The study aimed to assess if adherence to a total-neoadjuvant-treatment (TNT) protocol followed by observation(watch-and-wait) led to the successful nonoperative-management of low-rectal-cancer.
In ...this study, patients with primary, resectable-T3-T4, N0–N1 distal-rectal-adenocarcinoma underwent-chemoradiotherapy + consolidation-chemotherapy (TNT). During the-TNT-period, endoscopy, MRI, and FDG-PET/CT were performed. We allocated patients with complete-clinical-tumor-regression, who underwent endoscopy every two months, MRI every-four-months, and PET/CT every-six-months-after-treatment, to the observation-group(OG). All other patients were referred for surgery. The OG was followed-up. The primary endpoint was local tumor-ecurrence after allocation to the OG.
Between 2015 and 2018, we enrolled 66-patients. Of 60-patients who were eligible to participate, 39 had complete-clinical-response(cCR) and were allocated to the OG, six underwent local-excision (LE), and 15 underwent total-mesorectal-excision (TME). The median follow-up duration was 22 (9–42) months. The local-recurrence-rate in the OG was 15.3%, and the LE and TME rates were 16.6% and 0%, respectively. All recurrence cases were salvaged through either LE or TME. The-distant-metastasis rate was 5.1%, 16.6%, and 12.5% in the OG, LE, and TME groups, respectively. The endoscopic negative-predictive-value(NPV) was 50%, and the positive-predictive-value(PPV) was 76.9% in the surgery group (LE + TME). MRI; NPV-50%, PPV-76.9%. PET/CT; NPV-100%, PPV-93.3%. Six patients(28.57%) from surgery group achieved complete pathological response (cPR).
Our results indicated a high proportion of selected-rectal-cancers with-cCR after neo-adjuvant-therapy could potentially be managed non-operatively, and major surgery may be avoided.
Starting at birth, the immune system of newborns and children encounters and is influenced by environmental challenges. It is still not completely understood how γδ T cells emerge and adapt during ...early life. Studying the composition of T cell receptors (TCRs) using next-generation sequencing (NGS) in neonates, infants, and children can provide valuable insights into the adaptation of T cell subsets. To investigate how neonatal γδ T cell repertoires are shaped by microbial exposure after birth, we monitored the γ-chain (TRG) and δ-chain (TRD) repertoires of peripheral blood T cells in newborns, infants, and young children from Europe and sub-Saharan Africa. We identified a set of TRG and TRD sequences that were shared by all children from Europe and Africa. Thesewere primarily public clones, characterized by simple rearrangements of Vγ9 and Vδ2 chains with low junctional diversity and usage of non-TRDJ1 gene segments, reminiscent of early ontogenetic subsets of γδ T cells. Further profiling revealed that these innate, public Vγ9Vδ2⁺ T cells underwent an immediate TCR-driven polyclonal proliferation within the first 4 wk of life. In contrast, γδ T cells using Vδ1⁺ and Vδ3⁺ TRD rearrangements did not significantly expand after birth. However, different environmental cues may lead to the observed increase of Vδ1⁺ and Vδ3⁺ TRD sequences in the majority of African children. In summary, we show how dynamic γδ TCR repertoires develop directly after birth and present important differences among γδ T cell subsets.
This experimental study evaluated the histological response of peritoneal metastases (PM) from colorectal cancer (CRC) after preoperative systemic chemotherapy (pCT). The results demonstrated that ...the Peritoneal Regression Grade Score could be used in medical practice.
The aim was to evaluate the histological criteria used by the tumour regression grade (TRG) and Peritoneal Regression Grade Score (PRGS) for determining the response to chemotherapy (CT), in a mouse model of peritoneal metastases (PM) from colorectal cancer (CRC).
Twenty immunocompetent BALB/c mice were randomized into four groups at day (D) 10 after intraperitoneal (ip) injection with bioluminescent CRC tumour cells (CT26-luc). A histology before treatment group was obtained by sacrifice on D10; the other groups all received one of the following ip treatments over 15 days: 5% glucose (control, G5); 5-fluorouracil (5FU, 0.03 mg/g); or 5FU with oxaliplatin (Ox, 0.006 mg/g). The histological response (HR) was analysed by comparing the histology of PM before and after treatment, using both scores: TRG and PRGS.
All mice showed limited PM as visualised by bioluminescence and confirmed at the time of sacrifice in the histology before treatment group. The mean peritoneal carcinomatosis index (PCI) was = 8 6–10, The rate of complete HR was significantly higher in the Ox-5FU group (83.3%) than 5FU group (0%) and G5 group (0%) (p = 0.016). Fibrosis was present only in CT-treated groups (p = 0.05). PCI, ascites volume and haemorrhagic ascites were significantly higher in the G5 group than CT groups (p < 0.05).
The TRG score can be used in practice when we want to compare the HR between the primary tumour and the PMs. The PRGS is a good measure of HR and is correlated with the efficacy of CT.
Reliable predictors of a sustained clinical complete tumour response (cCR) after neoadjuvant therapy in rectal cancer (RC) are lacking. The aim of this study was to determine if the tumour regression ...grade (TRG) assessed by magnetic resonance imaging (MRI), at the first restaging after neoadjuvant therapy can predict organ preservation, and to estimate the time interval after which surgery should be recommended in patients who remain in near cCR.
Eighty-three consecutive patients were assessed by MRI as having a cCR (mrTRG 1) or near cCR (mrTRG 2) after neoadjuvant therapy. Cox proportional hazards regression models and Kaplan-Meier survival analyses were used to determine associations between resection-free survival (RFS) and mrTRG at the first restaging, and in relation to mrTRG with a landmark period. mrTRG and pathological findings were compared in operated patients.
mrTRG 2 at the first restaging significantly predicted poorer RFS during follow up. The best prediction of RFS was mrTRG at landmark 16 weeks after termination of radiotherapy; 42 out of 49 patients (86%) evaluated as mrTRG 1 had cCR at one year of follow up. In contrast, 12 out of 15 patients (80%) evaluated as mrTRG 2 had clinical signs of tumour and were recommended surgery.
The first mrTRG, and to an even greater extent mrTRG at landmark 16 weeks predicts RFS. Patients who remain mrTRG 2 at 5–6 months after radiotherapy with signs of tumour should be recommended surgery. These findings may help in patient counselling and surgical decision-making.
Human γδ T cells can contribute to clearance of hepatitis C virus (HCV) infection but also mediate liver inflammation. This study aimed to understand the clonal distribution of γδ T cells in ...peripheral blood of chronic HCV patients and following HCV clearance by interferon-free direct-acting antiviral drug therapies. To this end, γδ T cell receptor (TCR) repertoires were monitored by mRNA-based next-generation sequencing. While the percentage of Vγ9
T cells was higher in patients with elevated liver enzymes and a few expanded Vδ3 clones could be identified in peripheral blood of 23 HCV-infected non-cirrhotic patients, overall clonality and complexity of γδ TCR repertoires were largely comparable to those of matched healthy donors. Monitoring eight chronic HCV patients before, during and up to 1 year after therapy revealed that direct-acting antiviral (DAA) drug therapies induced only minor alterations of TRG and TRD repertoires of Vγ9
and Vγ9
cells. Together, we show that peripheral γδ TCR repertoires display a high stability (1) by chronic HCV infection in the absence of liver cirrhosis and (2) by HCV clearance in the course of DAA drug therapy.
The Camelidae species occupy an important immunological niche within the humoral as well as cell mediated immune response. Although recent studies have highlighted that the somatic hypermutation ...(SHM) shapes the T cell receptor gamma (TRG) and delta (TRD) repertoire in
Camelus dromedarius
, it is still unclear how γδ T cells use the TRG/TRD receptors and their respective variable V-GAMMA and V-DELTA domains to recognize antigen in an antibody-like fashion. Here we report about 3D structural analyses of the human and dromedary γδ T cell receptor. First, we have estimated the interaction energies at the interface within the human crystallized paired TRG/TRD chains and quantified interaction energies within the same human TRG/TRD chains in complex with the CD1D, an RPI-MH1-LIKE antigen presenting glycoprotein. Then, we used the human TRG/TRD-CD1D complex as template for the 3D structure of the dromedary TRG/TRD-CD1D complex and for guiding the 3D human/dromedary comparative analysis. The choice of mutated TRG alternatively combined with mutated TRD cDNA clones originating from the spleen of one single dromedary was crucial to quantify the strength of the interactions at the protein-protein interface between the paired
C. dromedarius
TRG and TRD V-domains and between the
C. dromedarius
TRG/TRD V-domains and CD1D G-domains. Interacting amino acids located in the V-domain Complementarity Determining Regions (CDR) and Framework Regions (FR) according to the IMGT unique numbering for V-domains were identified. The resulting 3D dromedary TRG V-GAMMA combined with TRD V-DELTA protein complexes allowed to deduce the most stable gamma/delta chains pairings and to propose a candidate CD1D-restricted γδ T cell receptor complex.
Chemotherapeutics fail to effectively treat tumors because they cannot reach quiescent regions far from blood vessels. Motile Salmonella are an attractive delivery system that could break this ...therapeutic barrier. However, little is known about the dissemination and tissue penetration of individual bacteria in tumors after intravenous administration. We hypothesized that eliminating the Trg receptor would improve accumulation in tumor quiescence. To test this hypothesis, we deleted the trg gene from nonpathogenic Salmonella. To quantify individual bacterial behavior, we measured tissue penetration in a tumor-on-a-chip device and measured colony localization in mouse tumors using immunofluorescence. In tumors in vitro and in mice, trg− Salmonella penetrated farther into tissue than control bacteria. This difference in localization was caused by the inability to sense sugars in well perfused tissue. Three distinct bacterial phenotypes were observed: proliferating, penetrating, and inactive. Large proliferating colonies, containing more than 40% of individual bacteria, only formed less than 60μm from blood vessels. Small colonies, in comparison, were present both near (inactive) and far (penetrating) from vessels. The farthest was 361.2μm from a vessel, demonstrating the ability to target avascular regions. In addition, colonization was most pronounced in poorly vascularized tumor regions. We show that deletion of trg amplifies Salmonella accumulation in quiescent tumor regions, and, for the first time, identify biological processes that control bacterial distribution in tumors. Understanding how Salmonella penetrate tissue, target quiescence and specifically replicate in tumors are essential steps toward creating a tightly controlled, tunable bacterial therapy.
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The consistent use of pre-operative treatment before surgery for gastric cancer (GC) has resulted in increased rates of complete response. However, factors associated with response have been scantly ...investigated.
Patients with GCs treated between 2017 and 2022 undergoing pre-operative treatment followed by resection were included. Clinicopathological data were analyzed for the association with tumor regression grades (TRG); secondary outcomes included the short-term overall (OS), disease-free (DFS) and disease specific survival (DSS).
Among 108 patients, 35.1% had an intestinal histotype GC, and 70.4% were treated with FLOT. Complete tumor regression (TRG1) was documented in 6.5% of patients. Univariable analyses documented that a higher pre-operative albumin (p = 0.04) and the expression of HER2 (p = 0.01) were associated to TRG1. In the multinominal regression model, the log-odds of being classified as TRG1 increased with the expression of HER2 by 170.247 times and with higher pre-operative albumin by 34.525 times, while with a higher Charlson Index and a diffuse hystotipe reduced it by 25.467 times and 3759.126 times, respectively. Among 49 patients (mean follow-up: 17.1 months), TRG1-2 was associated to better OS, DFS and DSS curves compared to TRG 3-5 (respectively p < 0.01, p 0.007 and p < 0.01), altogether with the reported negative impact of comorbidities in OS and DSS multivariable analyses (respectively p 0.04 and p 0.006). The random survival forest further confirmed the impact of HER2 and comorbidity on DSS.
A better clinical profile, HER2 expression and intestinal histotype significantly correlated with GC regression. A complete-major response was an independent factor for survival.
Past studies documented that microsatellite instability (MSI) is associated with improved survival in gastric cancer (GC). The aim of this study was to evaluate MSI status in a series of GCs treated ...with neoadjuvant therapy in relation to the tumors' characteristics and oncological outcomes.
Patients with GCs treated between 2017 and 2022 at a single Italian high-volume Institution undergoing pre-operative treatment followed by resection were included if studied for their microsatellite status. Clinicopathological data were analyzed for the association with MSI. The same features were analyzing pooling the series with a subset of patients from another European trial.
Secondary outcomes included the overall (OS), and disease-free (DFS) survivals comparing MSI vs microsatellite stable (MSS) GCs, and GCs presenting complete-major response (TRG1-2) vs partial response (TRG3-4) and absence of response (TRG5).
Among 73 patients selected, 12.3% were MSI. In the single institutional analysis, we documented a difference in the distribution of ypT stages with a prevalence of ypT0 patients in MSI vs MSS patients (ypT0 respectively 11.1% vs 1.6%, p < 0.0001). However, this difference was not of statistical value when pooling patients with those from the European trial (overall 108 patients, 9.2% MSI; ypT0 respectively 10.0% vs 2.0%, p 0.144). In the pooled analysis, a prevalence of female patients was reported in the MSI group comparing MSS (respectively, 70.0% vs 27.6%, p 0.01). At a mean follow-up of 27.7 months, OS and DFS survivals were reported similar comparing MSS and MSI (log-rank test respectively p 0.18 and p 0.96), however TRG1-2 GCs had improved OS and DFS comparing other sub-groups (TRG1-2 vs TRG3-4 vs TRG5, OS and DFS log-rank test respectively p 0.017 and p 0.0029).
This study could not demonstrate a correlation between microsatellite status and survival in gastric cancer patients who underwent pre-operative treatment. A complete/major response was the only variable correlated with mid-term survival.
•We investigated a cohort of gastric cancer patients resected after pre-operative treatment for their microsatellite status.•Statistical analyses were computed to correlate the microsatellite instability with clinical and pathological features.•Survivals were analyzed focusing on microsatellite instability and tumor’s regression.•A complete-major response (TRG 1–2) correlated with improved survival.
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