Pooled PCR Research Articles

Lessons Learned from Active Clinical and Laboratory Surveillance during the Sheep Pox Virus Outbreak in Spain, 2022-2023.

In September 2022, more than 50 years after its eradication from Spain, Sheep pox virus was confirmed by laboratory analysis in sheep showing characteristic lesions. This was the start of an outbreak that lasted 9 months and infected 30 farms dispersed over two different areas, Andalusia and Castilla-La Mancha. Early after the initial confirmation, an active surveillance based on clinical inspection with laboratory confirmation of sheep with clinical signs was started in restricted areas. This allowed the confirmation of Sheep pox in 22 out of 28 suspected farms, where limited numbers of sheep with mainly erythema and papules were found, indicative of early detection. Nevertheless, to improve active surveillance and stop the outbreak, clinical inspection was reinforced by laboratory analysis in all inspected farms, even when no clinically diseased sheep were detected. Although more than 35,000 oral swabs from 335 farms were analysed by real-time PCR in pools of five, only two out of six reported outbreaks in this period were detected by laboratory analysis before clinical signs were observed. Furthermore, additional insights were gained from the extensive laboratory surveillance performed on samples collected under field conditions. No evidence of Sheep pox virus infection was found in goats. Oral swabs proved to be the sample of choice for early detection in the absence of scabs and could be tested in pools of five without extensive loss in sensitivity; serology by ELISA was not useful in outbreak detection. Finally, a non-infectious genome of the virus could be detected months after cleaning and disinfection; thus, real-time PCR results should be interpreted with caution in sentinel animals during repopulation. In conclusion, the outbreak of Sheep pox virus in Spain showed that active clinical inspection with laboratory confirmation of clinically diseased sheep via oral swab testing proved a sensitive method for detection of infected farms, providing insights in laboratory surveillance that will be helpful for other countries confronted with Sheep pox outbreaks.

The efficacy and safety of neoadjuvant chemoradiotherapy combined with immunotherapy for locally advanced rectal cancer patients: a systematic review

BackgroundSeveral studies have explored the effectiveness of PD-1/PD-L1 inhibitors combined with neoadjuvant chemoradiotherapy (nCRT) in the treatment of locally advanced rectal cancer(LARC), particularly in microsatellite stable(MSS) or mismatch repair proficient(pMMR) LARC patients. We undertook a single-arm systematic review to comprehensively evaluate the advantages and potential risks associated with the use of PD-1/PD-L1 inhibitors in conjunction with nCRT for patients diagnosed with locally advanced rectal cancer.MethodsThe PubMed, Embase, Cochrane Library, ClinicalTrials.gov, ASCO and ESMO were searched for related studies. The main outcomes were pathologic complete response (pCR), major pathological response (MPR), anal preservation, and adverse effects (AEs).ResultsFourteen articles including 533 locally advanced rectal cancer (LARC) patients were analyzed. The pooled pCR, MPR, and anal preservation rates were 36%, 66% and 86%. Grade ≥3 adverse events occurred in 20%. Subgroup analysis showed that; dMMR/MSI-H had a pooled pCR (100%) and MPR (100%), pMMR/MSS had a pooled pCR (38%) and MPR (60%); the short-course radiotherapy and long-course radiotherapy had pooled pCR rates of 51% and 30%, respectively. The rates of pCR for the concurrent and sequential immuno-chemoradiotherapy subgroups at 30% and 40%, mirroring pCR rates for the PD-L1 and PD-1 inhibitor subgroups were 32% and 40%, respectively.ConclusionIn cases of locally advanced rectal cancer, PD-1/PD-L1 inhibitors combined with neoadjuvant chemoradiotherapy have shown promising response rates and acceptable toxicity profiles. PD-1/PD-L1 inhibitors combined with neoadjuvant chemoradiotherapy hence has a positive outcome even in MSS LARC patients.Systematic Review Registrationhttps://www.crd.york.ac.uk/prospero/#myprospero, identifier CRD42023465380.

Pathological response to neoadjuvant chemoradiotherapy for oesophageal squamous cell carcinoma in Eastern versus Western countries: meta-analysis.

Locally advanced oesophageal squamous cell carcinoma can be treated with neoadjuvant chemoradiotherapy or chemotherapy followed by oesophagectomy. Discrepancies in pathological response rates have been reported between studies from Eastern versus Western countries. The aim of this study was to compare the pathological response to neoadjuvant chemoradiotherapy in Eastern versus Western countries. Databases were searched until November 2022 for studies reporting pCR rates after neoadjuvant chemoradiotherapy for oesophageal squamous cell carcinoma. Multi-level meta-analyses were performed to pool pCR rates separately for cohorts from studies performed in centres in the Sinosphere (East) or in Europe and the Anglosphere (West). For neoadjuvant chemoradiotherapy, 51 Eastern cohorts (5636 patients) and 20 Western cohorts (3039 patients) were included. Studies from Eastern countries included more men, younger patients, more proximal tumours, and more cT4 and cN+ disease. Patients in the West were more often treated with high-dose radiotherapy, whereas patients in the East were more often treated with a platinum + fluoropyrimidine regimen. The pooled pCR rate after neoadjuvant chemoradiotherapy was 31.7% (95% c.i. 29.5% to 34.1%) in Eastern cohorts versus 40.4% (95% c.i. 35.0% to 45.9%) in Western cohorts (fixed-effect P = 0.003). For cohorts with similar cTNM stages, pooled pCR rates for the East and the West were 32.5% and 41.9% respectively (fixed-effect P = 0.003). The pathological response to neoadjuvant chemoradiotherapy is less favourable in patients treated in Eastern countries compared with Western countries. Despite efforts to investigate accounting factors, the discrepancy in pCR rate cannot be entirely explained by differences in patient, tumour, or treatment characteristics.

Pathologic complete response in patients with esophageal cancer receiving neoadjuvant chemotherapy or chemoradiation: A systematic review and meta-analysis.

Neoadjuvant chemoradiation and chemotherapy are recommended for the treatment of nonmetastatic esophageal cancer. The benefit of neoadjuvant treatment is mostly limited to patients who exhibit pathologic complete response (pCR). Existing estimates of pCR rates among patients receiving neoadjuvant therapy have not been synthesized and lack precision. We conducted an independently funded systematic review and meta-analysis (PROSPERO CRD42023397402) of pCR rates among patients diagnosed with esophageal cancer treated with neoadjuvant chemo(radiation). Studies were identified from Medline, EMBASE, and CENTRAL database searches. Eligible studies included trials published from 1992 to 2022 that focused on nonmetastatic esophageal cancer, including the gastroesophageal junction. Histology-specific pooled pCR prevalence was determined using the Freeman-Tukey transformation and a random effects model. After eligibility assessment, 84 studies with 6451 patients were included. The pooled prevalence of pCR after neoadjuvant chemotherapy in squamous cell carcinomas was 9% (95% CI: 6%-14%), ranging from 0% to 32%. The pooled prevalence of pCR after neoadjuvant chemoradiation in squamous cell carcinomas was 32% (95% CI: 26%-39%), ranging from 8% to 66%. For adenocarcinoma, the pooled prevalence of pCR was 6% (95% CI: 1%-12%) after neoadjuvant chemotherapy, and 22% (18%-26%) after neoadjuvant chemoradiation. Under one-third of patients with esophageal cancer who receive neoadjuvant chemo(radiation) experience pCR. Patients diagnosed with squamous cell carcinomas had higher rates of pCR than those with adenocarcinomas. As pCR represents an increasingly utilized endpoint in neoadjuvant trials, these estimates of pooled pCR rates may serve as an important benchmark for future trial design.

Pathologic complete response among patients with esophageal cancer receiving neoadjuvant chemotherapy or chemoradiation: A meta-analysis.

305 Background: Although neoadjuvant therapy improves overall survival in esophageal cancers, the benefit is largely confined to those with the greatest pathologic response. Current estimates of pathologic complete response (pCR) rates come from individual studies and lack precision. With this study, we sought to estimate summary pCR rates in patients with non-metastatic esophageal cancer who received either neoadjuvant chemotherapy or chemoradiation by conducting a systematic review and meta-analysis of clinical trials. Methods: Studies were identified from the Medline, EMBASE, and CENTRAL database searches. Eligible studies were published in English from 1992-2022 and consisted of clinical trials that focused on incident non-metastatic esophageal cancer or cancer of the gastroesophageal junction. Trials were required to contain at least one arm of patients receiving neoadjuvant chemotherapy (including perioperative) or neoadjuvant chemoradiation (including treatment with induction chemotherapy). Eligible studies had to report pCR in at least 20 patients who underwent neoadjuvant therapy and surgery. Pooled pCR prevalence was determined using the Freeman-Tukey double arcsine transformation and a random effects model. Results: Among 6,575 records first identified, we included 75 studies with 5,988 patients in the meta-analysis. Of the included studies, 38 (51%) were single arm trials, 35 (47%) were randomized trials, and 2 (3%) were non-randomized trials of multiple treatments. Geographically, 28 (37%), 24 (32%), 21 (28%), and 2 (3%) of the included trials were performed in Asia, Europe, North America, and Australia, respectively. Across 91 trial arms that delivered either neoadjuvant chemotherapy or chemoradiation, platinum and fluorouracil-based regimens were the most common (48.4%), followed by platinum and taxane-based regimens (26.4%), regimens that contained platinum-based agents, fluorouracil, and a taxane (13.2%), and other regimens (12.1%). The pooled prevalence of pCR after neoadjuvant chemotherapy in squamous cell carcinomas was 9% (95% CI: 6% – 14%) across 16 studies, ranging from 0%-32%. The pooled prevalence of pCR after neoadjuvant chemoradiation in squamous cell carcinomas was 32% (95% CI: 26% – 39%) across 21 studies, ranging from 8% to 66%. For adenocarcinomas, the pooled prevalence of pCR was 2% (95% CI: 0% – 7%) after neoadjuvant chemotherapy, across 3 studies, and 22% (17% - 27%) after neoadjuvant chemoradiation across 11 studies. Conclusions: In this meta-analysis, we found that under one-third of patients with non-metastatic esophageal cancer who receive neoadjuvant chemo(radiation) experience pCR. As pCR represents an increasingly utilized as an endpoint in neoadjuvant trials, these estimates of pooled pCR rates may serve as an important benchmark for future trial design.

Efficacy and safety of neoadjuvant PD-1 inhibitors or PD-L1 inhibitors for muscle invasive bladder cancer: a systematic review and meta-analysis.

This meta-analysis aims to evaluate the efficacy and safety of neoadjuvant PD-1 inhibitors or PD-L1 inhibitors [PD-(L)1 inhibitors] for muscle-invasive bladder carcinoma (MIBC). Four databases (Medline, Embase, Web of Science, and 21 CENTRAL) were searched for articles studying neoadjuvant PD-(L)1 inhibitors for MIBC. The search time period was from the establishment of each database to 21 July 2023. Meta-analyses of pCR, pPR, Grade≥ 3 irAEs rate, RFS, and OS were performed. In total, 22 studies were included for meta-analysis. The overall pooled pCR of neoadjuvant PD-(L)1 inhibitors was 0.36 (95%CI=0.30-0.42, p=0.00). In subgroup meta-analysis, the pooled PCR of PD-(L)1 inhibitors alone, PD-(L)1 inhibitors plus other ICI, and PD-(L)1 inhibitors plus chemotherapy was 0.27 (95%CI=0.19-0.35, p=0.1), 0.41 (95%CI=0.21-0.62, p=0.01), 0.43 (95%CI=0.35-0.50, p=0.06), respectively. The overall pooled pPR of neoadjuvant PD-(L)1 inhibitors was 0.53 (95%CI=0.46-0.60, p=0.00). In subgroup meta-analysis, the pooled pPR of PD-(L)1 inhibitors alone, PD-(L)1 inhibitors plus other ICI, and PD-(L)1 inhibitors plus chemotherapy was 0.36 (95%CI=0.22-0.51, p=0.01), 0.51 (95%CI=0.39-0.62, p=0.43), and 0.61 (95%CI=0.53-0.69, p=0.01), respectively. Kaplan-Meier curves for OS and RFS were reconstructed, but there was no significant difference among three groups in terms of OS or RFS. The pooled result of Grade≥ 3 irAEs rate for neoadjuvant PD-(L)1 inhibitors was 0.15 (95%CI=0.09-0.22, p=0.00%). In subgroup analysis, the pooled result of Grade≥ 3 irAEs rate for PD-(L)1 inhibitors alone, PD-(L)1 inhibitors plus other ICI, and PD-(L)1 inhibitors plus chemotherapy was 0.07 (95%CI=0.04-0.11, p=0.84), 0.31 (95%CI=0.16-0.47, p=0.06), and 0.17 (95%CI=0.06-0.31, I2 = 71.27%, p=0.01), respectively. Neoadjuvant PD-(L)1 inhibitors were feasible and safe for muscle invasive bladder cancer. Compared with PD-(L)1 inhibitors alone, PD-(L)1 inhibitors plus other ICI and PD-(L)1 inhibitors plus chemotherapy were associated with higher pCR and pPR, but higher Grade≥3 irAEs. Kaplan-Meier curves for OS and RFS indicated that neoadjuvant PD-(L)1 inhibitors had an acceptable long-term prognostic, but it was not possible to discern statistical differences between the three neoadjuvant subgroups. https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023452437, identifier PROSPERO (CRD42023452437).

Efficacy, safety, and survival of neoadjuvant immunochemotherapy in operable non-small cell lung cancer: a systematic review and meta-analysis.

Neoadjuvant immunochemotherapy may benefit patients with non-small cell lung cancer (NSCLC), but its impact requires further investigation. A meta-analysis was conducted. PubMed, Embase, Web of Science, and the Cochrane Library were searched. The study was registered in PROSPERO (registration no. CRD42022360893). 60 studies of 3,632 patients were included. Comparing with neoadjuvant chemotherapy, neoadjuvant immunochemotherapy showed higher pCR (RR: 4.71, 95% CI: 3.69, 6.02), MPR (RR, 3.20, 95% CI: 2.75, 3.74), and ORR (RR, 1.46, 95% CI: 1.21, 1.77), fewer surgical complications (RR: 0.67, 95%CI: 0.48, 0.94), higher R0 resection rate (RR: 1.06, 95%CI: 1.03, 1.10, I2=52%), and longer 1-year and 2-year OS, without affecting TRAEs. For neoadjuvant immunochemotherapy in NSCLC, the pooled pCR rate was 0.35 (95% CI: 0.31, 0.39), MPR was 0.59 (95% CI: 0.54, 0.63), and ORR was 0.71 (95% CI: 0.66, 0.76). The pooled incidence of all grade TRAEs was 0.70 (95% CI: 0.60, 0.81), and that of >= grade 3 TRAEs was 0.24 (95% CI: 0.16, 0.32). The surgical complications rate was 0.13 (95% CI: 0.07, 0.18) and R0 resection rate was 0.98 (95% CI: 0.96, 0.99). The pooled 1-year OS was 0.97 (95%CI: 0.96, 0.99), and 2-year OS was 0.89 (95%CI: 0.83, 0.94). Patients with squamous cell carcinoma, stage III or higher PD-L1 performed better. Notably, no significant differences were observed in pCR, MPR, and ORR between 2 or more treatment cycles. Pembrolizumab-, or toripalimab-based neoadjuvant immunochemotherapy demonstrated superior efficacy and tolerable toxicity. According to our analysis, reliable efficacy, safety, and survival of neoadjuvant immunochemotherapy for operable NSCLC were demonstrated. https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022360893, identifier CRD42022360893.

Neoadjuvant immunotherapy in hepatocellular carcinoma: A systematic review and meta-analysis.

e16232 Background: The addition of immunotherapy in neoadjuvant hepatocellular carcinoma (HCC) has been studied recently in early phase clinical trials due to high rate of recurrence after surgery. We aim to systematically review the evidence of efficacy and safety of neoadjuvant immunotherapy treatment. Methods: We carried out a systematic search on MEDLINE, Cochrane, and ASCO meetings library. Screening was done to include clinical trials with HCC patients who underwent any combination of neoadjuvant immune checkpoint inhibitors (ICIs). Quality assessment was performed using methodological index for non-randomized studies (MINORS) tool. The primary efficacy outcomes evaluated included complete pathological response (pCR), major pathological response (MPR), 1 year recurrence free survival (RFS) and overall response rate (ORR). Treatment related adverse events (TRAE) were assessed as a safety outcome. Predefined subgroup analysis was performed based on studies including of tyrosine kinase inhibitors (TKIs) in regimen. Data was analyzed using R version 4.2.1. Results: 5 phase I/II clinical trials were included consisting of 96 patients. Trials administered neoadjuvant immunotherapy agents nivolumab (with TKI cabozantinib) (N = 1), camrelizumab (with TKI apatinib) (N = 1), cemiplimab (N = 1) and nivolumab plus ipilimumab (N = 2). 78(81.2%) of patients were males. 56(59.3%) of patients had viral etiology. 14(14.5%) patients had surgeries delayed or cancelled due to any cause per trial protocols. Meta-analysis of 96 patients from 5 trials showed a pooled pCR rate of 14.49% (95% CI: 6.82 to 23.93%) with low heterogeneity (I2 = 0%, p value 0.55). Pooling the MPR resulted in an estimate of 35.30% (95% CI: 18.80% to 53.57%) with significant heterogeneity (I2 = 58.8%, p value 0.04). Three trials with total 45 patients reported a 12-month RFS rate of 51.08% (95% CI: 40.59 to 70.67%) with significant heterogeneity (I2 = 84.2%, p value 0.002). The overall response rate was 13.7% (95% CI: 6.9 to 22.1%) (I2 =0%, p =0.8). Overall rate of TRAE of any grade was 73.8% (95% CI: 63.1 to 82.5%) (I2 = 83.4%, p <0.001) among all trials and grade 3 adverse events was 21.21% (95% CI: 11.4 to 32.7%) (I2 = 33.8%, p = 0.159). 17(17.8%) patients had elevation in liver enzymes. On subgroup analyses, no difference in pathological outcomes, ORR and grade 3 adverse events was observed with addition of TKIs. Exploratory analysis showed no difference in pCR rates with single ICI vs combination with ipilimumab. Conclusions: The addition of ICIs in neoadjuvant settings appears to be a safe and feasible option. The addition of TKIs to neoadjuvant ICIs does not appear to affect pathological and safety outcomes. Further studies are needed to identify ICI based regimens to improve pCR rates and validate pathological outcomes in HCC after correlating with recurrence and survival.

Analysis of COVID-19 Infection Chains in a School Setting: Data From a School-Based rRT-PCR-Gargle Pool Test System.

School testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was implemented in some countries to monitor and prevent SARS-CoV-2 transmissions. Here, we analyze infection chains in primary schools and household members of infected students based on systematic real-time reverse-transcriptase polymerase-chain-reaction (rRT-PCR)-gargle pool testing. Students and school staff (N = 4300) of all 38 primary schools in the rural county of Cham, Germany, were tested twice per week with a gargle pool rRT-PCR system from April to July of 2021. Infection chains of all 8 positive cases identified by school testing were followed up. In total, 8 positive cases were found by gargle pool PCR testing based on 96,764 school tests. While no transmissions occurred in the school setting, 20 of 27 household members of the 8 cases tested positive. The overall attack rate was 74.1% in families. No school outbreaks occurred during the study period. All cases but 1 were initially picked up by school testing. No transmission from school to families was observed.

Evaluation of Clinical and Safety Outcomes of Neoadjuvant Immunotherapy Combined With Chemotherapy for Patients With Resectable Esophageal Cancer

A considerable number of clinical trials of neoadjuvant immunotherapy for patients with resectable esophageal cancer are emerging. However, systematic evaluations of these studies are lacking. To provide state-of-the-art evidence and normative theoretical support for neoadjuvant immunotherapy for locally advanced resectable esophageal cancer. PubMed, Embase, Cochrane Library, and ClinicalTrials.gov databases were searched for relevant original articles and conference proceedings that were published in English through April 1, 2022. Published phase 2 or 3 clinical trials that included patients with resectable stage I to IV esophageal cancer who received immune checkpoint inhibitors (ICIs) before surgery as monotherapy or in combination with other therapies. The Preferred Reporting Items for Systematic Reviews and Meta-analyses and the Meta-analysis of Observational Studies in Epidemiology guidelines for meta-analysis were followed to extract data. A random-effects model was adopted if the heterogeneity was significant (I2 statistic >50%); otherwise, the common-effects model was used. Data analyses were conducted from April 2 to 8, 2022. Pathological complete response (pCR) rate and major pathological response (MPR) rate were considered to be the primary outcomes calculated for the clinical outcomes of neoadjuvant immunotherapy. Incidence of treatment-related severe adverse events was set as the major measure for the safety outcome. The rate of R0 surgical resection was summarized. Subgroup analyses were conducted according to histologic subtype and ICI types. A total of 27 clinical trials with 815 patients were included. Pooled rates were 31.4% (95% CI, 27.6%-35.3%) for pCR and 48.9% (95% CI, 42.0-55.9%) for MCR in patients with esophageal cancer. In terms of safety, the pooled incidence of treatment-related severe adverse events was 26.9% (95% CI, 16.7%-38.3%). Most patients achieved R0 surgical resection (98.6%; 95% CI, 97.1%-99.6%). Regarding histologic subtypes, the pooled pCR rates were 32.4% (95% CI, 28.2%-36.8%) in esophageal squamous cell carcinoma and 25.2% (95% CI, 16.3%-35.1%) in esophageal adenocarcinoma. The pooled MPR rate was 49.4% (95% CI, 42.1%-56.7%) in esophageal squamous cell carcinoma. This study found that neoadjuvant immunotherapy with chemotherapy had promising clinical and safety outcomes for patients with resectable esophageal cancer. Randomized clinical trials with long-term follow-up are warranted to validate the findings and benefits of ICIs.

Efficacy and Safety of Neoadjuvant Immunotherapy Combined with Chemoradiotherapy vs. Combined with Chemotherapy in Esophageal Cancer: A Systematic Review and Meta-Analysis

<h3>Purpose/Objective(s)</h3> Immunotherapy has showed promising clinical benefit in esophageal cancer. Both the neoadjuvant immunochemoradiotherapy (NICRT) and neoadjuvant immunochemotherapy (NICT) are making great progress. This meta-analysis was to evaluate the efficacy and safety of neoadjuvant immunotherapy combined with chemoradiotherapy versus combined with chemotherapy by synthesizing various trials. <h3>Materials/Methods</h3> A search of PubMed, Embase and Cochrane, in addition of major conferences, for clinical trials including single-arm trials, was conducted up to 30 August 2021. Efficacy was assessed by pathological complete response (pCR), major complete response (MPR) and R0 resection rate. Safety was evaluated by the incidence of ≥ grade 3 treatment-related adverse events (TRAEs), neoadjuvant therapy completion rate, surgical resection rate, and surgical delay rate. Difference between NICRT and NICT groups was tested by Chi-square. <h3>Results</h3> A total of 20 studies was included, including 5 with NICRT and 15 with NICT. The overall pooled pCR, MPR, and R0 resection rate was 32%, 55%, and 96%, respectively. The pCR and R0 resection rates in NICRT vs NICT were 41% vs 30% (p=0.16) and 96% vs 96% (p=0.75), respectively. Only 1 trial in NICRT group reported a MPR of 89%, while the pooled MPR in NICT was 54%. Incidence of ≥ grade 3 TRAEs in NICRT vs NICT was 52% vs 20% (p=0.03), with high heterogeneity in both groups (I²=62%, p=0.10 vs I²=83%, p<0.01). Besides, the overall pooled rates of neoadjuvant therapy completion and surgical resection were 91% and 87%, respectively, which were proved not statistically different between the NICRT vs NICT group. <h3>Conclusion</h3> Neoadjuvant immunotherapy combined with chemoradiotherapy or chemotherapy is effective and safe. NICRT may not achieve better efficacy than NICT, but with potential increase of toxicity. Large trials are needed to confirm whether NICRT or NICT is more suitable for resectable esophageal cancer.

Evaluation of tumor regression by neoadjuvant chemotherapy regimens for esophageal adenocarcinoma: a systematic review and meta-analysis.

Locally advanced esophageal adenocarcinomas (EACs) are treated with multimodal therapy, namely surgery, neoadjuvant chemotherapy (NAC) or chemoradiotherapy (CRT) depending on patient and tumor level factors. Yet, there is little consensus on choice of the optimum systemic therapy. To compare the pathological complete response (pCR) after FLOT, non-FLOT-based chemotherapy and chemoradiotherapy regimes in patients with EACs. A systematic review of the literature was performed using MEDLINE, EMBASE, the Cochrane Review and Scopus databases. Studies were included if they had investigated the use of chemo(radio)therapy regimens in the neoadjuvant setting for EAC and reported the pCR rates. A meta-analysis of proportions was performed to compare the pooled pCR rates between FLOT, non-FLOT and CRT cohorts. We included 22 studies that described tumor regression post-NAC. Altogether, 1,056 patients had undergone FLOT or DCF regimes, while 1,610 patients had received ECF or ECX. The pCR rates ranged from 3.3% to 54% for FLOT regimes, while pCR ranged between 0% and 31% for ECF/ECX protocols. Pooled random-effects meta-meta-analysis of proportions showed a statistically significant higher incidence of pCR in FLOT-based chemotherapy at 0.148 (95%CI: 0.080, 0.259) compared with non-FLOT-based chemotherapy at 0.074 (95%CI: 0.042, 0.129). However, pCR rates were significantly highest at 0.250 (95%CI: 0.202, 0.306) for CRT. The use of enhanced FLOT-based regimens have improved the pCR rates for chemotherapeutic regimes but still falls short of pathological outcomes from CRT. Further work can characterize clinical responses to neoadjuvant therapy and determine whether an organ-preservation strategy is feasible.

Molecular Detection and Genetic Characterization of Ehrlichia ruminantium Harbored by Amblyomma hebraeum Ticks of Domestic Ruminants in North West Province, South Africa.

Simple SummaryBont ticks (Genus Amblyomma) transmit Ehrlichia ruminantium (E. ruminantium), a pathogen that causes a rickettsial disease called heartwater in ruminants. Heartwater disease is devastating and causes financial loss in livestock farming in most parts of southern Africa. The E. ruminantium tends to have many variants; as a result, it is difficult to develop vaccines for controlling it. Knowledge of E. ruminantium variant occurrence in a particular area may assist in designing appropriate vaccination control strategies. Thus, this study investigated the E. ruminantium variants found in the Ngaka Modiri Molema District, North West Province, South Africa. Diversity of these E. ruminantium variants was determined by PCR and sequencing of DNA pools extracted from the tick vectors. Six different DNA variants of E. ruminantium were detected and compared well with those known to be virulent from other parts of South Africa and other countries. The type of variant commonly used for the massive vaccination was not detected in the study area.Ehrlichia ruminantium (E. ruminantium) is the causative agent of heartwater disease and it is mainly transmitted to livestock by Amblyomma hebraeum (A. hebraeum) tick in South Africa. This study investigated the occurrence of E. ruminantium and its genetic diversity in ticks within Ngaka Modiri Molema district of North West Province in South Africa. Genomic DNA was extracted from whole A. hebraeum ticks totaling 876 and resulted in a total of 292 pooled DNA samples. Firstly, conventional PCR was used to detect Ehrlichia spp. targeting the dsbA gene, followed by nested PCR targeting the Map1 gene performed on DNA pool samples that were positive from the first PCR. One hundred and six tick DNA pool samples were positive by dsbA gene PCR for the presence of Ehrlichia spp. with minimum infection rate (MIR) of 121, while 13/106 were positive by Map1 PCR with MIR of 15. Different E. ruminantium Map1 genotypes (NWUe1, NWUe2, NWUe3, NWUe5, and NWUe6) were detected from tick samples and were closely related to more than 13 gene sequences of E. ruminantium from the NCBI GenBank database. These findings suggest that there is a significant diversity of E. ruminantium infecting ticks in the study area.

Association of Pathologic Complete Response and Long-Term Survival Outcomes Among Patients Treated With Neoadjuvant Chemotherapy or Chemoradiotherapy for NSCLC: A Meta-Analysis

IntroductionIncreased efforts to optimize outcomes for early stage NSCLC through the investigation of novel perioperative treatment strategies are ongoing. An emerging question is the role of pathologic response and its association with long-term clinical outcomes after neoadjuvant therapy. MethodsTo investigate the association of pathologic complete response (pCR) and event-free survival (EFS) and overall survival (OS), we performed a systematic review and meta-analysis identifying studies reporting on the prognostic impact of pCR after neoadjuvant chemotherapy or chemoradiotherapy. To evaluate this prognostic value, an aggregated data (AD) meta-analyses was conducted to estimate the pooled hazard ratios (HRs) of EFS and OS for pCR. Using reconstructed individual patient data (IPD), pooled Kaplan-Meier curves were obtained to estimate this association in a more granular fashion. Subgroup analyses were conducted to further explore the impacts of study-level characteristics. ResultsA total of 28 studies comprising 7011 patients were included in the AD meta-analysis, of which, IPD was available for 6274 patients from 24 studies. Results from our AD meta-analysis revealed a pooled pCR rate of 18% (95% confidence interval [CI]: 15%–21%), including significant improvements in OS (HR = 0.50, 95% CI: 0.45–0.56) and EFS (HR = 0.46, 95% CI: 0.37–0.57) on the basis of pCR status. Our IPD analysis revealed a 5-year OS rate of 63% (95% CI: 59.6–67.4) for patients with a pCR compared with 39% (95% CI: 34.5–44.5) for those without a pCR. ConclusionspCR after neoadjuvant chemotherapy plus or minus radiotherapy is associated with significant improvements in EFS and survival for patients with resectable NSCLC.

Estimating the sensitivity and specificity of serum ELISA and pooled and individual fecal PCR for detecting Mycobacterium avium subspecies paratuberculosis in Canadian cow-calf herds using Bayesian latent class models.

While Johne's disease (JD) is less common in beef than in dairy herds, consolidation is increasing transmission risk. Estimates of Mycobacterium avium spp. paratuberculosis (MAP) prevalence and test performance in cow-calf herds are needed to inform control programs. Objectives of this study included describing the prevalence of MAP in Canadian cow-calf herds and comparing the relative performance of a serum ELISA, pooled fecal PCR and individual fecal PCR using Bayesian latent class models, and to investigate factors associated with positive MAP tests. Blood and fecal samples (n = 3,171) were collected from 159 Canadian cow-calf herds. All samples were analyzed using serum ELISA and fecal PCR (pools of five samples) and a subset of 913 fecal samples were also tested with individual PCR. Based on latent class analysis, MAP prevalence was higher in eastern compared to western Canada for both animals {East, 3% [95% Credible Interval (CrI) 1–7%]; West, 1% [95% CrI 0.2–2%]} and herds [East, 15% (95% CrI 2–35%); West, 10% (95% CrI 1–26%), based on one or more positive results]. Sensitivity (Se) and specificity (Sp) for animal level individual PCR were 96% (95% CrI 80–100%) and 98% (95% CrI 96–100%), respectively followed by pooled PCR [Se = 54% (95% CrI 36–72%), Sp > 99.9% (95% CrI 99.8–100%)] and ELISA [Se = 36% (95% CrI 22–52%), Sp = 98% (95% CrI 96–99%)]. Based on 20 samples per herd, the herd level Se of ELISA was 79% (95% CrI 47–100%) (at least one positive sample) compared to 43% (95% CrI 14–94%) for pooled PCR. Herd-level Sp was 99% (95% CrI 96–100%) for pooled PCR and 90% (95% CrI 83–100%) for ELISA. Cows from herds with dairy cattle on farm and cows with symptoms of JD in the past 3 years were more likely to be MAP positive. Herds that had animals with JD symptoms in the previous 3 years and those with more breeding females were most likely to test positive for MAP. While serum ELISA can be effective for herd screening, PCR performed better for animal testing. Pooled PCR testing could be a less costly option; however, determining the most cost-effective approach will require further economic analysis.

Feasibility of community at-home dried blood spot collection combined with pooled reverse transcription PCR as a viable and convenient method for malaria epidemiology studies

BackgroundMany Plasmodium infections in endemic regions exist at densities below the limit of detection of standard diagnostic tools. These infections threaten control efforts and may impact vaccine and therapeutic drug studies. Simple, cost-effective methods are needed to study the natural history of asymptomatic submicroscopic parasitaemia. Self-collected dried blood spots (DBS) analysed using pooled and individual quantitative reverse transcription polymerase chain reaction (qRT-PCR) provide such a solution. Here, the feasibility and acceptability of daily at-home DBS collections for qRT-PCR was studied to better understand low-density infections.MethodsRapid diagnostic test (RDT)-negative individuals in Katakwi District, northeastern Uganda, were recruited between April and May 2021. Venous blood samples and clinic-collected DBS were taken at enrollment and at four weekly clinic visits. Participants were trained in DBS collection and asked to collect six DBS weekly between clinic visits. Opinions about the collection process were solicited using daily Diary Cards and a Likert scale survey at the final study visit. Venous blood and DBS were analysed by Plasmodium 18S rRNA qRT-PCR. The number of participants completing the study, total DBS collected, and opinions of the process were analysed to determine compliance and acceptability. The human internal control mRNA and Plasmodium 18S rRNA were evaluated for at-home vs. clinic-collected DBS and venous blood to assess quality and accuracy of at-home collected samples.ResultsOne-hundred two adults and 29 children were enrolled, and 95 and 26 completed the study, respectively. Three individuals withdrew due to pain or inconvenience of procedures. Overall, 96% of participants collected ≥ 16 of 24 at-home DBS, and 87% of DBS contained ≥ 40 µL of blood. The procedure was well tolerated and viewed favourably by participants. At-home collected DBS were acceptable for qRT-PCR and showed less than a one qRT-PCR cycle threshold shift in the human control mRNA compared to clinic-collected DBS. Correlation between Plasmodium falciparum 18S rRNA from paired whole blood and DBS was high (R = 0.93).ConclusionsAt-home DBS collection is a feasible, acceptable, and robust method to obtain blood to evaluate the natural history of low-density Plasmodium infections by qRT-PCR.

Gargle pool PCR testing in a hospital during medium and high SARS-CoV-2 incidence

BackgroundHospitals need to be protected from SARS-CoV-2 infections to protect vulnerable patients. Thus, a safe, efficient, and cost-effective SARS-CoV-2 testing system for hospitals, in addition to standard hygiene measures and vaccination of staff, is necessary. Here we report on the feasibility and performance of a pool real-time reverse-transcriptase polymerase-chain-reaction (rRT-PCR) test system at, medium and high incidence.MethodsWe implemented a testing concept based on gargling at home and pooling of samples in the hospital before PCR testing in the laboratory. We used two PCR systems (point of care and standard 96-well plate system) to adapt to challenges in the hospital setting and respond to a rising incidence in the Omicron wave.FindingsDuring our 10-week study period, we performed 697 pool PCRs (8793 tests in total) and identified 65 asymptomatic staff members by pool PCR and 94 symptomatic staff members by positive individual PCR. Virus loads in those detected by pool testing were significantly lower (P<0.001). The test system remained workable even during the peak of the Omicron wave and no outbreaks occurred in any specific area of the hospital during the study period. Unvaccinated individuals were over-represented in the positively tested (37% vs 22% positive tests, P=0.04). The test procedure was well accepted by a majority of the hospital staff (84%).ConclusionRepeated gargle pool rRT-PCR testing can be implemented quickly in hospitals and is an effective, easily adaptable and well-accepted test system for hospitals, even during phases with very high infection rates.

Incidence of SARS-CoV-2 Infection among Healthcare Personnel after Restarting an Elective Cataract Surgery during the First COVID-19 Wave

Background: During the COVID-19 pandemic, most elective surgeries were postponed, including cataract surgery. However, patients with severe and disabling visual impairment may have required urgent correction. Objective: To report the incidence of SARS-CoV-2 infection among healthcare personnel working with the patients requiring cataract surgery, under a pre-operative screening protocol. Materials and Methods: A retrospective observational study was conducted in the Suddhavej Hospital, Mahasarakham University, Mahasarakham, Thailand during the early unlocked phase in May 2020. The local pre-operative screening protocol used during the period included questionnaires and pre-operative nucleic acid testing to screen for COVID-19 infection among patients. A combination of serial single nucleic acid test and SARSCoV-2 IgG antibody testing were used to screen SARS-CoV-2 infection among healthcare personnel. Mask wearing and physical distancing were required during hospitalization. Results: One hundred fifty-eight patients underwent cataract surgery under local anesthesia. Thirty-three healthcare personnel were included. All tests for SARS-CoV-2 were negative for both patients and healthcare personnel. The incidence rate of COVID-19 infection among healthcare personnel was 0 (95% CI 0.000 to 0.003) per 100 person-hours. There were no reported symptoms compatible with COVID-19 during the observed period and follow-up. Conclusion: Due to a very low incidence rate of hospital-acquired SARS-CoV-2 infection among healthcare personnel, elective cataract surgery under local anesthesia could be continued during COVID-19 pandemic with strict adherence to screening protocol and other preventive measures. SARS-CoV-2 screening method by questionnaire alone may be feasible in a low COVID-19 incidence rate. Keywords: Cataract surgery; COVID-19; Pre-operative SARS-CoV-2 screening; Pool PCR testing; In-hospital transmission

83P Pathologic complete response (pCR) after neoadjuvant (neoadj) chemoimmunotherapy (chemo+IO) in resectable non-small cell lung cancer (NSCLC): A systematic review and pooled analysis

Early results evaluating immunotherapy (IO)-based neoadj strategies for NSCLC have been promising, with an emphasis on pathologic endpoints. Given the increasing number and variety of regimens, studies defining collective pCR rates are needed for future clinical trial design and eventual practice. Comparing these novel neoadj approaches to FDA approved chemotherapy (chemo) regimens can also provide insight into efficacy and utility. MEDLINE and SCOPUS databases were searched to identify articles and abstracts, published before 2021/11, of prospective clinical trials reporting pCR and major pathologic response (MPR) of neoadj IO, chemo and chemo+IO regimens in resectable NSCLC. Chemo trials published after 2000, using platinum-based regimens are included. Use of neoadj radiation was excluded given potential impact on pathologic assessment. Random effect meta-analysis was conducted to estimate pooled pCR and MPR rates of each regimen, and meta-regression was used to evaluate differences in pCR between regimens, by adjusting for stage (I/II vs. III). Sensitivity analyses were conducted to assess impact of cross-study variations. Forty-one studies with a total of 2964 patients were included. There were 22 chemo, 8 IO and 11 chemo+IO trials. pCR differed between regimens with pooled rates of 6% (95% CI: 4-8%), 10% (95% CI: 4-16%) and 34% (95% CI: 24-43%), respectively. Rates of MPR were 28% (95% CI: 15-41%) and 61% (95% CI: 50-73%) for IO and chemo+IO, respectively. Meta-regression suggests no significant difference between chemo versus IO (p=0.34), while chemo+IO had the highest pCR (p < 0.0001). Using 39 trials reporting pCR by stage, stage III disease trended toward improved pCR regardless of regimen (p=0.11). Chemo+IO significantly improved pCR regardless of disease stage (p<0.0001). Similar trends were not appreciated for either IO or chemo. Neoadj chemo+IO achieved highest rates of pCR, regardless of patient stage. There was a numerical difference in pCR between chemo and IO. These pooled rates provide helpful benchmarks to inform future neoadj trial design, prioritization and patient management.

Pathologic Complete Response in Urothelial Carcinoma Patients Receiving Neoadjuvant Immune Checkpoint Inhibitors: A Meta-Analysis.

Background. Immune checkpoint inhibitors (ICIs) have been evaluated as neoadjuvant treatment in urothelial carcinoma (UC) patients, with these agents reporting encouraging pathologic complete response (pCR) rates. Herein, we performed a systematic review and meta-analysis aimed at evaluating the incidence of pCR in UC patients treated with neoadjuvant ICI. Moreover, we investigated the impact of PD-L1 expression in this patient population, exploring the possible role of PD-L1 status as predictive biomarker. Materials and Methods. We retrieved all the relevant trials through PubMed/Medline, Cochrane Library and EMBASE; moreover, proceedings of the main international oncological meetings were also searched for relevant abstracts. Eligible trials assessed pre-operative ICI in UC patients. Results. Our meta-analysis has highlighted a pooled pCR rate of 36.6% in the overall population; interestingly, pCR was higher in PD-L1 positive compared with PD-L1 negative UCs (49.5% versus 35.1%, respectively). Conclusions. Positive signals emanating from neoadjuvant immunotherapy should encourage the scientific community to persist in the long road toward finding more effective treatments for UC patients.