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Purpose: The purpose of this study was to evaluate the radiotherapy planning feasibility of dose escalation with intensity‐modulated proton therapy (IMPT) to hypoxic tumor regions identified on 18F‐Fluoromisonidazole (FMISO) positron emission tomography and computed tomography (PET‐CT) in NPC. Materials and methods: Nine patients with stages T3‐4N0‐3M0 NPC underwent 18F‐FMISO PET‐CT before and during week 3 of radiotherapy. The hypoxic volume (GTVhypo) is automatically generated by applying a subthresholding algorithm within the gross tumor volume (GTV) with a tumor to muscle standardized uptake value (SUV) ratio of 1.3 on the 18F‐FMISO PET‐CT scan. Two proton plans were generated for each patient, a standard plan to 70 Gy and dose escalation plan with upfront boost followed by standard 70GyE plan. The stereotactic boost was planned with single‐field uniform dose optimization using two fields to deliver 10 GyE in two fractions to GTVhypo. The standard plan was generated with IMPT with robust optimization to deliver 70GyE, 60GyE in 33 fractions using simultaneous integrated boost technique. A plan sum was generated for assessment. Results: Eight of nine patients showed tumor hypoxia on the baseline 18F‐FMISO PET‐CT scan. The mean hypoxic tumor volume was 3.9 cm3 (range.9–11.9cm3). The average SUVmax of the hypoxic volume was 2.2 (range 1.44–2.98). All the dose‐volume parameters met the planning objectives for target coverage. Dose escalation was not feasible in three of eight patients as the D0.03cc of temporal lobe was greater than 75GyE. Conclusions: The utility of boost to the hypoxic volume before standard course of radiotherapy with IMPT is dosimetrically feasible in selected patients. Clinical trials are warranted to determine the clinical outcomes of this approach. [ABSTRACT FROM AUTHOR]

Gels are used in the oilfield. For example, during oil recovery, organogels are pumped underground into fractures within oil‐bearing rock, so as to block fluid flow. However, after several days, the gels must be degraded (liquefied) to enable oil extraction through the fractures. To degrade gels, 'degrading agents' as well as external stimuli have been examined. Here, a concept is demonstrated that avoids external agents and stimuli: self‐degrading organogels based on the self‐assembly of molecular gelators. The gels are a) extremely robust (free standing solids) at time t = 0 and (b) degrade spontaneously into a sol after a set time t = tdegr that can be minutes, hours, or days. These properties are achieved by combining two readily available molecules — the organogelator (1,3:2,4)‐dibenzylidene sorbitol (DBS) and an acid (e.g., hydrochloric acid, HCl) — in an organic solvent. DBS self‐assembles into nanoscale fibrils, which connect into a 3‐D network, thereby gelling the solvent. The acid type and concentration set the value of tdegr at a given temperature. Degradation occurs because the acid slowly hydrolyzes the acetals on DBS, thereby converting DBS into small molecules that cannot form fibrils. DBS gels with a pre‐programmed "degradation clock" can be made with both polar and non‐polar organic solvents. The concept can be a game‐changer for oil recovery as it promises to make it safer, more efficient, and sustainable. [ABSTRACT FROM AUTHOR]

Abstract Background In randomised clinical trials involving time-to-event outcomes, the failures concerned may be events of an entirely different nature and as such define a classical competing risks framework. In designing and analysing clinical trials involving such endpoints, it is important to account for the competing events, and evaluate how each contributes to the overall failure. An appropriate choice of statistical model is important for adequate determination of sample size. Methods We describe how competing events may be summarised in such trials using cumulative incidence functions and Gray's test. The statistical modelling of competing events using proportional cause-specific and subdistribution hazard functions, and the corresponding procedures for sample size estimation are outlined. These are illustrated using data from a randomised clinical trial (SQNP01) of patients with advanced (non-metastatic) nasopharyngeal cancer. Results In this trial, treatment has no effect on the competing event of loco-regional recurrence. Thus the effects of treatment on the hazard of distant metastasis were similar via both the cause-specific (unadjusted csHR = 0.43, 95% CI 0.25 - 0.72) and subdistribution (unadjusted subHR 0.43; 95% CI 0.25 - 0.76) hazard analyses, in favour of concurrent chemo-radiotherapy followed by adjuvant chemotherapy. Adjusting for nodal status and tumour size did not alter the results. The results of the logrank test (p = 0.002) comparing the cause-specific hazards and the Gray's test (p = 0.003) comparing the cumulative incidences also led to the same conclusion. However, the subdistribution hazard analysis requires many more subjects than the cause-specific hazard analysis to detect the same magnitude of effect. Conclusions The cause-specific hazard analysis is appropriate for analysing competing risks outcomes when treatment has no effect on the cause-specific hazard of the competing event. It requires fewer subjects than the subdistribution hazard analysis for a similar effect size. However, if the main and competing events are influenced in opposing directions by an intervention, a subdistribution hazard analysis may be warranted.

Abstract Background Over-expression of cyclooxygenase-2 (COX-2) enzyme has been reported in nasopharyngeal carcinoma (NPC). However, the prognostic significance of this has yet to be conclusively determined. Thus, from our randomized trial of radiation versus concurrent chemoradiation in endemic NPC, we analyzed a cohort of tumour samples collected from participants from one referral hospital. Methods 58 out of 88 patients from this institution had samples available for analysis. COX-2 expression levels were stratified by immunohistochemistry, into negligible, weak, moderate and strong, and correlated with overall and disease specific survivals. Results 58% had negligible or weak COX-2 expression, while 14% and 28% had moderate and strong expression respectively. Weak COX-2 expression conferred a poorer median overall survival, 1.3 years for weak versus 6.3 years for negligible, 7.8 years, strong and not reached for moderate. There was a similar trend for disease specific survival. Conclusion Contrary to literature published on other malignancies, our findings seemed to indicate that over-expression of COX-2 confer a better prognosis in patients with endemic NPC. Larger studies are required to conclusively determine the significance of COX-2 expression in these patients.

Background: The efficacy of a combination of nimotuzumab, a humanized monoclonal antibody to the epidermal growth factor receptor, with chemoradiation in locally advanced head and neck squamous cell carcinoma (HNSCC) was evaluated in a phase II study. Methods: Patients with stage III/IV HNSCC received 3‐weekly cisplatin 100 mg/m2 for three cycles and weekly nimotuzumab 200 mg for 8 weeks concurrently with radiotherapy. Primary endpoint was best overall response (BOR) and secondary endpoint was progression‐free survival (PFS). Results: Thirty‐seven patients were included; the majority were Chinese (76%), male (89%), and had stage IVA/IVB HNSCC (92%). BOR of complete and partial response was seen in 22/37 (59%) and 10/37 (27%) patients, respectively. Median PFS was 17.5 months (95% CI: 11.1–54.5) and 3‐year PFS was 40.4% (95% CI: 24.3–55.9). The frequency and type of adverse events observed were similar to standard chemoradiation. Conclusion: The combination of nimotuzumab with cisplatin and radiotherapy was safe and achieved high response rates in HNSCC. [ABSTRACT FROM AUTHOR]

Abstract Background In methodological studies and outcomes research, questionnaires often comprise several health-related quality of life (HRQoL) measures. Previous psychological studies have suggested that changing the sequential order of measurement scales within a questionnaire could alter the pattern of responses. Yet, information on the presence or absence of order effects on the assessment of HRQoL in cancer patients is limited. Methods An incomplete block design was used in this study of 1277 cancer patients. Each patient filled out a questionnaire package that contained two of the three major cancer-specific HRQoL instruments, namely the Functional Assessment of Cancer Therapy – General, the European Organization for the Research and Treatment of Cancer Core Quality of Life Questionnaire and the Functional Living Index – Cancer. Within a questionnaire package the sequential order of the instruments contained were randomised. Measurement properties of the instruments, including the number of missing values, mean HRQoL scores, known-groups validity and internal consistency were compared between samples of different presentation orders. Results No effect of presentation order on the four properties aforementioned was found. Conclusion Presentation order is unlikely to alter the responses to these HRQoL instruments administered in cancer patients when any two of them are used together.

Background: Lactate dehydrogenase (LDH) is a known prognostic biomarker for the endemic variant of nasopharyngeal carcinoma (NPC). Here, we investigate whether serial changes in LDH level between chemotherapy (CT) cycles are associated with tumour response to CT. Methods: Patients with biopsy-proven, recurrent or treatment-naïve metastatic NPC (mNPC) were recruited. All patients had received at least two cycles of platinum-based doublet or triplet CT, with serial assessment of LDH prior to every cycle of chemotherapy (CT1–6). Patients harbouring conditions that affect LDH levels (IU/L) were excluded. Tumour response was assessed after every two cycles of CT by RECIST v1.1. Results: A total of 158 patients were analysed, including 77 with recurrent and 81 with treatment-naïve mNPC. High pre-CT LDH was associated with an inferior overall survival [hazard ratio 1.93 for ⩾240 versus <240 (1.34–2.77), p < 0.001], which is consistent with published literature. We found that both absolute LDH levels and LDH ratios (LDHCTn: LDHCTn–1) were associated with tumour response [partial response versus progressive disease: median value across CT1–6 = 168–190 versus 222–398 (absolute); 0.738–0.988 versus 1.039–1.406 (ratio)], albeit LDH ratio had a tighter variance between patients. Finally, we showed that an LDH ratio cut-off of 1.0 at CT1, CT3 and CT5 was predictive of progressive disease at CT2, CT4, CT6 [area under the curve of 0.73 (0.65–0.80)]. Conclusion: Herein, we characterised the longitudinal variation of LDH in response to CT in mNPC. Our findings suggest the potential utility of interval LDH ratio to predict subsequent tumour response to CT. [ABSTRACT FROM AUTHOR]

Following the dispersal out of Africa, where hominins evolved in warm environments for millions of years, our species has colonised different climate zones of the world, including high latitudes and cold environments. The extent to which human habitation in (sub-)Arctic regions has been enabled by cultural buffering, short-term acclimatization and genetic adaptations is not clearly understood. Present day indigenous populations of Siberia show a number of phenotypic features, such as increased basal metabolic rate, low serum lipid levels and increased blood pressure that have been attributed to adaptation to the extreme cold climate. In this study we introduce a dataset of 200 individuals from ten indigenous Siberian populations that were genotyped for 730,525 SNPs across the genome to identify genes and non-coding regions that have undergone unusually rapid allele frequency and long-range haplotype homozygosity change in the recent past. At least three distinct population clusters could be identified among the Siberians, each of which showed a number of unique signals of selection. A region on chromosome 11 (chr11:66–69 Mb) contained the largest amount of clustering of significant signals and also the strongest signals in all the different selection tests performed. We present a list of candidate cold adaption genes that showed significant signals of positive selection with our strongest signals associated with genes involved in energy regulation and metabolism (CPT1A, LRP5, THADA) and vascular smooth muscle contraction (PRKG1). By employing a new method that paints phased chromosome chunks by their ancestry we distinguish local Siberian-specific long-range haplotype signals from those introduced by admixture. [ABSTRACT FROM AUTHOR]

Background: In randomised clinical trials involving time-to-event outcomes, the failures concerned may be events of an entirely different nature and as such define a classical competing risks framework. In designing and analysing clinical trials involving such endpoints, it is important to account for the competing events, and evaluate how each contributes to the overall failure. An appropriate choice of statistical model is important for adequate determination of sample size.Methods: We describe how competing events may be summarised in such trials using cumulative incidence functions and Gray's test. The statistical modelling of competing events using proportional cause-specific and subdistribution hazard functions, and the corresponding procedures for sample size estimation are outlined. These are illustrated using data from a randomised clinical trial (SQNP01) of patients with advanced (non-metastatic) nasopharyngeal cancer.Results: In this trial, treatment has no effect on the competing event of loco-regional recurrence. Thus the effects of treatment on the hazard of distant metastasis were similar via both the cause-specific (unadjusted csHR = 0.43, 95% CI 0.25 - 0.72) and subdistribution (unadjusted subHR 0.43; 95% CI 0.25 - 0.76) hazard analyses, in favour of concurrent chemo-radiotherapy followed by adjuvant chemotherapy. Adjusting for nodal status and tumour size did not alter the results. The results of the logrank test (p = 0.002) comparing the cause-specific hazards and the Gray's test (p = 0.003) comparing the cumulative incidences also led to the same conclusion. However, the subdistribution hazard analysis requires many more subjects than the cause-specific hazard analysis to detect the same magnitude of effect.Conclusions: The cause-specific hazard analysis is appropriate for analysing competing risks outcomes when treatment has no effect on the cause-specific hazard of the competing event. It requires fewer subjects than the subdistribution hazard analysis for a similar effect size. However, if the main and competing events are influenced in opposing directions by an intervention, a subdistribution hazard analysis may be warranted. [ABSTRACT FROM AUTHOR]

Purpose: To assess whether the benefits of adding cisplatin (CDDP) concurrent with radiotherapy, followed by adjuvant CDDP and fluorouracil, justifies the toxicity cost for nasopharyngeal cancer (NPC) using the quality-adjusted time without symptoms or toxicity (Q-TWiST) approach. Methods and Materials: One hundred seven patients treated with radiotherapy (RT) and 111 with concurrent chemotherapy and radiotherapy (CRT) were analyzed. The overall survival was divided into three health states: time on active treatment only, during which any subjective nonhematologic toxic event of grade > = 3 was reported; time without symptoms of disease relapse; or treatment and time following first disease RELapse. The relative advantage of CRT and RT was examined by conducting the analysis cumulatively at restriction times 3, 6, 24, 36, 48 months. Results: At 48 months, the improvement in disease-free survival was 14.4% for CRT, whereas that for overall survival was 18.9%. The differences in Q-TWiST were −0.4, −0.7, 0.1, 1.6, and 3.6 months at 3, 6, 24, 36, and 48 months, respectively, with positive differences favoring CRT. At 24 months, the difference in Q-TWiST began to favor CRT. At 36 months, CRT may be the preferred option from the patient''s viewpoint if the time spent in the REL state is valued to be <0.83, with the value of perfect health being 1. Finally, Q-TWiST accumulated within 48 months indicated a significant advantage in quality-adjusted survival time for CRT (p = 0.020). Conclusion: Irrespective of how patients valued periods of toxicity and delayed disease progression, concurrent chemotherapy and radiotherapy offered NPC patients significantly more quality-adjusted survival than radiotherapy alone in the long term. [Copyright &y& Elsevier]