SuPAR, biomarkers of inflammation, and severe outcomes in patients hospitalized for COVID-19: The International Study of Inflammation in COVID-19

Severe coronavirus disease 2019 (COVID-19) is a hyperinflammatory syndrome. The biomarkers of inflammation best suited to triage patients with COVID-19 are unknown. We conducted a prospective multicenter observational study of adult patients hospitalized specifically for COVID-19 from February 1, 2020 to October 19, 2022. Biomarkers measured included soluble urokinase plasminogen activator receptor (suPAR), C-reactive protein, interleukin-6, procalcitonin, ferritin, and D-dimer. In-hospital outcomes examined include death and the need for mechanical ventilation. Patients admitted in the United States (US, n = 1962) were used to compute area under the curves (AUCs) and identify biomarker cutoffs. The combined European cohorts (n = 1137) were used to validate the biomarker cutoffs. In the US cohort, 356 patients met the composite outcome of death (n = 197) or need for mechanical ventilation (n = 290). SuPAR was the most important predictor of the composite outcome and had the highest AUC (0.712) followed by CRP (0.642), ferritin (0.619), IL-6 (0.614), D-dimer (0.606), and lastly procalcitonin (0.596). Inclusion of other biomarkers did not improve discrimination. A suPAR cutoff of 4.0 ng/mL demonstrated a sensitivity of 95.4% (95% CI: 92.4%-98.0%) and negative predictive value (NPV) of 92.5% (95% CI: 87.5%-96.9%) for the composite outcome. Patients with suPAR < 4.0 ng/mL comprised 10.6% of the cohort and had a 0.8% probability of the composite outcome. Applying this cutoff to the validation cohort yielded a sensitivity of 93.8% (90.4%-96.7%) and NPV of 95.5% (93.1%-97.8%) for the composite outcome. Among commonly measured biomarkers, suPAR offered stronger discriminatory ability and may be useful in triaging low-risk patients with COVID-19.

Post-Progression Survival (PPS) and Overall Survival (OS) According to Treatment Type in Contemporary Phase III Trials in Advanced Breast Cancer (ABC)

Objective: Progression-free survival (PFS) and time to tumor progression (TTP) have been the most frequent primary endpoints in recent phase III trials in ABC. OS, the most frequent secondary endpoint (Katz ASCO 2009), is largely influenced by subsequent-line therapy, and the role of PFS/TTP as surrogates for OS is still uncertain, perhaps due to the influence of post-progression therapy. Thus, PPS is of interest as a determinant of OS, and may vary according to treatment type.Methods: Using the medical subject headings “breast neoplasms” and “drug therapy”, we searched PubMed for phase III trials on systemic antineoplastic therapies published between January 1, 1998, and December 31, 2007 in one of 11 leading medical journals (Ann Oncol, BCRT, Br J Cancer, Cancer, Clin Cancer Res, Eur J Cancer, JCO, JNCI, Lancet Oncol, Lancet and NEJM). We excluded trials with factorial design, studies on high-dose chemotherapy, papers reporting combined analyses of two or more trials, and companion studies on correlative biology or prognostic factors. PPS was calculated as median OS minus median PFS/TTP for each trial arm. The proportion of OS accounted for by PPS (PPS%OS) was calculated as 100 - [median PFS/TTP/median OS]% for each trial arm.Results: The search yielded 75 trials enrolling a total of 28,973 evaluable patients in 159 trial arms. The following table displays the results, considering trial arms with available medians for both PFS/TTP and OS. PPS%OS is larger in hormone-therapy trials than in chemotherapy trials (P&lt;0.01). Overall, PPS has a stronger correlation with OS than do PFS/TTP (R-squares of 0.83 and 0.24, respectively; both P&lt;0.01), at least in part because PPS is longer than PFS/TTP.Main results  Mean ofmedians(months) Trial typeN armsPFS/TTPOSPPSMedian PPS%OSOVERALL1276.920.513.665.7%1. Chemotherapy96718.311.463.7%1.1 Chemo 1st line only597.820.712.964.4%1.2 Chemo 2nd line only146.715.28.559.8%1.3 Other (mixed lines)235.014.19.164.4%2. Hormone therapy296.927.420.574.4%2.1 Hormone 1st line only139.331.121.869.0%2.2 Hormone 2nd line only135.023.218.177.9% Conclusion: The contemporary average median OS in ABC is 20.7 months for first-line chemotherapy ± targeted agents and 31.1 months for first-line hormone therapy ± chemotherapy trials. Subsequent lines of therapy play a major role in determining OS in ABC, and further studies are needed to understand the role of PFS/TTP versus PPS in determining OS, since first-line PFS/TTP have not been convincingly shown to be good surrogates for OS in the literature on ABC.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5116.

Leaf photosynthetic traits scale with hydraulic conductivity and wood density in Panamanian forest canopy trees

We investigated how water transport capacity, wood density and wood anatomy were related to leaf photosynthetic traits in two lowland forests in Panama. Leaf-specific hydraulic conductivity ( k(L)) of upper branches was positively correlated with maximum rates of net CO(2) assimilation per unit leaf area ( A(area)) and stomatal conductance ( g(s)) across 20 species of canopy trees. Maximum k(L) showed stronger correlation with A(area) than initial k(L) suggesting that allocation to photosynthetic potential is proportional to maximum water transport capacity. Terminal branch k(L) was negatively correlated with A(area)/ g(s) and positively correlated with photosynthesis per unit N, indicating a trade-off of efficient use of water against efficient use of N in photosynthesis as water transport efficiency varied. Specific hydraulic conductivity calculated from xylem anatomical characteristics ( k(theoretical)) was positively related to A(area) and k(L), consistent with relationships among physiological measurements. Branch wood density was negatively correlated with wood water storage at saturation, k(L), A(area), net CO(2) assimilation per unit leaf mass ( A(mass)), and minimum leaf water potential measured on covered leaves, suggesting that wood density constrains physiological function to specific operating ranges. Kinetic and static indices of branch water transport capacity thus exhibit considerable co-ordination with allocation to potential carbon gain. Our results indicate that understanding tree hydraulic architecture provides added insights to comparisons of leaf level measurements among species, and links photosynthetic allocation patterns with branch hydraulic processes.