Results from the UNITED study: a multicenter study validating the prognostic effect of the tumor-stroma ratio in colon cancer

BACKGROUND

The TNM (tumor-node-metastasis) Evaluation Committee of Union for International Cancer Control (UICC) and College of American Pathologists (CAP) recommended to prospectively validate the cost-effective and robust tumor-stroma ratio (TSR) as an independent prognostic parameter, since high intratumor stromal percentages have previously predicted poor patient-related outcomes.

PATIENTS AND METHODS

The 'Uniform Noting for International application of Tumor-stroma ratio as Easy Diagnostic tool' (UNITED) study enrolled patients in 27 participating centers in 12 countries worldwide. The TSR, categorized as stroma-high (>50%) or stroma-low (≤50%), was scored through standardized microscopic assessment by certified pathologists, and effect on disease-free survival (DFS) was evaluated with 3-year median follow-up. Secondary endpoints were benefit assessment of adjuvant chemotherapy (ACT) and overall survival (OS).

RESULTS

A total of 1537 patients were included, with 1388 eligible stage II/III patients curatively operated between 2015 and 2021. DFS was significantly shorter in stroma-high (n = 428) than in stroma-low patients (n = 960) (3-year rates 70% versus 83%; P < 0.001). In multivariate analysis, TSR remained an independent prognosticator for DFS (P < 0.001, hazard ratio 1.49, 95% confidence interval 1.17-1.90). As secondary outcome, DFS was also worse in stage II and III stroma-high patients despite adjuvant treatment (3-year rates stage II 73% versus 92% and stage III 66% versus 80%; P = 0.008 and P = 0.011, respectively). In stage II patients not receiving ACT (n = 322), the TSR outperformed the American Society of Clinical Oncology (ASCO) criteria in identifying patients at risk of events (event rate 21% versus 9%), with a higher discriminatory 3-year DFS rate (stroma-high 80% versus ASCO high risk 91%). A trend toward worse 5-year OS in stroma-high was noticeable (74% versus 83% stroma-low; P = 0.102).

CONCLUSION

The multicenter UNITED study unequivocally validates the TSR as an independent prognosticator, confirming worse outcomes in stroma-high patients. The TSR improved current selection criteria for patients at risk of events, and stroma-high patients potentially experienced chemotherapy resistance. TSR implementation in pathology diagnostics and international guidelines is highly recommended as aid in personalized treatment.

Neurotrophin receptors TrkB.T1 and p75NTR cooperate in modulating both functional and structural plasticity in mature hippocampal neurons

Tropomyosin-related kinase (Trk) receptors modulate neuronal structure and function both during development and in the mature nervous system. Interestingly, TrkB and TrkC are expressed as full-length and as truncated splice variants. The cellular function of the kinase-lacking isoforms remains so far unclear. We investigated the role of the truncated receptor TrkB.T1 in the hippocampus of transgenic mice overexpressing this splice variant by analyzing both neuronal structure and function. We observed an impairment in activity-dependent synaptic plasticity as indicated by deficits in long-term potentiation and long-term depression in acute hippocampal slices of transgenic TrkB.T1 mice. In addition, dendritic complexity and spine density were significantly altered in TrkB.T1-overexpressing CA1 neurons. We found that the effect of TrkB.T1 overexpression differs between subgroups of CA1 neurons. Remarkably, overexpression of p75(NTR) and its activation by chemical induction of long-term depression in slice cultures rescued the TrkB.T1-dependent morphological alterations specifically in one of the two subgroups observed. These findings suggest that the TrkB.T1 and p75(NTR) receptor signaling systems might be cross-linked. Our findings demonstrate that TrkB.T1 regulates the function and the structure of mature pyramidal neurons. In addition, we showed that the ratio of expression levels of p75(NTR) and TrkB.T1 plays an important role in modulating dendritic architecture and synaptic plasticity in the adult rodent hippocampus, and, indeed, that the endogenous expression patterns of both receptors change reciprocally over time. We therefore propose a new function of TrkB.T1 as being dominant-negative to p75(NTR).

Shear bond strength of adhesive composite systems to human dentin

This study was carried out to evaluate the following adhesive systems under different conditions from the point of view of the bond strength that is obtained on dentin: Scotchbond Multipurpose, 3M: Denthesive II, Kulzer; Optibond, Kerr with techniques # 1 and 5; and A.R.T. Bond. Coltene. Composite resin (Z100, 3M) cylindrical specimens were bonded to flat dentin surfaces and the adhesive strength was determined under shear. No significant differences were found between the group in which products were used with a separate step of dentin demineralization and the group in which this step is not recommended or was omitted. It can be concluded that the use of dentin acid treatment as a separate step is not necessarily required for high composite bond strength even when it could represent a convenient clinical step to prepare enamel surfaces simultaneously.

Effects of catechins on human blood platelet aggregation and lipid peroxidation

The activity of catechins was studied for inhibitory activity in human blood platelets. Platelet aggregation and peroxidation were evaluated in platelet rich plasma (PRP) obtained from samples of healthy volunteers. Human blood platelets were submitted to stimulation with 300 microM arachidonic acid, 3 microM adenosine diphospate (ADP) and 6 microM epinephrine. Treatment with (200 microg/mL) catechin or epicatechin was sufficient to exhibit a potent inhibitory effect of the three agents. The inhibitory effect was dose dependent at concentrations of 20-200 microg/mL. Using malondialdehyde (MDA) as an index of total lipid peroxidation capacity, decreased production of MDA of the platelets treated with catechin or epicatechin after stimulation by arachidonic acid was observed. These findings suggest that catechins protect platelets from peroxidative stress and their aggregation.