contain an antisense and a RNA interference mediating hairpin sequence, respectively. These vectors were used to knock down transcription of the heat shock protein 70 family gene HspA1. The two vectors were transformed into Trametes hirsuta AH28-2 by using a PEG/CaCl2 mediated transformation method. Based on Southern blot analysis, target sequences were integrated into the genome as multi-copies. Transcription analysis revealed that the antisense and hairpin sequences reduced the transcript number of HspA1 when compared to the wild type strain. Moreover, the antisense sequence resulted in a higher gene silencing efficiency when compared to the RNA interference vector. Together, antisense methodology provides a simple method for gene silencing in Trametes sp.

Disparities in the Local Management of Breast Cancer in the US according to Health Insurance Status.

Although standard practice guidelines for breast cancer are clear, the interplay between insurance and practice patterns for the US is poorly defined. This study was performed to test for associations between patient insurance status and presentation of breast cancer as well as local therapy patterns in the US, via a large national dataset. We queried the NCI Surveillance, Epidemiology, and End Results data base for breast cancer cases diagnosed from 2007 to 2011 in women aged 18-64 with nonmetastatic ductal/lobular cancers, treated surgically. We tested for associations between insurance status (insured/Medicaid/uninsured) and choice of surgical procedure (mastectomy/breast conserving surgery [BCS]), omission of radiotherapy (RT) following BCS, and administration of post-mastectomy radiation (PMRT). There were 129,565 patients with localized breast cancer analyzed. The health insurance classification included insured (84.5%), Medicaid (11.5%), uninsured (2.1%) and unknown (1.9%). Medicaid or uninsured status was associated with large, node positive tumors, black race, and low income. The BCS rate varied by insurance status: insured (52.2%), uninsured (47.7%), and Medicaid (45.2%), p < 0.001. In multivariable analysis, Medicaid insurance remained significantly associated with receipt of mastectomy (OR [95% CI] = 1.07 [1.03-1.11]), while RT was more frequently omitted after BCS in both Medicaid (OR [95% CI] = 1.14 [1.07-1.21]) and uninsured (OR [95% CI] = 1.29 [1.14-1.47]) patients. Insurance status was associated with significant variations in breast cancer care in the US. Although patient choice cannot be determined from this dataset, departure from standard of care is associated with specific types of insurance coverage. Further investigation into the reasons for these departures is strongly suggested.

The need for androgen deprivation therapy in patients with intermediate-risk prostate cancer treated with dose-escalated external beam radiation therapy.

INTRODUCTION: To evaluate if androgen deprivation therapy (ADT) improves outcomes for patients with localized, intermediate-risk prostate cancer treated with definitive external beam radiation therapy (EBRT) in the dose-escalated era. MATERIALS AND METHODS: This is a retrospective study using a single institutional database. We included patients with localized, intermediate-risk prostate cancer treated with dose-escalated radiation therapy (RT) with 3D conformal radiotherapy or intensity-modulated radiotherapy (74-80 Gy in daily fraction of 1.8 Gy-2.0 Gy, or 70.2 Gy in daily fraction of 2.7 Gy) from 1992 to 2013. To further risk stratify the patients, PSA 10 ng/mL-20 ng/mL, Gleason 3+4, and T2b-T2c were assigned risk score (RS) of 1, while Gleason 4+3 was assigned RS of 2. Patients with prior treatment for prostate cancer, those on long term ADT (>= 23 months), or those with follow up < 1 year were excluded. We defined initial ADT as initiation within 9 months prior to the start of RT, during RT, or within 2 months after the completion of RT. Outcomes for patients who received initial ADT were compared to men treated with RT alone. Covariates included number of intermediate risk factors, age, and baseline comorbidities. Kaplan Meier estimates were compared using log rank tests. Competing risk regression and Cox proportional hazards regression were used to estimate hazard ratios adjusted for covariates. RESULTS: Of 1,134 patients included in this study, 155 received initial ADT with median duration of 4.0 months (m) (range 0.5 m-22.0 m). The median follow up was 56.4 m (range 12.3 m-200.7 m). Patients on ADT had higher RS compared to those with radiation alone (RS 1: 48% versus 58%; RS 2: 35% versus 32%; RS 3: 14% versus 9%; RS 4: 3% versus 1%; p=0.01). When patients with ADT were compared to those treated with radiation alone, there were no significant differences in freedom from biochemical failure (FFBF) (84.0% versus 87.3%, p = 0.83), freedom from distant metastasis (FFDM) (94.4% versus 96.9%, p = 0.41), or overall survival (OS) (92.3% versus 90.7%, (p = 0.48) at 5 years. Among patients with RS >= 2, there were still no significant differences in FFBF, FFDM, or OS when patients treated with ADT were compared to those treated with radiation alone. In multivariable analyses adjusting for RS and age, the adjusted hazard ratio for ADT use was sHR = 0.89 (95% CI = 0.64-1.66, p = 0.64) for BCF; sHR = 1.13 (95% CI = 0.48-2.65, p = 0.77) for DM. For overall mortality, adjusted HR = 1.23 (95% CI = 0.76-2.01, p = 0.40) where comorbidities (including diabetes, cardiac disease, and hypertension) were also included as covariates. CONCLUSION: Our study suggested that treatment of intermediate-risk prostate cancer with definitive dose-escalated EBRT alone resulted in acceptable outcomes, and it failed to show improved outcomes in patients who received short term ADT.

Disparities in the management and outcome of cervical cancer in the United States according to health insurance status.

INTRODUCTION: Our study sought to characterize the presentation, local management and outcomes of invasive cervical cancer with regard to patient insurance status. METHODS: We queried the NCI-SEER database for invasive cervical cancer cases in patients aged 18-64 from 2007 to 2011. We analyzed clinical and socioeconomic data with regard insurance status (insured, Medicaid, or uninsured). We tested for associations between patient insurance status and treatment with definitive surgery for FIGO IA2-IB1 patients, and treatment with suboptimal radiation therapy (RT) for FIGO IB2-IVA patients (other than combination external beam and brachytherapy). We evaluated overall and cause specific survival according to insurance status. RESULTS: 11,714 cases were analyzed: 60% insured, 31% Medicaid, and 9% uninsured. FIGO III/IV stage at presentation was more frequent with Medicaid (40%) and uninsured (42%) compared to insured patients (28%) (p<0.001). For FIGO IA2-IB1 patients, receipt of definitive surgery was inversely associated with uninsured status (OR [95%CI]=0.65 [0.47-0.90], p<0.001) in univariable analysis; however the relationship lost significance after multivariable adjustment. For FIGO IB2-IVA patients, the use of suboptimal RT was associated with uninsured status (OR [95%CI]=1.33 [1.07-1.65], p=0.011) in adjusted analyses. Among all patients, overall mortality was increased with Medicaid (HR [95%CI]=1.16 [1.05-1.28], p=0.003) and uninsured status (HR [95%CI]=1.17 [1.01-1.34], p=0.031) in multivariable analysis. Cancer specific mortality survival trended towards significance in multivariable analyses for both Medicaid (HR [95%CI]=1.11 [1.00-1.24] and uninsured status (HR [95%CI]=1.14 [0.98-1.33]). CONCLUSIONS: Disparities in cervical cancer treatment with regard to insurance status are apparent in a recent cohort of American patients. Later stage at presentation and differences in management partially account for the inferior prognostic outcomes associated with Medicaid and uninsured status.

Dual inhibition of topoisomerase II and microtubule of podophyllotoxin derivative 5p overcomes cancer multidrug resistance.

Compound 5p is a 4ß-N-substituted podophyllotoxin derivative, which exhibited potent activity toward drug-resistant K562/A02 cells and decreased MDR-1 mRNA expression. Here, we further investigated its detail mechanism and tested its antitumor activity. 5p exerted catalytic inhibition of topoisomerase IIα, and didn't show the inhibitor of topoisomerase I. 5p exhibited the inhibitory effect on microtubule polymerization. 5p showed potent anti-proliferation against breast cancer, oral squamous carcinoma, and their drug-resistant cell lines, with resistance index of 0.61 and 0.86, respectively. 5p downregulated the expression levels of P-gp in KBV200 cells and BCRP in MCF7/ADR cells in dose-dependent manner. Moreover, 5p induced KB and KBV200 cells arrest at G2/M phase by up-regulating the expression of γ-H2AX, p-Histone H3 and cyclin B1. 5p induced apoptosis and pyroptosis by increased the expression levels of cleaved-PARP, cleaved-caspase3, N-GSDME as well as LDH release in KB and KBV200 cells. In addition, 5p efficiently impaired tumor growth in KB and KBV200 xenograft mice. Conclusively, this work elucidated the dual inhibitor of topoisomerase II and microtubule of 5p and its mechanism of overcoming the multidrug resistance, indicating that 5p exerts the antitumor potentiality.

IMB5036 overcomes resistance to multiple chemotherapeutic drugs in human cancer cells through pyroptosis by targeting the KH-type splicing regulatory protein.

AIMS: IMB5036 is a pyridazinone compound with antiproliferative and antitumour activity against hepatoma and pancreatic cancer. In this study, we attempted to identify the target protein of IMB5036 and test its potential for overcoming multidrug resistance and inducing pyroptosis. MATERIALS AND METHODS: We examined the effects of IMB5036 on cancer cells by in vitro assays, a molecular docking model and in vivo tumour models. We performed pull-down experiments using biotinylated IMB5036 and identified the binding proteins. Gene knockdown were used to investigate the oncogenic role of KH-type splicing regulatory protein (KSRP). Western blot was used to detect for mechanism-associated molecules. KEY FINDINGS: IMB5036 could overcome resistance to multiple chemotherapeutic drugs at the cellular level and in vivo. Furthermore, IMB5036 was not a P-glycoprotein (P-gp) substrate and downregulated the expression of P-gp. We identified KSRP as a binding protein of IMB5036. The knockdown of KSRP inhibited the proliferation of MCF7 and MCF7/adriamycin (MCF7/ADR) cells. In addition, IMB5036 induced pyroptosis in both MCF7 and MCF7/ADR cells via KSRP. SIGNIFICANCE: We found IMB5036 binds to KSRP and overcomes multidrug resistance via gasdermin E (GSDME)-dependent pyroptosis.

Nano-engineered optimal templates for surface-plasmon enhanced Raman scattering.

We investigated the critical conditions to realize reliable and nano-engineered templates for surface-plasmon enhanced Raman scattering (SERS). Ultra-sensitive SERSs of thymine oligonucleotides were successfully realized on the template of Au nanoparticle arrays which were prepared by the combination of electron-beam lithography and post-chemical modification techniques. Drastic enhancement of Raman signal from the thymine oligonucleotides was only observed on the optimized templates, where the tuning of the plasmon resonance condition and the formation of the hot spots were both critical. Our results suggest that the artificial generation of reproducible and controlled hot spots can be achieved by our approach.

IMB5476, a novel microtubule inhibitor, induces mitotic catastrophe and overcomes multidrug resistance in tumors.

IMB5046 is a nitrobenzoate microtubule inhibitor we reported previously. During screening of its structural analogues, we identified a novel compound IMB5476 with increased aqueous solubility. Here, its antitumor activity and the underlying mechanism were investigated. IMB5476 disrupted microtubule networks in cells and arrested cell cycle at G2/M phase. It inhibited purified tubulin polymerization in vitro. Competition assay indicated that it bound to tubulin at the colchicine pocket. Further experiments proved that it induced cell death by mitotic catastrophe and apoptosis. Notably, it was a poor substrate of P-glycoprotein and exhibited potent cytotoxicity against drug-resistant tumor cells. In addition, IMB5476 could inhibit angiogenesis in vitro. IMB5476 also inhibited the growth of drug-resistant KBV200 xenografts in mice. Conclusively, our data reveal a novel nitrobenzoate microtubule inhibitor with improved aqueous solubility and can overcome multidrug resistance.

Comparison of Local Control of Brain Metastases With Stereotactic Radiosurgery vs Surgical Resection: A Secondary Analysis of a Randomized Clinical Trial.

Importance: Brain metastases are a common source of morbidity for patients with cancer, and limited data exist to support the local therapeutic choice between surgical resection and stereotactic radiosurgery (SRS). Objective: To evaluate local control of brain metastases among patients treated with SRS vs surgical resection within the European Organization for the Research and Treatment of Cancer (EORTC) 22952-26001 phase 3 trial. Design, Setting, and Participants: This unplanned, exploratory analysis of the international, multi-institutional randomized clinical trial EORTC 22952-26001 (conducted from 1996-2007) was performed from February 9, 2017, through July 25, 2018. The EORTC 22952-26001 trial randomized patients with 1 to 3 brain metastases to whole-brain radiotherapy vs observation after complete surgical resection or before SRS. Patients in the present analysis were stratified but not randomized according to local modality (SRS or surgical resection) and treated per protocol with 1 to 2 brain metastases and tumors with a diameter of no greater than 4 cm. Interventions: Surgical resection or SRS. Main Outcomes and Measures: The primary end point was local recurrence of treated lesions. Cumulative incidence of local recurrence was calculated according to modality (surgical resection vs SRS) with competing risk regression to adjust for prognostic factors and competing risk of death. Results: A total of 268 patients were included in the analysis (66.4% men; median age, 60.7 years [range, 26.9-81.1 years]); 154 (57.5%) underwent SRS and 114 (42.5%) underwent surgical resection. Median follow-up time was 39.9 months (range, 26.0-1982.0 months). Compared with the SRS group, patients undergoing surgical resection had larger metastases (median 28 mm [range, 10-40 mm] vs 20 mm [range, 4-40 mm]; P < .001), more frequently had 1 brain metastasis (112 [98.2%] vs 114 [74.0%]; P < .001), and differed in location (parietal, 21 [18.4%] vs 61 [39.6%]; posterior fossa, 30 [26.3%] vs 12 [7.8%]; P < .001). In adjusted models, local recurrence was similar between the SRS and surgical resection groups (hazard ratio [HR], 1.15; 95% CI, 0.72-1.83). However, when stratified by interval, patients with surgical resection had a much higher risk of early (0-3 months) local recurrence compared with those undergoing SRS (HR, 5.94; 95% CI, 1.72-20.45), but their risk decreased with time (HR for 3-6 months, 1.37 [95% CI, 0.64-2.90]; HR for 6-9 months, 0.75 [95% CI, 0.28-2.00]). At 9 months or longer, the surgical resection group had a lower risk of local recurrence (HR, 0.36; 95% CI, 0.14-0.93). Conclusions and Relevance: In this exploratory analysis, local control of brain metastases was similar between SRS and surgical resection groups. Stereotactic radiosurgery was associated with improved early local control of treated lesions compared with surgical resection, although the relative benefit decreased with time. Trial Registration: ClinicalTrials.gov Identifier: NCT00002899.

Incidence and outcomes of radiation-induced late cranial neuropathy in 10-year survivors of head and neck cancer.

OBJECTIVES: To characterize the late cranial neuropathy among 10-year survivors of head and neck cancer treatment. MATERIALS AND METHODS: We retrospectively evaluated patients treated with curative-intent radiation for HNC between 1990 and 2005 at a single institution with systematic multidisciplinary follow-up ≥ 10 years. New findings of CNP were considered radiation-induced when examination, imaging and/or biopsy did not demonstrate a structural or malignant cause. Cox proportional hazards modeling was used for univariable analysis (UVA) and multivariable analysis (MVA) for time to CNP after completion of radiation. RESULTS: We identified 112 patients with no evidence of disease and follow-up ≥ 10 years (median 12.2). Sixteen (14%) patients developed at least one CNP. The median time to CNP was 7.7 years (range 0.6-10.6 years). Most common was CN XII deficit in eight patients (7%), followed by CN X deficit in seven patients (6%). Others included CN V deficit in three, and CN XI deficit in two. Eight of the thirteen patients with a CN X and/or CN XII deficit required a permanent gastrostomy tube. On UVA, site of primary disease, post-radiation neck dissection, chemotherapy, and radiation dose were significantly associated with increased risk of CNP. CONCLUSION: Iatrogenic CNP may develop years after head and neck cancer treatment and often leads to swallowing dysfunction. Long-term follow up is essential for these patients receiving head and neck radiation.

Complete genome of Gongronella sp. w5 provides insight into its relationship with plant.

Gongronella sp. w5 (w5) is a soil fungus isolated from Anhui, China. Here we report the high-quality genome sequence of w5 and its phenotypic characteristics based on genomic information. The genome of w5 consists of 34,723,828 bp assembled into 149 scaffolds and 11,302 predicted protein-coding genes. Genome analysis suggested that w5 may possess host cell infection capacity and maybe a biotrophic fungus that relies on plant sucrose as carbon source. W5 shows the ability of rapid invasion into the plant root cells based on CAZymes analysis. Further results evidenced that w5 can use sucrose as the carbon source. Plant inoculation revealed that w5 penetrates the root cells of Actinidia chinensis with its hypha, and simultaneously promotes plant growth. It may promote plant growth by secreting organic acid and facilitating phosphate acquisition. The new genomic data and phenotype features will facilitate future applications of this strain in biotechnology.

Effects of interruptions of external beam radiation therapy on outcomes in patients with prostate cancer.

INTRODUCTION: To evaluate if interruptions of external beam radiation therapy impact outcomes in men with localized prostate cancer (PCa). METHODS: We included men with localized PCa treated with three-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiation therapy (IMRT) of escalated dose (≥74 Gy in 1.8 or 2 Gy fractions) between 1992 and 2013 at an NCI-designated cancer centre. Men receiving androgen deprivation therapy were excluded. The non-treatment day ratio (NTDR) was defined as the number of non-treatment days divided by the total elapsed days of therapy. NTDR was analysed for each National Comprehensive Cancer Network (NCCN) risk group. RESULTS: There were 1728 men included (839 low-risk, 776 intermediate-risk and 113 high-risk), with a median follow up of 53.5 months (range 12-185.8). The median NTDR was 31% (range 23-71%), translating to approximately 2 breaks (each break represents a missed treatment that will be made up) for 8 weeks of RT with 5 treatments per week. The 75 percentile of NTDR was 33%, translating to approximately 4 breaks, which was used as the cutoff for analysis. There were no significant differences in freedom from biochemical failure, freedom from distant metastasis, cancer specific survival, or overall survival for men with NTDR ≥33% compared to NTDR<33% for each risk group. Multivariable analyses including NTDR, age, race, Gleason score, T stage, and PSA were performed using the proportional hazards regression procedure. NTDR≥33% was not significantly associated with increased hazard ratio for outcomes in each risk group compared to NTDR<33%. CONCLUSION: Unintentional treatment breaks during dose escalated external beam radiation therapy for PCa did not cause a significant difference in outcomes, although duration of follow up limits the strength of this conclusion.

Local Control and Toxicity of External Beam Reirradiation With a Pulsed Low-dose-rate Technique.

PURPOSE: To evaluate the efficacy and toxicity of external beam reirradiation using a pulsed low-dose-rate (PLDR) technique. METHODS AND MATERIALS: We evaluated patients treated with PLDR reirradiation from 2009 to 2016 at a single institution. Toxicity was graded using the Common Terminology Criteria for Adverse Events, version 4.0, and local control was assessed using the Response Evaluation Criteria In Solid Tumors, version 1.1. On univariate analysis (UVA), the χ2 and Fisher exact tests were used to assess the toxicity outcomes. Competing risk analysis using cumulative incidence function estimates were used to assess local progression. RESULTS: A total of 39 patients were treated to 41 disease sites with PLDR reirradiation. These patients had a median follow-up time of 8.8 months (range 0.5-64.7). The targets were the thorax, abdomen, and pelvis, including 36 symptomatic sites. The median interval from the first radiation course and reirradiation was 26.2 months; the median dose of the first and second course of radiation was 50.4 Gy and 50 Gy, respectively. Five patients (13%) received concurrent systemic therapy. Of the 39 patients, 9 (23%) developed grade ≥2 acute toxicity, most commonly radiation dermatitis (5 of 9). None developed grade ≥4 acute or subacute toxicity. The only grade ≥2 late toxicity was late skin toxicity in 1 patient. On UVA, toxicity was not significantly associated with the dose of the first course of radiation or reirradiation, the interval to reirradiation, or the reirradiation site. Of the 41 disease sites treated with PLDR reirradiation, 32 had pre- and post-PLDR scans to evaluate for local control. The local progression rate was 16.5% at 6 months and 23.8% at 12 months and was not associated with the dose of reirradiation, the reirradiation site, or concurrent systemic therapy on UVA. Of the 36 symptomatic disease sites, 25 sites (69%) achieved a symptomatic response after PLDR, including 6 (17%) with complete symptomatic relief. CONCLUSION: Reirradiation with PLDR is effective and well-tolerated. The risk of late toxicity and the durability of local control were limited by the relatively short follow-up duration in the present cohort.

Long-term toxicities in 10-year survivors of radiation treatment for head and neck cancer.

OBJECTIVES: To characterize the recognized but poorly understood long-term toxicities of radiation therapy (RT) for head and neck cancer (HNC). MATERIALS AND METHODS: We retrospectively evaluated patients treated with curative-intent RT for HNC between 1990 and 2005 at a single institution with systematic multidisciplinary follow-up ≥10years. Long-term toxicities of the upper aerodigestive tract were recorded and assigned to two broad categories: pharyngeal-laryngeal and oral cavity toxicity. Kaplan-Meier estimates and Chi-square tests were used for univariable analysis (UVA). Cox model and logistic regression were used for multivariable analysis (MVA). RESULTS: We identified 112 patients with follow-up ≥10years (median 12.2). The primary tumor sites were pharynx (42%), oral cavity (34%), larynx (13%), and other (11%). Forty-four percent received postoperative RT, 24% had post-RT neck dissection, and 47% received chemotherapy. Twenty-eight (25%) patients developed pharyngeal-laryngeal toxicity, including 23 (21%) requiring permanent G-tube placed at median of 5.6years (0-20.3) post-RT. Fifty-three (47%) developed oral cavity toxicity, including osteoradionecrosis in 25 (22%) at a median of 7.2years (0.5-15.3) post-RT. On MVA, pharyngeal-laryngeal toxicity was significantly associated with chemotherapy (HR 3.24, CI 1.10-9.49) and age (HR 1.04, CI 1.00-1.08); oral cavity toxicity was significantly associated with chemotherapy (OR 4.40, CI 1.51-12.9), oral cavity primary (OR 5.03, CI 1.57-16.1), and age (OR 0.96, CI 0.92-1.00). CONCLUSION: Among irradiated HNC patients, pharyngeal-laryngeal and oral cavity toxicity commonly occur years after radiation, especially in those treated with chemotherapy. Follow-up for more than five years is essential because these significant problems afflict patients who have been cured.

Tissue TGF-ß expression following conventional radiotherapy and pulsed low-dose-rate radiation.

The release of inflammatory cytokines has been implicated in the toxicity of conventional radiotherapy (CRT). Transforming growth factor ß (TGF-ß) has been suggested to be a risk marker for pulmonary toxicity following radiotherapy. Pulsed low-dose rate radiotherapy (PLDR) is a technique that involves spreading out a conventional radiotherapy dose into short pulses of dose with breaks in between to reduce toxicities. We hypothesized that the more tolerable toxicity profile of PLDR compared with CRT may be related to differential expression of inflammatory cytokines such as TGF-ß in normal tissues. To address this, we analyzed tissues from mice that had been subjected to lethal doses of CRT and PLDR by histology and immunohistochemistry (IHC). Equivalent physical doses of CRT triggered more cellular atrophy in the bone marrow, intestine, and pancreas when compared with PLDR as indicated by hematoxylin and eosin staining. IHC data indicates that TGF-ß expression is increased in the bone marrow, intestine, and lungs of mice subjected to CRT as compared with tissues from mice subjected to PLDR. Our in vivo data suggest that differential expression of inflammatory cytokines such as TGF-ß may play a role in the more favorable normal tissue late response following treatment with PLDR.

A comparison of robotic arm versus gantry linear accelerator stereotactic body radiation therapy for prostate cancer.

Prostate cancer is the most prevalent cancer diagnosed in men in the United States besides skin cancer. Stereotactic body radiation therapy (SBRT; 6-15 Gy per fraction, up to 45 minutes per fraction, delivered in five fractions or less, over the course of approximately 2 weeks) is emerging as a popular treatment option for prostate cancer. The American Society for Radiation Oncology now recognizes SBRT for select low- and intermediate-risk prostate cancer patients. SBRT grew from the notion that high doses of radiation typical of brachytherapy could be delivered noninvasively using modern external-beam radiation therapy planning and delivery methods. SBRT is most commonly delivered using either a traditional gantry-mounted linear accelerator or a robotic arm-mounted linear accelerator. In this systematic review article, we compare and contrast the current clinical evidence supporting a gantry vs robotic arm SBRT for prostate cancer. The data for SBRT show encouraging and comparable results in terms of freedom from biochemical failure (>90% for low and intermediate risk at 5-7 years) and acute and late toxicity (<6% grade 3-4 late toxicities). Other outcomes (eg, overall and cancer-specific mortality) cannot be compared, given the indolent course of low-risk prostate cancer. At this time, neither SBRT device is recommended over the other for all patients; however, gantry-based SBRT machines have the abilities of treating larger volumes with conventional fractionation, shorter treatment time per fraction (~15 minutes for gantry vs ~45 minutes for robotic arm), and the ability to achieve better plans among obese patients (since they are able to use energies >6 MV). Finally, SBRT (particularly on a gantry) may also be more cost-effective than conventionally fractionated external-beam radiation therapy. Randomized controlled trials of SBRT using both technologies are underway.

Effects of Time to Treatment on Biochemical and Clinical Outcomes for Patients With Prostate Cancer Treated With Definitive Radiation.

INTRODUCTION: The purpose of this study was to evaluate if time to treatment (TTT) has an effect on outcomes for patients with localized prostate cancer treated with definitive external beam radiation therapy (EBRT). PATIENTS AND METHODS: We included 4064 patients (1549 low-risk, 1612 intermediate-risk, and 903 high-risk) treated with EBRT. For each National Comprehensive Cancer Network (NCCN) risk group, TTT (defined as the time between initial positive prostate biopsy and start of RT) was analyzed in 4 intervals: < 3, 3-6, 6-9, and 9-24 months. We recorded the use of androgen deprivation therapy among patients with intermediate-risk and high-risk disease. RESULTS: The median TTT was 3.3 months (range, 0.6-23.5 months), and it was similar for each risk group (range, 3.3-3.4 months). The median follow up was 64 months. There were no significant differences in biochemical failure, distant metastasis, or overall survival for patients with TTT < 3, 3-6, 6-9, or 9-24 months for each risk group. There were also no significant differences in the outcomes at 5 years when patients with TTT > 3.3 months were compared with those with TTT ≤ 3.3 months for each risk group. For high-risk men, 328 of 450 (72.9%) with TTT > 3.3 months were on androgen deprivation therapy (ADT) versus 299 of 453 (66%) with TTT ≤ 3.3 months. Among men with high-risk cancer treated without ADT, there remained no significant difference in outcomes between TTT > 3.3 months and TTT ≤ 3.3 months. CONCLUSION: TTT was not associated with significant differences in outcomes among each risk group of men with localized prostate cancer treated with EBRT. Among the high-risk patients, there were no observed detriments in outcomes with TTT > 3.3 months regardless of androgen deprivation therapy use.