Patients' selection and trial matching in early-phase oncology clinical trials.

BACKGROUND: Early-phase clinical trials (EPCT) represent an important part of innovations in medical oncology and a valuable therapeutic option for patients with metastatic cancers, particularly in the era of precision medicine. Nevertheless, adult patients' participation in oncology clinical trials is low, ranging from 2% to 8% worldwide, with unequal access, and up to 40% risk of early discontinuation in EPCT, mostly due to cancer-related complications. DESIGN: We review the tools and initiatives to increase patients' orientation and access to early phase cancer clinical trials, and to limit early discontinuation. RESULTS: New approaches to optimize the early-phase clinical trial referring process in oncology include automatic trial matching, tools to facilitate the estimation of patients' prognostic and/or to better predict patients' eligibility to clinical trials. Classical and innovative approaches should be associated to double patient recruitment, improve clinical trial enrollment experience and reduce early discontinuation rates. CONCLUSIONS: Whereas EPCT are essential for patients to access the latest medical innovations in oncology, offering the appropriate trial when it is relevant for patients should increase by organizational and technological innovations. The oncologic community will need to closely monitor their performance, portability and simplicity for implementation in daily clinical practice.

Natural history and treatment efficacy in an ambispective case series of NTRK-rearranged mesenchymal tumors.

BACKGROUND: Apart for infantile fibrosarcoma (IFS), very little is known about NTRK-rearranged mesenchymal tumors (NMTs). The objective of this study is to describe the distribution, characteristics, natural history, and prognosis of NMT. PATIENTS AND METHODS: This study was carried out as a translational research program, retrospectively from a cohort of 500 soft tissue sarcoma (STS; excluding IFS) and prospectively both in routine practice and from the RNASARC molecular screening program (N = 188; NCT03375437). RESULTS: Using RNA-sequencing, NTRK fusion was detected in 16 patient tumors diagnosed as STS: 8 samples of sarcoma with simple genomics (4 NTRK-rearranged spindle cell neoplasm, 3 ALK/ROS wild-type inflammatory myofibroblastic tumor, and 1 quadruple Wild-type gastrointestinal stromal tumor) and 8 samples of sarcomas with complex genomics (dedifferentiated liposarcoma, intimal sarcoma, leiomyosarcoma, undifferentiated pleomorphic sarcoma, high-grade uterine sarcoma, malignant peripheral nerve sheath tumor). Among the eight patients with simple genomics, four were treated with tyrosine receptor kinase inhibitor (TRKi) at different stages of the disease and all benefited from the treatment, including one complete response. Among the eight other patients, six evolved with metastatic spreading and the median metastatic survival was 21.9 months, as classically reported in these tumor types. Two of them received a first-generation TRKi without objective response. CONCLUSIONS: Our study confirms low frequency and histotype diversity of NTRK fusion in STS. While the activity of TRKi in simple genomics NMT is confirmed, our clinical data encourage subsequent studies focusing on the biological relevance of NTRK fusions in sarcomas with complex genomics together with the efficacy of TRKi in this population.

Prevalence of SARS-CoV-2 among Belgian workers in long-term care facilities.

BACKGROUND: Healthcare workers (HCWs) can be a source of SARS-CoV-2 within long-term care facilities (LTCFs); therefore, we analysed the data from a testing programme among LTCF employees. AIMS: The aim of this study was to investigate the prevalence of SARS-CoV-2 and its determinants among employees of LTCFs and the risk for fellow workers and residents. METHODS: Testing started at week 15, the first wave's peak, using nasopharyngeal swabs for PCR up to week 23. At the start of the second wave (week 32), testing resumed. RESULTS: A total of 32 457 test results were available from 446 LTCFs: 2% were positive: 1% in men, 2% in women, 2% in HCWs (=having patient contact), 1% in non-HCWs, higher in younger age groups. In total, 30 729 employees were tested once, 823 twice, 66 thrice and 4 four times. Prevalence was 13% during the first week of testing (week 15) and declined to 7% (week 16) to stay at around 1% (from week 17 until week 23). At the start of the second wave (week 31-33), the prevalence was around 3%. In 70% of positive tests, the employee was asymptomatic. CONCLUSIONS: Our study confirms the presence of HCWs with SARS-CoV-2 as a possible source of infection in LTCFs even when the incidence in the general population was low; 70% were asymptomatic. To control the spread of SARS-CoV-2 in LTCFs vaccination, infection prevention and control measures are necessary as well as testing of all LTCF HCWs during possible outbreaks, even if asymptomatic.

Roles for redox regulation in leaf senescence of pea plants grown on different sources of nitrogen nutrition.

Leaf senescence and associated changes in redox components were monitored in commercial pea (Pisum sativum L. cv. Phoenix) plants grown under different nitrogen regimes for 12 weeks until both nodules and leaves had fully senesced. One group of plants was inoculated with Rhizobium leguminosarum and grown with nutrient solution without nitrogen. A second group was not inoculated and these were grown on complete nutrient solution containing nitrogen. Leaf senescence was evident at 11 weeks in both sets of plants as determined by decreases in leaf chlorophyll and protein. However, a marked decrease in photosynthesis was observed in nodulated plants at 9 weeks. Losses in the leaf ascorbate pool preceded leaf senescence, but leaf glutathione decreased only during the senescence phase. Large decreases in dehydroascorbate reductase and catalase activities were observed after 9 weeks, but the activities of other antioxidant enzymes remained high even at 11 weeks. The extent of lipid peroxidation, the number of protein carbonyl groups and the level of H(2)O(2) in the leaves of both nitrate-fed and nodulated plants were highest at the later stages of senescence. At 12 weeks, the leaves of nodulated plants had more protein carbonyl groups and greater lipid peroxidation than the nitrate-fed controls. These results demonstrate that the leaves of nodulated plants undergo an earlier inhibition of photosynthesis and suffer enhanced oxidation during the senescence phase than those from nitrate-fed plants.

A role for salicylic acid and NPR1 in regulating cell growth in Arabidopsis.

Salicylic acid (SA) plays a key role in activating defenses and cell death during plant-pathogen interactions. In response to some pathogens, SA also limits the extent of cell death, indicating that it acts positively or negatively depending on the host-pathogen interaction. In addition, we previously showed that SA affects cell growth in the Arabidopsis defense-related mutants accelerated cell death 6-1 (acd6-1) and aberrant growth and death 2 (agd2). Using acd6-1, agd2 and two other defense-related mutants, lesion simulating disease 6 (lsd6), suppressor of SA-insensitivity (ssi1), we show here in detail that SA regulates cell growth by specifically affecting cell enlargement, endoreduplication and/or cell division. We find that SA can act either positively or negatively to regulate cell growth depending on the context in which signaling occurs. Additionally, Nonexpressor of PR 1 (NPR1), a key SA signaling protein important for regulating defenses and cell death, also acts to promote cell division and/or suppress endoreduplication during leaf development. We propose that SA interacts with multiple receptors or signaling pathways to control cellular alterations during normal development, pathogen attack and/or stress situations. We suggest that SA and NPR1 play broader roles in cell fate control than has previously been understood.

Early H(2)O(2) accumulation in mesophyll cells leads to induction of glutathione during the hyper-sensitive response in the barley-powdery mildew interaction.

H(2)O(2) production and changes in glutathione, catalase, and peroxidase were followed in whole-leaf extracts from the susceptible (AlgS [Algerian/4* (F14) Man.(S)]; ml-a1 allele) and resistant (AlgR [Algerian/4* (F14) Man.(R)]; Ml-a1 allele) barley (Hordeum vulgare) isolines between 12 and 24 h after inoculation with powdery mildew (Blumeria graminis [DC]. Speer [syn. Erysiphe graminis DC] f.sp hordei Marchal). Localized papilla responses and cell death hypersensitive responses were not observed within the same cell. In hypersensitive response sites, H(2)O(2) accumulation first occurred in the mesophyll underlying the attacked epidermal cell. Subsequently, H(2)O(2) disappeared from the mesophyll and accumulated around attacked epidermal cells. In AlgR, transient glutathione oxidation coincided with H(2)O(2) accumulation in the mesophyll. Subsequently, total foliar glutathione and catalase activities transiently increased in AlgR. These changes, absent from AlgS, preceded inoculation-dependent increases in peroxidase activity that were observed in both AlgR and AlgS at 18 h. An early intercellular signal precedes H(2)O(2), and this elicits anti-oxidant responses in leaves prior to events leading to death of attacked cells.

Pathogen-induced changes in the antioxidant status of the apoplast in barley leaves

Leaves of two barley (Hordeum vulgare L.) isolines, Alg-R, which has the dominant Mla1 allele conferring hypersensitive race-specific resistance to avirulent races of Blumeria graminis, and Alg-S, which has the recessive mla1 allele for susceptibility to attack, were inoculated with B. graminis f. sp. hordei. Total leaf and apoplastic antioxidants were measured 24 h after inoculation when maximum numbers of attacked cells showed hypersensitive death in Alg-R. Cytoplasmic contamination of the apoplastic extracts, judged by the marker enzyme glucose-6-phosphate dehydrogenase, was very low (less than 2%) even in inoculated plants. Dehydroascorbate, glutathione, superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase, monodehydroascorbate reductase, and dehydroascorbate reductase were present in the apoplast. Inoculation had no effect on the total foliar ascorbate pool size or the redox state. The glutathione content of Alg-S leaves and apoplast decreased, whereas that of Alg-R leaves and apoplast increased after pathogen attack, but the redox state was unchanged in both cases. Large increases in foliar catalase activity were observed in Alg-S but not in Alg-R leaves. Pathogen-induced increases in the apoplastic antioxidant enzyme activities were observed. We conclude that sustained oxidation does not occur and that differential strategies of antioxidant response in Alg-S and Alg-R may contribute to pathogen sensitivity.